Resource use by two morphologically similar insectivorous bats (Nycteris thebaica and Hipposideros caffer)

Studies of morphologically dissimilar insectivorous bats have lead to the conclusion that morphology is the prime correlate of habitat use, and consequently of diet. This has lead to the prediction that morphologically similar bats should have similar diets. We examined the diet and morphology of two morphologically similar species, the slit-faced bat, Nycteris thebaica, and Sundevall's leaf-nosed bat, Hipposideros caffer, in the context of this prediction. Although both species foraged in the same habitat, they had distinctly different diets. The diet of N. thebaica consisted mainly of non-volant prey, primarily orthopterans and arachnids, and the diet of H. caffer, mainly of moths. Differences in wing design between the two taxa were small. The only significant difference was in aspect ratio. There were no differences in wing loading and wingtip shape ratio between the two species. The flying abilities reported for these two species are very similar, suggesting that these small differences in wing design do not translate into differences in flying ability, and cannot explain the dietary differences between these two species. On the other hand, there are marked differences in their prey detection systems which correspond to differences in their diets. H. caffer uses echolocation to detect the flapping wings of insect prey, whereas N. thebaica depends on prey-generated sounds (fluttering or scuffling) to locate its targets

Genetic variation among western populations of the Horned Lark (Eremophila alpestris) indicates recent colonization of the Channel Islands off southern California, mainland-bound dispersal, and postglacial range shifts

© 2014 American Ornithologists\u27 Union. The Channel Islands off the coast of southern California host \u3e50 species of terrestrial vertebrates with varying degrees of phenotypic differentiation. However, most organisms that breed on the Channel Islands remain unstudied with respect to genetic differentiation from mainland populations. By comparing patterns of genetic variation between the Channel Islands and the mainland, we aimed to further our understanding of the role that the Channel Islands have played in diversification of the North American biota. We evaluated long-standing, untested hypotheses regarding colonization patterns and evolutionary relationships among western populations of the Horned Lark (Eremophila alpestris), including the endemic Channel Island subspecies E. a. insularis. We also examined how many times Horned Larks have colonized the Channel Islands, whether the species exhibits asymmetrical patterns of gene flow between mainland and island populations, and whether E. a. strigata of the Pacific Northwest is closely related to the phenotypically similar, but geographically separated, island subspecies. We found that E. a. insularis is polyphyletic, which suggests either multiple colonization events from the mainland or incomplete lineage sorting of a large ancestral population. We also inferred higher rates of migration from the Channel Islands to the mainland, with E. a. strigata being closely related to individuals from the Channel Islands and coastal southern California. Moreover, ecological niche models for E. a. strigata identified suitable abiotic conditions in southern California and the Pacific Northwest during the Last Glacial Maximum, which suggests that E. a. strigata experienced a postglacial range shift in addition to a population bottleneck. Our results provide novel insight regarding the origins of the Channel Island avifauna and the evolutionary history of the Horned Lark in the western United States. Moreover, our findings suggest that Channel Island birds may be weakly differentiated from mainland populations despite phenotypic differences between recognized subspecies

Commentary: Design and analytical considerations for improving effectiveness of bird surveys that use autonomous sound recorders

No Abstrac

Molecular evidence that the Channel Islands populations of the orange-crowned warbler (Oreothlypis celata; Aves: Passeriformes: Parulidae) represent a distinct evolutionary lineage

We used molecular data to assess the degree of genetic divergence across the breeding range of the orange-crowned warbler (Oreothlypis celata) in western North America with particular focus on characterizing the divergence between O. celata populations on the mainland of southern California and on the Channel Islands. We obtained sequences of the mitochondrial gene ND2 and genotypes at ten microsatellite data for 192 O. celata from populations spanning all four recognized subspecies. We recovered shallow, but significant, levels of divergence among O. celata populations across the species range. Our results suggest that island isolation, subspecies (delineation by morphology, ecological, and life-history characteristics), and isolation-by-distance, in that order, are the variables that best explain the geographic structure detected across the range of O. celata. Populations on the Channel Islands were genetically divergent from those on the mainland. We found evidence for greater gene flow from the Channel Islands population to mainland southern California than from the mainland to the islands. We discuss these data in the context of differentiation in phenotypic and ecological characters

Fine-scale biogeography: tidal elevation strongly affects population genetic structure and demographic history in intertidal fishes

Numerous studies have demonstrated population genetic structuring in marine species, yet few have investigated the effect of vertical zonation on gene flow and population structure. Here we use three sympatric, closely related clinid species, Clinus cottoides, C. superciliosus and Muraenoclinus dorsalis, to test whether zonation on South African intertidal rocky shores affects phylogeographic patterns. We show that the high‐shore restricted species has reduced gene flow and considerably higher Fst values (Fst = 0.9) than the mid‐ and low‐shore species (Fst < 0.14). Additionally, we provide evidence for remarkably different demographic and evolutionary histories, ranging from extreme population bottlenecks to population persistence, which are probably linked to effective population size and habitat specialisation. This study further highlights the need for a multispecies approach to unravel the biological and evolutionary processes that drive extant population genetic patterns in marine species, as even closely related species with similar life histories show highly variable results

Vertebrate Natural History Laboratory and Field Syllabus – Integrative Biology 104LF

The primary objective of the laboratory and field work in this course is to aid the student in making personal, first-hand observations on the biology of living vertebrate animals in their natural environments. Containing a variety of habitats and ecological formations, such as coniferous forest, oak-bay woodland, chaparral, grassland, fresh-water marsh, lakes, and stream banks, East Bay Regional Parks support a rich variety of vertebrate species and are easily accessible. We will emphasize the behavior, adaptations, and way of life of Bay Area vertebrate species in an effort to understand their natural history, their interactions, and the ecosystems of which they are a part. Attention is given to techniques of field study, species identification, ecologic niches, foraging behavior, food habits, predator-prey relationships, habitat selection, competition within and among species, geographic distribution, and interactions between humans and vertebrate animals as they relate to conservation and human welfare. Although different species may be present in other areas, it should be realized that the techniques and principles of vertebrate natural history learned by the study of local animals will have broad geographic application

Vertebrate Natural History Laboratory and Field Syllabus – Integrative Biology 104LF

The primary objective of the laboratory and field work in this course is to aid the student in making personal, first-hand observations on the biology of living vertebrate animals in their natural environments. Containing a variety of habitats and ecological formations, such as coniferous forest, oak-bay woodland, chaparral, grassland, fresh-water marsh, lakes, and stream banks, East Bay Regional Parks support a rich variety of vertebrate species and are easily accessible. We will emphasize the behavior, adaptations, and way of life of Bay Area vertebrate species in an effort to understand their natural history, their interactions, and the ecosystems of which they are a part. Attention is given to techniques of field study, species identification, ecologic niches, foraging behavior, food habits, predator-prey relationships, habitat selection, competition within and among species, geographic distribution, and interactions between humans and vertebrate animals as they relate to conservation and human welfare. Although different species may be present in other areas, it should be realized that the techniques and principles of vertebrate natural history learned by the study of local animals will have broad geographic application