Breeding habitat preference and nest success of Red-necked Phalaropes on Niglintgak Island, Northwest Territories

Abstract

Red-necked Phalaropes (Phalaropus lobatus (L., 1758)) breed throughout arctic and subarctic wetlands. These wetlands provide Red-necked Phalaropes dense graminoid habitat that shelters and conceals nests, and freshwater ponds where phalaropes engage in social interactions and feed on small aquatic invertebrates. We studied breeding habitat preference of Red-necked Phalaropes at multiple scales and determined which, if any, nest-site characteristics influenced hatching success. Red-necked Phalaropes avoided habitat at the meso (home range) scale containing large areas of mud and shrub cover, and selected sites with greater cover of graminoids, aquatic emergents, and open water than that available in the environment. At the micro (nest) scale, phalaropes chose sites dominated by graminoids and water. In 2005, concealed nests experienced higher daily nest survival than exposed nests. In 2006, 40% of nests were destroyed during a summer storm surge and we detected no differences in habitat characteristics between the remaining successful and unsuccessful nests. We suggest that annual differences in the adaptive value of nest-site selection depend on the relative abundance of mammalian and avian predators. A habitat model using data at the meso scale correctly identified phalarope habitat and has the potential to be used broadly across the western Arctic.Résumé : Les phalaropes à bec étroit (Phalaropus lobatus (L., 1758)) se reproduisent dans l'ensemble des terres humides des régions arctique et subarctique. Ces terres humides procurent aux phalaropes à bec étroit un habitat de graminoïdes denses qui protège et dissimule les nids et des étangs d'eau douce dans lesquels les phalaropes mènent leurs interactions sociales et se nourrissent de petits invertébrés aquatiques. Nous étudions les préférences d'habitat de reproduction des phalaropes à bec étroit à plusieurs échelles et déterminons, lorsqu'il y a lieu, les caractéristiques des sites de nidification qui influencent le succès de l'éclosion. À l'échelle moyenne (du domaine vital), les phalaropes à bec étroit évitent les habitats contenant de grandes étendues de boue et une couverture de buissons et choisissent des sites avec une couverture plus importante de graminoïdes, de plantes aquatiques émergentes et d'eau libre que les sites généralement disponibles dans le milieu. À l'échelle fine (du nid), les phalaropes sélectionnent les sites dominés par les graminoïdes et l'eau. En 2005, les nids cachés ont connu une survie journalière des petits au nid plus élevée que les nids exposés. En 2006, 40 % des nids ont été détruits durant une vague de tempêtes estivales et nous ne détectons aucune différence de caractéristiques entre les nids restants qu'ils aient eu ou non du succès. Nous croyons que les différences annuelles de valeur adaptative du choix du site de nidification dépendent de l'abondance des mammifères et des oiseaux prédateurs. Un modèle d'habitat basé sur des données à l'échelle moyenne identifie correctement l'habitat des phalaropes et peut potentiellement ...

Broad‐scale changes in tundra‐nesting bird abundance in response to hyperabundant geese

“…Both Red‐necked Phalarope ( Phalaropus lobatus ; Walpole et al. ) and Pectoral Sandpiper ( Calidris melanotos ; Cunningham et al. ) nest in lowland sedge‐dominated wet meadows and therefore may be prone to goose‐induced changes in vegetation height or lateral concealment in sedge‐dominated meadows.…”

“…, Walpole et al. ). Studies relating arthropod abundance to habitat use by birds at larger spatial scales have not yet been conducted; as such, this hypothesis warrants further investigation.…”

“…We found that bird abundance was positively correlated with the proportion of lowland habitat present in plots. Many shorebird and passerine species select wet sedge-dominated sites for nesting and, specifically, select nest sites with higher vegetative cover that conceals nests from predators (Smith et al 2007a, Walpole et al 2008, Cunningham et al 2016). In the Arctic Coastal Plain of Alaska, habitat suitability for eight species of shorebird was found to be positively related to the proportional cover of lowland habitat (Saalfeld et al 2013).…”

“…White-rumped Sandpiper (Calidris fuscicollis), which were influenced up to 13 km from colonies, can be generalist in their nest-site selection, nesting in habitats ranging from damp sedge-dominated areas to drier sedge and scrubdominated sites (Flemming et al 2019). Both Red-necked Phalarope (Phalaropus lobatus; Walpole et al 2008) and Pectoral Sandpiper (Calidris melanotos; Cunningham et al 2016) nest in lowland sedge-dominated wet meadows and therefore may be prone to goose-induced changes in vegetation height or lateral concealment in sedge-dominated meadows.…”

“…Invertebrate communities upon which shorebirds and passerines prey may have lower abundances (Milakovic and Jefferies 2003) and diversities (Milakovic et al 2001) in goose-influenced areas, forcing these birds to forage in areas further from colonies. At the local scale, tundranesting shorebirds do not appear to select nest sites based on prey availability (Smith et al 2007a, Walpole et al 2008. Studies relating arthropod abundance to habitat use by birds at larger spatial scales have not yet been conducted; as such, this hypothesis warrants further investigation.…”