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CONTENTS

Introduction and General Information

Every wildlife casualty should ideally be identified regarding its species, sex and age. 
  • This information is important for correct husbandry (appropriate housing, provision of correct diet etc.) and safe handling. (B188, B363.9.w9, P24.233.w9, P24.335.w20, P62.1.w1) Additionally:
    • Species identification may indicate likely secondary disease problems;
    • The choice of release time and place is affected by species;
    • Accurate identification is required for correct assessment of normal weight and haematological parameters.
  • In the event of a large oil spill with limited resources, this information may be used to determine individuals, for example those of rare or endangered species, on which extra effort should be expended. (B188)
Published Guidelines linked in Wildpro

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Susceptibility to oil

Birds:

"The degree to which a species is vulnerable to oil exposure and to the toxic effects of oil depends on a complex of biological factors in addition to geographical considerations. These factors determine the relative risk posed by oil to different bird species and thus deserve special consideration." (B378.6.w6)

  • Species vary in their susceptibility to the direct and indirect effects of oil spills depending on their "foraging behaviour, migration patterns, nesting habits, flocking behaviour, and distribution." (D210.3.w3)
  • In general, seaducks and alcids are highly vulnerable, while gulls, terns and waders (shorebirds) appear to be less vulnerable. Gulls do get oiled relatively frequently, but appear to be fatally affected less often, with oiled individuals observed to survive for months. This may be because these species are more likely to fly away from oil, unless surprised by a spill during the night, and because flight and walking are more important to these species than swimming and diving. (D10)
  • The risk of individual birds contacting oil depends on the behaviour of the species: how much time individuals spend in contact with the water while foraging, resting etc.. (B378.6.w6, P14.5.w2)
    • Pelagic and diving species are most at risk of oiling. (J313.1.w2)
    • Species which dive in response to an alarming stimulus may have increased exposure following initial contact with oil than those which fly away. (B378.6.w6)
  • As well as becoming coated with oil, birds may inhale volatile components of oil. (D183.w3) This is most likely to occur in species spending large amounts of time at the air/water interface.
  • The risk to the population of contacting oil also depends on whether the population is concentrated or scattered: a large percentage of the population being oiled is more likely to occur with those species and populations which concentrate for breeding, moulting etc., rather than those which remain dispersed. (B378.6.w6, P14.5.w2)
  • Overall susceptibility of species to oiling also depends on the ability of the population to recover from additional mortality due to oiling: those with low fecundity (high age of first breeding, low clutch size, i.e. low reproductive capacity) are less able to recover from additional mortality due to oiling than are those. (P14.5.w2)
    • Because of their low reproductive potential, the population dynamics of seabird species is strongly affected by major losses of breeding-age adults. (B378.6.w6)
  • Note: mortality due to oiling is superimposed on other factors. (B378.6.w6)
  • In addition to direct mortality due to oiling, oil may act either additively or synergistically with other factors: for example the negative effect of oiling on reproduction may be increased in years of poor food availability, and the effects of oil might also interact with other pollutants. (B378.6.w6)

An "oil vulnerability index" (OVI) has been developed, ranking the susceptibility of birds to becoming oiled based on their range (breeding, migration, wintering, water orientation), habits (roosting, foraging, escape, flocking, nesting density and specialisation) and exposure (in spring, summer, autumn and winter) as follows: (D183.w4, J313.36.w1)

  • Range: birds with a large breeding range, covering long distances during migration, with large wintering areas, and avoiding open water and the intertidal zone are ranked low (score 1), while those with a small breeding range, short migration distance, restricted wintering areas and orientation in the open marine water rank high (score 5); other species are intermediate (score 3). (J313.36.w1)
  • Behaviour: roosting (on land (1), on shore (3) or at sea (5)), foraging (while walking (1), flying (3) or swimming (5)), escape behaviour (by taking off (1), swimming (3 and nesting) or diving (5)), flocking behaviour (small (1), medium (3) or large (5)) nesting density (low (1), medium (3) or high (5)), nesting specialisation (low (1), medium (3) or high (5)). (J313.36.w1)
  • Exposure: considering spring, summer, autumn and winter exposure from 0 (not in habitats exposed to oil at all) to 5 (at or near the sea at all times of the year). (J313.36.w1)

Overall:

  • Species groups which are usually considered to be very vulnerable to oil are those which:
    • Frequently dive for food;
    • Roost on water for prolonged periods;
    • Form large flocks;
    • Form dense breeding colonies in areas where spills are common or likely;
    • Spend high proportion of their time on the open ocean;
    • Have low reproduction rates.

    (D162.4.w4, D210.3.w3)

  • Species groups which are usually considered to be less vulnerable to oil spills are those which are rarely found in the open marine environment and/or are very adaptable. These species;
    • Are rarely found immersed in water;
    • Spend large percentages of their time on land, or on sheltered water bodies;
    • Are able to avoid oil by moving to unoiled habitats;
    • Are prolific breeders.

(D162.4.w4, D210.3.w3)

Following an oil spill, the breeding success of birds may be decreased either by direct effects on nesting and behaviour, or by indirect effects such as reduced prey availability resulting in birds not reaching an adequate body condition for breeding or, after breeding, not allowing sufficient provisioning of chicks. (D210.3.w3)

N.B. these groupings are generalisations on a global level. Some of the suggestions regarding relative susceptibility of different species groups are based on the likelihood of the birds' habitats being affected by an oil spill. If the habitat in which the birds are living is affected, then daily behaviours (e.g. spending time on water, or not) are most likely to affect whether or not birds are oiled. 

Mammals:

  • Mammals living in and near water (e.g. marine mammals and those associated with rivers), are more likely to become oiled than are other mammal species, although oiling of other species (e.g. bats, hedgehogs) does occur. (B284.9.w9, B259.w10, P14.2.w1, P14.4.w4)
  • Among aquatic [and semi-aquatic] mammals, susceptibility to oil is greater for those species which rely on their fur for insulation and thermoregulation, rather than a layer of blubber. (D208.1.w1, D210.3.w3, P14.2.w1, P14.4.w4)
  • Species which spend large amounts of time grooming to maintain fur condition and insulation are also more likely to ingest oil and have a higher risk of developing toxic effects than are species which do not spend much time grooming. (D208.1.w1, D210.3.w3)
  • Additionally, aquatic mammals may inhale volatile oil components at the air/water interface. (B377.15.w15, B377.17.w17)
  • Cetaceans and pinnipeds appear generally to detect and avoid surface oil slicks, and therefore have reduced susceptibility to oiling. (D208.1.w1)

Reptiles:

  • Only relatively small numbers of reptiles have been reported affected by oil spills. (P14.4.w3, P14.4.w4, P14.4.w18)
  • Marine and freshwater chelonia, snakes and lizards have been reported oiled. (B369.w6, P14.2.w1, P14.3.w29, P14.4.w3, P14.4.w4, P14.4.w18)

Amphibians:

  • Only relatively small numbers of amphibians have been reported affected by oil spills. (P14.4.w4)
  • Amphibians are not likely to be found in marine oil spill situations since they do not live in saltwater habitats, but some species may be found in brackish river estuaries (B382.1.w1) and they are susceptible to oil spills in their freshwater habitats. (D185.3.w3, P14.2.w1)
Associated techniques linked from Wildpro
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Identification

Oiled birds need to be identified to species level; additionally, if possible, the sex and age should be determined. (D133.4.w4) In an emergency situation, initial identification should be made at least to family level, since birds of a given family tend to have similar features and requirements. (P24.233.w9, P24.335.w20)
  • Bird identification normally involves a range of cues including known range, habitat type, observed behaviour, size, the overall shape of the body, the size and shape of the bill (including length relative to the head), the length of the neck and legs, the relative size and shape of the wings and the tail, and flight characteristics, as well as plumage details and voice. (B17, B164)
  • Identification of oiled birds is complicated by the fact that their natural colours may be completely or at least partially obscured by oil, and they will not be showing normal behaviour which might normally be useful. (D137)
  • It should be remembered that species which are commonly found in the affected area, and species from groups which are known to be at relatively high risk of being oiled are more likely to be found oiled than those which are rare and/or known to be at low risk of being caught in oil.
  • Volunteers from local ornithologists groups may be helpful in species identification. (B363.3.w3)
  • The general shape of the commonest species - their silhouettes - should be learned. (D137)
  • Note: A good field guide should be available to assist with species identification. (B363.App2.w15, P24.233.w9)

Key features which may assist in identification include:

  • Size: compare the bird to those which you are most familiar with. (D137)
  • General shape: for example "duck-like" "gull-like", "wader-like" or "penguin-like", long or short neck, long or short legs. (D137, B363.App2.w15, V.w5)
  • Bill type: long or short, pointed or flattened, with or without a hook on the end. (D137, B363.App2.w15)
    • Presence or absence of external nostrils. (B363.App2.w15)
  • Toes: shape (long and thin, or short), how many pointing forwards and backwards, are they webbed, and if so, partially or fully. (B363.App2.w15)
  • Wing shape: e.g. long or short, thin or broad, pointed or rounded. (B17)
  • Tail: length and shape. (B17)
  • Colours, if these are visible. (B17, B164, D137)
    • Note that plumage colour may vary with age (juveniles are often duller colours than adults of the same species), sex (females may be drab compared to males) and season (males of many ducks lose their bright colours after the breeding season). (B17, B164)
  • Location and season. It is unlikely that the bird to be identified will be one which does not occur at all in the area, or only in the opposite season. (B164)
  • The habitat in which the bird has been found may also be a clue, however some pelagic species can be found inland. (B164, D137)
Associated techniques linked from Wildpro

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Special Considerations for Auks (Alcids)

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In the UK these birds include: Alle alle - Dovekie (Little auk), Alca torda - Razorbill, Cepphus grylle - Black guillemot, Fratercula arctica - Atlantic puffinUria aalge - Common murre (Common guillemot)

Appearance:

  • Plumage generally black or dark brown above and white below. In most species the head in winter has white cheeks and throat. (D137)
  • Head large on a shortish neck, body chunky, wings relatively small, legs short and set far back on body, toes (three) are webbed, tail is short, plumage is dense. (D137, D160.App4.w12)
  • Body is long. (B17)
  • Wings are short. (B17)

Relevant Notes on Natural History: 

  • Generally pelagic, found on the open sea. (D137, D160.App4.w12)
  • Gregarious, mostly nesting in cliff colonies (mainland and offshore islands). (D137, D160.App4.w12)
  • Adults may return to nest sites as early as January in the UK. (D137)
  • Perch on rocks but spend most of time in the water. (D9)
  • Breeding season success can be seriously reduced by nest disturbance. (D160.App4.w12)
  • Awkward when walking on land. (D9)
    • When on land, Alle alle - Dovekie (Little auk), Alca torda - Razorbill, Uria aalge - Common murre (Common guillemot) stand on whole of foot and lower leg to hock. 
    • They rest their whole body weight on their hocks. (P14.7.w16)
  • Moult: Generally lose all flight feathers at one time therefore flightless for a period in August/September. (D137, D160.App4.w12)
  • Natural diet: Fish, some invertebrates. (D137)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • N.B. Even healthy auks are not easy to maintain in captivity. (J315.2S.w2)
  • Handling:
    • Beak and claws are sharp. Gloves and goggles should be worn when handling these species. (D9, D137)
    • Puffins bite in a similar manner to parrots, twisting and crushing the flesh. This is painful. (D133.3.w3)
  • Transport containers: 
    • Should be well padded, particularly for those species which stand on the whole leg to the hock, since these are more awkward on land. (D137, D160.App4.w12)
    • A non-slip substrate is important to prevent injury. (B284.18.w18)
    • May be transported two or three to a box. 
      • However, can be aggressive to one another particularly in such close confines. (D137)
  • Accommodation: 
    • Well padded or net-bottomed cages prior to washing. (D137)
    • Provide smaller species with hiding places such as shoe boxes or pieces of clean 120mm diameter drain pipe. (D137, D160.App4.w12)
    • Being social, these birds generally may be housed with others of the same species (and prefer being with others), however some individuals may be aggressive. (D137, D160.App4.w12)
    • Provide rocks for perching in post-washing accommodation. (B197.15.w15)
    • Ensure good ventilation. (B197.15.w15)
    • In many zoos, a polyvinyl hose-through matting is used on land areas of enclosures, allowing faeces and urates to drop through, and easily drying out after hosing down, thereby providing a dry substrate. (J23.33.w2)
  • Feeding:
    • Whole small fish - sprats and whitebait. (D137, D214.2.w2)
    • Slivers of fresh fish, cut to the same size as sprats and whitebait, may also be used. (D214.2.w2)
    • A common guillemot (Uria aalge - Common murre) will require about 6-8 sprats, each 20-25 cm long, per day. (D139)
    • Up to 20 large sprats per day may be eaten. (D214.2.w2)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:

Vulnerability to oil:

  • Vulnerable to oil on water. (D9)
  • Alcids are considered highly vulnerable to oil spills. They can be found in large flocks in areas along busy shipping routs where there are frequent pollution incidents. Their behaviour also makes them susceptible. They spend large periods of time on the water and they try to escape oil (as other hazards) by diving, apparently in a random direction, and if encountering a large patch or slick may therefore surface within the oil and get coated with the oil. (D10, D162.4.w4, J9.219.w2, J320.8.w1)
  • Not only may these birds be killed outright by oil, but exposure to oil may reduce egg production and viability and negatively impact breeding behaviour. (D162.4.w4)
Associated techniques linked from Wildpro

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Special Considerations for Gannets and Cormorants

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In the UK these birds include: Morus bassanus - Northern gannet, Phalacrocorax carbo - Great cormorant, Phalacocorax aristotelis - European Shag

Appearance:

  • Plumage: Phalacrocorax carbo - Great cormorant, Phalacocorax aristotelis - European Shag mostly black, Morus bassanus - Northern gannet white with black wing tips in adults, juveniles are black and gain adult plumage gradually over five years. (D137)
  • Head on a long neck, bill long and sharply hooked at the tip, with no external nares, body stout, legs short and set far back on body, toes (four) are webbed, tail is long and stiff. (D135.9.w9, D137)
    • The toes are webbed and all four toes point forwards (B363.App2.w15)
    • No external nares. (B336.13.w13, B363.App2.w15, D140)
  • Feet large, all four toes are joined by webbing. (B17)
  • Wings of gannets are slim and pointed (B17)
  • Body of cormorants is quite slender. (B17)

Relevant Notes on Natural History: 

  • Gregarious and nest in colonies although these may be rather loose. (D137)
  • Feeding behaviour: Gannets dive from the air to catch fish, cormorants and shags dive from the surface. (D135.9.w9, D137)
  • Swim low in the water and cormorants and shags may sink by squeezing air out of the plumage. (D135.9.w9, D137, D160.App4.w12)
  • Perching: Cormorants and shags are commonly seen perching with their wings outstretched. (D137, D160.App4.w12)
  • Natural diet: Varied diet of fish, also some crustaceans. (B336.13.w13, D135.9.w9, D137)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • These birds have a bill with a sharp end which is painful if it catches human skin. (D137)
      • These birds often strike towards the eyes. (D137, D140)
      • Gannet bill has very sharp inside edges and is very strong. (D140, P24.335.w20)
      • Cormorants and shags have a bill with a hook at the end of the upper bill. (D140)
      • Cormorants bite in a similar manner to parrots, twisting and crushing the flesh. This is painful. (D133.3.w3)
    • Control over the head must come first when these birds are caught and be maintained at all times. (D137, D140, D160.App4.w12, P24.335.w20)
      • Throw a towel over the bird's head, then grasp the head through the towel initially. Either grasp with the fingers under the lower mandible and the thumb on top of the head, or grasp the head from behind, the thumb and fingers coming forward to hold just behind the eyes. (P24.335.w20)
    • N.B. These birds have no external nostrils (nares) and must be allowed to open the mouth a little in order to breath. Do NOT tape the bill closed. (B336.13.w13, D133.3.w3, D135.9.w9, D137, D140, D160.App4.w12)
    • Goggles and stout gloves must be worn when handling these species. (D135.9.w9, D137, D140)
    • These birds may be easier to hold and struggle less if the feet are supported. (D137, D160.App4.w12)
      • The feet and claws are strong; they can be held up against the bird's body. (P24.335.w20)
    • Avoid handling soon after feeding or these birds will tend to regurgitate. (D135.9.w9)
    • When catching, handle through a light rug or similar cloth. (D140)
  • Transport containers: 
    • Should be padded. (D137)
    • Only one bird should be placed per box. (D9, D135.4.w4)
    • A non-slip substrate is important. (B284.18.w18)
  • Accommodation: 
    • Provide padding in pens prior to washing. (D137, D160.App4.w12)
    • Provide stable stumps, half-submerged branches or rocks for perching in rehabilitation accommodation following washing. (B363.7.w7, D135.9.w9, D137, D160.App4.w12)
      • Sufficient land space must be provided for cormorants to stand and dry their plumage. (B336.13.w13)
      • Dry areas with appropriate substrate are important to prevent the development of Bumblefoot. (B336.13.w13)
    • Give access to deep pools after washing. (D135.9.w9)
  • Feeding:
    • Whole fish - sprats, small herring or whiting, in dishes of water. (D135.9.w9, D137)
      • Medium sized mackerel or herring may be preferred to sprats by these species. (D140)
      • As many as seven or eight herring or mackerel per day may be taken per bird. (D214.2.w2)
      • Often will not eat voluntarily therefore force feeding is likely to be required. (D140)
      • May be coaxed to eat by waving a fish slowly in front of the bill, tapping the bill with the fish, and usually continue eating once started. (D140)
      • NOTE: Will tend to regurgitate if disturbed soon after eating. (D135.9.w9, D140)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:

Vulnerability to oil:

  • Cormorants and shags, being highly aquatic, and preying under water, tend to suffer at a local level during oil pollution incidents, although they represent only a small proportion of casualties overall. (D10)
  • Gannets may be most susceptible when congregating in large "rafts" of birds off their breeding sites at dusk. They can also become oiled while gathering nest material (as occurred during the Torrey Canyon spill). They are less likely to get oiled than some other seabirds, because they take to the water to feed only when they see food, and this is not likely where the water is covered in oil. (B378.6.w6, D10)
  • Cormorants may be affected during freshwater spills. In the Amer River spill in the Netherlands in 1970, in which more than 4,000 birds were found dead and heavily contaminated, casualties including up to 25 Phalacrocorax carbo - Cormorant. (J17.4.w1)
Associated techniques linked from Wildpro

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Special Considerations for Divers (Loons) and Grebes

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In the UK these birds include: Gavia arctica - Arctic loon, Gavia immer - Common loon, Gavia stellata - Red-throated loon, Podiceps auritus - Horned grebe, Podiceps cristatus - Great crested grebe, Podiceps grisegena - Red-necked grebe, Podiceps nigricollis - Black-necked grebe, Tachybaptus ruficollis - Little grebe.

Appearance:

  • Plumage varies widely, generally colourful in summer but drab in winter. Plumage may not be very useful for distinguishing among species of divers in winter. (D137)
    • Plumage of grebes is soft. (D160.App4.w12)
    • Plumage of divers is hard and compact. (D160.App4.w12)
  • Body elongated and streamlined, (D9, D137) grebes are generally smaller and plumper than divers (particularly the dabchick (Tachybaptus ruficollis - Little grebe). (B17)
  • Head streamlined on long neck, 
    • Grebes have longer necks than do divers. (B17)
  • Bill sharply pointed, dagger-like. (B17) No lamellae, not flattened top to bottom (unlike ducks). (B363.App2.w15)
  • The legs are set far back on the body. (B17, B336.12.w12, D9, D137, D160.App4.w12)
  • The toes of grebes and divers are lobed. (B17) rounded lobes on the three main toes (B363.App2.w15)
    • Grebes have lobed toes with partial webbing. (D160.App4.w12)
    • Loons have webbing on the front three toes. (D160.App4.w12)
  • The wings are quite short. (B17, D160.App4.w12); short and pointed in loons. (D160.App4.w12)
  • The tail is short (very short in the grebes). (B17); it is well developed in divers but nonfunctional in the grebes. (B336.12.w12)

Relevant Notes on Natural History:

  • Grebes are generally sedentary but divers are mainly migratory. (D137); some grebes migrate (B17)
  • Often solitary. (D9)
  • These birds may be found on fresh water and seawater. They are rarely seen on land and are unable to walk properly on land (divers in particular are practically unable to walk on land). (D9, D137, D160.App4.w12)
    • Loons and grebes rarely come onto land unless they have to. (D160.App4.w12) Any diver seen on land, except nesting, is showing abnormal behaviour. 
    • On land these relatively heavy-bodies birds rest their whole weight on their keels, putting excessive pressure onto this area, and the position leads to overflexion of the hocks with resultant reduced circulation, swelling and infection of these joints. (P14.7.w16)
  • Normally ingest feathers and sand while preening. (D135.9.w9)
  • Vulnerable to oil on the water surface. (D9)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Aggressive; the bill is sharply pointed and these birds stab strongly - the head must be controlled. (B336.12.w12, D9, D133.3.w3, D135.9.w9, D137, D160.App4.w12)
    • Gloves and goggles must be worn when handling these species. (D133.3.w3, D135.9.w9, D137)
    • Try to avoid projectile droppings while handing these species. (D160.App4.w12)
  • Transport containers: 
    • Thick padding is required to prevent keel and hock lesions from developing. (D133.3.w3, D137)
  • Accommodation: 
    • Thick padding (e.g. rubber mats, thick layers of newspaper, old towels, changed frequently) (B197.15.w15, D137), foam padding (D135.7.w7) or (preferably) net-bottomed cages required prior to cleaning. (B197.15.w15, D135.9.w9, J29.8.w1)
    • Bedding must be changed frequently. (D137)
    • Reduced lighting may help to decrease stress. (D137)
    • Avoid crowding; these birds will be aggressive to one another in crowded conditions. (D135.9.w9, D160.App4.w12)
    • Once cleaned, give access to deep pools of clean water (birds MUST be rinsed very thoroughly after washing), with access to padded platforms at water level or up a short shallow ramp, or floating net-bottomed rafts. (D135.9.w9)
    • Good ventilation is very important. (B197.15.w15)
  • Feeding:
    • Small fish: sprats and whitebait. (D137) also aquatic insects and crustaceans, in dishes of water. (D135.9.w9)
    • Note: For grebes, which normally eat feathers, prophylactic use of lactulose (0.3 mL/kg orally twice daily) as a laxative, and aggressive fluid therapy, may prevent digestive system problems. (J312.16.w1)
  • For further information see the relevant pages linked below.

Secondary diseases of particular importance:

Vulnerability to oil:

  • Grebes and divers represent less than 1% of total kills due to oil and are regularly found during oiling incidents; since their population sizes are not large, low absolute numbers of birds affected may represent a relatively serious proportion of the population. They are highly vulnerable to oil in their vicinity because they are highly aquatic and tend to concentrate and feed in offshore waters. (D10)
    • If surfacing in an oil slick, these bird may dive to escape the oil, only to surface again still in the oiled area. (J320.8.w1)
  • Grebes may be oiled during freshwater as well as marine spills. In the Amer River spill in the Netherlands in 1970, among other birds, up to 25 individuals each of Podiceps cristatus - Great crested grebe, and Tachybaptus ruficollis - Little grebe were oiled. (J17.4.w1)
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Special Considerations for Geese, Swans and Shelducks

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In the UK these birds include: Anser albifrons - Greater white-fronted goose, Anser anser - Greylag goose, Anser brachyrhynchus - Pink-footed goose, Anser erythropus - Lesser white-fronted goose, Anser fabalis - Bean goose, Branta bernicla - Brent goose, Branta canadensis - Canada goose, Branta leucopsis - Barnacle goose, Cygnus columbianus - Tundra swan, Cygnus cygnus - Whooper swan, Cygnus olor - Mute swan, Tadorna tadorna - Common shelduck.

Appearance:

  • Plumage white in all UK native swans, geese are variably greys and browns. Tadorna tadorna - Common shelduck is white with brown and black markings and a red bill.
  • Head with a stout bill is set on a long neck (very long in swans), body is large. Legs are set relatively far back in swans, further forward in geese. Feet are webbed. Wings are strong and in some species have a bony knob at the carpal joint (wrist). (D137, D160.App4.w12)
  • Bill is flattened, with lamellae at the edges. (B363.App2.w15) The bill of geese is stouter, rather triangular from base to tip in side view. Shelducks have a knob at the top of the upper bill, larger in males. (B17)
  • Feet: Three toes point forwards and are webbed. The fourth toe is much shorter, elevated and points backwards. (B17, B363.App2.w15)
  • Swans  are large with heavily-fingered wings; the neck is very long. Geese are smaller than swans and have shorter, although still long, necks. The shelduck also has a long neck. (B17)

Relevant Notes on Natural History: 

  • Swans swim and feed at water surface and commonly "up-end" to reach vegetation under the water. Geese graze on land but rest on water.
  • Highly social with lasting pair bonds and strong family bonds.
  • Geese are mainly grazers. Swans mainly eat aquatic vegetation, also some land-based vegetation.
  • Can be aggressive, particularly in the breeding season.
  • Flocks forming during migration may be vulnerable to oil spills. (D9)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • These birds walk and run well, particularly geese. Although a long run-up is generally required for these birds to take flight in favourable winds they may become airborne in short distances. (D137)
    • Powerful wings may produce severe bruises, will also nip strongly with bill. The wings should be controlled early and maintained close to the bird's body. Wrapping the bird in a sheet or towel may assist in control. (D9, D137, D160.App4.w12)
    • These birds may be carried tucked under one arm with the head and neck pointing backwards where only less vulnerable parts of the handler's body are available to be pecked. If carried in this manner the handler must remain aware of where other people are and ensure that the bird cannot reach them. (V.w5) Alternatively the head should be held under control. (D135.9.w9)
  • Transport containers: 
    • Geese and swans are quite heavy. If cardboard boxes are used these must be stout so that they do not fail even if damp. (V.w5)
  • Accommodation: 
    • "Calf matting" may be useful as a substrate. (D137)
    • Pens may need frequent cleaning due to copious droppings. (D137)
    • Can be group housed, but avoid crowding. (D135.9.w9)
    • Keep pairs/family groups together if possible. (D135.9.w9)
  • Feeding:
    • Chopped green food, soaked grains, sprouting seeds, waterfowl pellets, chick crumbs, mashed hard-boiled egg (complete with shell). (D137, D142, V.w5)
    • N.B. Bread may be the first human-provided food to be recognised by swans and geese which are human-habituated and commonly fed by members of the public. (V.w5)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:

Vulnerability to oil:

  • These species are most likely to be oiled by spills on inland waters including rivers, lakes, brooks, village ponds etc. as well as estuaries and dock areas. (D142)
  • In general, geese are not commonly found seriously oiled. However they may be affected occasionally, as in the Amer River spill in Holland in 1970. A large spill volume into an area being used by feeding, moulting, roosting or breeding birds might have a greater than usual impact. (D10)
    • Geese are highly vulnerable during migration, while using offshore and coastal marine waters for staging. (D162.4.w4)
  • Swans are generally not involved in spills in large numbers. (D10)
    • However, mute swans are susceptible to oiling due to residing in places such as navigable rivers in industrial areas. (J3.70.w1)
  • Geese, swans and shelduck can all be affected in relatively large numbers if a spill occurs on a river being used by these species. In the Amer River spill in Netherlands in 1970, at least 350 Anser anser - Greylag goose (more than 75% of the population), more than 10% of the population (about 7,000, in mixed species groups) of Anser albifrons - Greater white-fronted goose and Anser fabalis - Bean goose , with 500-600 dead and severely contaminated, about 150 of the 210 Bewick's swans (Cygnus columbianus - Tundra swan), and smaller numbers (up to 25 individuals per species) of Tadorna tadorna - Common shelduck, and Cygnus olor - Mute swan, as well as other species, were oiled. (J17.4.w1)
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Special Considerations for Seaducks, Sawbills and Diving Ducks

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In the UK Diving ducks and Seaducks include: Aythya fuligula - Tufted duck, Aythya marila - Greater scaup, Bucephala clangula - Common goldeneye, Clangula hyemalis - Long-tailed duck, Melanitta fusca- White-winged scoter, Melanitta nigra - Black scoter, Mergellus albellus - Smew, Mergus merganser - Common merganser, Mergus serrator - Red-breasted merganser, Oxyura jamaicensis - Ruddy duck, Somateria mollissima - Common eider.

Appearance:

  • Plumage. The plumage is dense. For plumage colouration of individual species, see the relevant individual species page.
  • Head bears a bill which is broad and flattened or in the sawbills long, narrow and serrated. (D137)
  • Legs are set quite far back on the body, the feet are large and webbed with the hind toe lobed. (D137, D160.App4.w12)
  • Wings are smaller and more pointed than in the dabbling ducks. (D137, D160.App4.w12)
  • Bill in sawbills (mergansers) is long and slender, with serrated edges, in seaducks is relatively large and heavy. (B17)
  • Feet: Three toes point forwards and are webbed. The fourth toe is much shorter, elevated and points backwards. (B17, B363.App2.w15) The feet are large. (D160.App4.w12)
  • The wings of ducks are generally relatively small and have pointed tips. (B17)
  • The diving ducks are relatively dumpy in build, as are the stiff-tails (Oxyura jamaicensis - Ruddy duck). The sawbills have slender, streamlined cigar-shaped bodies and the seaducks are larger and heavier. (B17)
  • Tail of stiff-tails is long and stiff. (B17, D160.App4.w12) The seaducks have short tails. (D160.App4.w12)
  • Legs are set well back on the body in all these ducks. (B17) The legs are also relatively short. (D160.App4.w12)

Relevant Notes on Natural History: 

  • These birds are nearly exclusively marine in England and Wales, being found on the open ocean and in bays but occasionally in estuaries and on coastal reservoirs. Most species are migratory.
  • These birds are highly aquatic. They normally spend little time on land and are reluctant to come ashore until they have to.
  • Diet: Fish, crustaceans and molluscs. 
  • Flocks forming during migration may be vulnerable to oil spills. (D9)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • A run-up over the water is required for diving ducks to become airborne. (D137)
    • These ducks, even when oiled, will only come ashore when they have to. (D137)
    • The hook on the end of the bill of sawbills may tear skin; gloves should be worn when handling these species.(D137)
    • Scoters and eider may go limp when being handled; this does not mean they have collapsed. (D133.3.w3, D137, D160.App4.w12)
    • These birds may be aggressive when handled, hissing and striking out. (D137, D160.App4.w12)
  • Transport containers: 
    • Must be well padded. (D137)
  • Accommodation: 
    • Must be well padded. (D137, D160.App4.w12)
    • Males may be very aggressive to females and juveniles/subadults, particularly if pens are crowded. (D137, D160.App4.w12)
  • Feeding:
    • Small fish: whole small sprats, whole whitebait, diced sprats. Molluscs. Proprietary seabird diets. 
    • Small sprats and whitebait. (D142, D214.2.w2)
    • Slivers of fresh fish, cut to the same size as sprats and whitebait, may also be used. (D214.2.w2)
    • The equivalent of twenty large sprats a day may be eaten. (D214.2.w2)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:

Vulnerability to oil:

  • Seaducks are considered highly vulnerable to oil spills. They can be found in large flocks in areas along busy shipping routes where there are frequent pollution incidents; they form large wintering congregations. Their behaviour also makes them susceptible. These species moult at sea, and are unable to fly during this time. Oiled seaducks which feed entirely in the water, if oiled, have the choice between remaining on water to feed, with a greatly increased heat loss (360% higher than normal in one study) or coming onto land to reduce heat loss, and starving. (D10)
  • Freshwater diving ducks and sawbills can be affected in large numbers by a spill if it occurs in their habitat. In the Amer River spill in the Netherlands in 1970, among other species, about 200-400 Aythya fuligula - Tufted duck, about fifty Anas penelope - Eurasian wigeon, and smaller numbers (up to 25 each) of Mergus merganser - Common merganser, and Mergellus albellus - Smew were dead and seriously contaminated. (J17.4.w1)
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Special Considerations for Dabbling Ducks

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In the UK the Dabbling Ducks include: Anas acuta - Northern pintail, Anas clypeata - Northern shoveler, Anas crecca - Common teal, Anas platyrhynchos - Mallard, Anas strepera - Gadwall, Anas querquedula - Garganey, Aythya ferina - Common pochard. The Perching Duck species Aix galericulata - Mandarin duck and the wigeon species Anas penelope - Eurasian wigeon, may be considered with this group.

Appearance:

  • Plumage: Bright in males in the breeding season and duller in females, juveniles and males in eclipse plumage. For plumage colouration of individual species, see the relevant individual species pages. (V.w5)
  • Head rounded, bill flattened, neck relatively short, body compact with legs close to the centre of the body. Feet are webbed and generally smaller than those of seaducks; the hind toe is not flattened or lobed. The wings are larger and less pointed than in the diving ducks. (D137)
  • Bill is flattened, with lamellae at the edges. (B363.App2.w15)
  • Feet: Three toes point forwards and are webbed. The fourth toe is much shorter, elevated and points backwards. (B17, B363.App2.w15)
  • The wings of ducks are generally relatively small and have pointed tips. (B17); those of dabbling ducks are generally larger and less pointed than those of diving ducks. (D160.App4.w12)

Relevant Notes on Natural History: 

  • Feed on aquatic plants, seeds, small insects, tadpoles, molluscs etc. in shallow water, dabbling on the surface and "up-ending" to reach food below the surface. (D137) Anas penelope - Eurasian wigeon is a grazer.
  • Generally dive only rarely but will dive to escape danger. (D137)
  • Able to get airborne without a run-up. (D137)
  • Generally gregarious. (D135.9.w9)
  • Flocks forming during migration may be vulnerable to oil spills. (D9)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Relatively easy to handle. (D137)
    • These species are less stressed by handling and captivity than are the other waterfowl. (D160.App4.w12)
    • Be ready when opening a box, as the duck can spring out into the air. (D137, D160.App4.w12)
  • Transport containers: 
    • Cardboard boxes with e.g. newspaper and a towel as a substrate may be used for short journeys. For longer journeys, boxes which will not disintegrate when wet are required; plastic pet carriers are suitable. (D24, V.w5)
  • Accommodation: 
    • Pens must be covered to prevent ducks flying out. (D137, D160.App4.w12)
    • Males may be aggressive to females and juveniles, particularly if pens are crowded. (D137)
  • Feeding:
    • Chopped green food, soaked grains, sprouting seed, proprietary pelleted waterfowl foods, whole whitebait. Food should also be offered as a wet gruel, made by placing pellets in water. (D135.9.w9, D137, D142)
    • N.B. Bread may be the first human-provided food to be recognised by ducks which are human-habituated and commonly fed by members of the public. (V.w5)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • Relatively resistant to stress (compared to most other water birds). (D137)

Vulnerability to oil:

  • Dabbling ducks, which can feed ashore, are probably less susceptible to oiling than are those waterfowl which must feed in the water. (D10)
  • Dabbling ducks have reduced susceptibility to oil spills partly because the inland habitats which they inhabit tend to be affected by oil spills less often than are marine habitats. (D162.4.w4)
  • These species are most likely to be oiled by spills on inland waters including rivers, lakes, brooks, village ponds etc. as well as estuaries and dock areas. (D142)
  • Dabbling ducks can be affected in large numbers if a spill occurs in their habitat, as seen in the Amer river spill in 1970 in the Netherlands, in which about 1,500-2,000 Anas platyrhynchos - Mallard (the whole population), at least 500 Aythya ferina - Common pochard, and about fifty each of Anas penelope - Eurasian wigeon, Anas acuta - Northern pintail and Anas crecca - Common teal were oiled (as well as other birds). (J17.4.w1)
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Special Considerations for Waders / Shorebirds

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In the UK these birds include: Arenaria interpres - Ruddy turnstone, Bartramia longicauda - Upland sandpiper, Burhinus oedicnemus - Eurasian thick-knee (Stone curlew), Calidris alba - Sanderling, Calidris alpina - Dunlin, Calidris ferruginea - Curlew sandpiper, Calidris maritima - Purple sandpiper, Calidris minuta - Little stint, Calidris temminckii - Temminck's stint, Calidris canutus - Red knot, Calidris tenuirostris - Great knot, Charadrius dubius - Little ringed plover, Charadrius hiaticula - Common ringed plover, Crex crex - Corn crake, Eudromias morinellus - Eurasian dotterel, Fulica atra - Common coot, Gallinago gallinago - Common snipe, Gallinula chloropus - Common moorhen, Haematopus ostralegus - Eurasian oystercatcher, Limosa lapponica - Bar-tailed godwit, Limosa limosa - Black-tailed godwit, Lymnocryptes minimus - Jack snipe, Numenius arquata - Eurasian curlew, Numenia phaeropus - Whimbrel, Phaloropus fulicaria - Red phalarope, Phalaropus lobatus - Red-necked phalarope, Philomachus pugnax - Ruff, Pluvialis apricaria - Eurasian golden plover, Pluvialis squatarola - Grey plover, Porzana porzana - Spotted crake, Rallus aquaticus - Water rail, Recurvirostra avosetta - Pied avocet, Scolopax rusticola - Eurasian woodcock, Tringa erythropus - Spotted redshank, Tringa glareola - Wood sandpiper, Tringa hypoleucos - Common sandpiper, Tringa nebularia - Common greenshank, Tringa ochropus - Green sandpiper, Tringa totanus - Common redshank, Vanellus vanellus - Northern lapwing

Appearance (not including plumage colouration):

  • Head generally has a long slender bill and in the larger species is on a long neck. Legs are long and slender. (D137, D160.App4.w12)
  • Plovers and dotterels have short stubby bills. (B17, B363.App2.w15)
  • Godwits, curlews, snipes and woodcock have long bills; sandpipers have slim bills. (B17)
  • Oystercatchers, avocets, stilts and stone curlews have long legs and relatively long necks. (B17) Numenius arquata - Eurasian curlew and Numenia phaeropus - Whimbrel) have very long bills which curve downward at the tip. Haematopus ostralegus - Eurasian oystercatcher has a more robust bill, while the (Recurvirostra avosetta - Pied avocet) avocet's bill is long and slender and turns up at the end. The (Burhinus oedicnemus - Eurasian thick-knee) stone curlew's bill is rather short (like that of plovers). (B17)
  • Oystercatchers (Haematopus ostralegus - Eurasian oystercatcher) have red eyes, stone curlews (Burhinus oedicnemus - Eurasian thick-knee) have yellow eyes, the others have dark eyes. (B17)
  • Coots (Fulica atra - Common coot) have lobed toes (B17)
  • Rails (Rallus aquaticus - Water rail) have laterally-flattened bodies and long thin toes. (B17)
  • Coots, rails and moorhens have short tails and small bills. (B363.App2.w15)
  • All the shorebirds have long pointed wings and a short tail. (B363.App2.w15)
  • Plovers and dotterels have three toes pointing forwards, without webbing, and no hind toe. They have a short bill, no longer than the head and often shorter, either blunt or sharp. (B363.App2.w15, P24.335.w20)
  • Sandpipers (including godwits, snipes, curlews) have three toes pointing forwards and a small elevated toe pointing backwards (Calidris alba - Sanderling has no back toe). Sandpipers have a bill longer than the bird's head, some much longer. (B363.App2.w15, P24.335.w20)
  • Stilts have three toes, partially webbed and no hind toe. The bill is long and straight, the legs are very long and thin (and pink). (B363.App2.w15)
  • Avocets have webbed toes. The legs are very long and thin (and blue/grey), the bill is very long and thin and turns upwards at the end. (B363.App2.w15)
  • The plumage of these birds is dense. (D160.App4.w12)

Relevant Notes on Natural History: 

  • Mainly found on the shore, particularly on mud flats, where oil will persist, and commonly in large flocks. (D9, D137, D160.App4.w12)
  • Able to walk and run quickly and fly well. (D137)
  • Do not sit floating on the water. (D9)
  • Feed on bivalves, small crabs, marine worms, molluscs and insects, probing mud or sand to find food items (D137)
  • Vulnerable to oil left on shore by high tides, rather than to oil on open water. (D9)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Not easy to catch until weakened. (D137)
    • Some species will hide in thick vegetation, making them particularly difficult to retrieve. (D185.w3)
    • These birds are easily frightened and easily stressed. (D9, P24.335.w20)
    • Care is required in handling these delicate birds. Handle gently and as little as possible. (D135.9.w9, D137, D160.App4.w12, P24.335.w20)
    • Take particular care when handling species with long legs, necks or bills to avoid damaging these fragile structures. (B10.23.w7, B336.16.w16, B363.5.w5, D133.3.w3, D135.9.w9, V.w5)
    • Control the head at all times and restrain the wings to prevent them becoming damaged. (B336.16.w16)
    • Hold the small species in one hand with the head between two fingers; hold the legs between the fingers at the top of the femur. (P24.335.w20)
    • For larger species (e.g. oystercatchers), hold at the lop of the legs with one hand and place the other hand behind the head. (P24.335.w20)
  • Transport containers: 
    • Birds of the smaller species may benefit from being boxed together. (D137, D160.App4.w12)
    • Species such as rails, which are territorial, require individual carrying containers. (D185.w3)
    • Folded towels provide a suitable substrate. (D185.w3)
      • A non-slip substrate is particularly important with long-legged species. (B336.16.w16)
    • Containers should be well ventilated but darkened. (B336.16.w16)
  • Accommodation: 
    • Small species may be preferentially kept together, but do not crowd. (D135.9.w9, D137, D160.App4.w12)
      • Species of shorebirds which are normally sociable may become territorial during the breeding season. (J23.17.w2)
      • Smaller species (e.g. Calidris - (Genus) spp.) may need to be separated from larger species to avoid their being out-competed for food. (J23.17.w2)
    • Some species such as rails are very territorial and require individual pens while indoors before washing, while great care is required to ensure that birds in outdoor pens are not overcrowded. (D185.w3, P14.7.w16)
    • Screen pens for privacy from humans and provide hiding places in pens. (D135.9.w9, D137, D160.App4.w12)
    • Pre-washing:
      • Standard veterinary cages are not suitable as these birds can walk through the barred doors. (D185.w3)
      • Avoid stainless steel or fibreglass cages in which scalping injuries may occur during capture. (B336.16.w16)
      • For nervous species, solid sided pens, preferably with a height of at least six feet (nearly 2 m), with tops of shade cloth (secured at multiple points along the top of the container) are recommended to minimise visual and auditory disturbance and reduce the risk of head injury when startled birds jump upwards. (D185.w3)
      • Lowered lighting levels may help reduce stress. (D137)
    • Pre-release:
      • Provide cleaned birds with shallow pools and spray with water to encourage preening and restoration of waterproofing. (D135.9.w9)
      • Solid walls are recommended to provide privacy, while netting tops allow sunlight and rain into the enclosure. (D185.w3)
      • Providing a naturalistic habitat is suggested, e.g. with reeds and other marsh vegetation for marshland birds. (D185.w3)
      • Pea gravel may be a better substrate than sand in enclosures for cleaned birds, providing better drainage and being less likely to harbour bacteria. (D185.w3)
      • A small observation hole with a removable cover is recommended to allow observation without the birds being disturbed. (D185.w3)
  • Feeding:
    • Worms, chopped fish, soaked grains, mealworms, proprietary insectivorous food. (D137) Provide food in dishes, in water, on sand, and on soil. (D135.9.w9)
    • Multiple feeding stations may be used to minimise aggression between group-housed birds. (P14.7.w16)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:

Vulnerability to oil:

  • Waders or shorebirds are generally considered to have relatively low susceptibility to oil spills, flying away from oiled areas unless taken by surprise in the dark. They are probably most susceptible when roosting at night or when going to feed as the tide turns. (D10)
  • These birds will avoid oil if suitable unoiled areas are available for feeding and resting. (D162.4.w4)
  • These species can often survive for months despite oiling. (D10)
  • Waders may get oil on their legs and abdomen, while their wings remain clean and they can still fly. The oil may affect these birds more slowly until they weaken and die from hypothermia or are predated. (D185.w3)
  • Small birds (body mass no more than 100 g) which become oiled are likely to suffer high mortality, due to hypothermia and toxic effects of petroleum oils, unless special efforts are made to capture them quickly. (P14.7.w16)
  • Apart from direct oiling, these species may be highly affected by habitat damage due to oil, with loss of food resources. (D10, D162.4.w4)
  • These birds may be affected during freshwater spills. In the Amer River spill in the Netherlands in 1970, in which more than 4,000 birds were found dead and heavily contaminated, the casualties included all the 200-300 Fulica atra - Common coot and 150 Gallinula chloropus - Common moorhen, and up to 25 Rallus aquaticus - Water rail. (J17.4.w1)
  • N.B. If oiled, early capture is important; these birds can be rehabilitated very successfully if searched for carefully and captured soon after oiling but are not likely to do well if rehabilitation is only attempted when they are already debilitated. (P14.7.w16)
  • Oiled waders which become hypothermic and exhausted are likely to be predated. (P14.7.w16)
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Special Considerations for Herons and Egrets

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In the UK these birds include: Ardea cinerea - Grey heron, Botaurus stellaris - Great bittern, Platalea leucorodia - Eurasian spoonbill, Egretta garzetta - Little egret

Appearance:

  • Head with a long bill is set on a long neck. (D137, B17, B363.App2.w15, D160.App4.w12)
    • Herons and egrets have sharp, stabbing bills. Spoonbills have a spatulate or "spoon-shaped" bill. (B363.App2.w15)
  • Legs are long and toes are long, thin and widely spread; the hind toe, which is also long, faces backwards and the toes are not webbed or lobed. (B17, B363.App2.w15, D137, D160.App4.w12, P24.335.w20)
    • There is a small amount of webbing at the base of the toes in spoonbills. (B363.App2.w15)
  • Wings are long and broad (B17, D137, D160.App4.w12)
  • Tail is short. (D137, D160.App4.w12)
  • Plumage: White in the Eurasian spoonbill and little egret, grey in the heron, grey/brown in the bittern. For detailed plumage colouration of individual species, see the relevant individual species page.

Relevant Notes on Natural History: 

  • Generally solitary except when breeding.
  • Feed by wading in the shallows. Eat fish, rodents, reptiles, amphibians, insects and molluscs. (D137)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Bills are long and sharply pointed and may be aimed for the eyes. Goggles or a face shield must be worn and the bird's head kept under control at all times. (B336.14.w14, B363.5.w5, D133.3.w3, D135.9.w9, D137, D160.App4.w12)
    • The long legs and neck legs are easily damaged and must be handled carefully. (B336.14.w14, D133.3.w3, D135.9.w9, D160.App4.w12)
    • The head can be held with a hand around the back of the head, or with the bill base held between forefinger and thumb. (P24.335.w20)
    • Keep one finger between the legs and hold these high up, on the femur. (P24.335.w20)
    • The long legs should not be kept folded except for very short periods. (V.w5)
    • NOTE: Will regurgitate if disturbed after force-feeding. (D135.9.w9)
  • Transport containers: 
    • Birds must be placed in a tall box in which they are able to stand. If transported with the legs folded for other than a very short time these birds may never stand again. (V.w5)
  • Accommodation: 
    • Provide visual barriers and hiding areas; these birds are shy and sensitive to human presence. (D135.9.w9, D137, D160.App4.w12)
    • Once cleaned provide a shallow pool for wading and spray with water to encourage preening for waterproofing. (D135.9.w9)
    • Provide high perches. (B363.7.w7, D137)
    • House alone. (D160.App4.w12)
  • Feeding:
    • Fish, worms, mice. (D137) Offer in shallow dishes or deeper buckets of water. D135.9.w9
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • Note: The keel of these species is very prominent and this should not be mistaken for emaciation. (D32)
  • Captive birds are susceptible to aspergillosis. (B336.14.w14) See: Aspergillosis in Birds

Vulnerability to oil:

  • These birds not considered very vulnerable to oil. They are most likely to get oil on their legs and heads only. (D162.4.w4)
    • However, because they may get oiled on the belly and legs while the wings remain sufficiently clean to allow flight, they may not be catchable but nevertheless may gradually succumb to the effects of oil and become hypothermic or be taken by predators. (D185.w3)
  • These birds may be affected during freshwater spills. In the Amer River spill in the Netherlands in 1970, in which more than 4,000 birds were found dead and heavily contaminated, including up to 25 Ardea cinerea - Grey heron. (J17.4.w1)
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Special Considerations for Gulls and Terns

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In the UK these birds include: Childonais niger - Black tern, Larus marinus - Great black-backed gull, Larus argentatus - Herring gull, Larus canus - Mew gull, Larus fuscus - Lesser black-backed gull, Larus ridibundus - Common black-headed gull, Larus melanocephalus - Mediterranean gull, Larus minutus - Little gull, Rissa tridactyla - Black-legged kittiwake, Stercorarius parasiticus - Parasitic jaeger, Stercorarius pomarinus - Pomarine jaeger, Sterna albifrons - Little tern, Sterna bengalensis - Lesser crested-tern, Sterna dougallii - Roseate tern, Sterna hirundo - Common tern, Sterna paradisaea - Arctic tern, Sterna sandvicensis - Sandwich tern, Catharacta skua - Great skua.

Appearance (not including plumage details):

  • Wings long (B17); long and narrow in terns, long and pointed in gulls. (D160.App4.w12)
  • Legs longish in gulls (shorter in terns) and feet webbed. (B17, D160.App4.w12); shortish legs (compared to the waders / shorebirds), three forward pointing toes, webbed (B363.App2.w15, P24.335.w20)
  • Bodies relatively dumpy (B363.App2.w15)
  • Terns are smaller and slimmer than gulls. (B17)
  • Bill is sharp and pointed in terns, while the tip is hooked in gulls. (D160.App4.w12)
  • The tail of terns is long and usually forked, while in gulls it is short and fan shaped. (D160.App4.w12)
  • Plumage is dense. (D160.App4.w12)

Relevant Notes on Natural History:

  • Terns hunt by diving into water from the air. Although they may land on the water they do not generally swim. (D135.9.w9)
  • Agile on land as well as on water and in the air. (D9)
  • Terns are poor swimmers, not swimming well on the surface. (D160.App4.w12)
  • Excellent sense of smell. (D9)
  • Gulls are scavengers and will feed on live and dead oiled birds. (D9)
  • Gulls often avoid oil and are less vulnerable to oiling than many other species. (D9)
  • These birds have a large wing span relative to their weight; they may be very difficult to capture unless heavily oiled. (D141)
  • Most gull species are able to forage for food on land and can cope with a small amount of oil on their plumage. (D141)
  • Gulls can take of straight up from either the ground or the water. (D160.App4.w12)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • These birds have sharp bills and will bite; the bills of the larger gulls are most dangerous. Edges of gulls' beaks can cut skin. Wear gloves. (D9, D135.9.w9, D141, D160.App4.w12)
    • Gulls bite in a similar manner to parrots, twisting and crushing the flesh. This is painful. (D133.3.w3)
    • These birds may aim for the eyes. (D141)
    • If a single person is working on a large gull the bill may be taped closed temporarily for safety. (D141)
      • It is essential to ensure that the tape does not cover the nostrils and that the tape is REMOVED as soon as the task is completed. (D141)
      • A bird must NEVER be left unattended with its bill taped. (D141)
      • It is important to recognised that bill taping is an additional stress on the bird. Working with two people per bird is faster and less stressful for the bird. (D141)
    • The body is light and relatively fragile. (D9)
    • These birds can be held with one hand holding behind the head, or with the head between the fingers, the winds held folded against the bird's body and the legs held in the other hand, holding at the top of the femur, or with the legs held against the body. (P24.335.w20)
    • Gulls may regurgitate food if they are alarmed. (D160.App4.w12)
  • Transport containers: 
    • Stout cardboard boxes or small pet carriers can be used. A non-slip substrate (e.g. rubber covered with towels) should be provided. (P24.335.w20, V.w26)
      • Note: a cardboard box may not be sufficiently strong for larger birds, particularly when the base gets wet or oily (P24.335.w20).
  • Accommodation: 
    • Can be group housed but can be aggressive within own species and gulls are commonly aggressive to smaller birds. Provide with hiding places and do not crowd. (D135.9.w9)
    • Provide shallow pools for cleaned birds and spray terns with water to encourage waterproofing. (D135.9.w9)
  • Feeding:
    • For gulls provide fish, mice, canned dog food etc. in shallow dishes. For terns provide mealworms in dishes of sand and vegetation, as well as small whole fish, worms and insects in water. (D135.9.w9)
    • Fish slivers (white-bait size) and pet food may be given to gulls. (D214.2.w2)
    • If the bird will not eat by itself force-feed with white bait (or similar size slivers of fish) or larger slices of fish for the larger gulls. (D141)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • --

Susceptibility to oil:

  • Gulls and terns are generally considered to have relatively low susceptibility to oil spills, flying away from oiled areas unless taken by surprise in the dark. They are probably most susceptible when roosting at night. (D10)
    • In an observation of gulls encountering a large patch of oil, it was noted that the birds flew away from the oil (in contrast to auks, which dived). (J9.219.w2)
  • These species can often survive for months despite oiling. (D10)
  • Apart from direct oiling, these species may be highly affected by habitat damage due to oil. (D10)
  • Nesting colonies of terns may be disturbed during oil clean-up operations. (D162.4.w4)
  • These birds may be affected during freshwater spills. In the Amer River spill in the Netherlands in 1970, in which more than 4,000 birds were found dead and heavily contaminated, including at least 300-400 gulls, mainly Larus ridibundas - Common black-headed gull and common gull (Larus canus - Mew gull). (J17.4.w1)
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Special Considerations for Raptors

In the UK these birds include: Accipiter gentilis - Northern goshawk, Accipiter nisus - Eurasian sparrowhawk, Aquila chrysaetos - Golden eagle, Buteo buteo - Common buzzard, Buteo lagopus - Rough-legged buzzard, Circus aeruginosus - Western marsh harrier, Circus cyaneus - Northern harrier, Circus pygargus - Montagu's harrier, Haliaeetus albicilla - White-tailed eagle, Milvus milvus - Red kite, Pernis apivorus - European honey buzzard, Pandion haliaetus - Osprey, Falco columbarius - Merlin, Falco peregrinus - Peregrine falcon, Falco subbuteo - Hobby, Falco tinnunculus - Common kestrel, Athene noctua - Little owl, Strix aluco - Tawny owl, Asio otus - Long-eared owl, Asio flammeus - Short-eared owl, Nyctea scandiaca - Snowy owl, Tyto alba - Barn owl

Appearance (not including plumage details):

  • Bill is sharply hooked. Feet are strong and have sharp talons. 
  • Bill is hooked and powerful; over the base is a fleshy pad, the cere, in which the nostrils are located. (B17) Eyes are large. 
  • Feet have powerful, sharp talons. (B17) The tarsus of the leg is unfeathered in many species (feathered in eagles and the rough-legged buzzard) (B17)
  • Wings of eagles are long and broad, with the tips heavily fingered. Falcons have pointed wingtips and long narrow tails, hawks have wings that are rounded and fingered, and have long tails. (B17)
  • Owls are stocky, with large heads and no obvious neck, long legs, feathered toes and strong sharp talons; the beak is hooked and powerful. (B17)
  • Wings of eagles and hawks are broad and rounded, while those of falcons are long and pointed. (B363.App2.w15)
  • Falcons have a characteristic notch in the ventral (lower) edge of the upper mandible; this is not present in hawks or eagles. (B363.App2.w15)

Relevant Notes on Natural History: 

  • Predators and scavengers (species-dependant). (D9)
  • Depending on the species raptors may be vulnerable to oil on water or on land when hunting and feeding. (D9)
  • Walk well on land. (D9)
  • These birds do not float well. (D9)

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • These birds should only be handled by experienced personnel, trained in handling techniques for these aggressive species. (D135.4.w4, D160.4.w4)
    • The talons and the beak are powerful. (D9) The talons are the most dangerous weapon of the raptor. The beak can also hurt. The feet should be controlled quickly, also the head. (D18.2.w2)
    • Throwing a towel over the bird then quickly grasping both legs is effective for catching these birds safely. (J312.4.w2)
  • Transport containers: 
    • Should have non-slip flooring and should not have bars or wire against which the wing and tail feathers may become damaged. (D18.2.w2, B284.22.w22)
  • Accommodation: 
    • Provide appropriate high perches; this is important in prevention of development of Bumblefoot. (B23.38.w2, B336.24.w24, B363.7.w7)
    • Should not have bars or wire against which the wing and tail feathers may become damaged. (B284.22.w22)
    • Provide flight pens prior to release to allow development of muscular tone and physical conditioning. (B336.24.w24)
      • Outdoor pens should have areas where the birds have the option to shelter from rain, wind, cold and direct sunlight. (B336.24.w24)
  • Feeding:
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:

Susceptibility to oil:

  • Raptors are not generally considered vulnerable to oil, except for certain eagles (e.g. the American Bald Eagle, ospreys). However, both diurnal raptors and owls do get oiled occasionally. (B381.7.w7, D137, J316.46.w1, P62.4.w1)
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Special Considerations for Passerines

In the UK these birds include a wide variety of species including crows and shrikes (Corvidae, Laniidae) larks, sparrows and wagtails (Alaudidae, Passeridae), Thrushes, flycatchers, starling, dipper and wren (Bombycillidae, Certhiidae, Cinclidae, Sittidae, Muscicapidae, Sturnidae), tits, goldcrests and warblers (Aegithalidae, Paridae, Regulidae, Sylviidae) and finches (Fringillidae) as listed in List of UK Bird Species.

Appearance (not including plumage details):

  • Passeriformes all have two toes facing forwards and two toes facing backwards.
  • These are all small species, the largest being the corvids.

Relevant Notes on Natural History: 

  • This group is very varied and different species may feed on, for example, seed and/or insects.

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Most of these species are unlikely to be able to harm a human, although some of the bolder species may well peck. Pecks from the largest species may be painful. The nails may be able to scratch skin, again particularly in the larger species.
  • Transport containers: 
    • Small boxes may be used.
    • A perch should be provided if possible.
    • Access to food and water, and sufficient light to allow feeding, is important if small birds are to be held in a transport container for more than a short time, since they need to feed frequently. (B203)
  • Accommodation: 
    • Passerines can be maintained in standard avicultural "breeder" cages, and later, before release, in aviaries. (B365.74.w74)
    • Natural perches should be provided at various heights.
  • Feeding:
    • Food should always be available. 
      • Passerines have a high basal metabolic rat (BMR): BMR = 129 x W0.75 for passerines (compared to BMR = 78 x W0.75 for non-passerines. (B365.74.w74)
    • Depending on the species, insectivorous food and/or seeds may be required.
    • Note: Birds may not recognise artificial food mixtures as being edible. For small birds in particular there is a relatively short time in which to initiate feeding, as the reserves of these birds is not large. (J23.26.w4)
      • Weak individuals, or those which refuse to take food, may be maintained on balanced elemental foods which are easy to digest and absorb. (B365.74.w74)
    • Several, well separated, feeding areas must be provided for group-housed birds to ensure dominant individuals cannot monopolise food resources. (B365.74.w74)
    • See: Feeding of Casualty Garden Birds etc. (Small Passerines); Feeding of Casualty Crows, Jay, Magpie etc.
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • Salmonellosis and colibacillosis are known problems where wild birds congregate at feeding tables and could be of concern if a high standard of hygiene is not maintained.
  • Avian Pox could spread rapidly if any infected bird was present. 

Susceptibility to oil:

  • These species are not generally considered vulnerable to oil. However, passerines do get oiled occasionally (B381.7.w7, D137, D221) and since Corvus corone - Carrion crow feed along the Thames foreshore at low tide (B371), it is possible that individuals could be found oiled. 
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Special Considerations for Kingfishers

In the UK the single kingfisher species is Alcedo atthis - Common kingfisher  

Appearance (not including plumage details):

  • Unmistakable in the UK. (B17)
  • Small (total length 17 cm). (B17)
  • "Dumpy" with a large head and a long pointed bill, black (with red at base of mandible in females). Eye large and black. (B17, B164)
  • Legs tiny, red (greyish in juveniles). (B17, B164)

Relevant Notes on Natural History: 

  • These small piscivorous birds dive to catch fish and could become oiled while hunting.

Special Considerations for oiled birds:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Handle gently but firmly.
  • Transport containers: 
    • Provision of a perch is important. (B151)
  • Accommodation: 
    • A Standard bird breeder cage with appropriate perches available at all times. (B151)
  • Feeding:
    • Whitebait is suitable (freshly thawed and supplemented with thiamine); force feeding may be required. (B99, B151, D24)
    • For debilitated birds, mixtures of liquidised fish and rehydration fluids can be given as for other fish-eating birds. (P24.355.w12, V.w26)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • --

Susceptibility to oil:

  • Kingfishers are susceptible to oil in their habitat because they feed on fish. (P24.327.w4)
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Special Considerations for Water voles

Arvicola terrestris - European water vole is found in a wide range of habitats but has declined greatly, partially associated with predation by Mustela vison - American mink. In London, significant populations are present at Rainham Marshes, Crayford-Erith Marshes, the River Cray and in the Lee Valley. (B376.2.w2, D206)

Appearance:

  • Rat sized vole-type rodent, with blunt muzzle, small ears and tail approximately half of body length. (B144, B155, D30)
    • Differentiated from Rattus norvegicus - Brown rat by darker fur, rounder body, blunter muzzle, smaller eyes, smaller ears mainly hidden in fur and shorter, haired tail.
    • Differentiated from other voles in Britain by much larger size.
    • Juveniles differentiated from field voles by larger head and feet, and longer tail.

    (B142, B155, D30)

Relevant Notes on Natural History: 

Special Considerations for oiled individuals:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • A small net is useful for catching.
    • May be scruffed for brief examination. Chemical restraint is recommended for longer procedures and if lack of movement is important. 
    • See: Catching and Handling of Mice & Voles
  • Transport containers: 
    • A small plastic or glass container is appropriate, with torn or shredded paper as bedding, and a mesh lid or with small holes in the lid for ventilation. 
    • See: Accommodation of Casualty Mice & Voles
  • Accommodation: 
  • Feeding:
    • Cereal-based baby foods may be suitable as convalescent diets. 
    • Hay, grass pellets, proprietary rodent feed mixes, apple, carrots and green leafy vegetables may be used longer term. 
    • See: Feeding of Casualty Mice & Voles
    • Note: Data from experimental oiling of another semiaquatic rodent, the muskrat Ondatra zibethica (Muridae - Rats, mice, voles, gerbils etc. (Family)), indicate that food requirements are increased markedly by even moderate oiling. (J30.52.w1)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • --

Susceptibility to oil:

  • As semiaquatic mammals which rely on their fur for insulation, these rodents are likely to be highly susceptible to oiling following oil contamination of their habitat. (B335.15.w15, B378.7.w7, J30.52.w1)
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Special Considerations for River Otters

Lutra lutra - European otter (Species) is not presently found on the River Thames in greater London, but the population size and range of this species is presently increasing in the UK (B221) and it may be found in some riverine habitats on the outskirts of London. 

Appearance:

  • Otters have an elongated body, short legs, flat head, short neck similar width to skull, small eyes and ears, broad muzzle, prominent whiskers, long flattened and smoothly tapering tail with a broad base. (B142, B144, B147, B148)
  • They are distinguished from other semiaquatic mammals in the UK by their larger size, flattened head and the thick-based tapering tail. On land, they may be distinguished from Mustela vison - American mink by their larger size and lighter coloured coat (mid-brown rather than dark brown/black) and from Martes martes - Pine marten by their broader, flatter head and more rounded muzzle. (B142, B148)

Relevant Notes on Natural History: 

  • These semi-aquatic mammals are mainly solitary with home ranges of variable size. (B142)
  • Those living on rivers in the UK are mainly nocturnal, while those living on coasts may be more active in daylight hours. (B142)
  • The main diet is fish, but in some places more frogs or crayfish are taken, and in coastal areas crabs may be up to 20% of diet. (B142, B144, B147, B148)

Special Considerations for oiled individuals:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Otters are extremely supple and very strong. They can be difficult to catch unless severely incapacitated by injury.
    • Approach and handle with caution: otters are capable of inflicting severe bites. (J60.2.w3, B151)
    • Adults are best examined under general anaesthesia unless collapsed or unconscious.
  • Transport containers: 
    • A container of heavy mesh is recommended, of small gauge to reduce tooth damage; a cage which can be used as a crush cage is useful.
    • The floor should be covered with a towel for bedding.
    • Open sides should be covered with a cloth to reduce stress.
  • Accommodation: 
    • A dimly lit and quiet pen is required, made of a strong material.
  • Feeding:
    • Fish (white not oily), e.g. trout are appropriate. (D24, B151)
    • For convalescent animals, either liquidised fish blended with rehydration solution, or a convalescent cat/dog diet (e.g. Hills A/D) blended with rehydration solution may be used. (V.w26)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • --

Susceptibility to oil:

  • As semiaquatic mammals which rely on their fur for insulation, river otters are likely to be highly susceptible to oiling following oil contamination of their habitat. (B335.15.w15, B378.7.w7)
  • Coastal populations may be more threatened by oil spills. (B221)
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Special Considerations for Seals

In the UK, two species of seals are found, Halichoerus grypus - Grey seal and Phoca vitulina - Common seal (also known as the harbour seal or harbor seal). Phoca vitulina - Common seal individuals are "frequent visitors" to the tidal Thames. (D170)

Appearance:

  • Elongated streamlined body (stubby torpedo) with no obvious neck. (B142)
  • Phoca vitulina - Common seal has more numerous and smaller spots of colours on its coat than Halichoerus grypus - Grey seal, a smaller head which is rounded on top with a concave forehead and short muzzle, and its nostrils are close together and form a "V" shape. Halichoerus grypus - Grey seal has fewer, larger spots on its coat, its head is larger, with a longer muzzle, a flat or convex "Roman-nose" rather than concave profile, and the top of head flattish rather than domed, and its nostrils are almost parallel to one another, and well separated at the base. (B142)

Relevant Notes on Natural History: 

  • These seal species, unlike otters, do not rely on their fur for insulation. However, thick oil can affect locomotion.

Special Considerations for oiled individuals:

These notes are for quick reference. For further information see the pages indicated at the bottom of this box.

  • Handling:
    • Seals are extremely strong, can move very quickly and inflict serious bites.

    • While experienced personnel may be able to catch seal pups by hand, herding boards and/or nets are required for capture of adults.

  • Transport containers: 
    • A heavy-duty plastic transport kennel (e.g. Vari Kennel, Sky Kennel) or wooden crate may be used.
    • Specially built aluminium cages may be required for larger individuals. These may be top-opening or have vertically sliding doors, and should be designed with lift points suitable for attachment of a winch (D60).
  • Accommodation: 
    • Pens need to be of strong construction.
    • Initial pens can be quite small, with cleanable floors (e.g. tiled) covered in rubber matting or layers of towels for insulation.
    • For rehabilitation, a large pen, with pool area at least 16 square metres surface area plus haul-out area or areas is required, preferably containing salt water to avoid development of skin and eye lesions.
  • Feeding:
    • Stomach tubing with a liquidised fish mixture may be required for individuals which will not take whole fish or pieces of fish initially. (P24.335.w9, V.w26)
    • Whole fish such as herring and smelt. (B224, P24.335.w9)
  • For further information see the relevant pages linked below.
Secondary diseases of particular importance:
  • Seals commonly develop ocular lesions when oiled. See: Oiling - Clinical signs

Susceptibility to oil:

  • Pinnipeds such as Halichoerus grypus - Grey seal and Phoca vitulina - Common seal rely on their blubber layer for insulation, rather than relying on fur. They are therefore less susceptible to the effects of oil contamination than are species which rely on their fur layer for insulation. (D208.1.w1, D210.3.w3, P14.2.w1, P14.4.w4)
  • Pinnipeds appear generally to detect and avoid surface oil slicks, and therefore have reduced susceptibility to oiling. (D208.1.w1)
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Special Considerations for Other Species

For information on the casualty management of other UK species not listed above, see: Wildlife: First Aid and Care
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Authors & Referees

Authors Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee Dr Virginia Pierce (V.w73)

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