The weights and fat of Blackcaps during autumnal and spring passages through Southern Spain have been studied. The birds passing during autumn have mean weight of 19.2 g, superior to the birds which winter in these areas (Herrera & Jordano 1981); 82.5% winter in the Mediterranean Basin (probably in Northern Africa) and 17.5% are long-distance migrants. The latter birds have a weight greater than 21 g, and they can be considered as long-distance migrants (Langslow 1976). The birds passing during the spring, with a mean weight of 22.3 g, are distributed into two groups with different weights and with different fat accumulations which must represent different migratory strategies related to their nesting areas. This supposition is supported by various authors that relate different weight and fat deposition in populations of one species with distinct areas for breeding or wintering (Berthold 1975, Ash 1969).
The knowledge of the diet of aquatic insects is important to assess the use of resources and overlap of trophic niche between species, as well as to understand their role in the food web of the freshwater ecosystems they inhabit. This is particularly necessary in tropical areas where information on this topic is scarce. The aim of the present work is to describe the feeding habits of the species Anacroneuria marta Zúñiga and Stark, 2002 and Anacroneuria caraca Stark, 1995 in the middle section of the Gaira River (Sierra Nevada de Santa Marta, Colombia). We performed three samplings during the rainy and dry seasons in the two main different microhabitats of the reach (leaf packs and gravel) in 2014. The diet of a total of 87 and 90 individuals of A. caraca and A. marta, respectively, was studied. With this information, niche breadth for each species and niche overlap between them in terms of trophic resources were calculated. The main trophic resource for both species in the dry and rainy season was the animal matter. In the dry season, FPOM was also important in the diet of A. caraca, and A. marta ingested a great quantity of CPOM in the rainy season. Larvae of Trichoptera, were the most ingested prey in both species, followed by Chironomidae, Coleoptera Hydrophilidae, and Ephemeroptera. No differences in diet between both species were detected, so this could favor the niche overlap in terms of trophic resources and could lead to competition between them. The possible ecological scenarios are discussed.
In this paper we present the results of a study of different populations of the genus Tyrrhenoleuctra, which includes morphologically cryptic species, in the Iberian Peninsula. A total of six populations were analysed from a molecular point of view and a behavioural study was conducted on three of them. Two phylogenetic trees, maximum likelihood (ML) and neighbour joining (NJ), were constructed using both new COI sequences and COI sequences already available in GenBank. Furthermore, intra- and interspecific p-distances were calculated within and between sequences of the different populations. As regards behavioural analyses, the male call of individuals from three of the studied populations was recorded, analysed and described. Both phylogenetic approaches used, ML and NJ, were congruent in discriminating five well-defined clusters, representing the four known Iberian Tyrrhenoleuctra species and a previously unknown taxon. The sequences from the six studied populations produced in this study fell within two clades: T. lusohispanica (four populations) and the new taxon (two populations). These results were supported also by the behavioral study, in which the drumming calls of individuals belonging to the two clades differed in some important parameters such as the number of sequences, intersequence interval and interbeat interval. The obtained results expand the previously known distribution of T. lusohispanica and show the existence of a new species (Tyrrhenoleuctra hynesi sp. n.) within this genus from a more restricted area, that will be described in this paper.
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