Health & Management / Reintroduction & Conservation Translocation / List of hyperlinked Techniques & Protocols:
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Introduction and General Information

Post-release monitoring, associated assessment, continued habitat protection (and if necessary, management) and ongoing education and communication should be an integral part of any release programme.
  • Post-release monitoring is essential in order to determine where, when and how released individuals have encountered problems, so that programmes can be adapted to minimise problems in future releases. (B709.36.w36)
  • An adaptive management strategy is recommended, in which following design and implementation of the programme, monitoring takes place, the results of the monitoring are assessed and this is then fed back into the design, together with other aspects of feasibility assessment and risk assessment (B708, P17.62.w1). 
  • Released animals should be monitored for their ability to adapt to the free-living situation, including feeding, predator avoidance, intraspecific social integration, habitat use and dispersal, the health and survival of the individual, recruitment, structure and size of the population and rate and causes of mortality. (J727.1.w1) 
  • It is essential that post-release monitoring is continued for a sufficient length of time (years) and that the results and published and made available to others who may be considering similar release programmes. (P17.62.w6)
  • Post-release monitoring (and possible support) may be required for longer after release of K-selected species in which offspring normally have a relatively long period of dependence on their parents. (J54.13.w1)
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Tracking the behaviour and performance of released individuals and the population as a whole are essential to enable assessment of  progress (or otherwise) towards a viable population. (P17.62.w1)
Indirect monitoring
  • Indirect monitoring involves detection of signs of the released animals, such as identifiable footprints, faeces or hair.
    • Hair caught on wire fences can be useful
    • For small rodents, hair tubes have been designed - tubes with sticky tape along the top on the inside, to which hairs will stick when the rodent runs through
Direct monitoring

Direct monitoring may make use of tags, bands/rings, other marking methods, radiotransmitters or satellite transmitters to enable researchers or other individuals to identify, track or otherwise monitor released animals.

  • All released individuals should be permanently identified prior to release. (J727.1.w1)
  • Preferably, the method used should enable identification without the need to capture the animals. (J727.1.w1)
  • It is important that any method used for marking and tracking released animals has no or minimal deleterious effects. Methods to be used should be tested before the animals are released, and modified as necessary both before they are used in the release programme and afterwards, as required.
  • Direct monitoring either visually using bands or tags, or via VHF radio-transmitters, is expensive in terms of personnel time. PIT (satellite) transmitters are more expensive but can be monitored remotely, reducing costs of personnel. (P142.1998.w1)
  • Attachment points and methods for transmitters must be chosen to minimise stress and interference with the animal. (P142.1998.w1)
  • Behavioural studies should be carried out to ensure that the released animals show normal feeding habits, progress in social development and are not declining in health status. (P17.62.w7)
  • Monitoring of the population demography should enable detection of unusual mortality which may indicate a need for further investigation. (P17.62.w7)
Health monitoring & Necropsy
  • Health monitoring should be an integral part of post-release monitoring; it is too often neglected, even if it was included in the project plan. (B482.9.w9, J64.12.w5)
  • Periodic monitoring of parasite loads via faecal egg counts is recommended. (P17.62.w7)
  • If practical, periodic immobilisation and sampling of individuals from the released population is recommended. (P17.62.w7)
  • Whenever possible, carcasses of released animals should be retrieved and examined.(P17.62.w7)
    • If field necropsy is required, equipment/facilities must be available for field storage of tissue samples. (P17.62.w7)
    • Parasites should be collected and samples stored in 70% alcohol, allowing later identification. (P17.62.w7)
  • The health status of domestic stock adjacent to the release area should be monitored. (P17.62.w7)

(B456 - full text included)

Crane Considerations Most release projects involving cranes have used a combination of direct monitoring techniques including leg bands (rings) and transmitters. Detailed monitoring of individual birds takes a large amount of time and effort.
  • In The Great Crane Project, most of the direct observations were carried out by a team of RSPB volunteers. Information was recorded on the cranes' location and habitat use, behaviour, social interactions and reactions to disturbance. A combination of direct observation, daily, satellite telemetry and faecal analysis was used. (D450)
Indirect monitoring
  • Following release of cranes in The Great Crane Project, about 10 faecal samples were collected weekly for future analysis of diet. (D449)

Cranes should be fitted with coloured leg bands and possibly radio transmitters before release. (B115.11D.w16)

Direct monitoring
Leg Bands
  • Flightless whooping crane chicks hatched under sandhill cranes in the Grays Lake Refuge experiment were caught by hand and marked with a US Fish and Wildlife Service leg band plus coloured plastic leg bands. (B709.25.w25)
  • Mississippi sandhill cranes were banded with an aluminium US Fish and Wildlife Service leg band, also with colour-coded leg bands or neck collars. Most released birds were also fitted with a radio transmitter mounted on a leg band. (J57.1.w1)
  • Colour leg bands have been used extensively for post-release monitoring of Mississippi sandhill cranes. (P87.6.w5)
  • Coloured leg bands were used to identify Florida sandhill cranes after translocation to Georgia. (P87.8.w9)
  • Whooping cranes released in Florida were fitted with coloured leg bands for identification. (P87.7.w16)
  • Released Grus leucogeranus - Siberian crane cranes were banded with standard metal bands and colour-coded plastic rings. (N48.5.w4)
  • In The Great Crane Project, aiming to return Grus grus - Common cranes widely to the UK, the first cohort were each fitted with a BTO metal ring below the hock, a set of three colour-coded individual identification rings on the right leg, with the lowest being red (2010) and a set of black-blue-black rings on the left leg to indicate the UK (agreed with the European Crane Working Group). (D449)
    • 2011 release year birds had the bottom ring in white. (D450)
    • The combination of green and blue adjacent to each other was avoided, as it had been found difficult to distinguish these in the field. (D450)
    • Birds were also microchipped. (D450)
  • Both standard very high frequency (VHF) radio-transmitters and platform transmitter terminal (PIT) transmitters (also known as satellite transmitters) have been used in post-release monitoring of cranes, as well as to monitor local movements and regional migration routes of wild cranes. (P142.1998.w1)
  • Radio-telemetry has been used extensively for post-release monitoring of Mississippi sandhill cranes. (P87.6.w5)
  • Transmitters have been used on Grus canadensis - Sandhill crane, Grus americana - Whooping crane, Grus leucogeranus - Siberian crane, Grus grus - Common crane, Grus virgo - Demoiselle crane, Grus vipio - White-naped crane, Grus japonensis - Red-crowned crane, Grus monacha - Hooded crane. (P142.1998.w1)
  • Whooping cranes released in Florida were fitted with radiotransmitters, mounted on leg bands, before release. (P87.7.w16)
  • Leg-band radio transmitters were used to monitor Florida sandhill cranes after translocation to Georgia. (P87.8.w9)
  • Both backpack-mounted and leg-band-mounted transmitters have been used. In North America, results with satellite transmitters mounted on leg bands were considered to be as good as those using backpacks, and without concerns about harnesses abrading skin or feathers or interfering with flight. Only for young chicks might body-mounted transmitters be needed. (P87.8.w22)
  • Following several collisions of released whooping cranes with power lines, leg-mounted transmitter housings were modified, by making the leading edge slope, to reduce the risk that the transmitters would catch on wires if the crane's legs brushed the wires in flight. (P87.11.w11)
  • A Grus leucogeranus - Siberian crane chick was fitted with a body-mounted PTT. (N48.4.w1)
  • A released Grus leucogeranus - Siberian crane was fitted with a leg-mounted satellite transmitter. (N48.4.w1)
  • In The Great Crane Project, aiming to return Grus grus - Common cranes widely to the UK, the first cohort were each fitted with a leg mounted battery-powered15g radio tag on the lowest ring on the right leg. Five were fitted with a solar powered GPS-PTT on the left leg, on a long band coloured black-blue-black to replace the three leg rings of those colours. Five males were fitted with battery powered GPS data loggers on backpack harnesses. (D449)
    • Due to faulty batteries, the five data loggers stopped working in the first autumn. (D449) In 2011, a software problem menat that they drained the batteries in days rather than 18 months. (D450)
    • No problems were noted with the backpack harnesses. (D450)
    • One leg-mounted GPS-PTT had to be removed as the ring was apparently slightly too tight and appeared to be causing leg irritation. (D449)
    • Remaining leg-mounted satellite PTTs were noted in2011 to "provide really invaluable and reliable data on the birds whereabouts and are particularly useful for ascertaining the whereabouts of the birds at nighttime roost." (D450)
    • In 2012, one bird appeared irritated by the backpack and it was found that some secondaries and greater coverts had become trapped under the elastic; the backpack was repositioned. Another backpack was seen coming off, caught on the carpal joint, and was removed. (D451)
Health Monitoring & Necropsy
  • Necropsy of released cranes found dead is recommended. (D449)
  • Necropsy of a Grus grus - Common crane which hit power lines showed fatal electrocution plus subsequent injuries [presumably from hitting the ground]. (D449)
  • Necropsy of one Grus grus - Common crane which disappeared overnight and was found partly buried had been partially eaten by a fox (either scavenged or killed by the fox) was found to have both Campylobacter infection and coccidial infection. (D450)
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When individuals which have been reared in controlled conditions are released, they may encounter difficulties; decisions must be made whether or not to intervene. (B429.29.w29)
  • Interventions needed may including supplementary feeding of released animals and veterinary care.
    • Initial provision of resources such as food, water and shelters may be an integral part of the release protocol (B429.29.w29) and might be considered part of soft-release.
      • Such resources also provide improved opportunities for monitoring and trapping of released animals. (B429.29.w29)
      • The point at which support should be withdrawn is a major decision within a release programme.(B429.29.w29)
  • In some programmes, a prolonged period of post-release support may be needed. (B444.w3)
  • Interventions, assisting released individuals, may be important in the early stages post-release, to improve survival of released animals and assist them in reaching breeding age. (B709.36.w36)
  • If intervention involves bringing an animal or animals back into care, then appropriate accommodation must be available. (B429.29.w29)
  • Criteria for interventions should be decided in advance. (B482.14.w14)
    • This avoids rushed decisions in confused, possibly emotionally-charged, conditions. (B429.29.w29)
Initial post-release provisioning
  • Provision of essential resources such as water, food and shelter can be advantageous in the post-release period both to support the released animals and to control their movements: it is easier to monitor animals which are coming to a set point.
  • Soft-released individuals may be more likely to utilise such resources than hard-released individuals. (J182.31.w1)
  • One of the important decisions to make in a release programme is the point at which such support should be withdrawn.
Crane Considerations
  • In soft-release sandhill cranes, provision of food within a predator-proof enclosure was used initially both to encourage the released juveniles to use the safe area and to entice wild cranes in for the captive-reared birds to socialise with them. 
    • Appropriate timing to stop supplementary feeding was found to be important in encouraging the released cranes to leave on migration with wild cranes.
  • At Grays Lake, during the whooping crane cross-fostering experiment (placing whooping crane eggs into sandhill crane nests), predator control was started when it became apparent that eggs and large numbers of pre-fledging whooping crane chicks were being lost to predation. Canids, particularly coyotes but also foxes, were the main targets of control efforts, with opportunistic control or Taxidea taxus - American badgers and Mephitis mephitis - Skunks. (P66.2.w1)
  • For Mississippi sandhill cranes released onto a refuge, supplementary food was provided in winter. (P91.1987.w10)
  • For whooping cranes released in Florida (Kissimmee Prairie), sick or injured birds were captured and treated. (P87.8.w19)
  • For whooping cranes released in Florida to form a nonmigratory population, interventions have included translocation of cranes from inappropriate (urban) habitats and/or inappropriate social groups (sandhill cranes) to more appropriate rural areas with other whooping cranes. Of nine translocations, four returned to their original location (three birds) or sandhill crane mate (one bird) within two days to a month, one moved to another urban location and four remained at the translocation site, with three pairing with other whooping cranes. (P87.10.w10)
  • When one of seven isolation-reared Grus leucogeranus - Siberian crane released onto an island in the Big White Lake, Belozersky Refuge, Russia in August 2001, did not leave on migration with the other cranes, it was captured and returned to Oka Crane Breeding Center. (N48.1.w1)
  • Two isolation-reared and hang-glider flown Grus leucogeranus - Siberian crane chicks released in Iran were recaptured, one after being injured by a villager and one after failing to bond with other cranes. (N48.4.w1)
  • For Grus grus - Common crane in The Great Crane Project, UK, it was agreed that interventions would move along a sliding scale from "Birds are our responsibility" and "They need all the help they can get" towards "Birds are now wild and free" and "Survival of the fittest" over time. (D449, D450)
    • Supplementary food was provided throughout the first winter and particularly during freezing weather, but reduced after the frosts. (D449)
    • In the initial post-release period, one crane was treated with antibiotics after showing lethargy and wheezing. Another had to have a strand from the release pen aviary shade-netting removed after it became tangled around her tongue, another was briefly taken into care after suffering a long cut on one wing due to some aerial collision, and was released two weeks later after treatment with antibiotics and anti-inflammatories. A crane which developed a limp was monitored. Another whish started a backwards-kicking leg gait was checked and a leg-mounted PTT removed as the ring appeared to be too small and causing irritation. (D449)
    • In the initial post-release period in 2011, one bird was found having apparently flown into the fence of the release enclosure, fallen down behind the gate and been trapped there. She had bruising and abrasions on both wings and was unable to stand initially. She was treated, including using a sling initially, was released again a month later and returned to the flock 42 days after the accident. (D450)
    • In the second year of the project, as an alternative method of ensuring supplementary feed, arrangements were made for an acre of spring barley to stay unharvested on Allen Moor, and for two acres of maize to be planted "within farmland bird cover-crop areas." (D450)
      • The cranes were reluctant to use the standing barley, despite the presence of crane decoys, but did use it once it had been flattened for them(as did large flocks of starlings). (D450)
      • Use of the adjacent maize was enhanced after some cattle escaped and flattened part of the crop. (D450)
    • An automatic feeder was provided during the winter. (D450)
      • It was noted that while the fledglings used this, the birds which had been out for a year used it less and thatuse reduced considerably during March; it was removed in late March 2011. (D450)
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Habitat Management

Both during and following the release phase, it may be necessary to not only protect but also manage or restore appropriate habitat. (B482.14.w14, P87.11.w11, P91.1987.w10)
Crane Considerations
  • For Mississippi sandhill cranes released onto a refuge, important habitat management included improvement and restoration of breeding, feeding and roosting habitat, and predator control. (P91.1987.w10)
  • When a pair of non-migratory whooping cranes in Florida nested on a 5 hectare urban lake (after the marshes dried in drought), with their primary feeding area being on the other side of a four-lane highway, researchers erected 206 metres of fence to prevent the chick from reaching the road; the cranes flew to the feeding area a few days after the chick fledged. (P87.11.w11)
  • During the period 1974 - 2003, habitat in Florida suitable for cranes declined by 42%. It was noted that "too few acres of conservation lands are being actively managed in ways that benefit cranes." (P87.11.w11)
  • Management of open grassland habitats using grazing/trampling and seasonal burning, as well as wetland restoration are needed for cranes in Florida. (P87.11.w11)
  • In Florida, marking of a stretch of power line 8 km long where several mortalities had occurred appeared useful in reducing collisions: after this modification, in which the line was marked with Firefly Bird Flappers (PR Technologies, Portland, Oregon, USA), plus streamlining of leg-mounted transmitters to reduce the chance of those catching on power lines, no further mortalities on only one non-injury contact with the line have been documented. (P87.11.w11)
  • In the UK, for The Great Crane Project, after one crane died hitting a power line, the power company was approached and plans agreed to fit reflectors to the stretch of line most likely to cause problems. (D449)
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Studies and Assessment

Appropriate achievement indicators, such as rate of survival and of recruitment, should be identified by which the success of the programme can be determined and which should enable prediction of the required duration of the programme (e.g. for how many years releases are required).  (J727.1.w1)
  • The ultimate measure of success of a reintroduction effort success is the establishment of a self-sustaining and viable population. (J50.104.w2, J727.1.w1)
    • The key achievement indicators should be determined before the start of any releases. (J727.1.w1)
    • The percentage of released individuals surviving to breed would be one measure of success. (J50.104.w2)
  • Cost-effectiveness and success should be assessed.
  • It is essential that if a programme is unsuccessful, information which may indicate why the project failed is properly recorded. (P17.62.w5)
    • Methods used at all stages need to be recorded, including rearing techniques, release conditions, handling, pre-lease training, release habitat conditions etc. (B444.w3, J50.104.w2)
  • Monitoring for a prolonged period (years) is required for proper assessment. (P17.62.w6)
  • Factors to be monitored include predator avoidance, social integration with conspecifics, habitat use, dispersal, health and survival, breeding and recruitment, population structure, population size and causes of mortality. (J727.1.w1)
  • It is important to monitor as many individuals as possible, not just to estimate population size. (P17.62.w5)
    • In order to enable released individuals to be monitored it is essential for them to be marked pre-release. (J50.104.w2)
  • In a study with mallard, soft release (ducklings initially released into a large, predator-proof pen, supplementary fed and allowed to fly out when fledged), showed higher survival than direct-released birds. Also, survival was higher for those released early in the season than those released later. Additionally, those released by the gentle method returned earlier in the spring, which may beneficial for nesting. (J59.9.w2)
  • Note: the results of assessment should be fed back into the programme with techniques adjusted based on the assessment. The results of the assessment may also indicated that the reintroduction/conservation translocation programme should be discontinued. (J727.1.w1)
Crane Considerations Studies have shown that recently-released juvenile whooping and sandhill cranes show relatively low amounts of time being alert towards predators, but this increases with time. Post-release survival has been very variable. In general, costume rearing in combination with gentle release has been reasonably successful, with resultant high first-year survival. Variations on this theme which have been successful include one-by-one release of fledgling cranes into flocks of conspecifics, after rearing involving large amounts of time in natural conditions, and costume rearing followed by ultralight-guided migration.
Grus canadensis - Sandhill crane reintroductions
Mississippi sandhill cranes
  • For released parent-reared Mississippi sandhill cranes, survival was higher for nine birds soft-released in February-March 1981 (six still alive after nearly two years) than for five birds released February-March 1982. The difference was considered possibly related to the longer period for which the cranes were held together prior to release in 1981, forming a more cohesive group which stayed together better following release. It was considered that remaining as a group may have reduced vulnerability to predators and improved detection of food items. (P92.1983.w1)
  • After parent-reared (in captivity) Mississippi sandhill cranes (mostly juveniles, one yearling) were released on a refuge, 1979-1985, by December 1986, 19/41 (46%) were still known to be alive. Of the 22 deaths, 16 (73%) occurred during the first year, with only three (14%) in the second year post-release and three (14%) in their third year post-release. Eight of the cranes were killed by predators in their first year in the wild: three by dogs or coyotes, two by Lynx rufus - Bobcat, one by a raptor, two by unknown predators. Two were hit by vehicles on roads, one was shot, one was killed by an anti-predator device which it accidentally triggered. Three succumbed to disease. One "mortality" was re-captured at a shipping centre 145 days after being released. There was large variability by year, from 0% to 100% survival. Cranes released without having a period together to form a flock showed high dispersal, emaciation (seen at necropsy) and zero survival. Deaths due to predation were greater at the woodland site than at the site with more open habitat. (J57.1.w1)
  • Out of 45 parent-reared Mississippi sandhill cranes soft released (placed in an acclimatization pen on the refuge for 4-6 weeks before release), 1981-1986, by 1987, 17 survived (one was then seven years old, four were five years old, one was four years old, five were three years old and three each were two and one years old. Causes of death in 26 cranes were predation (10), accidents (four), disease/parasites (four) while one was shot and two were returned to captivity. During 1987, two of the released birds paired with each other and laid eggs, while three others paired with wild cranes and the pairs nested and produced eggs. (P91.1987.w10)
  • For Mississippi sandhill cranes, of 52 birds released December 1982 to January 1989, all integrated well into the wild flock and there was 65% survival to at least a year after release. Of birds reaching at least four years of age (breeding age), 10 have been confirmed involved in 26 breeding attempts, with at least 15 fertile eggs, at least nine hatched chicks and at least six fledged chicks. (P87.6.w5)
  • For the first two years of release of costume-reared Mississippi sandhill cranes, six-month survival of the 28 birds was 96% and one-year survival 93%. (P87.6.w5)
Florida sandhill cranes
  • Two Florida sandhill cranes were successfully released gradually.  (P87.1975.w6)
  • Following translocation of subadult (two-year-old) Florida sandhill cranes to the Grand Bay Wildlife Management Area, Georgia, USA, in October 1993 and October 1994, monitoring showed that the birds remained in the area during the winter and stayed there rather than migrating with greater sandhill cranes in spring, and some of the released birds were confirmed breeding in the area in spring/summer 1996. (P87.8.w9)
Greater sandhill cranes
  • For greater sandhill cranes Grus canadensis tabida released at Mormon Lake, northern Arizona, USA, recently-released parent-reared juveniles spent less time alert for predators and less time foraging, but more time loafing than did surviving costume-reared subadults which had been released a year earlier. The juveniles appeared to learn important survival behaviour from the older cranes. The older cranes were particularly alert in the early morning, less in the middle of the day and more again in late afternoon (although less than in the early morning). (P87.8.w8)
  • For parent-reared greater sandhill cranes aged 1-3 years hard released at Grays Lake Refuge, Idaho, USA, released birds were noted to spend more time foraging and preening and less time showing vigilance behaviours than wild birds. (P87.1981.w8)
  • Although the first three released greater sandhill crane juveniles associated with the subadults and started off on migration with them (the subadults had been taught a migration route by being led by trucks), they failed to complete the whole migration with the older birds. A further five juveniles released later never associated with the older birds.  (P87.8.w8)
  • For isolation-reared greater sandhill cranes, reared and released at Senay National Wildlife Refuge, Michigan, home ranges of six birds were determined during 1992-1993. Home ranges varied in size from about 50 - 300 hectares, with a mean of about 200 hectares. Feeding grounds were either adjacent to or separate from nesting habitat. Open water and bog were avoided, while emergent palustrine wetlands were preferred and cranes varied in their use of upland habitats - two selected open upland habitat, two selected forested palustrine habitat while four avoided it. Nesting occurred in marshlands. Feeding areas used varied depending on  availability; open hayfields and other open fields were used by some cranes, and mudflats created by draw-downs of pools were used by others.; the border between open upland and forested upland was preferred, while deep forested uplands were rarely used. (P87.7.w11)
  • Following group-rearing of greater sandhill cranes and whooping cranes in Idaho (after initial rearing at Patuxent Wildlife Research Center, Maryland in the case of whooping cranes ) flight training and ultralight-led migration to Bosque del Apache NWR, New Mexico in 1997, the released cranes were observed to show alert responses to coyotes during daytime. They associated with wild cranes; whooping cranes associated more with a cross-fostered whooping crane from the Grays Lake experiment and the adult whooping crane x sandhill crane hybrid. Two of the whooping cranes were predated in their first winter, by coyote and bobcat respectively, and another was found scavenged 670 days after release, in north-central Utah. The other ultralight guided whooping cranes and the surviving sandhills migrated north in spring 1998. Two whooping cranes were caught by night-lighting and moved from a power-line hazardous area in Colorado to Yellowstone National Park. One of the whooping cranes was confirmed at Grays Lake in summer 1999. (P87.8.w10)
  • Costume-reared greater sandhill cranes flight-trained in Ontario and led by ultralight  863 km to a wintering site in Virginia, migrated north in spring to approximately the same latitude as where they were reared, but they took a different route. They also stopped close to human habitation. they were then led back to the fledging site using the ultralights. (P87.8.w11)
    • Cranes transported by truck for the southward journey and wintered with the ultralight-led migrated cranes did not migrate north with the ultralight-led cranes in the spring. (P87.8.w11)
    • The ultralight-led cranes did migrate north successfully, but were insufficiently wary of humans. Although they had been costume-reared, the protocols had not been strict, in particular, they had become used to human voices during the later stages. (P87.8.w11)
  • Isolation-reared greater sandhill cranes reared and released in south Texas showed a strong affinity for their natal area. Although they started migrating with wild cranes in the spring, they returned to their rearing area in Texas rather than completing the northward migration. (P87.6.w4)
  • Isolation-reared, flight-trained greater sandhill cranes, given extensive experience of foraging in cohorts in natural areas pre-release, with pens designed to look natural and with some anti-human conditioning both during rearing and after release, showed appropriate behaviours post-release including foraging on natural foods, showing preference for appropriate habitats (including roosting in water, and avoiding tall grass and bushy habitats), and not approaching human habitation nor e.g. landing in school yards. Nevertheless, when fed by well-meaning people, they did become too tame. (P87.8.w12)
  • Following costume-rearing and truck-led migration in 1996, with subsequent one-by-one release into flocks of wild cranes on the wintering grounds, greater sandhill cranes integrated with the wild flocks and became unapproachable by uncostumed humans; all survived the winter. One possibly migrated with the wild birds. Five were captured and transported to the summering area. Three migrated in mid-March within 75 km of the desired summer area but responded to deep snow by returning to the wintering area; they flew again in April and landed about 75 km southeast of the desired area and were then transported to the summering area. These eight cranes then tended to fly in two groups within a 100km radius; these flights were stopped by using brailing or feather clipping to prevent the dominant bird in each group from flying; the feather-clipped bird was found dead three months later. In autumn, three flew to the winter area, four initially flew east, were retrucked to an appropriate starting point and then migrated, with a prolonged stop at a staging area. In spring 1998, three flew to within 40 km of the summering area while one flew in the wrong direction; all were transported to the summering area and in October all four birds correctly migrated to the wintering area. In spring 1999, two migrated to the summering area, one to within 40 km and the fourth to west-central Nevada (probably with wild cranes). Another of the cranes was found in California. Three of the cranes were considered too tame to stay free-living therefore were caught and placed in zoos. Spring 2000, four cranes were seen north of Mormon Lake which were probably survivors of the 1996 group, and one was seen in 2001 in the White Mountains. (P87.8.w14)
  • Juvenile cranes parent-reared in captivity, when compared with costume-reared cranes which had been free-living for a year, spent less time foraging and less time alert, and spent more time loafing and locomoting. With time, the fledglings spent more time alert and less time loafing (P87.8.w8)
  • Costume/isolation-reared sandhill cranes given experience in natural habitats after fledging, then released singly (one-by-one method) into wild flocks at staging areas, showed rapid integration into wild flocks (sometimes two or three releases were required), with adoption of behaviour patterns similar to those of the wild birds, successful autumn migration with the wild flocks, appropriate wintering with wild cranes, return to central Wisconsin the following summer and appropriate wintering, migration and summering thereafter (some variation in migration associated with mild winters).
  • Costume/isolation-reared sandhill cranes given experience in natural habitats after fledging, led on migration by ultralight aircraft and encouraged to use a safe roosting site for the first winter, successfully migrated back to the rearing area before dispersing over the summer. Most of the birds then migrated a shorter distance than expected during the following mild winter, overwintering with many wild birds at Jasper-Pulaski SFWA or Hiwassee Wildlife Refuge; most of the birds returned to the general rearing area the following spring and several were found back at this location the following year. (P87.9.w7)
  • Greater sandhill cranes cross-fostered to wild Florida sandhill cranes in Florida showed only 39% survival from hatching to dispersing from their natal home range (and only 15% of transferred eggs resulted in dispersing young), possibly because the differences in nesting season meant that the transfers of eggs and hatching of chicks took place quite late in the Florida sandhill crane nesting season, when water levels were dropping and conditions were not optimal for nesting and chick rearing. (J40.57.w2)
Grus americana - Whooping crane
Florida non-migratory Grus americana - Whooping crane flock
  • Whooping cranes soft-released at Kissimmee Prairie, Florida, were checked daily during the first year after release and then at least twice a week. Survival rates were 0.36 for 1993, 0.32 for 1994, 0.47 for 1995. The highest mortality occurred in the first month post-release (45%) with 65% of first-year mortality occurring in the first three months. The main cause of mortality was predation by bobcats. Two cranes which appeared lethargic and were losing weight were captured and metal was removed from their gizzrads before they were re-released. Four pairs developed, one starting in December 1993 when the birds were 18 and 20 months old, one in March 1994 (11 and nine months old), one in October 1994 (28 and 17 months old) and one of two females who were the only survivors of their cohort. The first pair were seen copulating in 1994 and in 1995 constructed a nest platform in a marsh and defended this territory from pairs of sandhill cranes. The third pair also appeared to defend a territory in 1995.(P87.7.w16)
  • Whooping cranes soft-released at Kissimmee Prairie, Florida showed first-year mortality of averaging 50% with a low of 29% in 1997 and a high of 64% in 1998. The major cause of mortality was predation by bobcats, with predation by alligators increasing in the later years. The increase in mortality from 1998 onwards was thought related to drought. Annual mortality after the first year was 14.5%. Dispersal was higher in drought years, with one pair, having been in Florida since winter 1996-1997 dispersing as far as Illinois in May 2000 and then to Michigan. The prevalence of lesions of Disseminated Visceral Coccidiosis appears to have increased. From 1998 onwards, birds of three years old or older have been noticed showing simultaneous moult of primary feathers, resulting in temporary flightlessness; this had not been seen previously. From 1996-2000, 16 pairs showed territory maintenance (one pair in 1996, one in 1997, five in 1998, eight in 1999 and 2000). Nests were built (one, one, five, five and six respectively), with two pairs laying eggs in 1999 and three laying eggs in 2000, one of these hatching chicks although one chick was lost at 1-2 weeks and the other was predated by a bobcat at nearly 10 weeks old.  (P87.7.w16)
  • Whooping cranes costume reared with water conditioning (used to roosting in water) showed higher post-release survival than cranes reared without such conditioning. One release cohort in which all the birds had been given such conditioning showed 100% survival to one year, and in general water-conditioned cranes showed 85% one-year survival compared with 52% for control birds reared without such conditioning. (P87.8.w20)
  • Parent-reared whooping crane chicks were found to show more vigilance behaviour and be found in larger groups, compared to hand-reared (costume-reared) cranes, during the first two weeks post-release. (J288.93.w1)
  • In the nonmigratory Grus americana - Whooping crane flock of Florida, USA, 289 whooping cranes were released into central Florida, USA in releases taking place 1993 - 2005. By 2006, 50 cranes (25.25) were known to have survived, including 16 pairs, and 10 others were thought to have survived, giving a population of about 60 birds. During this period: (P87.10.w10)
    • There was a high incidence of predation [particularly by bobcats] in newly-released cranes.
      • This was reduced after chicks were conditioned to roost in water at night, and the release protocol was changed to using portable pens, set up where habitat conditions were better.
    • Birds ingested pieces of metal, primarily from pen construction, with resultant problems of zinc toxicity.
      • Use of portable pens which did not include potential sources of metal scraps reduced this problem.
    • Collisions with power lines causing the deaths of 18 birds.
      • Lines which were between roosting and feeding areas were most problematic and the owner of the lines agreed to start marking the top, smaller-diameter (i.e. least visible) "static" lines.
    • There was a severe drought, 1998-2002, which resulted in cranes dispersing much more than normal, not only within Florida but also to Georgia, east central Michigan, Western Virginia and coastal South Carolina.
    • Some individuals developed prolonged and strong bonds with Florida sandhill cranes. While initial bonds with sandhill cranes may have been beneficial for young released cranes to learn about foraging, safe roosting etc., prolonged association into breeding age is more problematic.
      • In some cases it was possible to catch the crane and translocate it to an area with whooping cranes; some of these cranes then re-associated with conspecifics while others returned to sandhill cranes.
    • Cranes ventured into urban habitats, generally following sandhill cranes. Cranes are attracted to urban areas with open settings (mown grass) and available food such as earthworms, acorns, turf grubs and food set out either specifically for cranes, or falling from feeders set ut for other birds.
      • People have been asked not to feed cranes (education) feeding of cranes in Florida was prohibited by law in 2002.
      • Some cranes have been captured and handled (for health check and transmitter replacement) in urban environments in the hope that this would be an aversive experience which might haze the cranes from that location.
      • Some cranes have been caught and translocated to more appropriate, rural areas; success of this has varied.


  • Monitoring of whooping cranes in the nonmigratory flock in Florida has shown that the birds exhibit simultaneous moult of the flight feathers (remiges) every 2-3 years (occasionally four years). (P87.10.w11)
  • Reproductive success for the non-migratory flock of Grus americana - Whooping crane  introduced into Florida has been lower than expected. Out of 289 introduced cranes, 67 males and 65 females survived for at least three years (i.e. to potential breeding age). The first pairs had developed by 1995. First eggs were laid in 1999. To 2005, 47 nests had contained chicks, with 17 hatched chicks and four fledged young. Drought conditions through to 2001 may have been one factor for poor reproduction. In 2003, chicks hatched from 71% of nests containing eggs, but in 2004 - 2005 while more cranes laid eggs only 17% hatched. (P87.10.w13)
  • Both survival and productivity in the non-migratory whooping crane flock in Florida have been lower than expected. Males have not lived forlonger than 10 years, although some females have lived to at least 15 years. The main causes of mortality in the older males were predation and power line collisions. By 3rd September 2008, there were 30 birds (12.18) with 11 pairs, distributed across six counties of central Florida. During 1999 - 2008 68 nests were monitored, which produced 31 chicks; nine fledged, giving a fledging rate of 0.13 per nest. All cranes which fledged (two males, seven females) survived to become independent from their parents. Three of the fledged birds are known to have died with a fourth missing, presumed dead. Once formed, most pairs nested yearly, except they did not nest during drought years when the marshes were dry. In six of the 10 study years wetland water levels were too low for chick production. During the 2007 and 2008 breeding seasons, in droughts, seven of the nine nests were built in lakes (not usually used) by two pairs. Three nests hatched two chicks during these two years and two hatched one chick each; one of the eight chicks fledged. (P87.11.w11)
  • Reproductive performance of the nonmigratory flock of whooping cranes in Florida has been much lower than expected and most of the causes of this are unclear. Successful fledging of chicks by first-time parents suggests that failure to rear chicks is not due to lack of experience and that the abilityto rear chicks is inate rather than learned. Causes of pre-hatch failure included flooding, drought, human disturbance and interference from other cranes. Climate or disease may be playing a role. (P87.11.w14)
Eastern migratory Grus americana - Whooping crane flock
  • Reintroduced migratory whooping cranes have consistently demonstrated that young whooping cranes, after returning to Chassahowitzka NWR, leave the area within 1 - 10 days and move to inland sites, mostly on private lands such as cattle ranches. Older cranes show a high level of site fidelity once they have chosen a wintering site. The rapid development (building) occurring in central Florida is of concern. (P87.10.w12)
  • Whooping cranes costume-reared at Patuxent Wildlife Research Center, Maryland, migrated behind an ultralight from Necadah NWR, Juneux County, Wisconsin to Florida in autumn 2001and soft-released, with care continuing through the winter, migrated in April 2002, with the five surviving cranes of the cohort all setting off together and four arriving at the rearing area after 11 days, of which seven were flight days. One female became separated from the group, spent time in Kentucky, Indiana and southcentral Wisconsin, arriving at the rearing area 25 days after leaving Florida. The cranes then moved around, mostly south and east of the rearing site, mainly using agricultural lands, deeding on waste corn and roosting in nearby wet areas or temporary pools. Three of the cranes often associated with sandhill cranes. Two cranes stayed together, the others staged with sandhill cranes; all migrated back to Florida. The two cranes which migrated together remained so all winter. One crane joined the 2002 migrated juveniles at the release pen for the winter; the others chose other wintering areas within Florida, all remaining at their respective chosen areas (similar behaviour to wild sandhill cranes). (P87.9.w6)
    • The Chassahowitzka pen site is not an ideal wintering area; there are no consistently useable safe roosting habitats and the general habitat is not ideal for foraging either. However, this does mean that returning cranes tend to scatter to more desirable locations, preventing them from interfering with the new cohort each year.  (P87.9.w6)
  • During the period 2001-2005, 53 juvenile Grus americana - Whooping crane were reared, fledged in Necadah NWR, Wisconsin and ultralight-guided migrated to Chassahowitzka NWR, Florida and wintered there. Of these birds: (P87.10.w14)
    • All except six successfully migrated back to Central Wisconsin in their first spring. One female only returned to Wisconsin in her second spring and a group of five took an eastern migration route, were unable to navigate around Lake Michigan and terminated their migration in Lower Michigan.
    • Following spring migration, they showed a spring wandering period, with males then mainly summering in the central reintroduction area while females dispersed further except for individuals associating with males: three yearling females summered in South Dakota, one in Minnesota (and the following year in Michigan). Three males staged to Minnesota in autumn.
    • Many of the released cranes associated with sandhill cranes.
    • Cranes commonly migrated in autumn back to the Chassahowitzka NWR area but the moved inland to spend the winter in freshwater habitats in Florida. During winter 2004-2005 dispersal was greater, with 14 of 34 cranes wintering in other states: South Carolina, North Carolina or Tennessee.
    • Of the 53 cranes, 12 died: seven due to predation: five from bobcats in the southeastern USA, two in Wisconsin, one of these being a bird roosting on land due to a fractured leg. After the first winter a protective protocol was used at the release site and was effective.
    • In spring 2005 there were seven breeding pairs found on or near Necadah NWR in Wisconsin, with at least five building nests and two each laying an egg, although nest attendance by the young, inexperienced birds was inadequate and neither egg survived to hatch. By summer 2005 four other potential pairs were noted.


  • During the period 2001-2007, 125 juvenile Grus americana - Whooping crane were costume-reared and released, with 106 being ultralight guided (UL) on migration from Necada NWR in central Wisconsin to Chassahowitzka NWR in central Florida, while 19 cranes were released during their hatch year, at Necadah (direct autumn release, DAR) with one of these released 2004, four in 2005, four in 2006 and 10 in 2007. (P87.11.w13)
    • UL juveniles self-initiated spring migration from the winter release site between 25 March to 9th April each year; older birds and DAR birds showed more variability but generally started migrating during March. 72/86 (84%) of UL birds and 5/13 (38%) of DAR birds returned unassisted to central Wisconsin as yearlings, generally first arriving at Necadah NWR then dispersing mainly to southern/eastern Wisconsin but also as far wast as north Dakota and as far east as Vermont.
      • For 16 yearlings which migrated too far to the east, Lake Madison became a barrier; seven of these, and some others, were successfully retrieved and translocated to Wisconsin.
    • Autumn migrations of yearlings and older birds started 22 October to 11 December, mainly November, with some showing significant staging movements to southern Wisconsin before their main migration, and finished November to early January.
    • Many of the birds returned to Chassahowitzka NWR in central Florida, but generally after a short time then moved inland for the winter. Overall, 48% of returning bird-winters for UL cranes occurred within 88 km of the original wintering site with a further 12% at a site 82-103 km north of this (Payes Prairie State Preserve area). Other wintering sites were elsewhere in Florida, or in South Carolina, Georgia, Alabama and Indiana.
    • As of 30 September 2008, 63.0% of birds were alive. Survival was higher for males (69.2%) than females (55.6%) in the UL cranes, and for females (72.7% versus 37.5% for males) for the small number of DAR birds.
      • In 2007 there was a catastrophic loss of the whole group of 17 UL cranes in a weather-related incident (electrocution/drowning) . Other than this there were 40 deaths during the first seven years, with at least 50% due to predation, particularly in UL cranes, while 37.5% of DAR mortalities were due to power line collisions.
      • Annual mortality increased from 7.1% previously to 26.7% during May 2006 - late September 2007, during severe drought in both the wintering areas and Wisconsin; once water conditions improved, mortality rates dropped again.
    • Apart from two of the 2001-hatch year birds, all females of at least four years of age, summering in the core reintroduction area, were paired, with pairs being found on territories. Females first nested at 3-5 years (mean 3.92) and males at 3 - 6 years (mean 3.85). There were 24 nests 2005-2008, found in two main areas of Necadah NWR plus one each in two other areas.
    • All 22 of the first nests containing eggs, from 14 pairs, failed to hatch. Two renests during this period produced two chicks from one nest, one of which fledged.
      • Nest failures were noted to be synchronous, usually coinciding with warm, sunny days, and possibly related to Simulidae (blackflies).
      • This needs to be addressed if this population is to be successful.


Grus carunculatus - Wattled crane
  • Following release of one female bird near a flock of 36 non-breeding wattled cranes in February, initially the wild cranes directed a number of highly aggressive behaviours towards the juvenile, such as charges, raking aggressively downwards at her with the legs while in flight, and stabbing towards her head; on all occasions she reacted submissively. After 11 days she started following the flock to an open-water roost; before this, she roosted on dry ground. From this time she was often close to individuals and groups and was seen showing increased wariness of humans and vehicles. At 23 days post-release a lone juvenile of a similar size and plumage joined the flock and thereafter the released crane showed synchronised behaviour with this individual. (J445.S15.w1)
  • Following release of two cranes, five minutes apart, into a flock of wild cranes, the male immediately left the immediate area and after a week settled by itself on a property about 5 km from the release site, where it showed inappropriate behaviour including foraging under trees and roosting in upland habitat rather than in water. The female also moved away on the first day but returned after 24 hours and foraged mainly with a Grus paradisea - Blue crane but aso with wattled cranes and Balearica regulorum - Grey crowned-crane. She later joined the previously-released crane and the other juvenile and after some initial mild aggression, was accepted by the other birds. Two weeks post-release they left and were found 30 km distant in a group with two adults, often foraging in harvested maize fields together with a larger flock (more than 100) of the smaller crane species (blue cranes and grey crowned cranes). (J445.S15.w1)
Grus leucogeranus - Siberian crane
  • Isolation-reared Grus leucogeranus - Siberian crane released onto an island in the Big White Lake, Belozersky Refuge, Russia in August 2001, where Eurasian cranes roost, flocked with the Grus grus - Common crane, feeding on crop fields and flying over the release area. Three weeks later, six of the seven released birds set off on migration with the Grus grus - Common crane. The seventh bird did not migrate. (N48.1.w1)
  • When one isolation-reared and one parent-reared Grus leucogeranus - Siberian crane were released in the Astrakhan Nature Reserve, Russia. The release site was the Obzhorovo site, where wild Siberian cranes were known to be found during autumn migration, three Siberian cranes had left the area two days before the birds were released. The released birds were last seen two days post-release. (N48.1.w2)
  • A parent-reared Grus leucogeranus - Siberian crane chick released in Iran at a site used by a wild Siberian crane and a Grus grus - Common crane. soon started feeding with the other cranes and flying with them. (N48.4.w1)
  • Two isolation-reared and hang-glider flown Grus leucogeranus - Siberian crane chicks gradually improved at flying and started feeding as close as 100m from an adult pair of wild Siberian cranes, but the adults ignored them. One of the chicks was then injured when they flew near a village and a shepherd threw a bamboo stick. The other chick was then captured and re-released in the same area as a parent-reared chick released a month earlier, a wild Siberian crae and a Eurasian crane. However, he never bonded with the other birds and was eventually recaptured. (N48.4.w1)
  • Out of three yearlings released near Kunovat Lake in June 2003, none of the birds could be found on 11th August 2003, despite surveys and attempts to locate a transmitter on one of the cranes. However, no signs of dead cranes were found either. (N48.5.w2)
  • After two Siberian crane eggs were placed into the nest of a pair of Grus grus - Common crane in June 2003, the pair were fond with one Siberian crane chick on 11th August 2003; the chick was caught, banded and released. (N48.5.w2)
  • Five isolation-reared and one parent-reared Grus leucogeranus - Siberian crane chicks released at Kunovat River Basin, Russia, in August 2003, initially stayed near the release pen. Initial flights were in response to approaches by release personnel, with the first spontaneous flight occurring after four days. . The released birds were noted to stay together, forage together and fly together, and to keep in sight of each other when threatened. They were seen to feed on dragonflies, tipulids and on blueberries and (in the forest) lingberries. (N48.5.w2)
  • Following release of two parent-reared chicks in Iran, near a pair with a chick, the young birds were noted to interact with the wild cranes. The adult pair were aggressive but the young birds merely walked away when threatened, rather than fleeing. (N48.5.w3)
  • Grus leucogeranus - Siberian crane chick reared for release at Oka Crane Breeding Center, Russia, initially stayed on the release island  and remained as a group of 10 birds, then were disturbed, left the island and split into two groups corresponding to cohorts formed pre-release. They were last seen in the reserve on 27th September. (N48.6.w2)
  • Four male Grus leucogeranus - Siberian crane chicks mostly stayed as a group after release in Astakhan Nature Reserve in October 2004.They stayed together  (one disappeared) and remained near the release site right through to late January when a sudden drop in temperature led to most of the area freezing and many wintering birds left the reserve; the signal from the transmitter (PTT) attached to one crane indicates that the cranes had left with the other waterbirds and arrived at Dagestan on the known flyway. Unfortunately the transmitter then failed and there was no more data. (N48.6.w3)
  • An isolation-reared female Grus leucogeranus - Siberian crane which had been recaptured after dropping out of a migration with wild cranes in March 2004 and was  released in the Freydoon Kenar Trapping Area (Damgah) in Iran, two days after the arrival of two individual (not paired) wild Siberian cranes in early November 2005 immediately joined one of these cranes and they appeared to have paired, being seen feeding, roosting and flying together, with the released bird acting like a wild crane. (N48.7.w1)
  • A female parent-reared Grus leucogeranus - Siberian crane bred 2004 and released in January 2007 in Fereydoon Kenar Damgah (wintering site in Iran) where a wild male was present nearly immediately joined the wild crane and they started unison calling together after three days. A month later, they flew off on migration; unfortunately no satellite data was received from the leg-mounted PTT after this time. (N48.8.w1)
  • A male parent-reared Grus leucogeranus - Siberian crane bred 2005, kept in Iran in a pen near Fereydoon Kenar Damgah during spring and summer 2007 and released in November 2007, flew out of the damgah and was caught in a night net at Sooteh and released again on 17th December. On 29th December he joined a wild Siberian crane and they were seen flying together after that; they set off on migration together on 23 February 2008.(N48.9.w1)
  • A female parent-reared 2005-hatch Grus leucogeranus - Siberian crane released at Fereydoon Kenar Damgah where a wild male was present initially joined the wild bird, but failed to fly with him to his roosting site. A week later she left and went to a local farm, possibly to feed on small fish there about two weeks later (5th January) the two birds aired and on 25th February they migrated northwest; PTT data from a backpack transmitter was received 2nd March from northwest Iran near Bujagh National Park. (N48.10.w1)
  • When two three-year-old Grus leucogeranus - Siberian crane were released in the Kunovat Federal Wildlife Refuge after only a three-day acclimation period in a netted pen at the site, they soon adapted to feed on natural food items, avoid people, and use open, accessible habitats. Their ability to fly also quickly improved. (N48.11.w2)
  • Two yearling and four juvenile Grus leucogeranus - Siberian crane transferred from Oka Crane Breeding Centre to Obzhorovo site, Astrakhan State Nature Reserve in the Volga River Delta (a site traditionally used by western flyway Siberian cranes as a stopover site during migration) were observed following release in 2009. They were soon seen to adapt and feed themselves on natural foods including shellfish, insects, small fish and freshwater crayfish - the last being an item they had never previously encountered. Flight improved and they started using a larger area. By migration time they were considered to be showing wild crane behaviour. They were last seen on the site on 14th November 2009 and were assumed to have migrated with other waterbirds, but the satellite transmitters (on two of the birds) stopped providing data soon after the start of migration. (N48.11.w3)
  • In 2010, after three juvenile and two yearling Grus leucogeranus - Siberian crane were released a day after arrival on the site in late September, they appeared to adapt quickly, although remains of one juvenile were found two months post-release. At the end of November they set off westward on migration and flew to the Damchik site of the Astrakhan State Nature Reserve, where it is thought they spent the night before moving to Bolshoye Tatarskoye site of Astrakhan State Nature Reserve the following day where according to satellite data they remained (live or dead) at least until 17th February 2011 (it was a warm winter). (N48.11.w3)
  • A group of two juvenile and one 1.5 year old Grus leucogeranus - Siberian crane together with a juvenile Grus grus - Common crane released late August after a one day adaptation period in a pen on site on Omelino Island, Big White Lake, at Belozersky Wildlife Refuge, Tyumen Region. This is a staging area for Grus grus - Common crane which usually roost on the island. The older bird soon separated from the juveniles. One of the juveniles disappeared and was presumed eaten by foxes. The remaining three juveniles fed and roosted with the wild Grus grus - Common crane and started flying with them to agricultural fields; they appeared to successfully integrate with the wild flock and left the reserve with them for migration on 1st October. The other bird left on 8th September and flew 80 km east where she remained to at least 3rd October, after which no more data was received from the transmitter. (N48.11.w4)
  • In 2012, two yearling parent-reared Grus leucogeranus - Siberian crane released following a three-day adaptation period in a pen on the release site in Tyumen Region, Russia, were observed to adapt quickly, eating natural foods (not eating the pellets provided) and showing typical wild crane behaviour. (N48.12.w2)
  • One juvenile costume-reared Grus leucogeranus - Siberian crane which started migration with Grus grus - Common cranes just a week after release at Belozersky Wildlife Refuge dropped out of the migration near Kumai Village in Akmala Province, Kazakhstan after nearly 500 km. (N48.12.w3) The crane lost more than 1 kg during this time (pre-release 6.9 kg, compared to 5.45 kg when rescued and returned to Oka Crane Breeding Center). (N48.12.w4)
    • The crane became tame very quickly when given contact with lots of people. (N48.12.w4)
  • Of 126 Grus leucogeranus - Siberian crane released into the wild on the breeding grounds, wintering grounds or migration areas, 1992 and 2009, there have been few confirmed sightings of released birds. Reasons for this include high mortality, the large and remote range of this species and limited post-release monitoring systems. Development of release techniques is ongoing.s (P143.1.w1)
Grus grus - Common crane
  • In The Great Crane Project, aiming to return Grus grus - Common cranes widely to the UK, after release of the first cohort of 21 cranes in 2010, the cranes were monitored carefully. Data was entered into a web-based database for analysis.(D449)
    • One crane which appeared to fail to behaviourally adapt after release was returned to captivity after about five weeks and was found to be shedding Salmonella. (D449)
    • One crane died after striking a power line and the right leg of another crane was found more than two months after he went missing in early November 2010. (D449)
    • The other birds appeared to adapt well. (D449)
    • In spring, the birds initially stayed as one flock through April2011, although in May seven flew off for a few hours and were seen over Graylake Reserve. Throughout June 2011 they few on Aller Moor in the daytime and roosted on West Sedgemoor, moving there at the start of July, feeding in pasture and roosting in the Hambridge Pond area. They remained there through August, and started interacting with the new cranes being released in the middle of August. (D450)
    • The yearlings tolerated the presence of costumed aviculturists inside the pen, but started flying off when they returned to fill feeders etc. after the 2011 birds had been released (D450)
    • Grus grus - Common crane in The Great Crane Project, UK in 2011 were seen flying in the 60 x 30m release aviary. (D450)
      • After about two weeks in the aviary, birds released the previous year started visiting the enclosure; there was a lot of calling and aggressive display from the hatch-year birds and the yearlings. (D450)
      • By nine days they were all leaving the pen of their own accord, and only a week or so later were roosting outside the enclosure, in Hambridge pool. (D450)
      • During September, they explored further and often mingled with the 2010 birds during the day, although they roosted separately at night, with most of the 2011 birds in the pen. (D450)
      • One crane left Somerset in early September and was then seen in Kent, after which she was not re-found and was thought to have probably gone to continental Europe.
      • In November, they made good use of flattened maize areas. They were also joined by a wild (unringed) crane. (D450)
        • An attempt to catch some cranes, by costumed aviculturists, to re-fit GPS data-loggers was unsuccessful because the released birds appeared to take their cue from the wild crane. (D450)
      • One individual disappeared in early December, his remains being found the following day. (D450)
      • In January the cranes started roosting in a new location, and fed on potatoes when these were made available. (D450)
      • By late February and March, the cranes were breaking up more into smaller flocks and sometimes pairs. (D450)
    • In May 2012 four cranes moved to Gloucestershire, including to Slimbridge Wildfowl & Wetlands Trust Reserve, and, other than a brief trip back to Somerset at the end of May, remained there for six months. (D451)
    • The 2012 cohort, like the previous cohorts, adapted quickly after release in September. During October they stopped roosting in the pen regularly, rather feeding and roosting alongside the older birds, although they generally tended to keep as a separate group, other than one individual who had been a loner in the 2012 cohhort and now joined with the 2010/2011 birds. (D451)
    • Older birds showed pairing behaviour in 2012 - lots of display and courtship behaviour. The male and three females at Slimbridge were seen nest building towards the end of March 2012. One pair which formed in Somerset were actually siblings from the same clutch of eggs. (D451)
    • One of the 2012 release birds broke a leg and was later found partly-eaten, either scavenged by or more probably killed by a fox. (D451)
    • Supplementary foods provided in 2012 were used by the 2012 cohort birds but little used by the previous cohorts- there was ample natural, preferred food available. (D451)
Grus japonensis - Red-crowned crane
  • In April 2012, a red-crowned crane parent reared and released into the wild in 2011 was seen in Khinganskiy SNR. (N49.12.w1)
  • In October 2012, a pair of red-crowned cranes was seen with a chick. One of the parents was a two-year-old crane which had been artificially incubated and hand-reared prior to release in 2012. It was noted that this was an unsually early age of breeding. (N49.12.w1)
  • In December 2012 a marked red-crowned crane was seen in a flock of wild cranes in Yancheng National Nature Reserve, Jiangsu Province, China. The band number corresponded to a crane parent-reared in captivity in the RSRB in 2010 and released at Khinganskiy SNR near Kleoshinskoye Lake in 2011; the sighting confirmed that the crane was successfully coming through its second winter in the wild. (N49.12.w1)
  • In the south of the Republic of Korea, two banded red-crowned cranes were seen which had been hand-reared and released into the wild in April 2012; the birds were 1,600 km (1,000 miles) from where they had been released. (N49.12.w1)
Grus vipio - White-naped crane
  • In winter 2011-2012, a crane which had been parent-reared in captivity at RSRB in 2008 and released into the wild in spring 2009 was seen as one of a pair with a chick in the Demiliterized Zone in the Republic of Korea. (N49.12.w1)
  • In winter 2011-2012, a crane which had been hand-reared in 2001 and released into the wild in 2002 was seen as one of a pair with a chick in the Demiliterized Zone in the Republic of Korea. In February 2013 again this bird was seen as part of a family containing a chick in the DMZ; the crane was also seen in winter 2004-2005 and 2006-2007. (N49.12.w1)
  • In December 2012, a hand-reared crane white-naped crane bred 2011 and released April 2012 near Kleoshinskoye Lake was seen in rice paddies in Fukai Prefecture, Japan. (N49.12.w1)
Associated techniques linked from Wildpro
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Education and Dissemination

It is important that both successes and failures should be documented and the information disseminated. (J727.1.w1)
  • This enables future programmes to benefit from lessons learned. (J727.1.w1)
Public relations
  • Local and wider educational activities and mass media coverage are needed following as well as during the release programme.
  • Publications should be produced for scientific audiences (e.g. papers in peer-reviewed journals).
  • Publications in the popular media are also important.
  • It is essential that information gathered and lessons learned, from unsuccessful as well as successful programmes, should be made available to assist in future projects.

(J727.1.w1, P17.62.w1, P17.62.w5, P17.62.w6)

Crane Considerations Details of most of the crane reintroductions in North America have been presented at the various North American Crane Workshops; the proceedings of these (P87) and some other proceedings are available from the ICF website (W657.Mar2014.w1)
  • Education was used to discourage people from feeding cranes in urban areas of Florida.
  • Education was used to try to keep airboats away from a whooping crane nest on Lake Kissimmee, which is heavily used. On the day of a festival using a ramp just 1.6 lm from the nest, the area around the nest was marked with signs as being closed, and leaflets were distributed. Unfortunately while most people respected the fact that the area around the nest was closed, several groups of boats crossed the area and one of them ran over the nest, destroying the eggs. (P87.11.w11)
  • Note: When a juvenile Grus leucogeranus - Siberian crane which started migration with Grus grus - Common cranes just a week after release at Belozersky Wildlife Refuge dropped out of the migration near Kumai Village in Akmala Province, Kazakhstan after nearly 500 km, the villager who found the crane and let it stay in his yard, eating with his domestic birds, contacted the Deputy Head of the State Forest and Hunting Committee of Kazakhstan to say that a Siberian crane with three colour bands had been found, and the message was then passed to the Oka Crane Breeding Center, Russia. This shows the importance of public awareness. It was considered highly likely that the fact that The President of the Russian Federation had visited the project and taken part in one of the training flights had improved public awareness of the released cranes. (N48.12.w4)
  • In The Great Crane Project in the UK, multiple news articles appeared in various print publications from local newspapers to glossy magazines. There were also radio and TV-broadcasts, and web-based articles, blogs and news stories. A large number of outreach talks were given to the public by various project partners (WWT, Pensthorpe Conservation Trust, RSPB), (D449, D450, D451)
    • Visitors to the project's website included both new and repeat visitors, with about half being repeat visitors. (D450, D451)
  • MSc theses and papers have been generated by The Great Crane Project in the UK. (D450, D451)
Associated techniques linked from Wildpro
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Authors & Referees

Authors Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee --

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