RESUMEN
Although considered an evolutionary force responsible for shaping ecosystems and biodiversity, fires' natural cycle is being altered by human activities, increasing the odds of destructive megafire events. Here, we show that forest type modulates the responses of terrestrial mammals, from species to assemblage level, to a catastrophic megafire in the Brazilian Pantanal. We unraveled that mammalian richness was higher 1 year after fire passage compared to a pre-fire condition, which can be attributed to habitat modification caused by wildfires, attracting herbivores and open-area tolerant species. We observed changes in assemblage composition between burned/unburned sites, but no difference in mammalian richness or relative abundance. However, by partitioning the effects of burned area proportion per forest type (monospecific vs. polyspecific), we detected differential responses of mammals at several levels of organization, with pronounced declines in species richness and relative abundance in monospecific forests. Eighty-six percent of the species presented moderate to strong negative effects on their relative abundance, with an overall strong negative effect for the entire assemblage. Wildfires are predicted to be more frequent with climate and land use change, and if events analogous to Pantanal-2020 become recurrent, they might trigger regional beta diversity change, benefitting open-area tolerant species.
Asunto(s)
Biodiversidad , Bosques , Mamíferos , Incendios Forestales , Animales , Brasil , Ecosistema , IncendiosRESUMEN
The goal of this study is to provide a taphonomic analysis of bone fragments found in harpy eagle nests in the Brazilian Amazonia, utilizing the largest sample of prey remains collected to date. Harpy eagle kill samples were collected from nine nests, between June 2016 and December 2020 in Mato Grosso, Brazil. We identified the specimens, calculated the number of identified specimens (NISP) and minimum number of individuals (MNI). These metrics were used to estimate bone survivability and fragmentation. A total of 1661 specimens (NISP) were collected, representing a minimum number of 234 individuals (MNI). We identified at least nine species of primates, which represent 63.8% of the individuals in the kill sample. Harpy eagles preyed mostly on the medium-sized capuchin and bearded saki monkeys (28.2% of the MNI), and two-toed sloths (17.7% of the MNI). The large woolly monkeys also represented a significant portion of the sample (11.5% of the MNI). Three distinct patterns of bone survivability were found, one characterizing two-toed sloths, another characterizing medium-sized monkeys, and a third typical of woolly monkeys. We conclude that harpy eagle predation leaves an identifiable signature on the prey with a bone survivability pattern specific to each taxon. The intertaxon variations observed in the taphonomic signatures of harpy eagle kills should be taken into account when evaluating the potential influence of these raptors as accumulators of bone material in both paleontological and neontological assemblages.
Asunto(s)
Atelinae , Águilas , Perezosos , Animales , Paleontología , Conducta Predatoria , Haplorrinos , CebusRESUMEN
Two Portuguese institutions, the Museu Maynense da Academia das Cincias de Lisboa (ACL), and the Museu da Cincia da Universidade de Coimbra (MCUC), house a collection of 85 dried fish specimens prepared in what can be called a fish-herbaria following a process similar to that developed by the Dutch naturalist Johan Frederic Gronovius (16901762). These specimens date back to the late eighteenth century and represent Brazilian taxa. Previous authors assumed that they were part of the collections amassed by the Brazilian-Portuguese naturalist Alexandre Rodrigues Ferreira (17561815) during his philosophical voyage to the Amazon. Here we present a review of these specimens, suggesting that they belonged to Friar Jos Mariano da Conceio Veloso (17421811) and describe the history of dispersal of these collections up the present day. A total of 58 species in 50 genera, 32 families and 19 orders are represented in the collection. Only 8.6% of these specimens represent freshwater species, while 91.4% are marine or brackish water species. The present known distribution of these taxa is focused on southwestern Brazil, which agrees with the area where Veloso collected natural history specimens. A good percentage of the species were undescribed at the time Veloso collected them, and had they been published by him, would have had priority over species described decades later by famous eighteenth and nineteenth century ichthyologists. We also present a brief discussion on the challenges and opportunities of studying historical natural history specimens, with special focus on those amassed during the late eighteenth and early nineteenth century by Brazilian-Portuguese naturalists.
Asunto(s)
Historia Natural , Humanos , Masculino , Animales , BrasilRESUMEN
Ticks collected in the last two decades from free-living and captive wild animals from 28 municipalities of the Brazilian state of Mato Grosso were identified and tested using molecular methods for the presence of rickettsial agents. A total of 4467 ticks (229 larvae, 1676 nymphs, 1565 males, 997 females) representing 27 ixodid species were collected from 235 species of amphibians, reptiles, birds, and mammals from three different ecoregions (Pantanal, Cerrado, and Amazonia). The species Amblyomma parkeri, Amblyomma romitii, Amblyomma varium and Ixodes luciae are reported for the first time in the state of Mato Grosso. Amongst 538 ticks tested by molecular methods for rickettsial infection, we detected 'Candidatus Rickettsia amblyommii' infecting Amblyomma cajennense sensu stricto and Amblyomma coelebs, Rickettsia sp. strain Atlantic rainforest infecting Amblyomma ovale, Rickettsia sp. strain NOD infecting Amblyomma nodosum, and 'Candidatus Rickettsia andeanae' infecting Amblyomma sculptum. Our results represent an impressive expansion of knowledge on tick fauna and rickettsiae and are essential for understanding the ecology of ticks and tick-borne diseases in the Neotropical region, particularly in midwestern Brazil.