Non-breeding habitat of hooded plovers (Thinornis rubricollis) – Filling critical information gaps to aid recovery

The temporal partitioning of species’ life history phases according to seasonal environmental variation is pervasive, yet most ecological studies have focused on breeding rather than non-breeding periods. This study explores the habitat selection of a non-breeding, resident shorebird on a southern hemisphere, high energy shore (the hooded plover Thinornis rubricollis). I identify, characterise and describe differences in beachscapes between distinct types of non-breeding habitat occupation: flocking sites, year-round territories, breeding season only territories, and sites without birds. Potentially important habitat variables (36) were measured within a Geographic Information System (GIS) and analysed using multivariate techniques and multinomial regression following variable selection (Least Absolute Shrinkage and Selection Operator [LASSO]). Plovers evidently make distinct choices about which habitats to use during the non-breeding season. These were mainly driven by beach aspect, amount of available swash area and distance to the nearest neighbouring breeding territory. Flocking sites were characterised by having south facing beaches and were closer to nearest neighbours than no bird sites, and year-round territories had closer nearest neighbours than no bird sites and typically were at southwest facing beaches. Breeding territories that were unoccupied during the non-breeding period had less available swash area, were further from nearest neighbours than year-round territories and typically were southwest facing. Sites without birds were further from nearest neighbours than occupied sites and typically were southeast facing. These differences are likely driven by social and ecological factors (i.e. foraging habitat and ecological productivity). This study has identified sites and habitat features that warrant priority protection from threats such as development, disturbance, marine pollution events and sea level rise.