Habitat selection of foraging male Great Snipes on floodplain meadows: importance of proximity to the lek, vegetation cover and bare ground

Abstract

Drainage of wetlands and agricultural intensification has resulted in serious biodiversity loss in Europe, not least in grasslands. Consequently, many meadow birds have drastically declined, and the habitats they select for breeding currently rely on land management. However, the selection of habitats maintained by agriculture may contribute to reduced fitness and thus remain maladaptive for individuals, which makes conservation challenging. An understanding of the relationships between species’ habitat selection, food supply and land management in the context of species’ behaviour is therefore crucial for conservation. Lowland populations of Great Snipe Gallinago media are currently declining at a moderate rate, causing a conservation concern. We examined the daytime site selection (assumed as foraging sites) and food supply of radiotracked Great Snipe males breeding on a floodplain in NE Poland. Foraging sites were classified at micro‐ and macro‐scale levels using the logistic regression in a use–availability design. On the micro‐scale level, males selected moderate sward height and density, and a large amount of bare ground patches, and the importance of these increased as the breeding season progressed. On the macro‐scale level, these conditions were associated with (1) meadows mown twice per season and grazed thereafter (associated with the most abundant food resources – earthworms) and (2) extensively managed pastures, suggesting the importance of grazing. Abandoned or late‐mown meadows under agri‐environmental schemes (AES) were avoided by foraging males. However, parcels with delayed mowing offer safe breeding sites for females nesting close to leks, unlike land‐use types preferred by foraging males, which may act as an ecological trap. Effective conservation of Great Snipes on floodplain meadows requires precisely targeted AES schemes that will provide a mosaic of intensive and extensive land‐use patches in the vicinity of identified leks.

Habitat selection and population status of breeding Wood Snipe Gallinago nemoricola in an alpine meadow in Sichuan, China

“…Therefore, the occurrence of the Wood Snipe seemed to be largely driven by soil conditions and food density rather than vegetation variables. This reflects similar findings for the breeding Common Snipe (Gallinago gallinago) and Great Snipe (G. media), in which habitat selection and body condition are associated with certain soil conditions and higher food availability (Green et al 1990, Korniluk et al 2021, Witkowska et al 2022. However, unlike the Great Snipe, we did not find strong evidence of Wood Snipe selecting habitat with moderate vegetation height and density to avoid potential predators (Løfaldli et al 1992), even though predation attempts by raptors were observed in the field.…”

“…Owing to the very limited information on Wood Snipe ecology, we considered a range of terrain, vegetation, soil, and human disturbance variables noted to be important to the habitat selection of other snipe species (Table 1) (Hoodless et al 2007, Mongin 2006, Korniluk et al 2021, Løfaldli et al 1992). At each site, we recorded elevation, slope aspect, and grade, as well as soil variables including moisture and penetrability.…”

The level of water in the river flowing through the breeding site shapes the body condition of a lekking bird—the Great Snipe Gallinago media

“…In such hydrological circumstances, the remaining unflooded soil layer is thin, and earthworms are bound to occupy it in great densities. The Great Snipe uses the tactile foraging strategy, probing the soil and mud with a bill in search for prey (Cramp and Simmons 1983), and prefers feeding sites with high soil penetrability (Korniluk et al 2020). This parameter relies on the hydrological conditions of the meadow, as higher soil moisture can cause the top layer of the soil to become easier to penetrate (Armstrong 2000;Milsom et al 2002).…”

“…Therefore, males must rely on abundant prey available at feeding sites on their breeding grounds, as breeding display constrains the replenishment of energetic resources by foraging during the day. The location of the Great Snipe leks is determined by the proximity of such rich feeding sites, especially with easily accessible and abundant earthworms Lumbricidae that compose 90% of the diet in this species (Løfaldli et al 1992;Kålås et al 1997;Korniluk et al 2020). Hence, it is possible, that the availability of high quality food such as earthworms determines the body condition of lekking birds.…”

Invertebrate abundance increases with vegetation productivity across natural and agricultural wader breeding habitats in Europe

“…We test whether invertebrates decline with increasing land use intensity, which would support the hypothesis that intensive farming practices are a key driver of invertebrate prey. We also examine whether and how invertebrates are affected by soil moisture content, a key variable for many wader species as it affects the ability of adult birds to probe the soil for invertebrate prey (Korniluk et al, 2021;Smart et al, 2006;Struwe-Juhl, 1995) and known to influence vegetation productivity (Heisler-White et al, 2009).…”