Testis and brown adipose tissue xenografts from yellowish myotis (Myotis levis)

Yellowish myotis present a seasonal reproduction, influenced by rainfall distribution, in which the testis mass, germ cell composition, and brown adipose tissue (B.A.T.) mass change along the reproductive stages. In the present study, tissue xenografts were performed in immunodeficient mice to investigate spermatogenesis development in a stable endocrine milieu and the possible androgenic role of B.A.T. In this study, 41 adult male bats were captured in the Santuário do Caraça, Minas Gerais, Brazil. The gonads and B.A.T. were collected, weighed, and grafted under the mice's back skin. Mice biometric and hormonal data were evaluated after grafting, and the testis grafts and mice gonads were fixed for histological and immunohistochemical analyses. As a result, testis grafts from adult bats presented a continuous germ cell development in all reproductive stages, showing round spermatids in all testis tissues. Furthermore, testis fragments in the Rest stage presented elongating spermatids as the most advanced germ cell type in the seminiferous epithelium after 7 months of grafting. These data indicated that yellowish myotis spermatogenesis could be continued (presenting a constant spermatogonial differentiation) in a stable endocrine milieu, as found in mice. In addition, the best spermatogenic development was achieved when testis fragments were transplanted at their lowest activity (Rest stage). Regarding the B.A.T. grafts, the adipose tissue consumption by mice increased seminal vesicle mass and testosterone serum levels. This data proves that B.A.T. is related to testosterone synthesis, which may be critical in stimulating the differentiation of spermatogonia in yellowish myotis

Core area and centre of activity of maned wolves, Chrysocyon brachyurus (Illiger) (Mammalia, Canidae), submitted to supplemental feeding

Based on the finding of remains (tracks, scats, and hairs), an analysis was made of the core area and centre of activity of maned wolves, Chrysocyon brachyurus (Illiger, 1815), living in a private natural reserve in which ecotourism activities are developed and these animals are daily fed bovine meat. A total of 465 samples of remains were recorded. Using the fixed kernel method, the area encompassing all samples recorded was estimated at 25.7 km², yet 50% of all samples were found in an area of only 1.5 km², representing 5.8% of the total area covered. For estimating the core area of the animals, the frequency of occurrence of the samples was determined by superimposing a 50 x 50 m cell grid over a map of the area encompassing all recorded occurrences. Based on the cells containing more than six occurrences, the animals' core area was 0.99 km², which included the place where the animals are fed. The centre of activity was located only 0.50 km from this place. The high negative correlation (r = -0.93, p < 0.05) between the densities of the recorded occurrences and the distances from these to the sanctuary indicates that the core area and centre of activity are conditioned by artificial feeding.<br>A área central e o centro de atividade de lobos-guará, Chrysocyon brachyurus (Illiger, 1815), foram determinados através de seus vestígios (fezes, pegadas e pêlos) em uma reserva natural particular, onde esses animais estão sujeitos à alimentação artificial e sofrem influência de atividades turísticas. No total, foram registrados 465 vestígios, sendo que 65,8% corresponderam à estação seca. Através do método Kernel fixo, a área compreendida por todos os vestígios foi de 25,7 km², sendo que 50% encontravam-se em uma área de apenas 1,5 km², o que representou 5,8% do total da área amostrada. A área central de atividade dos animais foi obtida pelo cálculo da freqüência dos registros dos vestígios através da sobreposição de uma quadrícula subdividida em células de 50 x 50 m sobre a área que abrangia todos os registros. Considerando as células com mais de seis registros a área central de atividade atribuída aos animais foi de 0,99 km², o que abrangeu a sede da reserva onde os animais são alimentados. O centro de atividade localizou-se somente a 0,50 km da sede. A alta correlação negativa (r = -0,93, p < 0,05) obtida entre as densidades dos registros e suas distâncias até a sede da reserva indicaram que o centro de atividade e o tamanho da área de maior intensidade de uso são condicionados pela alimentação artificial

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data