Expedition to the Breeding Grounds
At the end of May a small group of Russian scientist lead by Alexander Kondratyev from St. Petersburg University strated research on the breeding biology of White-fronted and Barnacle geese in the Northeastern tundra of Kolguev Island. In the middle of July Helmut Kruckenberg, Christoph Zöckler and Johan Mooij from Germany arrived at the island and joined the fieldwork.
After a small delay German team members arrived on Kolguev Island on 18-07-2006. Using huge lorries and walking at least three hours the crew arrived the expedition camp, situated on a bank of the Peschanka-River.
The Russian crewmembers already mapped all goose nests in most of this part of the island. All clutches were counted, measured and GPS-fixed and every nest photographed. On the basis of these data the nesting density on Kolguev was calculated. According to these results Kolguev Island might be the most important breeding site for White-fronted, Bean and Barnacle geese in the Western Palaearctic. Approximately 37.-45.000 pairs of Barnacles were nesting in the colony close to the camp. The density of the non-colonial Whitefronts was 40-90 breeding pairs/10km² depending on the habitat. However, doing a rough estimate approximatly 50% of Barnacle and 20-30% of the Whitefronted gooe population may nest on Kolguev alone.
Surprisingly we found an extremely high predation pressure. This was unexpected,because of absence of lemmings on this island made everybody believe that there would be no or only little predation at all. But in contrast, we found high densities of Glaucous Gulls, Arctic Foxes, Rough-legged Buzzards and Skuas, preying mainly geese chicks.
During the expedition we caught many geese and waders and sampled them for Avian-Flu-Analyses. We also ringed them and put colour-rings to all birds old enough to carry it. So, we marked 15 Barnacles, 19 Whitefronts and 3 Beans.
For reading a long version of our expedition report (German only) with a lot of photos klick here.
Since 29-5 the russian participants worked intensivly at the northwestern part of the island searching and measuring nests and mapping all kinds breeding birds in the tundra. Altogether they found more than 500 nests of grey goose in the area. So, this means a average density of 40 nests per km². Also they estimated the size of the Barnacle Goose colony by using transsect counts. So they came to result of 35-40,000 pairs of Barnacle breeding in this colony. So, based on this results maybe half of the Barnacle Goose and 1/4 of the White-fronted Goose populations might breed on Kolguev. So, our results show a very high importance of this island for the arctic breeding goose populations of the western parlearctic.
Based on the data of Morozov & Syrochekovski who worked on the same study plots in 1995 we can compare our results with previous data. So, the Barnacle colony increase 7x during the last 10 years while the density of White-fronts kept stabil. Like the results from waddensea-area we also found a decrease in breeding densities of Dunlin, Little Stint and Golden Plover.
We found a remarkable high predation rate on this lemming-free island. Dens of Polar foxes were found in 2-3km distance, nests of Peregrine Falcons and Ruff-legged Buzzards were also common and we observed high number of chicks killed by Glaucous Gulls. Nevertheless we found a lot of chicks been fledged in the end of summer. However, pairs who lost their nest and young chicks seems to leave the island to migrate to other sites for moulting.
We observed different defence strategies against predators of Barnacle and White-fronted Goose: While Barnacles grouped in large flocks and in case of an attack build up a defence wall like musk ox do, the White-fronted tried to espace by hiding in bushes and running family by family. So, especially when adults start moulting they lost lots of their chicks.
Altogether we were able to colour-mark 19 White-fronts and 3 Bean Geese with neckbands and 15 Barnacle geese with coloured legrings. Young chicks were marked with metall ring only. Further we restarted one of the shot satellite transmitters on Kolguev. The bird was named "Sasha". He was rearing his family in Erkapenya River lowlands. Unfortunatly he was able to kick the PTT off. Read the whole story here!
We collected 130 sample from rachae and cloake of artic birds to be analysed back home for avian flue viruses by the Friedrich-Löffler-Institut (FLI). So sampled geese, but also waders, Peregrine Falcons, Glaucous Gulls and grouse. In laboratory in 4 of 130 samples was found a kind of flue virus, but it was no H5N1 or other high pathogeous virus found.
Read our extended expedition report here. Also have a look to our camp weblog!
Movies from the breeding grounds
On Kolguev we found breeding Branacle and White-fronted Geese as well as Bean Geese. The breeding behaviour of Barnacle and Whitefronts is extremely different. While Barnacles flock together with numerous families and defend their chicks in teams, Whitefront families went alone and hide themselves in bushes. Here you can see movies from Kolguev showing you scenes from their behaviour.
Movie of Barnacle families.
Movie of Whitefronts family.
In a large colony of breeding Barnacles Alexander Kondratyev made a movie of a mixed pair of Ross Snow goose and Barnacle goose.
Movie of mixed breeding pair.