329 research outputs found
A multiscale analysis of gene flow for the New England cottontail, an imperiled habitat specialist in a fragmented landscape
Landscape features of anthropogenic or natural origin can influence organisms\u27 dispersal patterns and the connectivity of populations. Understanding these relationships is of broad interest in ecology and evolutionary biology and provides key insights for habitat conservation planning at the landscape scale. This knowledge is germane to restoration efforts for the New England cottontail (Sylvilagus transitionalis), an early successional habitat specialist of conservation concern. We evaluated local population structure and measures of genetic diversity of a geographically isolated population of cottontails in the northeastern United States. We also conducted a multiscale landscape genetic analysis, in which we assessed genetic discontinuities relative to the landscape and developed several resistance models to test hypotheses about landscape features that promote or inhibit cottontail dispersal within and across the local populations. Bayesian clustering identified four genetically distinct populations, with very little migration among them, and additional substructure within one of those populations. These populations had private alleles, low genetic diversity, critically low effective population sizes (3.2-36.7), and evidence of recent genetic bottlenecks. Major highways and a river were found to limit cottontail dispersal and to separate populations. The habitat along roadsides, railroad beds, and utility corridors, on the other hand, was found to facilitate cottontail movement among patches. The relative importance of dispersal barriers and facilitators on gene flow varied among populations in relation to landscape composition, demonstrating the complexity and context dependency of factors influencing gene flow and highlighting the importance of replication and scale in landscape genetic studies. Our findings provide information for the design of restoration landscapes for the New England cottontail and also highlight the dual influence of roads, as both barriers and facilitators of dispersal for an early successional habitat specialist in a fragmented landscape
Movements and Habitat Use of Coyotes on the Wichita Mountains National Wildlife Refuge
The purpose of this study was to determine the movement patterns and habitat utilization of coyotes on the Wichita Mountains National Wildlife Refuge. 'Radio-location telemetry was used to monitor coyotes throughout the study. Home range size, habitat use, and seasonal food habits were determined.Wildlife Ecolog
An Evaluation of Trapping Efforts to Capture Bobcats, Coyotes, and Red Fox
Wildlife biologists are often involved in efforts to capture free-ranging felids and canids. The objective of these efforts is usually to remove individuals causing unwanted or excessive predation, or to obtain study animals. The most common method used to capture carnivores includes some type of leg-hold trap. Numerous references provide information on the technique of leg-hold trapping (Taylor 1971, Musgrove and Blair 1979); however few reports include an evaluation of these methods
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Bee Assemblages in Managed Early-Successional Habitats in Southeastern New Hampshire
We examined the abundance and species richness of bees at 10 sites managed for Sylvilagus transitionalis (New England Cottontail Rabbit) in southeastern New Hampshire. In 2015, we sampled bees using a streamlined bee-monitoring protocol (SBMP) developed for rapid assessment of bee communities, and in 2015 and 2016, we employed bee bowls (modified pan traps) painted fluorescent blue, yellow, or white and filled and with soapy water that were intended to mimic flower colors and attract bees. We compared the abundance of all species combined and species richness among management treatments (clearcuts, old fields, and gravel pits), patch area, and time since management action. We also compared the combined captures from bee bowls to relative abundance indices from the SBMP, as well as flower abundance and richness. Neither captured bee abundance nor species richness differed among management treatments; however, by removing a possible outlier, both abundance and richness were greatest in gravel pits compared to other habitats. There was no correlation between bee captures and the SBMP, and no correlation between captures and flower abundance or floral diversity. Our study demonstrates that habitats managed for New England Cottontail support a diverse assemblage of native bees. Gravel pits are potentially valuable targets for native bee conservation, but old fields and clearcuts offer alternatives in landscapes without gravel pits. Native bees are essential to support ecosystem function, and understanding their distribution and natural history is important to develop habitatmanagement efforts that benefit not only bees but multiple species of conservation concern within early-successional habitats
Policládidos (Platyhelminthes: "Turbellaria") del Atlántico Tropical Occidental
El phylum Platyhelminthes es considerado una ramificación ancestral dentro de los phyla bilaterales (Hyman 1951). A éste pertenecen gusanos acelomados y dorsoventralmente aplanados que carecen de sistemas circulatorio y respiratorio (Hyman 1951). Aunque Ehlers (1986) define las siguientes apomorfías para el taxón: a) ausencia de mitosis en células somáticas, por ejemplo: las células somáticas se diferencian a partir de blastómeros o células totipotenciales en estado post-embriónico; y b) células multiciliadas, donde los cilios carecen de centriolo accesorio, la monofilia del grupo no ha podido ser establecida con seguridad hasta el momento. Tradicionalmente, los platelmintos han sido divididos en gusanos de vida libre Turbellaria y los grupos parásitos Trematoda, Monogenea y Cestoda. Pero hasta la fecha ninguna apomorfia ha sido encontrada para definir los Turbellaria; se ha demostrado que caracteres como vida libre y cuerpo cubierto por epidermis multiciliada no representan características para el taxón. El término Turbellaria actualmente es usado en una manera descriptiva. Dentro de los turbelarios dos grupos pueden ser reconocidos: microturbelarios y macroturbelarios, sin embargo estas designaciones no tienen valor sistemático y sólo son usados para describir la talla
Diagnostic PCR can be used to illuminate meiofaunal diets and trophic relationships
Analysis of the meiofaunal food web is hampered because few prey have features that persist long enough in a predator’s digestive tract to allow identification to species. Hence, at least for platyhelminth predators, direct observations of prey preference are almost nonexistent, and where they occur, prey identification is often limited to phylum. Studies using an in vitro approach are rare because they are extremely time-consuming and are subject to the criticism that predators removed from their natural environment may exhibit altered behaviors. Although PCR-based approaches have achieved wide application in food-web analysis, their application to meiofaunal flatworms suffers from a number of limitations. Most importantly, the microscopic size of both the predator and prey does not allow for removal of prey material from the digestive tract of the predator, and thus the challenge is to amplify prey sequences in the presence of large quantities of predator sequence. Here, we report on the successful use of prey-taxon-specific primers in diagnostic PCR to identify, to species level, specific prey items of 13 species of meiofaunal flatworms. Extension of this method will allow, for the first time, the development of a species-level understanding of trophic interactions among the meiofauna
A simple method for measuring colour in wild animals: validation and use on chest patch colour in geladas ( Theropithecus gelada )
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72620/1/j.1095-8312.2008.00981.x.pd
Molecular evidence for the presence of malaria vector species a of the Anopheles annularis complex in Sri Lanka
<p>Abstract</p> <p>Background</p> <p><it>Anopheles annularis s.l</it>. is a wide spread malaria vector in South and Southeast Asia, including Sri Lanka. The taxon <it>An. annularis </it>is a complex of two sibling species viz. A and B, that are differentiated by chromosome banding patterns and ribosomal gene sequences in India. Only species A is reported to be a malaria vector in India while the occurrence of sibling species in Sri Lanka has not been documented previously.</p> <p>Findings</p> <p>Anopheline larvae were collected at a site in the Jaffna district, which lies within the dry zone of Sri Lanka, and reared in the laboratory. Emerged adults were identified using standard keys. DNA sequences of the D3 domain of 28S ribosomal DNA (rDNA) and the internal transcribed spacer-2 (ITS-2) of the morphologically identified <it>An. annularis </it>were determined. BLASTn searches against corresponding <it>An. annularis </it>sequences in GenBank and construction of phylogenetic trees from D3 and ITS-2 rDNA sequences showed that the Sri Lankan specimens, and <it>An. annularis s.l</it>. specimens from several Southeast Asian countries were closely related to species A of the Indian <it>An. annularis </it>complex.</p> <p>Conclusions</p> <p>The results show the presence of the malaria vector <it>An. annularis </it>species A in Sri Lanka and Southeast Asia. Because <it>An. annularis </it>vectors have been long associated with malaria transmission in irrigated agricultural areas in the Sri Lankan dry zone, continued monitoring of <it>An. annularis </it>populations, and their sibling species status, in these areas need to be integral to malaria control and eradication efforts in the island.</p
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