Identificação taxonômica de crânios de vertebrados encontrados em egagrópilos de corujas suindaras (Tyto furcata) que habitam cavernas do oeste potiguar
Sther Gomes Santana
UFERSA
Vitor de Oliveira Lunardi
Diana Golçalves Lunardi
Palavras-chave: Biodiversidade, Cavernas, Conservação, Ecologia trófica, Strigiformes
Resumo
The caves of the Caatinga biome represent an important feeding, resting, and breeding site for the barn owl Tyto furcata (Temminck, 1827) (Aves: Strigiformes). Studying the diet of barn owls can contribute to a better understanding of the ecological relationships of ecosystems, since these birds of prey feed on a wide variety of small animals. This study aimed to taxonomically analyze the skulls of barn owl prey that inhabit the caves of Furna Feia National Park (5°4'14.88”S; 37°32'1.51”W). This study used skulls extracted from barn owl prey samples collected monthly between 2016 and 2024 from the soil inside caves in this Park and deposited in the Laboratory of Evolutionary and Molecular Ecology of the Federal Rural University of Semi-Arid. Obtaining barn owl prey skulls for morphotaxonomic identification followed these steps: (i) screening of barn owl prey samples to extract the skulls and mandibles of consumed prey; (ii) morphotaxonomic identification of prey skulls and mandibles at the family, genus, and/or species levels by consulting specialized bibliography and comparing them with skulls of specimens deposited in scientific collections; and (iii) quantification of these identified skulls and mandibles. A total of 768 barn owl prey samples were screened. The screening and analysis of these samples resulted in 737 whole skulls and 128 mandibles of vertebrates, which were taxonomically identified as: 68.2% order Chiroptera, 25.8% order Rodentia, 3.5% order Didelphimorphia and 2.5% class Aves. The taxonomic study of the skulls belonging to the order Chiroptera, found in the samples of barn owl egagropiles, enabled the identification of: Phyllostomus discolor (n=398 individuals), Desmodus rotundus (n=3), Myotis sp. (n=5) and Trachops sp. (n=1). The taxonomic study of the skulls and/or mandibles belonging to the order Rodentia enabled the identification of: Oligoryzomys sp. (n=79), Necromys lasiurus (n=86), Wiedomys sp. (n=40), Galea spixii (n=6), Rattus rattus (n=6), Thrichomys inermis (n=3) and Calomys sp. (n=3). The taxonomic study of the skulls and mandibles of the Didelphimorphia found enabled the identification of: Monodelphis domestica (n=25) and Gracilinanus agilis (n=3). And the taxonomic study of the skulls of the Birds enabled the identification of: Paroaria dominicana (n=5), Sporophila sp. (n=5), Tyrannidae (n=3), Thamnophilidae (n=2), Columbina sp. (n=2), Chrysomus ruficapillus (n=1), and Coryphospingus pileatus (n=1). These results indicate that the barn owls inhabiting Furna Feia National Park feed primarily on bats and rodents, and less frequently on marsupials and birds. The species most frequently preyed on by barn owls was the bat P. discolor (54% of prey). This study corroborated the premise that the barn owl is a bird of prey that occupies a high position in food chains in Caatinga caves, preying on a significant number of small vertebrates. Therefore, this species of owl plays an important role in naturally controlling the population size of other species, especially bats and rodents, contributing to the dynamic balance of the ecological community in which it is inserted.