The evolution and diversification of animal reproductive modes have been pivotal questions in behavioural ecology. Amphibians present the highest diversity of reproductive modes among vertebrates, involving various behavioural, physiological and morphological traits. One such feature is the amplexus, which is the clasp or embrace of males on females during reproduction and is found almost universally in anurans. Hypotheses about the origin of amplexus are limited and have not been tested thoroughly, nor have they taken into account evolutionary relationships in most comparative studies. However, these considerations are crucial to an understanding of the evolution of reproductive modes. Here, using an evolutionary framework, we reconstruct the ancestral state of amplexus in 685 anuran species. We investigate whether the type of amplexus has a strong phylogenetic signal and test whether sexual size dimorphism could have influenced amplexus type or male performance while clasping females. Overall, we found evidence of ≥34 evolutionary transitions in amplexus type across anurans. We found that amplexus type exhibits a high phylogenetic signal and that amplexus type does not evolve in association with sexual size dimorphism. We discuss the implications of our findings for the diversity of amplexus types across anurans.
Urbanization is currently one the most important causes of biodiversity loss. The
Colombian Andes is a well-known hotspot for biodiversity, however, it also
exhibit high levels of urbanization, making it a useful site to document how
species assemblages respond to habitat transformation. To do this, we compared
the structure and composition of bird assemblages between rural and urban
habitats in Armenia, a medium sized city located in the Central Andes of
Colombia. In addition, we examined the influence of urban characteristics on
bird species diversity within the city of Armenia. From September 2016 to
February 2017 we performed avian surveys in 76 cells (250 x 250 m each) embedded
within Armenia city limits; and in 23 cells (250 x 250 m each) in rural areas
around Armenia. We found that bird diversity was significantly lower in urban
habitats than in rural habitats, and differed in species composition by 29%. In
urban cells, with higher abiotic noise intensity and higher impervious surface
area, we found lower bird diversity than that in urban cells with higher guadual
(
Guadua angustifolia
patches), and forested surface areas.
We did not find segregation of urban cells according to the species composition,
although additional bird surveys inside urban forests remnant are needed to be
more conclusive about this aspect. Altogether, our results highlight the
importance of green areas embedded within cities to conserve bird diversity
through reducing the ecological impact of urbanization on avian
biodiversity.
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