Spatial differences in breeding success in the pied avocet Recurvirostra avosetta: effects of habitat on hatching success and chick survival

Abstract

Lengyel, S. 2006. Spatial differences in breeding success in the pied avocet Recurvirostra avosetta : effects of habitat on hatching success and chick su\rvival. Á J. Avian Biol. 37: 381 Á395.I studied the breeding biology of pied avocets Recurvirostra avosetta in natural habitats (alkaline lakes), and in semi-natural sites (dry fishpond, reconstructed wetlands) in Hungary to relate habitat selection patterns to spatial and temporal variation in breeding success. Colonies were initiated earlier in semi-natural sites than in natural habitats, and earlier on islands than on the mainland. Hatching success was higher on islands than on the mainland, in semi-natural sites than in natural habitats, in colonies of at least 15 pairs than in smaller colonies, and for nests initiated earlier than later within a colony. Fledging success was higher in the wet years (1999 Á2000) than in the dry year (1998), decreased strongly by season in both habitats and increased with average daily temperature in the first week post-hatch in 1999 Á2000. Most pairs hatching young in semi-natural sites attempted to lead their chicks to feeding areas in natural habitats, whereas no such movement occurred in the opposite direction. Chick mortality due to predation was high during brood movements and only 23% of the pairs moving their young produced fledglings, compared to 43% for pairs remaining in semi-natural sites and 68% for pairs hatching and rearing young in natural habitats (total n 0/192 broods). These results suggest that semi-natural sites were more suitable for nesting, whereas natural habitats were more suitable for chick-rearing. The opposing trends in habitat-related breeding success between nesting and chickrearing suggest sub-optimal habitat selection by Pied Avocets due to an incorrect assessment of the potential for successful reproduction of semi-natural sites, which may thus function as ecological traps.

Habitat use and nesting success of the Great Reed Warbler (Acrocephalus arundinaceus) in different reed habitats in Serbia

“…First, canals (VBC and Č onić) with straight artificial channels had the lowest nesting success overall and in most years, even though they were often used for nesting. Artificial habitats such as these, therefore, may function as ecological traps (Dwernychuk and Boag 1972, Kokko and Sutherland 2001, Lengyel 2006. It is also possible that in 2010, Bager also functioned as an ecological trap, where despite the high nesting density (21.2 nests/ha) the nesting success was extremely low because of a large amount of precipitation and rapid water level increase (Mérő et al 2014).…”

“…However, habitat selection decisions are often compromised by mismatches between habitat quality/suitability and attractiveness (Cody 1985), which can result in some habitats becoming ecological traps and others becoming perceptual traps. Ecological traps occur when some habitats are attractive to individuals but provide suboptimal conditions for breeding (Dwernychuk and Boag 1972, Kokko and Sutherland 2001, Lengyel 2006. In contrast, some other habitats can provide good conditions for breeding but lack the cues of an attractive habitat, which results in perceptual traps (Gilroy and Sutherland 2007).…”

Movements and Fledging Success of Snowy Plover (Charadrius alexandrinus) Chicks

“…However, other species, moved longer distances to brood-rearing areas, often several kilometers away from the nest. Average distance moved by young Northern Lapwing (Vanellus vanellus; Blomqvist and Johansson 1995), Pied Avocet (Recurvirostra avosetta; Lengyel 2006), Greater Snow Goose (Chen caerulescens; Mainguy 2006), Wood Duck (Aix sponsa; Granfors and Flake 1999) and Mallard (Anas platyrhynchos; Yerkes 2001) greatly exceed the average daily distance moved (216 ± 12m) by Snowy Plovers on Clam Beach. We hypothesize that this interspecific variation stems from landscape features (i.e.…”

“…shorebirds, waterfowl) leave the nest shortly after they hatch and are led by parents to areas that provide food, cover and protection from danger posed by predators and humans (Loegering and Fraser 1995;Lengyel 2006). Brood-rearing areas occur at varying distances from the nest (Newell et al 1985;Cooper 1994;Robinson et al 1997;Mainguy et al 2006).…”

Sex ratios of Mountain Plovers from egg production to fledging

“…Prey resources, predator communities, and weather exhibit spatio-temporal variability and have been suggested to influence chick survival in shorebirds (Smith and Rotenberry 1990, Lengyel 2006, Schekkerman and Beintema 2007, Schekkerman et al 2009). Prey abundance and biomass in a previous study were not related to Mountain Plover chick survival (Dreitz 2009).…”