Effects of Environmental Factors on the Timing and Success of Breeding of Common Snipe Gallinago gallinago (Aves: scolopacidae)

Abstract

(1) Seven plots of lowland wet grassland were systematically searched for snipe nests in 10 plot-years and the outcome of nesting attempts was determined. Vegetation height and the availability of food were measured. Snipe feed on soil invertebrates by probing soil or mud with the bill, so prey density and the force required to probe the soil were measured. Soil was easier to probe when moist or waterlogged than when dry. (2) The majority of breeding attempts failed. Egg predation and trampling of nests by cattle were the most frequent causes of failure during incubation. However, individually marked females that lost clutches or broods before a critical date all laid replacement clutches. (3) The dates on which nesting started and on which replacement nesting ceased varied greatly between plot-years. The start of nesting could be delayed for up to 70 days by flooding. Nesting stopped later in plot-years when the soil remained moist and easy to probe. (4) The number of chicks hatched per female over the whole breeding season was determined by the rate of failure of individual breeding attempts and the duration of the nesting season. Management of water levels to prolong the period during which snipe can probe the soil would increase breeding success.