An Analysis of Overstory Tree Canopy Cover in Sites Occupied by Native and Introduced Cottontails in the Northeastern United States with Recommendations for Habitat Management for New England Cottontail

The New England cottontail (Sylvilagus transitionalis) is a high conservation priority in the Northeastern United States and has been listed as a candidate species under the Endangered Species Act. Loss of early successional habitat is the most common explanation for the decline of the species, which is considered to require habitat with dense low vegetation and limited overstory tree canopy. Federal and state wildlife agencies actively encourage landowners to create this habitat type by clearcutting blocks of forest. However, there are recent indications that the species also occupies sites with moderate overstory tree canopy cover. This is important because many landowners have negative views about clearcutting and are more willing to adopt silvicultural approaches that retain some overstory trees. Furthermore, it is possible that clearcuts with no overstory canopy cover may attract the eastern cottontail (S. floridanus), an introduced species with an expanding range. The objective of our study was to provide guidance for future efforts to create habitat that would be more favorable for New England cottontail than eastern cottontail in areas where the two species are sympatric. We analyzed canopy cover at 336 cottontail locations in five states using maximum entropy modelling and other statistical methods. We found that New England cottontail occupied sites with a mean overstory tree canopy cover of 58% (SE±1.36), and was less likely than eastern cottontail to occupy sites with lower overstory canopy cover and more likely to occupy sites with higher overstory canopy cover. Our findings suggest that silvicultural approaches that retain some overstory canopy cover may be appropriate for creating habitat for New England cottontail. We believe that our results will help inform critical management decisions for the conservation of New England cottontail, and that our methodology can be applied to analyses of habitat use of other critical wildlife species

Fine-Scale Habitat Comparison of Two Sympatric Cottontail Species in Eastern Connecticut

Changing landscapes in the Northeastern United States over the past century have had a profound effect on the abundance and distribution of native wildlife species that prefer early successional habitat, including New England cottontail (Sylvilagus transitionalis). Populations of New England cottontail have been in decline for several decades, whereas during this same time period the nonnative eastern cottontail (S. floridanus) range has expanded. We conducted intensive vegetation analyses at 17 known locations of New England cottontail and 19 known locations of eastern cottontail in Connecticut to better describe their chosen habitat and identify any difference in habitat used by the two species. Sites that were occupied by New England cot- tontail had greater canopy closure (73.7%) and basal area (12.3 m2/ha) than sites occupied by eastern cottontail (45.3% and 6.8 m2/ha). Our findings suggest management plans to create habitat for New England cottontails should include retaining more basal area and canopy closure than what is currently prescribed in southern New England; however, further fine-scale research is required to determine if this recommendation applies throughout the range of New England cottontail

Mitochondrial DNA analysis of critically endangered Chinese Pangolins (Manis pentadactyla) from Nepal

Chinese Pangolins (Manis pentadactyla) are Critically Endangered and one of the most illegally traded mammals globally. We generated first COI sequences from five individuals of this species from Nepal. BLASTn search of our 600bp sequences at GenBank showed pair-wise identity between 99.17% and 100% to M. pentadactyla. There were three haplotypes and a total of five variable sites among five M. pentadactyla sequences. Neighbor-joining tree revealed that all M. pentadactyla from Nepal clustered into same group further splitting into two sub-groups albeit with low bootstrap value, suggesting potential multiple geographic origins. The K2P distance was 0.3% within group and 0.7% between four sequences from Bhaktapur and Kavrepalanchok districts (Mape2, Mape3, Mape5 and Mape6) and museum sample (Mape10). This study has generated reference samples for M. pentadactyla from Nepal and will be helpful in understanding dynamics of illegal trade of this species and in successful identifi- cation of M. pentadactyla from Nepal even in the absence of intact specimens

Fuzzy Sphere Dynamics and Non-Abelian DBI in Curved Backgrounds

We consider the non-Abelian action for the dynamics of $N Dp'$-branes in the background of $M Dp$-branes, which parameterises a fuzzy sphere using the SU(2) algebra. We find that the curved background leads to collapsing solutions for the fuzzy sphere except when we have $D0$ branes in the $D6$ background, which is a realisation of the gravitational Myers effect. Furthermore we find the equations of motion in the Abelian and non-Abelian theories are identical in the large $N$ limit. By picking a specific ansatz we find that we can incorporate angular momentum into the action, although this imposes restriction upon the dimensionality of the background solutions. We also consider the case of non-Abelian non-BPS branes, and examine the resultant dynamics using world-volume symmetry transformations. We find that the fuzzy sphere always collapses but the solutions are sensitive to the combination of the two conserved charges and we can find expanding solutions with turning points. We go on to consider the coincident $NS$5-brane background, and again construct the non-Abelian theory for both BPS and non-BPS branes. In the latter case we must use symmetry arguments to find additional conserved charges on the world-volumes to solve the equations of motion. We find that in the Non-BPS case there is a turning solution for specific regions of the tachyon and radion fields. Finally we investigate the more general dynamics of fuzzy $\mathbb{S}^{2k}$ in the $Dp$-brane background, and find collapsing solutions in all cases.Comment: 49 pages, 3 figures, Latex; Version to appear in JHE

Dispersal Ability Predicts Spatial Genetic Structure in Native Mammals Persisting across an Urbanization Gradient

As the rate of urbanization continues to increase globally, a growing body of research is emerging that investigates how urbanization shapes the movement—and consequent gene flow—of species in cities. Of particular interest are native species that persist in cities, either as small relict populations or as larger populations of synanthropic species that thrive alongside humans in new urban environments. In this study, we used genomic sequence data (SNPs) and spatially explicit individual‐based analyses to directly compare the genetic structure and patterns of gene flow in two small mammals with different dispersal abilities that occupy the same urbanized landscape to evaluate how mobility impacts genetic connectivity. We collected 215 white‐footed mice (Peromyscus leucopus) and 380 big brown bats (Eptesicus fuscus) across an urban‐to‐rural gradient within the Providence, Rhode Island (U.S.A.) metropolitan area (population =1,600,000 people). We found that mice and bats exhibit clear differences in their spatial genetic structure that are consistent with their dispersal abilities, with urbanization having a stronger effect on Peromyscus mice. There were sharp breaks in the genetic structure of mice within the Providence urban core, as well as reduced rates of migration and an increase in inbreeding with more urbanization. In contrast, bats showed very weak genetic structuring across the entire study area, suggesting a near‐panmictic gene pool likely due to the ability to disperse by flight. Genetic diversity remained stable for both species across the study region. Mice also exhibited a stronger reduction in gene flow between island and mainland populations than bats. This study represents one of the first to directly compare multiple species within the same urban‐to‐rural landscape gradient, an important gap to fill for urban ecology and evolution. Moreover, here we document the impacts of dispersal capacity on connectivity for native species that have persisted as the urban landscape matrix expands

Divergencia en coloración y especiación ecológica en el complejo de especies de Anolis marmoratus

Adaptive divergence in coloration is expected to produce reproductive isolation in species that use colourful signals in mate choice and species recognition. Indeed, many adaptive radiations are characterized by differentiation in colourful signals, suggesting that divergent selection acting on coloration may be an important component of speciation. Populations in the A nolis marmoratus species complex from the C aribbean island of Guadeloupe display striking divergence in the colour and pattern of adult males that occurs over small geographic distances, suggesting strong divergent selection. Here we test the hypothesis that divergence in coloration results in reduced gene flow among populations. We quantify variation in adult male coloration across a habitat gradient between mesic and xeric habitats, use a multilocus coalescent approach to infer historical demographic parameters of divergence, and examine gene flow and population structure using microsatellite variation. We find that colour variation evolved without geographic isolation and in the face of gene flow, consistent with strong divergent selection and that both ecological and sexual selection are implicated. However, we find no significant differentiation at microsatellite loci across populations, suggesting little reproductive isolation and high levels of contemporary gene exchange. Strong divergent selection on loci affecting coloration probably maintains clinal phenotypic variation despite high gene flow at neutral loci, supporting the notion of a porous genome in which adaptive portions of the genome remain fixed whereas neutral portions are homogenized by gene flow and recombination. We discuss the impact of these findings for studies of colour evolution and ecological speciation

Data from: Divergence in coloration and the evolution of reproductive isolation in the Anolis marmoratus species complex

Adaptive divergence in coloration is expected to produce reproductive isolation in species that use colorful signals in mate choice and species recognition. Indeed, many adaptive radiations are characterized by differentiation in colorful signals, suggesting that divergent selection acting on coloration may be an important component of speciation. Populations in the Anolis marmoratus species complex from the Caribbean island of Guadeloupe display striking divergence in adult male color and pattern that occurs over small geographic distances, suggesting strong divergent selection. Here we test the hypothesis that coloration is locally adaptive and is linked to reduced gene flow among populations. We quantify variation in adult male coloration across a habitat gradient between mesic and xeric habitats, use a multilocus coalescent approach to infer historical demographic parameters of divergence, and examine gene flow and population structure using microsatellite variation. We find that color variation evolved without geographic isolation and in the face of rampant gene flow, consistent with strong divergent selection, and that both ecological and sexual selection are implicated. However, we find no significant differentiation at microsatellite loci across populations, suggesting little reproductive isolation and high levels of contemporary gene exchange. Strong divergent selection on loci affecting coloration likely maintains clinal phenotypic variation despite high gene flow at neutral loci, supporting the notion of a porous genome in which adaptive portions of the genome remain fixed while neutral portions are homogenized by gene flow and recombination. We discuss the impact of these findings for studies of color evolution and ecological speciation

Response curve of eastern cottontail (EC): probability of presence and mean overstory tree canopy cover within 75m, generated by Maximum Entropy Modelling (MaxEnt) with training area limited to 3km dispersal areas.

<p>Response curve of eastern cottontail (EC): probability of presence and mean overstory tree canopy cover within 75m, generated by Maximum Entropy Modelling (MaxEnt) with training area limited to 3km dispersal areas.</p

Proportion of samples and New England cottontail (NEC) range by land use type.

<p>Notes:</p><p>* Land use is based on the Coastal Change Analysis Program of the US National Oceanic and Atmospheric Administration, but does not include open water, aquatic bed or unconsolidated shore.</p><p>** This is a rough approximation of the NEC range based on a rectangle surrounding all known NEC sample locations.</p><p>Proportion of samples and New England cottontail (NEC) range by land use type.</p

Logistic regression of the probability of New England cottontail (NEC) presence versus eastern cottontail presence based on average percent tree canopy closure within 75 m of detection location (Wald = 6.2230, p < 0.05).

<p>Notes: The frequencies of the two species in each canopy classes are provided in parentheses. New England cottontail: 0(6); 0.01–0.1 (0); 0.11–0.2 (4); 0.21–0.3 (13); 0.31–0.4 (19); 0.41–0.5 (38); 0.51-.06 (44); 0.61–0.7 (32); 0.71–0.8 (12); 0.81–1.0 (0). Eastern cottontail: 0 (13); 0.01–0.1 (1); 0.11–0.2 (2); 0.21–0.3 (17); 0.31–0.4 (35); 0.41–0.5 (29); 0.51-.06 (40); 0.61–0.7 (19); 0.71–0.8 (12); 0.81–1.0 (0).</p