Director Great Bustard Group, Kingdom of Great Britain
The Great Bustard became extinct as a breeding bird in the UK in 1832. The decline and extinction appeared to have happened quite quickly. The causes were
changes in agriculture that lead to the widespread use of the corn drill and the horse hoe. These implements allowed crops to be sown in a straight line, and allowed inter row weeding to be conducted as the crops grew. The Great Bustards in the UK
apparently selected cultivated land for their nest sites and egg destruction and collection both increased significantly. Another cause of extinction was direct persecution by early ornithologists obtaining their specimens for the growing fashion of bird collecting.
A captive-breeding project for Great Bustards was set up and operated during the 1970s and 1980s. No birds were released, and it is only mentioned in this text as a matter of clarification as the author often encounters a wide spread, but erroneous
belief that a reintroduction project took place and failed at this time.
In 1998 David Waters set up the Great Bustard Group with the intention of exploring the feasibility of and if appropriate, implementing a reintroduction scheme. A feasibility study was commissioned (Osborne and Martin, 2001) and as the UK legislation now classified the Great Bustard as a non native species this was followed by the commissioning of a formal licence application to the UK Government (Osborne, 2002). The IUCN guidelines for Reintroductions were the basis for the application (IUCN Reintroductions, 1995). Suitable habitat was identified across the south west of the UK centred upon the Army training area of Salisbury Plain. The UK Government in 2004 granted a 10-year licence for a reintroduction trial.
The UK reintroduction project does not receive direct financial support from either Government or mainstream conservation sources. The project is self financed and depends on its fundraising activities, memberships and support from local business producing such items as Great Bustard beer, wine, cheese and jewellery.
A donor population was identified in Saratovskaya oblast’, Russia. Here a large Great Bustard population existed. Its size is not known with any accuracy and its distribution even less well known. Estimates vary from 5000 – 7000 individuals (pers. com. Antonchikov) to 8000 – 11000 individuals (Litzbarski & Watzke, 2007).
The population is widely considered to be stable or slowly increasing.
A cultivated field in Saratov Oblast
The cultivation of the land in Saratovskaya oblast includes the creation of a stale seedbed through repeated weed cutting for winter. This weed cutting takes place repeatedly from mid May to July and causes widespread destruction of Great Bustard nests. The female Great Bustards are seemingly attracted to the fields between the cultivations which may be 2 weeks apart. The scale of the landscape makes finding nests prior to cultivation very difficult or even impossible to achieve on a meaningful scale. The fields are huge, and may be up to 100 square kilometres. The cultivation is carried out by teams of tractors with 4 – 10 tractors in a team and may continue over 24 hours with a shift pattern. The vast fields, dark soils and subsequent heat haze and low density of nests per square km make finding a meaningful number of nests prior to cultivation an impossible task for the resources available. The only way any number of nests may be located is by receiving reports from the tractor drivers themselves.
Preparing a stale seed bed
Working with the A. N. Severtsov Institute of Ecology and Evolution tractor drivers are given mobile phones and asked to report any Great Bustard nests they discover during cultivation. The actions taken upon receiving such a report are determined by an egg collection protocol formulated jointly by the Great Bustard Group and the University of Bath, MME (Birdlife Hungary), RBCU, A. N. Severtsov Institute and the Russian Federal Service for the Management of Wildlife.
In essence, the tractor driver should leave an uncultivated area around the nest of 1 hectare; with the hope being that the eggs may continue to be incubated by the
female. In practice the nest is only discovered when the female flushes which may be very close to the tractor, and the nest is often right at the edge of the uncultivated
Experience has shown that all nests left in small-uncultivated plots in these large fields are abandoned or predated within 48 hours normally within 24 hours. Leaving an uncultivated strip to join the plot to the edge of the field is not feasible when the plot may be several kilometres from the edge of the field. The staff of the A. N. Severtsov Institute carries dummy eggs which are substituted for the real eggs if there is any sign that the female is still in the vicinity of the nest by the arrival of the staff which is usually within a few hours of the report.
By implementing the egg collection protocol a source of birds has been identified which will have no negative impact on the donor population.
Eggs are incubated at the A. N. Severtsov Institute’s Field Station at Diakovka. The hatched chicks are fed by a puppet and human contact is reduced to the obligatory heath checks. A dehumanisation suit is used to disguise human features
when access to the chick rearing areas is needed.
The dehumanisation suit
Feeding the chicks with a puppet
The Reintroduction to the UK
The first batch of chicks was imported into the UK in 2004. There have been subsequent imports in each year since then. The time of the import has been
dependent on the considerable paperwork that needs to be generated from both the Russian Federation and the UK to allow the import. Experience has shown that chicks under 4 weeks do not thrive during a long transport phase (it takes 48 hours
from the Field Station in Russia to the UK site). A minimum age of 4 weeks is now implemented and, contrary to advice received, no problems have been encountered transporting larger chicks.
Once in the UK there is a mandatory quarantine period of 30 days, with
periodical heath checks. Apart from these checks the isolation rearing protocol is continued.
The birds are released into a 4-hectare open release enclosure. No
supplementary food is supplied, but the enclosure is sown with crops selected to be attractive to Great Bustards.
Post Release Monitoring
The birds are all fitted with soft plastic wing tags to both wings. The colour denotes the year and a unique number the individual bird. Since 2004 different methods of tracking the birds have been used.
In 2004 the project suffered a set back when 20 out of 22 birds released were fitted with poorly made and poorly fitted back pack type harnesses. All the birds carrying the harnesses died, and the harnesses were found to have cut into the birds and caused injury and severely restricted their ability to fly. In 2005 and 2006
necklace type and tail mounted transmitters were used. In 2007 GPS/ Satellite PTTs were used. These entailed a reversion to a back pack type harness and these were fitted by Prof. Juan Carlos Alonso, who has extensive experience of fitting
transmitters to Great Bustards and a record of success. No problems have been encountered with the harnesses and the PTTS provide excellent data.
Fitting the GPS/SatelitePTTs
Discounting the data from 2004, when the behaviour and survival of the birds was so adversely affected by the poor harnesses, the results can be seen in the table.
GBG, Status of released Great Bustards (25th February 2008).
* One bird from 2007 is permanently disabled and resides within the bustard enclosure.
In summary, of known mortality, 2 birds have died through collision with electricity wires. One was some 50 km south of the release site, and the other in the Loire Valley I central France. The others have been predated. Foxes are believed to have been responsible in all the cases, but carcasses have been recovered in a scavenged condition where the predator or indeed the actual cause of death cannot be ascertained. Whenever a reasonably intact carcass has been recovered a post mortem has been carried out. There appear to be no problems indicating any underlying issue of illnesses, disease or any indications of poor body condition due to nutritional deficiencies or other causes that may relate to the habitat, climate or any other factor attributable to the UK environment.
The general pattern has been for released birds to remain within 2 km of the release site until the end of November and then to disperse, usually in a southwest
direction. 3 Birds are known to have crossed the Channel to France. One bird was recovered under electricity lines in the Loire Valley, and other female was photographed near Toulouse in the south, but has not been seen since. A male bird
was seen in Brittany and then reported to have crossed back to the UK.
Males and females have been observed to have returned to the release site in the spring, but male birds have disappeared for a full 18 months before returning to display in the release enclosure.
A recent development has been over the 2007/8 winter when a small group of birds (male and female) have spend the entire winter in the vicinity of the release enclosure. The first returning female (a 2005 release) who had spent the early winter
some 60-km to the south and west joined them at the end of January.
Example of data from GPS/Satelite PPT
The male display has been observed in the vicinity of the release site. It was first seen in 2007 and the first known nest was observed that year. The eggs were incubated for at least 17 days before the female abandoned them. A subsequent
examination showed them to be infertile (Chitty. GBCC minutes).
Displaying males have again been observed in early 2008.
At the time of writing a mid term review of the reintroduction is underway.
The general progress of the reintroduction trial is, in the opinion of the author, at least satisfactory. The obvious area for development is the number of birds released in the UK. It has been low for 2 successive years. If this point can be suitably addressed, the existing UK Great Bustard population may be quickly increased, and if the breeding activity can be repeated with birds gaining maturity successful breeding may be expected within the next one or two years.
The ability to create a new Great Bustard population, or move Great Bustards from one population to another may prove to be a useful conservation tool in what may become a rapidly changing European landscape.
Материал взят из: Дрофиные птицы Палеарктики: разведение и охрана. Межвед. сб. науч. и науч.-метод. тр.