Many species, including shorebirds, feed during both day and night, yet little is known about how this affects behavior and habitat preferences. European Golden-Plovers (Pluvialis apricaria) and Northern Lapwings (Vanellus vanellus) feeding on arable farmland were more widely dispersed at night: nocturnal flocks were smaller, typically monospecific, and occurred in many more fields than diurnal mixed-species flocks. Diurnal numbers of European Golden-Plovers could not be used to predict nocturnal numbers; this indicates that ranging behavior differed between day and night. For both species, nocturnal feeding was recorded on almost all nights, irrespective of moon phase. Northern Lapwing nocturnal feeding activity decreased with increasing cloud cover and decreasing ground temperature, but no clear relationships were detected between European Golden-Plovers’ nocturnal feeding activity and environmental variables. Habitat selection differed between day and night, and between species at night. Diurnal studies of habitat choice and site selection may misrepresent the full requirements of such species.

Los Estudios Diurnos no Predicen la Preferencia Nocturna de Hábitat ni la Selección Nocturna de Sitio en Pluvialis apricaria y Vanellus vanellus