Much of what remains of the Earth's tropical forests is embedded within agricultural landscapes, where forest is reduced and fragmented. As native forest ungulates are critical to maintaining forest function, it is imperative to understand how this functional group responds to declines in forest cover and connectivity resulting from agricultural expansion. We addressed this issue by evaluating selection of forest cover and forest connectivity by a key native ungulate of Neotropical forests, the white‐lipped peccary (Tayassu pecari Link 1795, Tayassuidae, Cetartiodactyla), in agricultural landscapes of Brazil. We evaluated selection using compositional analysis at two hierarchical levels, landscape, and home range. From 2013 to 2019, we GPS‐tracked eight white‐lipped peccary herds in Southwest Brazil, resulting in a total of 14,460 GPS locations. We found that herds can live in landscapes with a wide range of forest cover (35%–81% of home ranges covered by native forest), with significant, but not strong, selection at the landscape level (p = .045). Nevertheless, herds strongly select for forest cover within their home ranges (81%–97% of locations within native forest; highly significant selection at the home‐range level: p = .008). As for connectivity, herds significantly select the largest, most connected forest fragments at the landscape level (p = .04), but not at the home‐range level (p = .07). Our results support that Neotropical forests within agricultural landscapes need to be well connected in order to preserve this key native ungulate and maintain long‐term forest function.
Abstract in Portuguese is available with online material.
Here we describe two new notoungulate taxa from early Oligocene deposits of the Abanico Formation in the eastern Tinguiririca valley of the Andes of central Chile, including a notostylopid (gen. et sp. nov.) and three basal toxodontians, cf. Homalodotheriidae, one of which is formally named a new species. The valley's eponymous fossil mammal fauna became the basis for recognizing a new South American Land Mammal "Age" intervening between the Mustersan and Deseadan of the classical SALMA sequence, the Tinguirirican. As a temporal intermediate between the bracketing SALMAs (Deseadan and Mustersan), the Tinguirirican is characterized by a unique cooccurrence of taxa otherwise known either from demonstrably younger or more ancient deposits, as well as some taxa with temporal ranges restricted to this SALMA. In this regard, two of the notoungulates described here make their last known stratigraphic appearances in the Tinguiririca Fauna, Chilestylops davidsoni (gen. et sp. nov.), the youngest notostylopid known, and Periphragnis vicentei (sp. nov.), an early diverging toxodontian, the youngest representative of the genus. A second species of Periphragnis from the Tinguiririca valley is provisionally described as Periphragnis, sp. nov., but is not formally named due to its currently poor representation. A specimen referred to Trigonolophodon sp. cf. T. elegans also is described. This taxon is noteworthy for also being reported from Santiago Roth's long perplexing fauna from Cañadón Blanco, now considered Tinguirirican in age. A phylogenetic analysis of notostylopids identifies Chilestylops as closely related to Boreastylops lumbrerensis from northern Argentina.
How species persist in fragmented habitats is essential to understanding species resilience in response to increasing anthropogenic pressures. It has been suggested that expansion in dietary niche allows populations to persist in human-modified landscapes, yet this hypothesis has been poorly tested in highly diverse ecosystems such as tropical forests where frugivory is ubiquitous. Here, we measured dietary niche expansion of a large forest-dwelling mammal, the white-lipped peccary (Tayassu pecari), in the Atlantic Forest, Brazil, by comparing its diet using stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes. We collected hair of white-lipped peccaries in three continuous and three fragmented forests and compared δ 13 C and δ 15 N values, resource use and isotopic niches among populations and between forest types. We also tested the relationship between isotopic values of the populations and the forest cover percentage. White-lipped peccaries fed mainly on forest sources (C 3 resources), especially in continuous forests, but 28% of the individuals in fragmented sites also incorporated C 4 resources to some extent. In fragmented forests, the populations had isotopic niches from 3-to 3.6-fold the size of those in continuous forests. This niche expansion was due to the consumption of food items with higher δ 15 N values and C 4 crops. Differences among populations were larger among fragmented forests, suggesting variable site-specific strategies to cope with habitat loss. The mean isotopic values of white-lipped peccary populations were negatively correlated with the loss of forest cover. Some small forest fragments might still retain relatively high habitat quality, and white-lipped peccaries might be able to capitalize on such variety of resources, shifting their diets from those observed in continuous forests. We suggest that high dietary flexibility and dietary expansion toward consumption of non-forest resources might facilitate the persistence of large frugivores in fragmented habitats.
The impacts of COVID-19 on early career tropical researchers are diverse and complex, including lack of funding opportunities, limitations to conducting fieldwork in remote places, reduced collaborations and networking, and difficulties when living and collecting data abroad. Here, we examine the current and future impacts of the COVID-19 pandemic on this population through a survey of 213 students and early career tropical researchers from around the world. As of September 2020, 55% of participants had already experienced financial repercussions due to the pandemic. Future worries were diverse and included equal concern regarding advancement (collaborations and networking), job uncertainty, fieldwork, and funding, as well as mental health concerns. Successful strategies to support student and early career researchers with regards to the pandemic should include mentoring from those in more advanced career positions on how to reframe research that is no longer feasible to complete as originally intended. Additionally, those responsible for hiring decisions should not penalize applicants for gaps in productivity during this time.
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