GREAT BUSTARDS (Otis tarda) IN CAPTIVITY THE EXPERIENCE OF THE GREAT BUSTARD GROUP

David Waters

Great Bustard Group, Kingdom of Great Britain

Introduction

The Great Bustard Group’s (GBG) experience of holding the Great Bustard

(Otis tarda) in captivity is related, almost exclusively, to the rearing process and then transport and a quarantine period. In a partnership with the A. N. Severtsov

Institute of Ecology and Evolution (Saratov Branch), a Branch of the Russian

Academy of Sciences, the Great Bustard Group transports young Great Bustards from Saratov region to the UK where they are released into the wild as a part of a

reintroduction project.

The Great Bustard Group has worked in partnership with the A. N. Severtsov

Institute of Ecology and Evolution since 2003, and Great Bustards were first exported to the UK in 2004 and have been exported annually since 2004. The

numbers have varied from 38 to 6 individual Great Bustards.

The eggs are collected under the appropriate licences and in accordance with a protocol developed by a variety of agencies, including the project partners, Birdlife

Hungary, the Federal Service for the Supervision of Wildlife Management and the

RBCU. The essence of the protocol is to ensure that the only eggs collected are ones from nests disturbed by agricultural cultivation and are either judged to be

abandoned by the female at the time of collection, or are in such hopeless circumstances that abandonment or predation is inevitable. The eggs are incubated

and the early stages of rearing conducted at the A. N. Severtsov Institute’s field station at Diakovka, Krasny Kut Rayon, Saratovskaya obl.

Incubation

Incubation is carried out in Brinsea Octagon 40 incubators with auto turn cradles at

37.2degrees Celsius. Hatching is conducted in a Brinsea Polyhatch incubator with the auto turn disabled. Upon hatching the chicks are cared for by staff of the A. N.

Severtsov Institute under a protocol jointly developed with the Great Bustard

Consortium (UK). As the chicks are destined for release into the wild there are reared with minimum contact with humans to discourage any imprinting or even

habituation with humans.

Chick Rearing

The chicks require bill feeding for the first 5-7 days, after which they are able to feed themselves. Bill feeding is carried out through the use of a feeding model. This is a life size replica of a female Great Bustards head, and the functioning bill is

mechanically operated by squeezing a shaft in the neck of the model. The operator either remains hidden behind a curtain, operating the model through a small hole, or wears an elaborate dehumanisation suit. This suit is not intended to represent

anything recognisable by the chick. Its function is to disguise the features of the wearer which allow them to be recognised as human. The features include a long length robe to hide the form of legs, sleeves being large and joined to the waist to

hide the shape and form of arms, a helmet and silver mirror visor to hide the form and features of the face and the 2 colours being split in a vertical plane, from back to front, to distinguish the wearer from recognisable humans who almost invariably

have a colour split in the horizontal plane about the waist. Once the chicks have developed the ability to feed themselves the feeding model is no longer used, but the dehumanisation suit is used for any operations conducted within sight of the chicks. These operations include provision of food in bowls, cleaning and provision of

water. The food used is a mixture of locally caught invertebrates (primarily crickets), fresh green leaf vegetable matter, soft cheese and a proprietary bird food developed for young Cranes. The crickets may be fed live to chicks once they have the ability

to feed themselves and management of the live crickets is assisted by cooling them in a refrigerator before offering them to the chicks. Angel wing has been observed in

the young chicks. This condition is manageable by taping the primary feathers against the wing in a closed position. The tapes should not be left in place for more than 48 hours without a break of 24 hours before replacement. Two repetitions of this cycle are normally sufficient to allow the wing to recover. Excess protein, particularly animal protein, has been observed to increase the incidence of this condition.

Access to natural daylight is encouraged as soon as possible. Prevailing weather conditions will dictate at what age this is possible, and the isolation rearing discourages manually moving the chicks inside and out. Due to the collection of eggs being determined by the agricultural activity there is a wide range of dates over which chicks may be hatching. The chicks are accommodated in one of three separate areas. Only one, the first, has no natural light, but is strongly warmed by heat lamps. As they grow they are moved through an intermediate area and then to an outside enclosure of approximately 12 m by 5 m. This is constructed from a heavy string or rope net suspended from straining wires. This provides sg model. This is a life size replica of a female Great Bustards head, and the functioning bill is

mechanically operated by squeezing a shaft in the neck of the model. The operator either remains hidden behind a curtain, operating the model through a small hole, or wears an elaborate dehumanisation suit. This suit is not intended to represent

anything recognisable by the chick. Its function is to disguise the features of the wearer which allow them to be recognised as human. The features include a long length robe to hide the form of legs, sleeves being large and joined to the waist to

hide the shape and form of arms, a helmet and silver mirror visor to hide the form and features of the face and the 2 colours being split in a vertical plane, from back to front, to distinguish the wearer from recognisable humans who almost invariably

have a colour split in the horizontal plane about the waist. Once the chicks have developed the ability to feed themselves the feeding model is no longer used, but the dehumanisation suit is used for any operations conducted within sight of the chicks. These operations include provision of food in bowls, cleaning and provision of

water. The food used is a mixture of locally caught invertebrates (primarily crickets), fresh green leaf vegetable matter, soft cheese and a proprietary bird food developed for young Cranes. The crickets may be fed live to chicks once they have the ability

to feed themselves and management of the live crickets is assisted by cooling them in a refrigerator before offering them to the chicks. Angel wing has been observed in

the young chicks. This condition is manageable by taping the primary feathers against the wing in a closed position. The tapes should not be left in place for more than 48 hours without a break of 24 hours before replacement. Two repetitions of this cycle are normally sufficient to allow the wing to recover. Excess protein, particularly animal protein, has been observed to increase the incidence of this condition.

Access to natural daylight is encouraged as soon as possible. Prevailing weather conditions will dictate at what age this is possible, and the isolation rearing discourages manually moving the chicks inside and out. Due to the collection of eggs being determined by the agricultural activity there is a wide range of dates over which chicks may be hatching. The chicks are accommodated in one of three separate areas. Only one, the first, has no natural light, but is strongly warmed by heat lamps. As they grow they are moved through an intermediate area and then to an outside enclosure of approximately 12 m by 5 m. This is constructed from a heavy string or rope net suspended from straining wires. This provides soft sides and a soft roof, and which ever direction a bird flies in, it will only hit the soft yielding net. The development is regarded as an important one and the use of the heavy net is regarded as superior to the use of a light net that requires tensioning to prevent entanglement. Food is provided twice a day and the dehumanisation suit is used to prevent any association with humans and food.

Transporting Great Bustards

The chicks are transported to the UK at the end of July or early August. The

age of the chicks will vary from 4 to 10 weeks old. Earlier advice given to the project to move chicks at the earliest age possible, aiming for 10 – 14 days, has been

discounted and the experience has been that older birds tolerate transport more successfully than very young ones. Transport is carried out with the young Bustards being in IATA compliant wooden boxes of a size dependent on the age and sex of the chicks, the males being larger. A typical box would be approximately 150 cm long by 100 cm wide and 70 cm high and hold 4 birds. The total transport time, including customs and security processes at Moscow and London, is about 43 hours. By allowing a minimum age of 4 weeks no problems with the birds is encountered.

Quarantine

Once the Great Bustards arrive in the UK they must be kept in strict, licensed

quarantine for a minimum of 30 days. The quarantine is divided into units each being approximately 5 m by 5 m and a limit has been set of each unit holding no more than 6 birds. The units are all screened from each other and have separate bio security measures between them, inside the bio security for the whole quarantine facility. The units have solid opaque sides made from wooden panelling. The roof consisting of two layers of thick nylon mesh and one of wire mesh leaves the birds open to the elements. The birds are protected from the wooden sides of the unit by nets being hung down from the roof, some 30cm away from the sides and pegged into the ground. Which ever way a bird flies it will hit only a soft yielding surface and not be injured. Food is provided through a feeding hatch, which is large enough for a 40 cm plastic tray to be admitted. The diet is based on a propriety bird food (Lundi) which is supplemented by fresh green vegetables, crickets, mealworms and mice. Water is provided in game bird style drinkers. No use is made of artificial warmth or shelter from rain.

The birds undergo a number of health checks before and after the export/import. These checks combine the required health screening and also represent an opportunity to ensure the birds are fit for release into the wild. The screening, which requires the collection of orophareangeal and cloacal swabs as well as blood samples, is conduced without the dehum, and has a selection of food and invertebrate encouraging crops planted inside. Two permanently injured Great Bustards live inside this enclosure without any supplementary feeding.

The dispersal of the birds has varied over the 4 years of releases. A typical pattern would be for the birds to remain inside the enclosure for 1- 2 weeks and then spend more and more time outside the enclosure. Releases typically take place in September and predation from foxes is prevalent during the first 2 months. To the knowledge of the GBG no Great Bustard has been predated after the middle of December.

Great Bustards in Permanent Captivity

In addition to the released birds, the GBG holds three Great Bustards in permanent captivity. They are all male. Two are males from the first year of releases,

2004, who both suffered wing injuries. These are attributed to an intermediate phase in the release process which has been dispensed with. The concept was that after the relative confinement of quarantine the birds would be moved to a larger pen where

the supplied food would be reduced and the birds would have a greater range of natural food (again sown food crops and invertebrate rich plants) along with more room to develop flight muscles. The enclosures were about 20m by 20m and had

soft net sides and a soft roof. This idea was flawed because given the extra room the males were able to build up sufficient momentum that a collision, even with a soft net caused serious injury. Females were observed to be more manoverable and able

to turn and avoid collision more successfully. In a short space of time 3 males had seriously injured themselves. Two suffered compound fractures of the humorous and one of these birds subsequently died. A third bird dislocated the wing. Of these two surviving birds, one is kept in the large release enclosure on Salisbury Plain and

receives no supplementary food, living on the crops grown inside the enclosure. The second is kept in a small aviary with the third captive Great Bustard. This third bird is a male given to the Great Bustard Group after its seizure from an illegal collection

in Belgium. At the time of writing it is believed to be 18 years old and a blood sample was kindly examined by Prof Pitra from Berlin University who was able to identify the bird’s origin as Spain. It is pinioned.

The two male Great Bustards in the aviary are used as ambassador birds for the Great Bustard Group and provide useful data on occurrences such as times of moult, display and behavioural change. The pen has a fox proof 2m high electrified

fence around it and the floor of the pen is a mixture of grass and sand with green leafy crops being planted in pots for the birds during the spring and summer. The birds are fed once a day with water and a propriety bird food always being available.

This bird food is supplemented with a mixture of the following: mice, mealworms, crickets, heart, cheese, lettuce and other green leafed vegetables. The birds are encouraged to interact with humans as much as possible in order to decrease the stress caused when people enter the pen. The Russian bird has been in captivity for

3 years and will eat readily from the hand and interacts with all visitors to the pen. The Spanish bird that has only been in our pen for 2 years will approach humans but is not keen to be hand fed. The birds can be observed easily and details of displaying

and moulting are kept. The birds do interact with each other and there is a hierarchy

The birds are encouraged to interact with humans as much as possible in order to decrease the stress caused when people enter the pen. The Russian bird has been in captivity for

3 years and will eat readily from the hand and interacts with all visitors to the pen. The Spanish bird that has only been in our pen for 2 years will approach humans but is not keen to be hand fed. The birds can be observed easily and details of displaying

and moulting are kept. The birds do interact with each other and there is a hierarchy

Conclusions

 

within the pen. Both males display in the pen with the older bird dominating the younger one and chasing him around the pen whilst displaying.

The observations from the Great Bustard Group can be split into the main headings.

Aviary space should have soft sides and if roofed, the roof should be such as

to not act as a spring, catapulting birds back into the ground. The aviary should have no intruding diagonal or vertical supports as these are likely to cause collisions and injury.

The size of the aviary should not be too large. A preferable option is to have a smaller enclosure and a low number of birds. A low density can be maintained by having several such units. The Great Bustard Group suggests a size of 10 m by 10 m,

but does not have experimental data to propose this is an optimal size.

Transportation over long distances is best endured by Great Bustards over 4 weeks and preferably over 6 weeks old. Care is taken to ensure the birds can move, stand and turn around, but beyond that, excessive space is considered detrimental as

the birds can open wings and gain speed, thus causing injury.

достаточны для лечения птицы. Птенцов следует приучать к естественному фотопериоду как можно быстрее. Для адаптации к климатическим условиям местности необходимо иметь свободный выход для птенцов из внутреннего помещения в наружное. Во внутреннем помещении необходимо иметь обогреватель без дополнительного освещения, чтобы избе — жать нарушения фотопериода. Наружный вольер может быть величиной 12 х 5 м. Он строится из металлической или веревочной сетки с фиксирующим про — водом. Все работы по инкубации яиц и выращиванию дрофят осуществлялись сотрудниками ИПЭЭ в соответствии с двусторонними российско-английскими договоренностями.

Перевозка птенцов дроф в Великобританию осуществлялась в конце ию — ля – начале августа. Возраст перевозимых птенцов колебался от 4 до 10 недель. Более старшие птенцы и более устойчивы к стрессам, чем младшие. Размеры

транспортных ящиков зависят от возраста и пола дрофят. Типичный ящик мо — жет иметь размеры 120 х 100 см и 70 см высотой. В нем можно перевозить 4-х птиц. Полное транспортное время, включая таможню и проверку безопасности

в Москве и Лондоне, занимает приблизительно 43 часа. Минимальный возраст

транспортируемых птенцов не должен быть менее 4 недель, в этом случае ни-каких проблем с птицами не происходит.

Как только дрофы прибывают в Великобританию, они должны содер-жаться в строгом, имеющем лицензию карантине как минимум 30 дней. По 6 птиц содержат в клетках размерами 5 х 5 м. Клетки изолированы друг от друга для предотвращения распространения инфекций в период карантина. Стены клеток изготовлены из деревянных панелей, а верх – из двух рядов толстой нейлоновой сетки и слоя металлической сетки. Птицы защищены от деревян — ных сторон клетки сетями, идущими от крыши и фиксируемые к полу, нахо — дящимися в 30 см от стен. Даже если птицы летают, они не разбиваются о твердые стенки и сохраняются в хорошем физическом состоянии. Пища дос — тавляется через специальный люк, который достаточно велик для пластмассо — вого подноса шириной 40 см. Диета основана на смеси (Lundi), в которую до — бавлены зелень, овощи, сверчки, мучные черви и мыши. Бесполезно устанав — ливать в этой клетке обогреватель или убежища от дождя. Птицы ими не поль — зуются. Птицы подвергаются множеству проверок их здоровья до и после экс — порта/импорта. Эти проверки комбинируют необходимый контроль здоровья и также дают возможность гарантировать, что птицы пригодны для выпуска в дикую природу. Исследование здоровья, которое требует сбора ротоглоточных и клоачных проб, а так же образцов крови, способствует развитию боязни пти — цами человека. Идея в том, что, если птицы восприимчивы к созданию усло — вий от человеческого взаимодействия, единственное взаимодействие, которое они испытают с опознаваемым человеком – напряженная ситуация ограничи — вающаяся сбором медицинских образцов.

Мечение и выпуск. После того, как птицы прошли эти 30 дней карантина и заключительную проверку здоровья, мы освобождены из юридических огра-ничений и можем приступать к выпуску. Все птицы метятся легкими пласти- ковыми крылометками. Каждый год крылометки имеют уникальный цвет, а некоторое число птиц оснащены различными типами передатчиков. Крыло-метки, кажется, не вызывают дискомфорта или неудобства птицам и нет ника — кой тенденции, чтобы они увеличили в дальнейшем уязвимость к хищничест — ву. Мы экспериментировали с радио-передатчиками GBG, приспособленными

к креплению на спине, лапах и на хвосте. Наибольшим успехом пользовались крепленные к спине спутниковые передатчики GPS-PTTS. Опыт GBG также состоял в том, что использование обратных ремней безопасности пакета пере-датчика не вызывает проблемы, если они правильно приспособлены и что только опытный и компетентный штат исследователей используется для этой цели. Помеченные птицы содержатся в карантине еще в течение 2х дней, что — бы проверить их адаптацию к крылометке и передатчику. После чего птиц пе-ревозят в центральную часть огороженной территории, размеры которой 4,5 га. Эта вольера по периметру имеет двухметровое ограждение с электропастухом от проникновения лисиц и в ней имеется набор природных кормов от беспо-звоночных, до любимых птицами зерновых культур. Две дрофы с травмами крыла постоянно живут в этой вольере без любой дополнительной подкормки.

За четыре года выпусков дрофы продемонстрировали возможность к разлету от места выпуска на различные расстояния. Первые 1-2 недели молодые птицы после выпуска находятся в вольере, а затем начинают покидать ее все чаще и чаще. Выпущенные в сентябре они больше страдают от нападения лисиц в те- чение первых двух месяцев. Радиопередатчик зафиксировал такой случай и во второй половине декабря.

Постоянное содержание дроф в неволе. В настоящее время мы содержим в вольере три самца дрофы. Два из них имеют травмы крыла, полученные в

2004 году вскоре после выпуска в природу. Предполагалось, что птицы после прохождения карантина будут помещены в большой загон, где их первое вре-мя будут кормить, но с каждым днем все меньше, с тем, чтобы дрофы перешли на природные корма и добывали их самостоятельно. Эта вольера имеет сторо — ны 20 х 20 м, огорожена с боков и сверху мягкой сеткой. Эта идея не выдержа-ла испытания временем, поскольку два самца могли создать ситуацию и пока — лечить себя даже о мягкие стенки. В результате было два осложненных пере — лома и одна из птиц впоследствии пала. Как оказалось, самки успешнее избе-гали травмоопасных ситуаций. В короткое время три самца получили серьез — ные травмы – переломы костей крыла, один из которых пал. Итак, два остав — шихся в живых самца были разделены. Один помещен в огромную вольеру,

используемую под выпуск дроф, и там приспособился кормиться природными кормами. А другого поместили в маленькую вольеру при Центре реабилитации вместе с вновь прибывшим самцом, конфискованным в Бельгии. Позже выяс — нили, что он из испанской популяции, которая генетически отличается от сара-товской и выпускать его в природу не имеет смысла. Самец из России живет в неволе 3 года, и хорошо привык к людям, беря пищу из их рук, а самец из ис- панской популяции лишь два года живет в нашей вольере и сторонится людей.

Здесь доминирует старший самец. Младший обычно обходит его стороной. Прямых между ними конфликтов не замечено. Этих птиц легко изучать в вольере и наблюдать их поведение и брачные позы.

Таким образом, для проведения успешной работы с дрофами необходи-мо:

— в авиарии иметь мягкие стенки и потолок, а также, во избежание травм, не должно быть внутри него вертикальных или диагональных подпорок;

— вольер для содержания дроф не должен быть слишком большим, а число птиц в нем должно быть минимальным. Предлагаем вольер 10 х 10 м как

оптимальный. Лучше иметь их несколько.

— Для транспортировки на большие расстояния возраст дроф не должен быть менее 4 месяцев, оптимальный – 6 месяцев. Важно, чтобы транс — портный ящик был достаточен для того, чтобы птицы могли встать, по-вернуться кругом, но мал настолько, чтобы они не смогли расправить крылья, набрать скорость и получить травму.

Материал взят из: Дрофиные птицы Палеарктики: разведение и охрана. Межвед. сб. науч. и науч.-метод. тр.