17PTAKI LAK I MOKRADEL POLSKI.pdf

Fundacja IUCN Poland
1.3. Design of the census
Two surveys have been conducted during one census (2 days) at sunrise, beginning
from different starting points every time. Dawn hours were assigned for surveys
along osier-beds and the edges of alder forests (higher numbers of singing birds of
fairly numerous species than at open areas). More open areas were checked at midday
and in the afternoon (waders, ducks estimated on the basis of the numbers of alarmed,
frightened birds etc.). To estimate the numbers of ducks, wide drainage canals, peat
excavations and partly flooded osier-beds were checked. Nests of crows (Corvidae)
were inspected, particularly in the first half of May, since Long-eared Owls (Asio otus)
could lay eggs in nests of Magpies (Pica pica).
1.4. Bird species included
Dominant species, which were counted at primary plots, were excluded from these
surveys. There were mainly: Skylark (Alauda arvensis), Meadow Pipit (Anthus
pratensis), Yellow Wagtail (Motacilla flava), Whinchat (Saxicola rubetra), and for the
most shrubby fragments of meadows: Marsh Warbler (Acrocephalus palustris),
Whitethroat (Sylvia communis), Sedge Warbler (Acrocephalus schoenobaenus),
Yellowhammer (Emberiza citrinella), Reed Bunting (E. schoeniclus), Thrush Nightingale
(Luscinia luscinia), Nightingale (L. megarhynchos), Garden Warbler (Sylvia borin) and
Linnet (Carduelis cannabina).
However some waders, which are local dominants: Lapwing (Vanellus vanellus),
Black-tailed Godwit (Limosa limosa) and Snipe (Gallinago gallinago) were counted at the
whole secondary plot. It was decided that all observed species during the survey
would be recorded, also nonbreeding and migratory species e.g. ruffs (Philomachus
pugnax) and put into final reports.
All information were put on a map in the 1:10 000 scale, according to an improved
version of the mapping technique (a combined mapping) for censusing breeding
birds (Tomia³ojæ 1990).
In 1995 the surveys have been conducted on selected plots in the whole country,
which are described later. Following data were collected:
a list of breeding species, their breeding category and estimated numbers;
the list of other species, found on each plot; all species observed on the investigated
area were considered. Large aggregations or flocks of selected species –
geese (Anser), shorebirds (Charadrii) and cranes (Grus grus) etc. were recorded;
results of previous ornithological investigations on these areas;
directions of changes in the avifauna;
valorisation of studied areas on regional and national level (European – if they
were of European value);
conservation problems, the place in an existing or planned protection system,
serious agricultural threats (agricultural drainage schemes, intensification of
agricultural production, change in land use etc.);
proposals regarding conservation activity including active protection.
Special attention was paid to both actual and potential agricultural threats, mainly:
changing green lands into arable lands;
excessive and uncontrolled use of agro-chemicals (pesticides) and fertilisers;
agricultural drainage;
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