Browsing by Autor "Ana Gabriela de Luna"

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HIGH FREQUENCY OF BATS IN THE DIET OF THE BARN OWL TYTO ALBA IN A LOWLAND DRY FOREST IN TOLIMA, COLOMBIA
(2024) Laura María Baldrich; Ronald Castellanos Florez; Ana Gabriela de Luna; Andrés Link
The cosmopolitan distribution of the Barn Owl Tyto alba and its relatively well documented diet through the study of pellets have provided evidence of the broad diversity of prey it relies on. In most studies, both in tropical and temperate regions, rodents are its main prey, with other small mammals and vertebrates, and insects complementing its diet. Although bats have been recorded in the diet of T. alba at many localities, they seldom represent an important part of its diet. This study describes the diet of a small colony of T. alba from a mosaic of agricultural fields, pastures for cattle ranching and tropical dry forests in Tolima, central Colombia. Overall, we collected 516 pellets between 2016 and 2017 in a non-systematic manner, and recovered 335 skulls of rodents (67%), bats (29%), birds (3%) and shrews (1%), as well as invertebrate prey. The large proportion of bats in the diet of T. alba in this study is only matched by a few other studies, and further documents the wide range of prey included in the diet of this nocturnal raptor. This is one of the first studies on the diet of T. alba in tropical dry forests in Colombia and complements the existing data on its diet in the American tropics and worldwide.
Increased folivory in brown spider monkeys Ateles hybridus living in a fragmented forest in Colombia
(Inter-Research, 2016) Ana Gabriela de Luna; Alissa R. Link; Ana Lucía Sánchez Montes; F. Alfonso; Luz Enith Guerrero Mendieta; Anthony Di Fiore
Brown spider monkeys Ateles hybridus are one of the most threatened primates in the Neotropics. Most of the remaining populations of this species already live either in forest fragments or in areas that face imminent anthropogenic disturbance. Understanding how these animals cope with the challenge of living in small fragments, while at the same time being a large, frugivorous mammal is crucial to design effective conservation and management strategies. We studied the diet of wild A. hybridus and measured forest productivity in a small (~65 ha) fragment in the Magdalena Region of northern Colombia over a period of 26 mo. Spider monkeys at this site spent far less time feeding on fruits than reported in previous studies of Ateles spp. living in less fragmented sites. Moreover, we registered a high consumption of leaves in every month (on average 37% of their feeding time) as well as the consistent inclusion of decayed wood in the diet. Ficus trees can be considered staple feeding items, as they were present in high proportions in the monkeys' diet throughout the study. Although wild populations of spider monkeys can have flexible diets that include large proportions of leaves over long periods of time, they may also be exposed to a suboptimal diet which may have negative implications for their reproduction and well-being in the long run, further compromising the viability of wild populations living in disturbed habitats.