Monday, January 24, 2011

Sniping About the Weather

Snipe, Gallinago gallinago, feeding

The Snipe (Gallinago gallinago) is an unmistakable bird, most commonly seen in Ireland in winter when resident numbers are swelled by migrant populations from northern Europe (1). Its is similar in shape to the Woodcock and the Jack Snipe, but its size and the yellow bars on its head and down its buff-brown plumage make it easily recognisable (2). It inhabits wetlands and moors where it uses its almost disproportionally long bill to probe the mud for invertebrates. This it tends to do alone, although small groups are sometimes seen foraging together.
While there has been a decline in numbers of Snipe over the past 30 years (3), the species is so numerous that the International Union for Conservation of Nature sees it as of least concern (4). The situation may become critical however due to continued destruction of wetland habitats by draining and further intensification of grassland management (5). Most grassland systems in Ireland lack botanical diversity, being composed typically of just a handful of ryegrass species (6). This results in a lack of invertebrate numbers and development of impenetrable rhizosphere areas, making feeding for the Snipe almost impossible (7).
Habitats where feeding is easy due to wet or waterlogged soil lead to longer nesting times for Snipe (5), and while wet weather does provide this increase in feeding ability, it also brings the problem of flooding. Flooding has been shown to delay Snipe nesting by up to 70 days, suggesting they are quite weather dependent breeders.

References:
  1. Sterry 2004, Collins Complete Guide to Irish Wildlife p. 60
  2. Hayman and Hume 2002, The New Birdwatcher's Pocket Guide to Britain and Europe p. 117
  3. Henderson et al. 2002, Bird Study 49 pp. 17-25
  4. www.iucnredlist.org/apps/redlist/details/150697/0
  5. Green 1988, Journal of Applied Ecology25 pp. 79-93
  6. Byrne 2009, Euphytica 166 pp. 61 – 70.
  7. McCracken and Tallowin 2004, The International Journal of Avian Science 146 pp. 108-114

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