Catching Jack Snipe with dip-nets in the non-breeding seas
70 – 75
1 December 05
Institute for Ornithology, Polish Academy of Sciences, Nadwislanska 108, 80-680 Gdansk, Poland.
Jack Snipe Lymnocryptes minimus is one of the least known waders and is difficult to study because of its skulking behaviour and cryptic plumage. Thanks to the use of dip-nets and with the development of more effective detection methods, the number of Jack Snipe ringed in Poland increased from 97 during the 58 years 1931–1998, to 1,682 during 1999–2004. Ninety-two per cent are now caught in dip-nets. Trapping Jack Snipe in this way takes advantage of their passive anti-predator strategy. Footprints, signs of foraging, droppings, and feathers lost during moult were used to detect the species. The capture efficiency in N Poland averaged 47% (birds captured as a percentage of the total observed) and varied with season, group-size, habitat and weather. The highest capture efficiency was achieved during winter (70%) when it was especially high in irrigation ditches (76%). In contrast, much lower percentages were caught during spring (25%) and in flooded meadows. Capture efficiency was the highest in the case of small groups (1–5) (65%), and decreased gradually as group-size increased.