Evidence of Latitudinal Migration in Tri-colored Bats, Perimyotis subflavus

Background: Annual movements of tri-colored bats (Perimyotis subflavus) are poorly understood. While this species has been considered a regional migrant, some evidence suggests that it may undertake annual latitudinal migrations, similar to other long distance North American migratory bat species. Methodology/Principal Findings: We investigated migration in P. subflavus by conducting stable hydrogen isotope analyses of 184 museum specimen fur samples and comparing these results (dDfur) to published interpolated dD values of collection site growing season precipitation (dDprecip). Results suggest that the male molt period occurred between June 23 and October 16 and 33 % of males collected during the presumed non-molt period were south of their location of fur growth. For the same time period, 16 % of females were south of their location of fur growth and in general, had not travelled as far as migratory males. There were strong correlations between dDfur from the presumed molt period and both growing season dD precip (males – r 2 = 0.86; p,0.01; females – r 2 = 0.75; p,0.01), and latitude of collection (males – r 2 = 0.85; p,0.01; females – r 2 = 0.73; p,0.01). Most migrants were collected at the northern (.40uN; males and females) and southern (,35uN; males only) extents of the species ’ range. Conclusions/Significance: These results indicate a different pattern of migration for this species than previously documented, suggesting that some P. subflavus engage in annual latitudinal migrations and that migratory tendency varie

Role of IL-1β in experimental cystic fibrosis upon P. aeruginosa Infection

Cystic fibrosis is associated with increased inflammatory responses to pathogen challenge. Here we revisited the role of IL-1β in lung pathology using the experimental F508del-CFTR murine model on C57BL/6 genetic background (Cftrtm1eur or d/d), on double deficient for d/d and type 1 interleukin-1 receptor (d/d X IL-1R1-/-), and antibody neutralization. At steady state, young adult d/d mice did not show any signs of spontaneous lung inflammation. However, IL-1R1 deficiency conferred partial protection to repeated P. aeruginosa endotoxins/LPS lung instillation in d/d mice, as 50% of d/d mice succumbed to inflammation, whereas all d/d x IL-1R1-/- double mutants survived with lower initial weight loss and less pulmonary collagen and mucus production, suggesting that the absence of IL-1R1 signaling is protective in d/d mice in LPS-induced lung damage. Using P. aeruginosa acute lung infection we found heightened neutrophil recruitment in d/d mice with higher epithelial damage, increased bacterial load in BALF, and augmented IL-1β and TNF-α in parenchyma as compared to WT mice. Thus, F508del-CFTR mice show enhanced IL-1β signaling in response to P. aeruginosa. IL-1β antibody neutralization had no effect on lung homeostasis in either d/d or WT mice, however P. aeruginosa induced lung inflammation and bacterial load were diminished by IL-1β antibody neutralization. In conclusion, enhanced susceptibility to P. aeruginosa in d/d mice correlates with an excessive inflammation and with increased IL-1β production and reduced bacterial clearance. Further, we show that neutralization of IL-1β in d/d mice through the double mutation d/d x IL-1R1-/- and in WT via antibody neutralization attenuates inflammation. This supports the notion that intervention in the IL-1R1/IL-1β pathway may be detrimental in CF patients

Latitudinal diversity gradients in New World bats: are they a consequence of niche conservatism?

The increase in species diversity from the Poles to the Equator is a major biogeographic pattern, but the mechanisms underlying it remain obscure. Our aim is to contribute to their clarification by describing the latitudinal gradients in species richness and in evolutionary age of species of New World bats, and testing if those patterns may be explained by the niche conservatism hypothesis. Maps of species ranges were used to estimate species richness in a 100 x 100 km grid. Root distances in a molecular phylogeny were used as a proxy for the age of species, and the mean root distance of the species in each cell of the grid was estimated. Generalised additive models were used to relate latitude with both species richness and mean root distance. This was done for each of the three most specious bat families and for all Chiroptera combined. Species richness increases towards the Equator in the whole of the Chiroptera and in the Phyllostomidae and Molossidae, families that radiated in the tropics, but the opposite trend is observed in the Vespertilionidae, which has a presumed temperate origin. In the whole of the Chiroptera, and in the three main families, there were more basal species in the higher latitudes, and more derived species in tropical areas. In general, our results were not consistent with the predictions of niche conservatism. Tropical niche conservatism seems to keep bat clades of tropical origin from colonizing temperate zones, as they lack adaptations to survive cold winters, such as the capacity to hibernate. However, the lower diversity of Vespertilionidae in the Neotropics is better explained by competition with a diverse pre-existing community of bats than by niche conservatism.MJRP was supported by Foundation for Science and Technology, Portugal (www.fct.pt), fellowship SFRH/BD/19620/2004 and SFRH/BPD/ 72845/2010. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank J. P. Granadeiro and R. Lemos for advice on statistical methods, J. A. Diniz-Filho for support with SAM software, and M. A. Dias and P. E. Cardoso for help with the distributional maps. O. R. P. Bininda-Emonds kindly gave us access to the Chiroptera species-level phylogeny. Bat data was provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, the Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE - http://www.natureserve.org/infonatura.publishe

Do bigger bats need more time to forage?

We test the hypothesis is that bats using the same area and at the same time would be using similar preys, but they would have different foraging times due to specific differences in biomass. A total of 730 captures was analyzed 13 species of Vespertilionidae and Molossidae bats netted over a small dam in southeastern Brazil from 1993 and 1999. The relationship between the average time of captures and the biomass of the species of Vespertilinidae and Molossidae most frequent (captures > 4) was positive and significant (r = 0.83, p = 0.022, N = 7). Two lines are discussed to answer the longer foraging time for bigger bats: 1) larger insectivorous bats don't consume proportionally larger preys and 2) larger insects are less available