Aquatic Warbler in Western Siberia

Aquatic Warbler Conservation Team

First short Report on the 3rd Expedition to W-Siberia
19 June - 4 July 2001
Chelyabinsk, Tyumen' and Omsk Oblasts

by Martin Flade

General Information, Schedule

The expedition could be successfully realised according to our previous plans. In the meanwhile, all participants of expedition arrived at home in good health.

On 19 July we started from Moscow to Ekaterinburg, from there, one group of 6 people under the leadership of Alexander Kozulin went to the south (southern Ekaterinburg and northern Chelyabinsk region) to visit the 'Karyakin sites' ('Southern Team'), the others (11 people, 'Eastern Team') went to the east to Tyumen' to visit the wetlands N of Tura river. On 25 June both teams met in Tyumen' and went to Tobolsk, from there we visited the huge sedge fen mires between Tobol and Ishim rivers as well as the Jarovskoe mire by helicopter.

On 29 June, the three Belarussians, H.-G. Bauer and the two people from Ekaterinburg went back to Ekaterinburg and Germany/Belarus, the others visited again the mires at lake Busly N of Omsk. On 4 July, we flew back from Ekaterinburg to Moscow.

Independently, Sergey Soloviev started on 12 June from Omsk to Lake Busly, Kileynoe and Jarovskoe mires and met with us at Motorovo (near Jarovskoe) on 26 June.

Main Results

Besides the 'Karyakin sites' we were able to visit five large, previously unknown sedge fen mire tracts between Ekaterinburg and Ishim river, out of which three are only accessible by helicopter. This means, that during the 2000 and 2001 expeditions all larger open fen mires of the fen mire belt between Ekaterinburg and Tara (Irtysh) except one (S of Tyumen, not visited because of bad weather) have been investigated by our team! Additionally we visited again the two best sites from 2000, in which Aquatic Warblers were recorded in the previous year. We obtained habitat and vegetation descriptions as well as bird transect counts from all these mires, supported by our two excellent botanists from Belarus. For the first time, high-quality vegetation analyses of most of the visited mires could be prepared (e.g. some very rare plant associations and more than 1000 plant species recorded!). It is now possible to prepare a nearly complete evaluation of W-Siberian fen mires for conservation purposes.

Aquatic Warbler

Despite the occurrence of huge areas of superb potential AW habitats (at least five mires with several hundred to several thousand ha of suitable habitat each within the fen mire belt between Ekaterinburg and Ishim), Aquatic Warbler was not found by our team. Although Sergey Soloviev reported 5-6 singing males at lake Busly in mid-June 2001, these birds could not be found by us anymore on 1/2 July. Another excellent habitat area discovered nearby (8 km NE Lake Busly) was also studied very thoroughly (by sunset and morning visits and mist-netting, also using tape lures), but AW was absent for sure.

Thus our previous results were confirmed: Despite large suitable sedge fen mires, there exists no larger AW population in W-Siberia. The actual population is very small and fluctuating, most probably declining, and is actually estimated at somewhere between <50 and 500 singing males. 30-40 years ago, the population must have been much larger and bred up to c. 1000 km further to the east (see skins from Vengerovo district from 1962, records in Shegarka mire at the middle Ob near Tomsk).

We believe, that the species is going to become extinct in W-Siberia in the next future, because a population of such small size and such low abundance in a distance of several thousands of km from the core population can not be viable.

The reasons for this are thought to be:

1.) Decline of the core population in the Central-European Polessie (Belarus/NW-Ukraine/E-Poland) for more than 90 % since the 1960s due to habitat destruction.

2.) Isolation of the W-Siberian breeding area due to nearly complete loss of suitable habitats in European Russia since 1960 (see 1998 Report from Ryazan and Perm Regions).

3.) Negative changes in the migration and wintering areas (for which we have no clear evidence at the moment) could additionally have been contributed to the population decline, leading to a contraction of the species' range at it's eastern border.

Feather samples

To support several projects on DNA and trace element analyses, feathers from 80 birds were collected in the fen mire belt between Ekaterinburg and Lake Busly.

(...)

Data on bird communities

Transect counts were performed in 7 fen mires, out of which 5 have not been visited before and 2 were already counted during the 2nd W-Siberia expedition.

Other bird records of special interest

Highlights of the expedition, contributing to the knowledge on distribution range and population size, were (examples):

Asian Dowitcher Limnodromus semipalmatus: The observation of 4 birds in the Tura floodplain (flooded crops and meadows) E Borki, NE Tyumen, represents the westernmost record of this species at all and the second record in Omsk and Tyumen Oblasts since 90 years (see LIMICOLA 2/2001).

Black-winged Stilt Himantopus himantopus: A small breeding colony of 4 pairs NE Tyumen and a record in the Tobol floodplain S of Tobolsk are north of the known range.

Pallas' Bunting Emberiza pallasi: All open fen mires are inhabited up to the Tobol in the west. This moves the western border of the known range further 150 km to the west. Density mostly >10 bp/km², several nests found.

Pallas' Grashopper Warbler Locustella certhiola: a record in Jarovskoe mire (singing male) is far west of the known range.

Pallid Harrier Circus macrouros: Small breeding populations in Jarovskoe (2 bp., nest found) and N Lake Busly (3-4 bp, nest found) are at the northernmost edge of the known range.

Penduline Tit Remiz pendulinus: a female and a singing male N of Tyumen are north of the known range.

Breeding records of other species such as Ferruginous Duck Aythya nyroca (Busly mire), Spotted Eagle Aquila clanga (widespread in the whole subtaiga belt between Tobol and Novosibirsk!), Baillon's Crake Porzana pusilla (up to the north of Tyumen), Richard's Pipit Anthus richardi (northern Omsk oblast) are interesting as well.

The Corncrake Crex crex is extremely abundant everywhere (in meadows, pastures, steppe grasslands, fen mires, floodplains, forest clearings, lake shores, sometimes also crops, suburbs...) and is estimated by us to be the most numerous crake of the Eurasian continent. Regarding the broad range and character of occupied habitats there is no evidence, that the species has declined in Siberia during the last decades!

NABU-Home

	Aquatic Warbler Conservation Team First short Report on the 3rd Expedition to W-Siberia 19 June - 4 July 2001 Chelyabinsk, Tyumen' and Omsk Oblasts by Martin Flade General Information, Schedule The expedition could be successfully realised according to our previous plans. In the meanwhile, all participants of expedition arrived at home in good health. On 19 July we started from Moscow to Ekaterinburg, from there, one group of 6 people under the leadership of Alexander Kozulin went to the south (southern Ekaterinburg and northern Chelyabinsk region) to visit the 'Karyakin sites' ('Southern Team'), the others (11 people, 'Eastern Team') went to the east to Tyumen' to visit the wetlands N of Tura river. On 25 June both teams met in Tyumen' and went to Tobolsk, from there we visited the huge sedge fen mires between Tobol and Ishim rivers as well as the Jarovskoe mire by helicopter. On 29 June, the three Belarussians, H.-G. Bauer and the two people from Ekaterinburg went back to Ekaterinburg and Germany/Belarus, the others visited again the mires at lake Busly N of Omsk. On 4 July, we flew back from Ekaterinburg to Moscow. Independently, Sergey Soloviev started on 12 June from Omsk to Lake Busly, Kileynoe and Jarovskoe mires and met with us at Motorovo (near Jarovskoe) on 26 June. Main Results Besides the 'Karyakin sites' we were able to visit five large, previously unknown sedge fen mire tracts between Ekaterinburg and Ishim river, out of which three are only accessible by helicopter. This means, that during the 2000 and 2001 expeditions all larger open fen mires of the fen mire belt between Ekaterinburg and Tara (Irtysh) except one (S of Tyumen, not visited because of bad weather) have been investigated by our team! Additionally we visited again the two best sites from 2000, in which Aquatic Warblers were recorded in the previous year. We obtained habitat and vegetation descriptions as well as bird transect counts from all these mires, supported by our two excellent botanists from Belarus. For the first time, high-quality vegetation analyses of most of the visited mires could be prepared (e.g. some very rare plant associations and more than 1000 plant species recorded!). It is now possible to prepare a nearly complete evaluation of W-Siberian fen mires for conservation purposes. Aquatic Warbler Despite the occurrence of huge areas of superb potential AW habitats (at least five mires with several hundred to several thousand ha of suitable habitat each within the fen mire belt between Ekaterinburg and Ishim), Aquatic Warbler was not found by our team. Although Sergey Soloviev reported 5-6 singing males at lake Busly in mid-June 2001, these birds could not be found by us anymore on 1/2 July. Another excellent habitat area discovered nearby (8 km NE Lake Busly) was also studied very thoroughly (by sunset and morning visits and mist-netting, also using tape lures), but AW was absent for sure. Thus our previous results were confirmed: Despite large suitable sedge fen mires, there exists no larger AW population in W-Siberia. The actual population is very small and fluctuating, most probably declining, and is actually estimated at somewhere between <50 and 500 singing males. 30-40 years ago, the population must have been much larger and bred up to c. 1000 km further to the east (see skins from Vengerovo district from 1962, records in Shegarka mire at the middle Ob near Tomsk). We believe, that the species is going to become extinct in W-Siberia in the next future, because a population of such small size and such low abundance in a distance of several thousands of km from the core population can not be viable. The reasons for this are thought to be: 1.) Decline of the core population in the Central-European Polessie (Belarus/NW-Ukraine/E-Poland) for more than 90 % since the 1960s due to habitat destruction. 2.) Isolation of the W-Siberian breeding area due to nearly complete loss of suitable habitats in European Russia since 1960 (see 1998 Report from Ryazan and Perm Regions). 3.) Negative changes in the migration and wintering areas (for which we have no clear evidence at the moment) could additionally have been contributed to the population decline, leading to a contraction of the species' range at it's eastern border. Feather samples To support several projects on DNA and trace element analyses, feathers from 80 birds were collected in the fen mire belt between Ekaterinburg and Lake Busly. (...) Data on bird communities Transect counts were performed in 7 fen mires, out of which 5 have not been visited before and 2 were already counted during the 2nd W-Siberia expedition. Other bird records of special interest Highlights of the expedition, contributing to the knowledge on distribution range and population size, were (examples): Asian Dowitcher Limnodromus semipalmatus: The observation of 4 birds in the Tura floodplain (flooded crops and meadows) E Borki, NE Tyumen, represents the westernmost record of this species at all and the second record in Omsk and Tyumen Oblasts since 90 years (see LIMICOLA 2/2001). Black-winged Stilt Himantopus himantopus: A small breeding colony of 4 pairs NE Tyumen and a record in the Tobol floodplain S of Tobolsk are north of the known range. Pallas' Bunting Emberiza pallasi: All open fen mires are inhabited up to the Tobol in the west. This moves the western border of the known range further 150 km to the west. Density mostly >10 bp/km², several nests found. Pallas' Grashopper Warbler Locustella certhiola: a record in Jarovskoe mire (singing male) is far west of the known range. Pallid Harrier Circus macrouros: Small breeding populations in Jarovskoe (2 bp., nest found) and N Lake Busly (3-4 bp, nest found) are at the northernmost edge of the known range. Penduline Tit Remiz pendulinus: a female and a singing male N of Tyumen are north of the known range. Breeding records of other species such as Ferruginous Duck Aythya nyroca (Busly mire), Spotted Eagle Aquila clanga (widespread in the whole subtaiga belt between Tobol and Novosibirsk!), Baillon's Crake Porzana pusilla (up to the north of Tyumen), Richard's Pipit Anthus richardi (northern Omsk oblast) are interesting as well. The Corncrake Crex crex is extremely abundant everywhere (in meadows, pastures, steppe grasslands, fen mires, floodplains, forest clearings, lake shores, sometimes also crops, suburbs...) and is estimated by us to be the most numerous crake of the Eurasian continent. Regarding the broad range and character of occupied habitats there is no evidence, that the species has declined in Siberia during the last decades! NABU-Home