TECHNIQUE

Hand-rearing American Black Bears  (Disease Investigation & Management - Treatment and Care)

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Summary Information
Type of technique Health & Management / Mammal Husbandry and Management / Techniques:
Synonyms and Keywords Hand-rearing Ursus americanus - American black bear
Description Hand-rearing of captive-bred bear cubs is not recommended. (D247.6.w6) Hand-rearing may be required for wild cubs which have been orphaned or abandoned. 
Initial Care
  • Give a full physical examination. (B338.23.w23)
  • Take blood;
    • Assess packed cell volume (PCV), total protein and blood glucose. (B338.23.w23)
    • A complete blood count and biochemistry panel should be carried out. (J417.20.w1)
  • Check a faecal sample for internal parasites. (J417.20.w1, P62.13.w2)
  • Thoroughly examine the cub's eyes and ears. Grass awns and other plant material have been found commonly in the external auditory canals of Pacific Northwest black bears. One case of a grass awn penetrating the cornea of a bear cub has also been observed. (J417.20.w1, V.w93)
  • Check for ectoparasites. Consider doing a skin scraping for mites; numerous sarcoptic mange (Sarcoptes scabei) infections have been seen in black bears at PAWS. (Diagnosis was based on skin scrapings done in-house (V.w93)). See: 
  • If necessary, take radiographs to detect fractures. (J417.20.w1, V.w93)
  • Note: Orphaned cubs, unless found immediately after their mother's death, will be underweight when taken into care. (D252.14)
  • Young cubs may be debilitated and have a low blood glucose.
    • If the blood glucose is less than 80 mg/dL (4.44 mmol/L), give lactated Ringer's solution (LRS) or Normosol-R with 2.5% dextrose subcutaneously or intravenously (a high dextrose percentage can be used if it is given intravenously). (B338.23.w23)
  • Give subcutaneous fluids as required for dehydration. (P62.13.w2)
  • For the initial feed give oral rehydration solution such as Pedialyte or lactated Ringer's solution. (B338.23.w23, P62.9.w1)
  • Handling & Restraint:
    • Use manual restraint if possible; sedation should be used only if required for the safety of those performing the physical assessment. (B338.23.w23)
    • Small cubs can be scruffed (picked up by the skin over the shoulders). (J417.20.w1)
    • Cubs under 7.2 kg (16 lb) (J417.20.w1); or under 9 kg (P62.9.w1), can be handled and restrained using heavy gloves or blankets to protect the handler.
    • Young cubs should be anaesthetised by masking down with isoflurane while hand-held (gloves and blanket) to allow blood sampling and e.g. removal of ticks. (P62.13.w2)
    • Cubs over 9 kg, anaesthetise with 4 mg/kg Tiletamine-Zolazepam, intramuscularly, given by pole-syringe or dart pistol. (P62.13.w2)
    • From about 7.2-18 kg, restrain with a strong net then inject with immobilising drugs using a pole syringe. (J417.20.w1)
    • Juveniles weighing more than about 18 kg need to be chemically restrained for handling, as with adults. (J417.20.w1)
    • For further information on handling and restraint see: Mammal Handling & Movement
    • For further information on bear anaesthesia see Treatment and Care - Bear Anaesthesia
General Care (including warmth and hygiene)
  • Young cubs should be kept warm and dry. (B288.w11)
  • Raise with conspecifics if at all possible. For a lone cub, make every attempt to find another centre with a solitary cub and place the cubs together in one centre or the other. (B338.23.w23, J417.20.w1, P62.13.w2)
Suggested housing for minimum-handling:
Suggestion 1)
  • Run constructed of concrete and chain link, including a concrete floor and chain-link roof. Protected from draughts and inclement weather for cubs under eight months of age. (B338.23.w23) The run should contain: 
  • For young cubs, airline kennels, plenty of towels and blankets "to provide warmth and a "denlike" environment." (B338.23.w23)
  • External heat source for young or weak cubs or any cub not thermoregulating (maintaining normal body temperature) properly. (B338.23.w23)
  • For older cubs, small pools of water, logs for climbing, large culverts, open at both ends, indestructible sterilisable toys (e.g. boomer ball). (B338.23.w23)
  • Provide environmental enrichment such as whole apples and watermelons tossed in the water, and raisins, berries, mealworms and grubs hidden in log crevices. (B338.23.w23)
  • Doors should have both padlocks and secondary security clips. (B338.23.w23)
  • N.B. The enclosure should be divided into two sections so that with the cub(s) in one side the other side can be cleaned and food put in without the inhabitants seeing the carer(s). The carer(s) should not talk while in the enclosure. (B338.23.w23)
  • There should be a second boundary fence outside the enclosure to ensure that if a bear escapes the enclosure it is still confined. (B338.23.w23)
Suggestion 2) 
  • A three-section cage, one part under cover, with the sections connected by sliding steel hatch doors. Each section about 3.65 x 4.20 m and 2.74 m high, with cement block walls, cement floors with floor drains, and a chain link ceiling. Containing: (P62.13.w2)
    • A culvert and a wooden den are provided for sleeping and privacy; 
    • A stock-watering trough;
    • A large vertical log for climbing, rotting logs, branches, rocks and bowling balls;
    • Monitored by closed-circuit cameras.
    • For cubs less than 12 weeks of age, and cubs which are weak and malnourished on arrival, provide heat using heat lamps.

    (P62.13.w2)

Suggestion 3) (PAWS)
  • For cubs under 12 weeks, a large airline kennel can be used. (J417.20.w1)
    • Heat using a heating pad under one half (allowing the cub to choose its preferred temperature) or a heat lamp. (J417.20.w1)
    • Line the kennel with towels or blankets; these must be free from holes and loose threads. (J417.20.w1)
    • If the cub is single, provide a stuffed animal (without any plastic parts), for comfort; a large, dark stuffed bear is ideal. (J417.20.w1)
    • Keep in a room away from other species and away from human activities. (J417.20.w1)
  • For older cubs: (J417.20.w1)
    • PAWS has three indoor areas and two outdoor areas, made from concrete blocks with cement floors (with floor drains), solid steel and chain-link doors; these can be divided or combined using sliding doors which can be moved from outside the enclosures. Indoor areas about 2.7 by 2.1 m, 2.4 m high (9 ft x 7ft and 8 ft high), and have skylights; outdoor areas have heavy-duty chain link ceilings. The concrete floors are covered with rubber mats to avoid foot problems. Note: natural substrates would be preferable. (J417.20.w1)
      • Keep cubs in indoor areas to about three months, then give access to outdoors. Give furnishings such as hollow logs, rotting logs, large rocks, soil and mulch. Provide only small water containers initially. (J417.20.w1)
      • For older cubs (over three months), give more logs placed for climbing, larger low water troughs, large, tough containers of soil and mulch for digging. (J417.20.w1)
      • At six months provide further items such as tyre swings, large bowling balls, culverts, large galvanised water containers for swimming (as well as drinking and fishing), large vertical and horizontal logs, hollow and rotten logs. (J417.20.w1)
    • Always secure all enclosure doors with padlocks. (J417.20.w1)
    • Move cubs between enclosures by closing the sliding doors, so the cubs are in one area while another area is cleaned and maintenance carried out. (J417.20.w1)
      • For small cubs which are ambulatory but not very fast on their feet, avoid use of sliding doors, instead herd into airline kennels and keep in these, covered against visual stimuli, during cleaning of the enclosure. (J417.20.w1)
    • Keep changing furnishings in enclosures, and provide natural vegetation and hidden foods for them to find. (J417.20.w1)
      • Cubs kept in a static environment are more likely to develop negative behaviours such as approaching cage doors, reaching out to caretakers, repeatedly trying to climb rooftops etc., and may show weight loss and hair loss. (J417.20.w1)
Suggestion 4) Housing used at Idaho Black bear Rehab Inc.:
  • For cubs under nine weeks old, nurture is important. (D252.14)
    • Provide a soft object which the cub can snuggle up to, e.g. a small fake-fur pillow stuffed with towels. (D252.w9)
      • Keep one corner open to allow the towels to be washed as well as the fur. (D252.w9)
      • Cubs which are old enough to pull the towels out through the hole no longer need the pillow. (D252.w9)
    • Ensure the cub has a set routine. (D252.14)
    • The cub should be cared for and fed by one person; this foster-mother should be there when the cub needs reassurance. (D252.14)
  • As the cub gets older, they will become more interested in their environment and less interested in the carer. Reduce contact. As the cub becomes weaned, they should not need contact with the foster-mother. (D252.14)
  • Keep to a routine. (D252.15)
  • Provide a hiding place - a dog kennel with blankets or towels and a piece of fake fur. (D252.15)

Housing for young cubs

  • Night-time: large vari-kennel indoors. (D252.w6)
    • Until cubs are eight weeks old. (D252.w6)
  • Daytime: small enclosure, 4 ft by 5 ft and 3 ft 6 inches high, wooden frame covered with two inch square weldmesh. Wooden floor covered with hay, full length door plus small "windows" on the top side. Containing:
    • a vari-kennel with hay bedding;
    • a metal water tub, 1.5 ft diameter;
    • two log stumps and a branch for climbing/playing. (D252.w6)

Housing for slightly older cubs:

  • 8 ft by 24 ft long enclosure, 6 ft high, chain link netting and roof, with a solid roof over this. The floor is earth; the chain link is buried two feet deep and three feet under to the inside. Single gate. Containing:
    • Insulated den;
    • Water tub;
    • Logs for climbing;
    • 7ft section at one end which can be divided off e.g. for young cubs initially.

    (D252.w6)

Intermediate housing:

  • 35 ft by 45 ft, eight feet high chain link netting enclosure, with chain link roof covered by a solid roof. Earth floor; chain link buried 1 ft deep and 3 ft in. Double-door on one end (6 ft 6 inches wide, 8 ft high and single door on the far end. (D252.w6) Containing:
    • 160 gallon tub for swimming;
    • Large logs for climbing;
    • Log gym;
    • Seven ft long, 2 ft 6 inches diameter hollow "log" made from 2x4 wood (can be used as a den for hibernation);
    • Wood and plastic dog houses (for dens);
    • Large permanent dry dog food feeder: 2 ft high, 1 1/2 ft wide, 4 1/2 ft long, made from 2x4 wood. 

    (D252.w6) [full text provided

Older cub housing (June to hibernation):

  • 40 ft by 100 ft enclosure, 10 ft high. Chain link fencing and roof (roof seams use overlapping chain link reinforced by metal poles woven through both pieces of wire, and joined with strong metal rings). Two entrances. Western end covered with 40 ft of shade netting. Sprinkler system. Containing:
    • 160 gallon swim tub;
    • Large tree trunks, cemented into the ground, for climbing;
    • Smaller trunks and logs for climbing and playing;
    • Natural vegetation (grasses etc.);
    • Seven ft long, 2 ft 6 inches diameter hollow "log" made from 2x4 wood;
    • Large permanent dry dog food feeder: 3 ft high, 3ft wide, 5 ft long, made from 2x4 wood. 
    • 4 ft by 4 ft partially buried den with 3ft long entrance;
    • Partially buried culvert pipe, sectioned into three dens, buried.
    • Wooden deck area over dens, "roof" over this about 1ft below chain link .

    (D252.w6) [full text provided

Milk Replacer
  • Note: bear milk tends to be high in dry matter and in energy, with a large proportion of the energy as fat, and low levels of lactose. (J332.53.w1, P17.57.w2) For further information on the composition of black bear milk see: American black bear Ursus americanus - Life Stages (Literature Reports) - Lactation / Milk Production
  • Esbilac, KMR and Multi-Milk have been used to rear black bear cubs. (P62.9.w1)
  • Esbilac puppy milk replacer made up one part powder to two parts water. (B338.23.w23, P62.13.w2, J417.20.w1)
  • Multi-Milk diluted 1:1 with water; this gives the closest approximation to the composition of black bear milk. (P62.9.w1)
  • After an initial feed of rehydration solution, gradually change onto milk formula (B338.23.w23, P62.9.w1). This may be carried out over three days: (B338.23.w23, J417.20.w1)
    • first day rehydration solution (e.g. Pedialyte, Abbott Laboratories)
    • second day, 2/3 rehydration solution, 1/3 formula; 
    • third day, 1/3 rehydration solution, 2/3 formula;
    • fourth day onwards 100% formula. (B338.23.w23, J417.20.w1)
  • Ursus americanus - American black bear cubs have been successfully reared on whole cow's milk. (B288.w11)
    • [Note: formulas such as Esbilac are generally preferable if available.]
  • Idaho Black bear Rehab Inc.:
    • Initial formula: (D252.w8) [full text provided]
      • 25% Esbilac powder (Pet-Ag), 75% Multi-Milk powder (or Milk Matrix 30/55). Mix the two powders together, then mix with water at one part powder to two parts water. Plus 
      • One jar Gerbers strained fruit baby cereal (third foods) or applesauce per two cups of formula. Plus 
      • 1-2 tablespoons Gerbers baby rice cereal per 2-3 cups of liquid. Plus
      • Vionate vitamin powder (amount based on the cub's weight).
      • Honey or corn syrup to sweeten and increase acceptance.
    • From four months, add yoghurt; (D252.w8)
Utensils
  • Feeding bottle and nipple.
    • The correct size of hole in the nipple to give sufficient flow but without choking may vary between cubs and is determined by trial and error. (D252.w9)
  • Use a normal baby bottle with a human premature infant nipple for young cubs. (J417.20.w1)
  • Keep feeding utensils sterile. (P62.9.w1)
Feeding Frequency

Suggested schedule 1

  • Birth to four weeks old: every four hours day and night. (B338.23.w23)
  • Four to ten weeks old: five times daily, lapping from a dish. (B338.23.w23)
  • Ten to 12 weeks old: four times daily from a dish (during weaning from formula). (B338.23.w23)
  • Twelve to 14 weeks old: three times daily from a dish (no longer getting any formula). (B338.23.w23)
  • Fourteen to 18 weeks old: two to three feeds daily from a dish. (B338.23.w23)
  • 18 to 20 weeks: single daily feed. (B338.23.w23)
Suggested schedule 2 (Idaho Black bear Rehab Inc.)
  • Three weeks old: bottle (formula) feed every two hours, including at night. (D252.w9)
  • Six weeks old: bottle (formula) feed every two hours, including at night. (D252.w9)
  • Three months: bottle (formula) feed every three to four hours, no night feeds. (D252.w9)
  • 5.5 - 6 months: one or two bottle (formula) feeds per day. (D252.w9)
    • Note: Bottle-fed cubs wean themselves by six months of age. (D252.w9)
Feeding Technique
Bottle feeding formula
  • First feeds
    • Use a syringe (3 mL or 5 mL) initially to give the cubs the taste of formula. (D252.w9)
    • Let the cub suckle on your hand/arm, then after a minute slip the feeding nipple into the cub's mouth. (D252.w9)
    • It may be necessary to start in this way for the first several feeds. (D252.w9)
    • Keep getting formula into the cub using the syringe until it is sucking properly on the bottle (but keep trying to get it onto the bottle). (D252.w9)
    • Cubs may suckle better if lying on a piece of fake fur. (D252.15)
  • Some cubs suckle well, others may pull and tug at the nipple rather than sucking properly. (D252.w9)
  • Cupping the cub's jaw in a hand, or holding your hand under its chin, may encourage sucking. (D252.w9)
  • Small cubs suckle lying on their belly, head raised to the nipple. Larger cubs may stand to feed. (D252.w9)
  • Once the cub is used to the bottle it may be very aggressive. If more than one bottle of formula is required, have the second bottle ready. (D252.w9)
  • Thick clothes may be needed when feeding older cubs and even safety glasses (e.g. for cubs 7-8 weeks old). (D252.w9)
  • Note: older cubs (eyes open) may insist on being fed in a particular order, or with one always on the right and the other on the left, or using a particular nipple. Good observation allows recognition of behavioural cues to promote good feeding. (D252.w9)
  • Bottle feeding is required for cubs with their eyes still closed. (J417.20.w1)
    • Do not talk to the cubs during feeding. (J417.20.w1)
  • Note: bear cubs must be fed lying on their front with the head slightly elevated holding the nipple of the bottle. A bear cub fed lying on its back may inhale milk and this may result in aspiration pneumonia (Aspiration Pneumonia in Birds, Elephants and Bears). (B123.19.w19)
Dish feeding formula
  • Place the formula in a heavy dish. Find a way to anchor this down, e.g. inside a frame of 2 x 4 inch wood, or hold it down with a hand while the cub drinks. (D252.w9)
    • If the dish is not anchored well the cub will tip it over. (D252.w9)
    • More formula is wasted when dish feeding rather than bottle feeding. (D252.w9)
  • Dish-feeding can be used for cubs after their eyes have opened. (B338.23.w23, J417.20.w1)
    • Initially it may be necessary to direct them to the dish and even at first to hold the cub to keep it focused on the dish. (B338.23.w23, (J417.20.w1))
    • One the cub feeds from the dish by itself they can be fed without human contact. (B338.23.w23)
    • Note that cubs are messy eaters, climb in their dishes, and are easily distracted. (J417.20.w1)
    • Provide one dish per cub, but do not interfere if cubs share or compete with one another; this is normal.
    • Cubs vocalising loudly while eating is normal. (J417.20.w1)
    • Do not talk to cubs during feeding, nor make eye contact with them. (J417.20.w1)
    • Once the cubs reach three months old, shut them into one area, place the food in there then let the bears in, so that food provision is no longer directly associated with human presence. (J417.20.w1)
Quantities
  • Do not overfeed. (P62.9.w1)
  • Six weeks: 2-3 oz formula per feed (feeding every two hours). (D252.w9)
  • Three months: 10 oz or more per feed (every 3-4 hours during the day only). (D252.w9)
  • Four months: 9 - 16 oz per feed (every four hours during the day only). (D252.w9)
  • Five months: 40 - 60 oz per feed (two feeds per day). (D252.w9)
  • Note: Quantities of milk taken will decrease as intake of solid food increases; the age and rate of changeover varies between cubs. (D252.w9)
  • The quantity of formula required should be calculated according to the cub's daily caloric requirement then divided between the number of feeds to be given. (B338.23.w23)
    • As a guide, give 10% body weight of formula per day (100 mL per kg bodyweight or 1.5 oz per pound bodyweight). (B338.23.w23)
    • As an additional check, observe the cub's stomach while feeding and do not overfill. (B338.23.w23)
    • Calculated energy requirement for placental mammals is: Basal Metabolic Rate = (body weight)0.75 x 70; daily requirement (kilocalories) = 2-3 x BMR. (B338.23.w23)
Toileting/Elimination
  • Stimulation of urination and defecation is required for about the first eight weeks; stimulate both before and after feeding, by rubbing gently with a warm wet cloth in a circular motion. (D252.17 - full text provided)
  • Expect the bear to urinate at each feed. (D252.17)
  • Young cubs will not necessarily defecate at each feed . Stools may be formed or loose and yellow to greenish-blue to brown, depending on the formula given. (D252.17)
  • Burp the cub after each feed at least until its eyes are open and for longer if necessary (until it starts to burp without assistance). (D252.17)
  • Two cubs hand-reared from mid-April defecated and usually urinated within 5-15 minutes after suckling. (J345.2.w1)
Weighing
  • Weigh daily initially to monitor progress and to accurately calculate the quantity of feed required. (B338.23.w23, P62.9.w1)
  • Weigh every 2-3 days initially. (P62.13.w2)
    • Keep cubs wrapped in a blanket while weighing to minimise visual contact with people. (P62.13.w2)
Weaning 
  • Two cubs hand-reared from mid-April decreased their milk intake from the beginning of June onwards. They started eating solid foods in May, and in June began eating more fresh fruit and vegetables; by July they were eating mainly dry dog food (initially mixed with applesauce) together with fruit and vegetables. Meat such as ground beef was taken, but neither meat nor fish was eaten in large quantities until the cubs were seven-eight months old. (J345.2.w1)
Suggested schedule 1) Idaho Black bear Rehab Inc. [D252 - full text provided]
  • Start introducing solid food when the cub is nine to ten weeks old. (D252.w10)
  • Provide soft food in a dish; leave this with the cub between feedings. Suggested foods include tinned peaches/pears/fruit cocktail, dry cereal soaked in formula, oatmeal, bread covered with Gerbers strained fruit baby cereal (third foods) and cottage cheese - offer one each time. (D252.w10)
  • Gradually switch to dry complete dog food (chunks/pellets, not mix) mixed with formula or with fruit or with Gerbers fruit baby cereal (third foods). (D252.w10, D252.w12)
  • Note: initially cubs will scatter the food and play with it rather than eat it. Gradually they will start to eat it. (D252.w10)
  • Later also provide fresh fruit and vegetables. (D252.w10)
  • Dry dog food should be being eaten when cubs are about four months old. (D252.w10)
  • By five-and-a-half to six months the cub should be eating mainly solid food. Continue providing formula in a bowl at this time to improve growth.
  • The diet for weaned cubs includes: "fruits, dry dog food, vegetation, fish, willows, acorns, bees, wasps, ants, and an occasional mouse who tried to join the picnic."
    • Before hibernation in fall, offer occasional deer or elk carcass if available. (D252.w10)
      • Packaged meat is not eaten. (D252.w12)
    • Carrots are usually eaten; many other vegetables are rejected. (D252.w10)
    • The preferred fish are salmon or trout; other fish are usually not eaten. (D252.w10, D252.w12)
    • Cubs will eat grasses if available. (D252.w10)
    • Willow leaves are eaten and appear to act as a mild tranquilliser. (D252.w10)
    • Cubs will dig for worms and insects. (D252.w10)
  • Note: by October, a cub may eat five pounds of dog food per day plus half a five-gallon bucket of fruit. (D252.w10)
Suggested schedule 2)
  • Add Gerber baby cereal to milk formula once the cub is lapping formula from a dish well. (B338.23.w23)
  • 8-10 weeks; gradually add "bear mush" to formula in bowl: (B338.23.w23)
    • "Bear mush" is 1/2 cup (120 mL) ground kibbled puppy chow, 1/2 cup (120 mL) baby cereal, one tablespoon powdered milk formula (Esbilac), one cup (240 mL) warm water (to consistency of oatmeal), three tablespoons cottage cheese. (B338.23.w23, J417.20.w1)
  • 10-12 weeks: gradually increase the quantity of ground puppy chow in the "bear mush", decrease the quantity of formula, and add up to 10% fruit to the mush. (B338.23.w23)
  • 12-14 weeks: mixture of "bear mush" and soaked puppy chow, no formula. (B338.23.w23)
  • 14-18 weeks "bear mush"/soaked puppy chow, plus introduce dry puppy chow, fruits and natural vegetation. (B338.23.w23)
  • 18 weeks onwards: weaned. Feed dry puppy chow, fruit and vegetables. (B338.23.w23)
Suggested schedule 3)
  • Start weaning once the cub's eyes are open and the cub is focusing - at about six weeks of age. (P62.9.w1)
  • Mix milk formula with puppy chow or pablum and offer it in a bowl. (P62.9.w1)
  • Other weaning foods which have been used successfully include cottage cheese, soft fruits and softened omnivore diet (all mixed with milk formula). (P62.9.w1)
  • Once the cub is weaned, offer omnivore diet supplemented with berries still on the stems, sweet potatoes, apples, grapes, skunk cabbage, mealworms (offered sprinkled on rotting logs), fish and available natural foods such as insects, small mammals, nuts, berries and cherries. (P62.9.w1)
Suggested schedule 4)
  • Offer milk formula (Esbilac, mixed one part powder to two parts water) from a bowl from about eight weeks old. (P62.13.w2)
    • Initially it may be necessary to hold the bowl, and to push the cub's muzzle into the bowl once or twice.
    • The cub may suck rather than lap initially.
    • After a couple of days, when the cub is feeding well from the bowl, lodge the bowl between rocks to steady it rather than having a human hold the bowl.
  • When the cub has been taking formula from the bowl readily for 3-4 days, start adding baby cereal to the formula.
  • From about 10-12 weeks old, start adding ground high-quality puppy food to the formula.
  • Gradually increase the proportion of puppy food and decrease the proportion of milk formula.
  • Start adding fruit (e.g. berries, grapes), as less than 10% of the diet.
  • From 14 weeks, introduce soaked puppy food (rather than ground).
  • From 18 weeks, introduce dry puppy food and dry omnivore diet.
  • Until release, feed half dry puppy food, half dry omnivore diet, plus fruits and vegetables (e.g. salmonberries Rubus spectabilis, blackberries and raspberries (Rubus spp.), huckleberries Gaylusscia sp., blueberries Vaccinium sp., strawberries Frageria sp., skunk cabbage Symplocarpus foetidus, apples Malus pumila, carrots Daucus carota, mushrooms Agaricus bisporus, mealworms Tenebrio molitor (larvae)) and occasional fish (e.g. smelt Osmerus sp., rainbow trout Salmo gairdneri). 

(P62.13.w2)

Suggested schedule 5) (PAWS)
  • To 10 weeks, infant formula (Esbilac, powder mixed 1:2 with water), from a bottle. (J417.20.w1)
  • From 25 days, offer formula mixed with bear mush in a dish. (J417.20.w1)
  • At 10-12 weeks, offer formula and bear mush in a dish, with a few fruits. (J417.20.w1)
  • 14 weeks, introduce fruits, soaked puppy chow and natural vegetation. (J417.20.w1)
  • 18 weeks, introduce hard puppy chow and Mazuri Omnivore diet, also give natural vegetation and fruits. (J417.20.w1)
  • Six months onwards, Mazuri Omnivore diet, good-quality puppy chow, fruits, berries, mealworms, fish and natural vegetation. (J417.20.w1)
    • Fruits, vegetables and mealworms should be hidden in the enclosure for the cubs to find. (J417.20.w1)
Note: Feeding of weaned cubs should be done in a manner such that the bears do not associate humans as the source of food. Food items should be scattered around the enclosure following cleaning, with a lag period of time before the bears are allowed back into the enclosure. The items should be distributed in a manner to encourage normal foraging behaviour and not be associated with a routine vessel such as a food bowl. Enrichment devices should also be employed as a means of food delivery. Observation of bear feeding behaviours should be accomplished remotely (i.e., via video monitoring or from a blind) so the bears do not become accustomed to being observed by humans. (V.w93)
Release
  • Many hand-reared black bear cubs are given sufficient nutrition to grow large enough to survive hibernation. These cubs can be encouraged to hibernate and then released into a hibernation den. For immature cubs, either they are sufficiently grown for a similar release in late winter (February) or they have to be kept until late spring when wild food resources are plentiful.
  • Information on release is provided in Release of Hand-reared American Black Bears (Techniques)
Appropriate Use (?)
  • Wild black bear cubs may require hand-rearing if they are orphaned. (D252.w4)
  • Hand-rearing for later release is also an option when a female with cubs has become a nuisance bear and has to be euthanased, avoiding the need to euthanase the whole family group. (D270.IX.w9)
  • Options available for orphaned wild-born bear cubs include:
    • Leaving cubs in the wild. (D270.I.w1)
      • Bear cubs have a chance of surviving alone from as young as 5-7 months, although survival is higher for cubs which are older and larger. (D270.I.w1)
      • Young cubs without their mother are more vulnerable than are older cubs to predation. (D270.I.w1)
    • Placing cubs into permanent captive facilities. (D270.I.w1)
      • Bears are long lived and such places are limited. (D270.I.w1)
      • For many people, keeping wild-born bears captive is not desirable. (D270.I.w1)
      • Individuals put into permanent captivity are lost to the wild population. (D270.I.w1)
      • This may be necessary for cubs which are too human-orientated and become nuisance bears after release, or are judged likely to be problem bears if released. (J417.20.w1)
    • Hand-rearing for release.
      • This requires careful rehabilitation in appropriate facilities with experienced personnel. (D270.I.w1, J417.20.w1)
      • Survival rates of such cubs after release can be similar to that of wild cubs. (D270.I.w1)
      • Hand-reared cubs, following appropriate rehabilitation methods, can function behaviourally as wild bears. (D270.I.w1)
      • Minimising human contact, particularly as bears get older, is important. (B432.w13)
      • Costs of rearing and rehabilitation are substantial. (D270.I.w1)
      • There is a potential disease risk to the wild population unless care is taken to ensure that released bears are free of diseases and parasites. (D270.I.w1)
      • It is important to ensure that release takes place into suitable habitat with a bear population of an appropriate status (indicated by age structure) and similar genotype to the bear being released. (D270.I.w1)
      • In small, threatened or endangered populations, every cub successfully reared and released may make a difference to the chance of the population surviving. Lessons learned from rehabilitation in non-threatened populations increase the chance of success if it is required in threatened populations. (D252.w4)
      • Even very underweight cubs in fall (e.g. 15 pounds bodyweight) can recover, put on weight and be fit for release by spring. (D252.w14)
      • There are concerns that released bears could become problem bears and might be dangerous.
        • Note: "there are no reports of released bears injuring or killing a person." (D270.I.w1)
        • It has been disputed whether habituated bears are particularly likely to become nuisance animals or aggressive towards people. Initial analysis of a few hundred rehabilitated bears "indicate that only a tiny fraction of bears hand-reared from infancy engaged in nuisance behaviour once independent; few of these were ever aggressive towards people." (N20.12.w4)
        • Although a few released black bears do become nuisance bears, the majority do not. (D252.w24, D252.w25)
      • Frequent contact between cub and caretaker is required in young cubs being bottle fed, and bottle-fed cubs may continue to show dependence on their caretaker for a period after weaning. However, over time they become more independent and, particularly if other cubs are present to interact with, show less interest in their caretakers. Independence increases as cubs reach the age of normal family break-up in the wild. (D270.VII.w7)
    • Euthanasia.
      • This is an inexpensive option, and humane. (D270.I.w1)
      • This option eliminates any disease risks to the bear or any population it is released into, and avoids any genetic issues. (D270.I.w1)
      • This option is viewed negatively by many people, and may generate negative publicity for a government department in charge of managing and protecting bear populations if used as the default option for orphaned bears. (D270.I.w1)
      • This is an appropriate option for individuals with severe disabilities. (P62.13.w2)
  • Note: bear cubs are individuals and have individual personalities; suitability for release may have to be assessed at the time for release. (D270.I.w1)
Notes
  • The goal in hand-rearing wild-born cubs is a successful release of a bear in good health, with its wild instincts developing normally, and able to survive on its own. (D252.w4) [full text provided]
  • If wild cubs are euthanased rather than reared and released, it may send the wrong message to the general public. (D252.w4)
  • To minimise human contact: handle only when necessary; use methods to diminish sensory perception and ensure human handling is an aversive experience (e.g. covering with a blanket) if handling is necessary; get cubs to self-feed as soon as possible; house in a cage where it is possible to provide food and clean the cage without the bears seeing the caretakers; house with conspecifics; do not talk near the bear cage; use closed-circuit television to allow observation remotely. (P62.13.w2)
  • When small cubs are handled (e.g. scruffed or handled with blankets), rough but safe handling has been recommended to avoid the experience giving cubs a positive association with humans. (J417.20.w1)
  • Security: in designing housing it is important to remember that black bears are adept at finding weaknesses in enclosures, working out locks and finding escape routes. (J417.20.w1)

Mixing milk: 

  • Esbilac powder may need sifting to remove lumps.(D252.w8)
  • Milk is mixed in a blender, using hot water (which mixes better). However, the cubs appear to prefer the milk after it has been cooled then warmed for each feed. (D252.w8)
  • Mix sufficient milk for 24 hours and store in the refrigerator, then heat sufficient for each feeding. (D252.w8)
  • Mixed formula can be frozen and a batch thawed each day (e.g. mix sufficient for the whole week at one time). (D252.w8)
  • Powder stored in the freezer keeps better. (D252.w8)

Bottle versus dish feeding:

  • There are differences of opinion regarding whether cubs should be bottle fed until weaning at 5-6 months or should be fed formula from a dish with minimal human contact once their eyes are open.
    • If cubs are fed from a dish once their eyes are open, it is possible to remove the cub's mental link between humans and food from an early age. It is suggested that this reduces the risk of the cub associating humans with food and continuing to make this association after release. If the bear associates humans with food it is more likely to become a "problem bear" following release. (B338.23.w23)
    • Conversely, it is suggested that all babies, including bear cubs, require nurturing and that this can be given without imprinting. Nurturing "means a routine feeding schedule, a secure environment in which they feel protected, the awareness that if they bawl for help you are there." Bottle feeding is part of that. Bottle feeding satisfies the need to suckle, reducing the chance they will suckle on a sibling's ear or their own paw. A cub bottle fed by one person until weaning will naturally recognise that person as "mum" but will still become independent from that person after weaning and will not associate humans in general with food. Additionally, it is suggested that cubs given such nurture are more self-confident and independent when older than are those fed by lapping at an early age. (D252.w9) [full text provided]

Behaviour

  • Two cubs hand-reared from about 1 kg bodyweight (mid-April) made a pulsating sound, stretched out their claws and kneaded while sucking from a bottle, often with eyes closed and appearing very contented. Once the milk was finished, they would start growling and attacking one another. (J345.2.w1)
  • Cubs may suckle other objects including e.g. the finger or arm of a caretaker or part (e.g. ear) of another cub. A cub can be very persistent in this behaviour. (J345.2.w1)
Complications/ Limitations / Risk
  • Zoo-born bear cubs should not be hand-reared routinely. (J23.14.w3)
  • The EEP Ursid Guidelines state that hand-rearing of cubs is not recommended. (D247.6.w6)
  • There is a risk that hand-reared rehabilitated bears will become problem animals. This can be minimised by:
    • Not releasing close to humans;
    • Education to discourage feeding of bears;
    • Relocating bears which are just beginning to become problem bears (i.e. when they first start coming to humans/human habitations for food). 
  • Gloves may be needed when feeding cubs to avoid injuries from the claws of cubs too eager to feed. (D252.w9)
  • Dehydration: skin pinched up on the cub's neck should spring back down when released; if it stays tented, the cub is dehydrated. (D252.w9)
  • Latex gloves should be worn to reduce the risk of transmission of zoonoses from the cubs. For very young or sick bears, or non-aggressive individuals, these alone may be sufficient. For other cubs, latex gloves should be worn under thicker protective work gloves. (B338.23.w23)
  • Avoid rearing a lone cub: try to find another black bear cub of about the same age or sex and move one of the cubs between facilities so they have company. (B338.23.w23, J417.20.w1, P62.13.w2) 
    • If cubs are not quite matching in age/weight, introduce gradually and with care; the cubs may not be able to be kept together if the larger cub is too aggressive. (B338.23.w23)
  • Do not use an animal of another species (e.g. deer, dog) as a companion. (B338.23.w23)
    • However, one successful rehabilitator uses a good-natured dog (German Shepherd) as a play-companion if she has a lone cub, but only until another cub arrives and not as the cub gets larger. She has found that the cubs recognise this individual dog as non-threatening but still react appropriately (i.e. with fear) to other dogs. (D252.w17)
  • Nematode (hookworm, ascarid) infections are common; it is advisable to treat cubs with an appropriate anthelmintic. (P62.9.w1)
Equipment / Chemicals required and Suppliers
  • Multi-Milk is a high-fat low lactose milk replacer. (W494.May06.w2)

  • Milk Matrix 30/50 (Pet-Ag) is a milk replacer with only trace lactose. (W494.May06.w1)

  • Multi-milk has the closest nutritional match to black bear milk. (P62.9.w1)

  • Esbilac (Pet-Ag) is a standard puppy milk replacer. (W494.May06.w3)

    • Esbilac is a good formula for black bear cubs but is expensive to use in the quantities required for rearing bear cubs. (D252.w8)

Expertise level / Ease of Use
  • Rearing bear cubs is time-intensive and requires dedication and experience.
  • Rearing wild cubs should be carried out by a licensed rehabilitator.
  • Experienced personnel are required for rearing bear cubs. (J417.20.w1)
  • Persons rearing black bear cubs should already be experienced at rearing other mammals. (P62.9.w1)
Cost/ Availability
  • Rearing bear cubs is expensive in terms of:
    • Quantities of milk formula required;
    • Quantities of food (dog chow, fruit etc.) for older cubs;
    • Building a sufficiently large bear-proof enclosure, with appropriate furnishings.
Legal and Ethical Considerations
  • Zoo-born bear cubs should not be hand-reared as a matter of routine. Failure of females to rear cubs usually occurs due to disturbance; every effort should be made to avoid the female being disturbed.
  • Orphaned/abandoned wild-born bear cubs should not be taken for hand-rearing if they are of an age where they are likely to survive alone.
    • For black bears, this is from about six months of age. (P62.8.w1)
  • Hand-rearing should not be started unless the carer is prepared to give the time and effort required for rearing to release, or to ensure that appropriate care will be continued through to release. 
  • Consider whether hand-rearing is the best option for the individual compared with leaving it in the wild. 
  • Consider whether euthanasia is a more humane/kinder option for the individual than attempting hand-rearing. 
  • If wild-born cubs are hand-reared, every effort should be made to rear them with conspecifics, and to ensure that the cubs are maintained suitable for release, preferably not habituated to humans, dogs etc. 
Author Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee John Huckabee (V.w93)
References B123.19.w19, B338.23.w23, B432.w13, D252 [full text provided], B432.w7, D270.I.w1, D270.VII.w7, J345.2.w1, J417.20.w1, N20.12.w1, P62.8.w1, P62.9.w1, P62.13.w2, W494.May06.w2, W494.May06.w3, V.w93

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