Nocturnal feeding of the southern lapwing vanellus chilensis (charadriidae) in anthropically illuminated environments

Abstract

The Southern Lapwing Vanellus chilensis is a species with a wide distribution range, from northern South America (Venezuela) to the southernmost part of the continent, excluding the Amazon basin and the western slope of the Andes from Ecuador to northern Chile. Its diet is diverse, relying heavily on earthworms and other invertebrates. It can feed both day and night, and as it belongs to shorebird families that need light to forage, artificial nocturnal lighting may offer opportunities to increase daily intake of trophic resources. In this study, we present observations made during a week in July 2023 in a riverside area located in Yasuní National Park, where a permanent group of V. chilensis is present. In addition to daytime foraging near the Tiputini River, we noted that at night they took advantage of artificial light provided by a volleyball court at the scientific station of the Pontifical Catholic University of Ecuador. During approximately 10 hours of nocturnal observation throughout the week, we identified various medium- and large-sized moths that fell to the ground due to the heat emitted by electric bulbs, which were then consumed by the present V. chilensis. Similar observations have been recorded in other regions, such as Rio de Janeiro, Brazil, suggesting that these are not isolated observations but rather adaptive strategies to increase resource intake when predator numbers are low and resource access is easy.