Coexistence of predators in time: Effects of season and prey availability on species activity within a Mediterranean carnivore guild

The degree of coexistence among predators can determine the structure of ecological communities. Niche partitioning is a common strategy applied by species to enhance their coexistence. Diet, habitat, or time use can be responsible for segregation among carnivore species, the latter factor being the least studied in Mediterranean ecosystems. Terrestrial medium‐sized carnivores (i.e., mesocarnivores) carry out important functions in ecosystems, and identifying their interactions is essential for their conservation. In this study, we explore the activity of a terrestrial mesocarnivore guild in order to determine seasonal differences in daily activity patterns of competitors and prey. We also investigate how the abundance of a common mesocarnivore prey in the region, small mammals, influences the activity of predators. During a year, camera trap devices (n = 18) were installed in Montseny Natural Park (Catalan Pre‐Coastal Range, North‐East Iberian Peninsula), a region that hosts five mesocarnivore species. Camera trapping detections were used to estimate their daily activity patterns and corresponding overlaps. We also surveyed small mammal plots (n = 5) in order to calculate prey abundance and test its effect on the relative activity of each carnivore species. Despite all target mesocarnivores are mainly nocturnal, the activity overlap among them varies according to species particularities and season. Red fox (Vulpes vulpes) appears as a generalist species in terms of time use, whereas stone marten (Martes foina) and genet (Genetta genetta) show the most similar activity patterns and both of them seem to be positively influenced by small mammal abundance. Overall, the diversity found in the way mesocarnivore species use time could facilitate their coexistence. Despite activity pattern similarities among carnivore species should not be directly translated to negative interactions, they can have a strong influence in habitat and resource‐limited ecosystems. Therefore, activity overlaps should be taken into account when discussing wildlife management actions

DNA metabarcoding Passerine bird feces at tree-line uncovers little intra- and inter-species dietary overlap

High-elevation insectivorous birds are currently confronted with the reality of a changing climate, land use shifts, and the decline of many prey groups. The diet dynamics among many imperiled animals in this group are still unresolved. Examining the diets of tree-line Passerine birds to the species level of the prey allows for stronger population predictions. This study uses DNA metabarcoding to identify prey arthropods from adult Passerine bird feces at and slightly below tree-line in a Pyrenean forest. Our objective was to quantify the intra-and inter-species richness and overlap of Passerine bird diet over time and space. The results showed that adult Passerine diets have high inter- and intra-species dietary variability and low inter- and intra-species dietary overlap. The lack of association between dietary richness and open space, season, and elevation and lack of differences between dietary overlap and open space and elevation suggest high-elevation Passerine birds have very high dietary flexibility. The results also showed that aphids known to be pests to conifers, and other conifer pests, were prevalent in the birds' diets. The Passerine diets and high rate of rare dietary items are mainly in line with other recent DNA metabarcoding studies. Implications for the long-term projections relative to tree-line Passerine populations are discussed

Do pre- and post-copulatory sexually selected traits covary in large herbivores?

BACKGROUND: In most species, males compete to gain both matings (via pre-copulatory competition) and fertilizations (via post-copulatory competition) to maximize their reproductive success. However, the quantity of resources devoted to sexual traits is finite, and so males are predicted to balance their investment between pre- and post-copulatory expenditure depending on the expected pay-offs that should vary according to mating tactics. In Artiodactyla species, males can invest in weapons such as horns or antlers to increase their mating gains or in testes mass/sperm dimensions to increase their fertilization efficiency. Moreover, it has been suggested that in these species, males with territory defence mating tactic might preferentially increase their investment in post-copulatory traits to increase their fertilization efficiency whereas males with female defence mating tactic might increase their investment in pre-copulatory sexually selected traits to prevent other males from copulating with females. In this study, we thus test the prediction that male’s weapon length (pre-copulatory trait) covaries negatively with relative testes size and/or sperm dimensions (post-copulatory traits) across Artiodactyla using a phylogenetically controlled framework. RESULTS: Surprisingly no association between weapon length and testes mass is found but a negative association between weapon length and sperm length is evidenced. In addition, neither pre- nor post-copulatory traits were found to be affected by male mating tactics. CONCLUSIONS: We propose several hypotheses that could explain why male ungulates may not balance their reproductive investment between pre- and post-copulatory traits

Multiple geographic origins and high genetic differentiation of the Alpine marmots reintroduced in the Pyrenees

International audienc

DNA metabarcoding Passerine bird feces at tree-line uncovers little intra- and inter-species dietary overlap

High-elevation insectivorous birds are currently confronted with the reality of a changing climate, land use shifts, and the decline of many prey groups. The diet dynamics among many imperiled animals in this group are still unresolved. Exam- ining the diets of tree-line Passerine birds to the species level of the prey allows for stronger population predictions. This study uses DNA metabarcoding to identify prey arthropods from adult Passerine bird feces at and slightly below tree-line in a Pyrenean forest. Our objective was to quantify the intra-and inter-species richness and overlap of Passerine bird diet over time and space. The results showed that adult Passerine diets have high inter- and intra-species dietary variability and low inter- and intra-species dietary overlap. The lack of association between dietary richness and open space, season, and eleva- tion and lack of differences between dietary overlap and open space and elevation suggest high-elevation Passerine birds have very high dietary flexibility. The results also showed that aphids known to be pests to conifers, and other conifer pests, were prevalent in the birds’ diets. The Passerine diets and high rate of rare dietary items are mainly in line with other recent DNA metabarcoding studies. Implications for the long-term projections relative to tree-line Passerine populations are discussed

DNA metabarcoding Passerine bird feces at tree-line uncovers little intra- and inter-species dietary overlap

High-elevation insectivorous birds are currently confronted with the reality of a changing climate, land use shifts, and the decline of many prey groups. The diet dynamics among many imperiled animals in this group are still unresolved. Exam- ining the diets of tree-line Passerine birds to the species level of the prey allows for stronger population predictions. This study uses DNA metabarcoding to identify prey arthropods from adult Passerine bird feces at and slightly below tree-line in a Pyrenean forest. Our objective was to quantify the intra-and inter-species richness and overlap of Passerine bird diet over time and space. The results showed that adult Passerine diets have high inter- and intra-species dietary variability and low inter- and intra-species dietary overlap. The lack of association between dietary richness and open space, season, and eleva- tion and lack of differences between dietary overlap and open space and elevation suggest high-elevation Passerine birds have very high dietary flexibility. The results also showed that aphids known to be pests to conifers, and other conifer pests, were prevalent in the birds’ diets. The Passerine diets and high rate of rare dietary items are mainly in line with other recent DNA metabarcoding studies. Implications for the long-term projections relative to tree-line Passerine populations are discussed

Next-generation sequencing propels environmental genomics to the front line of research

International audienc