Habitat selection of Marbled Teal and White-headed Duck during the breeding and wintering seasons in south-eastern Spain

Abstract

SummaryUnderstanding habitat requirements is vital for developing successful management strategies for threatened species. In this study we analyse the habitat selection of two globally threatened waterbirds (Marbled Teal Marmaronetta angustirostris and White-headed Duck Oxyura leucocephala) coexisting in an internationally important wetland (El Hondo Natural Park, south-eastern Spain) at three spatial scales. We surveyed adults and broods of these species fortnightly during two consecutive years and we related density and presence of birds to several habitat variables. At a pond-selection scale, the density of both species was related to the surface area of the ponds, with Marbled Teal showing avoidance of medium-sized ponds, and White-headed Ducks strong selection for the largest ponds. Within ponds, Marbled Teal avoided open waters, and was mainly associated with Phragmites reedbeds, but also selected areas with saltmarsh and Scirpus vegetation, especially for brood-rearing. White-headed Duck made more use of deeper areas with open water, especially in winter, and Phragmites was the only emergent vegetation with which it associated. When breeding success was very high in 2000, strong creching of broods was observed in White-headed Duck, but not in Marbled Teal. In order to provide suitable habitat for both species, there is a need to maintain spatial diversity with a combination of large wetlands suitable for both species and small, vegetated ones suitable for the Marbled Teal.

Habitat Use by Waterbirds in Relation to Pond Size, Water Depth, and Isolation: Lessons from a Restoration in Southern Spain

“…Water depth has previously been shown to be an important determinant of the occurrence of some waterbird species (Kreakie et al ), but different species favor different depths even within foraging guilds such as ducks (Green ; Sebastián‐González et al ). In our system, shallow ponds were preferred by small‐sized species, probably because they require shallower waters than other species to feed, owing to limited leg and bill length.…”

“…We excluded isolated ponds (all medium size) from these analyses to avoid confounding the effects of pond size with those of isolation. See Sebastián‐González et al (, ) for other studies with similar statistical approaches.…”

Ecological factors affecting wetland occupancy by breeding Anatidae in the southwestern mediterranean

“…This could be attributed to a marked difference in breeding habitats requirements between these species. Indeed, the Ruddy Shelduck generally breeds, far away from wetlands, in the holes of trees and rocks, whereas the Marbled Teal and Red-Crested Pochard use exclusively habitats of coastal wetlands for nesting (e.g., Phragmites reedbeds and Scirpus vegetation) (Defos du Rau et al 2005;S e b a s t i á n- Gonza´lez et al 2013;Cherkaoui et al 2016). The effect of geographical location has additionally differed among years, in particular for Red-Crested Pochards.…”

“…Waterfowl are known to be highly sensitive to environmental conditions during breeding period (Lant et al 2005;Holopainen et al 2015). For example, human disturbances are known to negatively affect breeding waterfowl by reducing hatching success and duckling survival (Korschgen and Dahlgren 1992;Fox et al 2015), while wetland features are key determinants of habitat use in numerous breeding ducks [e.g., the Marbled Teal (Green 1998;Green and El Hamzaoui 2000;Sebastia´n-Gonza´lez et al 2013), White-Headed Duck (Castro et al 1994;Sebastia´n-Gonza´lez et al 2013), Mallard (Amat 1982;Merendino and Ankney 1994), and Red-Crested Pochard (Amat 1982;Broyer and Curtet 2010)]. For these reasons, we hypothesized that wetland occupancy might be especially influenced by habitat features and human activities, but the significance and direction of these relationships may vary among species according to their ecological requirements.…”

Diversity of waterbirds wintering in Douz wetlands (south Tunisia): factors affecting wetland occupancy and species richness

“…This issue has repeatedly been addressed in the European wetlands (e.g. Carvalho et al 2013;Sebastia´n-Gonza´lez et al 2013;Sebastia´n-Gonza´lez and Green 2014), but less attention has been paid to wetlands situated at the southern border of the Mediterranean, such us North African wetlands. However, numerous North African wetlands are recognized as important bird areas and seem to play crucial roles as wintering and breeding sites for a great diversity of waterbirds (Bensaci et al 2013;Cherkaoui et al 2015;Hamza and Selmi 2015;Cherkaoui et al 2017).…”