Hunting practices in southwestern Amazonia: a comparative study of techniques, modalities, and baits among urban and rural hunters.

BACKGROUND: Hunting is a vital means of obtaining animal in various human populations. Hunters rely on their knowledge of species ecology and behavior to develop and employ hunting techniques and increase their chances of success. The comparison of the hunting practices of different human societies can shed light on the sustainability of hunting and the impact it has on species' populations. In this study, we examine and compare the techniques, modalities, and baits used by urban and rural hunters in Rondônia, a state in southwestern Amazonia, Brazil. We expected that rural hunters would use these elements and have greater knowledge when compared to urban hunters. We also expect that the use of specific hunting techniques and modalities will have greater selectivity and specificity of capture for rural hunters and that this knowledge will differ between groups. METHODS: We conducted 106 semi-structured interviews with rural and urban hunters from October 2018 to February 2020. We analyzed the data using PERMANOVA and Network analyses to compare and contrast the hunting practices of each group. RESULTS: We recorded four main hunting techniques divided into ten modalities with three techniques and seven modalities being the preferred choices among hunters. Waiting for at a Fruit Tree was cited as the primary technique employed by hunters living in urban and rural areas indicated. While the techniques and modalities were similar among hunters, the composition of species targeted and baits used differed between groups. Our network approach showed that modularity in urban areas was numerically lower than in rural areas. All species had one to more techniques associated with their capture. CONCLUSIONS: Hunters living in urban and rural environments showed high similarity in their practices, probably due to sharing similar environments to hunt containing similar species, as well as targeting preferably the same species.

Influence of body size, topography, food availability and tree-fall gaps on space use by yellow-footed tortoises (Chelonoidis denticulatus) in Central Amazonia.

Habitat selection and extension of the area used by a given species may vary during different phases of its life and are often determined by the distribution and availability of resources throughout the landscape, such as food, breeding sites, and shelters. In this study, we assessed the influence of body size on the areas used by 21 individuals of the yellow-footed tortoises (Chelonoidis denticulatus) from January to June 2017 in a dense rain forest area in Central Amazonia. We also investigated whether individuals selected different ranges of terrain slope, elevation, areas with high food availability, or areas with treefall gaps that could be used for shelter or thermoregulation. We monitored tortoise movements using thread-bobbins, and sampled terrain characteristics, availability of potential food resources and forest gaps along the routes used by the tortoises. We also measured the same variables in plots distributed systematically throughout the study area to evaluate resource availability. Tortoises used an average area of 1.56 ha (SD = 1.51, min = 0.03, max = 6.44). The size of the area used was positively associated with the individual body size, but did not vary between sexes. Small individuals selected higher and flatter areas where the availability of fallen flowers was higher, whereas the area used by larger individuals did not differ from the natural availability of topographic traits and food in the region. Although tortoises did not select areas according to availability of tree-fall gaps, most larger tortoises were found sheltered under fallen trees (85%). Conversely, small individuals were mainly found hidden under litter (66%). Body size determined the patterns of landscape use by tortoises; larger individuals were mainly generalists, but small individuals occupied high and flat areas. The yellow-footed tortoise is endangered by hunting, illegal collection for the pet trade, habitat destruction and effects of climate change. Size-related differences in habitat selection should be taken into account in species-distribution models for the identification of suitable areas for reintroduction and the development of management plans in protected areas.

Venom in Furs: Facial Masks as Aposematic Signals in a Venomous Mammal.

The function of colouration in animals includes concealment, communication and signaling, such as the use of aposematism as a warning signal. Aposematism is unusual in mammals, and exceptions help us to understand its ecology and evolution. The Javan slow loris is a highly territorial venomous mammal that has a distinctive facial mask and monochromatic vision. To help understand if they use aposematism to advertise their venom to conspecifics or predators with different visual systems, we studied a population in Java, Indonesia. Using ImageJ, we selected colours from the facial masks of 58 individuals, converted RBG colours into monochromatic, dichromatic and trichromatic modes, and created a contrast index. During 290 captures, we recorded venom secretion and aggressiveness. Using Non-metric Multidimensional Scaling and generalised additive models for location, scale and shape, we found that young slow lorises differ significantly from adults, being both more contrasting and more aggressive, with aggressive animals showing fewer wounds. We suggest aposematic facial masks serve multiple purposes in slow lorises based on age. Change in colouration through development may play a role in intraspecific competition, and advertise toxicity or aggressiveness to competitors and/or predators in juveniles. Aposematic signals combined with intraspecific competition may provide clues to new venomous taxa among mammals.

Comparative Genomic In Situ Hybridization and the Possible Role of Retroelements in the Karyotypic Evolution of Three Akodontini Species.

South American Akodontini rodents are characterized by a large number of chromosome rearrangements. Among them, the genus Akodon has been extensively analyzed with classical and molecular cytogenetics, which allowed the identification of a large number of intra- and interspecific chromosomal variation due to Robertsonian rearrangements, pericentric inversions, and heterochromatin additions/deletions. In order to shed some light on the cause of these rearrangements, we comparatively analyzed the karyotypes of three Akodontini species, Akodon cursor (2n = 14, FN = 19), A. montensis (2n = 24, FN = 42), and Necromys lasiurus (2n = 34, FN = 34), after GTG- and CBG-banding. The karyotypes differed by Robertsonian rearrangements, pericentric inversions, centromere repositioning, and heterochromatin variation. Genome comparisons were performed through interspecific fluorescent in situ hybridization (FISH) with total genomic DNAs of each species as probes (GISH). Our results revealed considerable conservation of the euchromatic portions among the three karyotypes suggesting that they mostly differ in their heterochromatic regions. FISH was also performed to assess the distribution of telomeric sequences, long and short interspersed repetitive elements (LINE-1 and B1 SINE) and of the endogenous retrovirus mysTR in the genomes of the three species. The results led us to infer that transposable elements have played an important role in the enormous chromosome variation found in Akodontini.