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Latta S.C.,National Aviary | Ricklefs R.E.,University of Missouri-St. Louis
Journal of Avian Biology | Year: 2010

We used PCR to screen for the presence of haemosporidian parasites (Phylum: Apicomplexa; Order: Haemosporida) in avian blood samples, and sequenced the parasite mitochondrial cytochrome b gene from infected hosts, to study patterns in the prevalence of haemosporidians in 1,166 individuals of 50 species in four habitats along an elevation gradient in the Sierra de Bahoruco, Dominican Republic, island of Hispaniola. We found an overall prevalence of 0.44 among species with ≥10 individuals sampled per year, but this varied considerably among species. We found no difference in infection rates between years, between males and females, between second-year (<1y old) and older birds, or among members of different foraging guilds. Prevalence differed significantly among migratory, endemic resident, and non-endemic resident species, with endemics having the highest rates of infection. Prevalence also varied among habitats, decreasing with increasing elevation, but the pattern was confounded by variation in the host species present at each elevation. From 215 sequenced parasites from 171species of avian hosts, we recovered multiple examples of 12 lineages of Haemoproteus (Parahaemoproteus), two lineages of a Columbiformes-specific clade of H. (Haemoproteus), and 10 lineages of Plasmodium, with an additional seven lineages sampled only once. A single parasite lineage was responsible for 34.4% of all infections, but five more lineages made up 41.8% of all infections. Several lineages were broadly distributed across multiple host species, but six lineages, all H. (Haemoproteus) or H. (Parahaemoproteus), were recorded from at least five individuals of a single host, suggesting host specialization. The number of host species from which each parasite lineage was recovered varied from one to nine; several host species harbored as many as 5-9 parasite lineages. Longitudinal data suggest that while hosts might harbor the same parasite lineage for more than a year, some hosts appear to clear infections from their circulating blood, while others manifested infections by a different parasite lineage. © 2010 The Authors. Journal compilation © 2010 Journal of Avian Biology.

Sly N.D.,Cornell University | Townsend A.K.,Cornell University | Rimmer C.C.,Vermont Center for Ecostudies | Townsend J.M.,New York University | And 2 more authors.
Molecular Ecology | Year: 2011

With its large size, complex topography and high number of avian endemics, Hispaniola appears to be a likely candidate for the in situ speciation of its avifauna, despite the worldwide rarity of avian speciation within single islands. We used multilocus comparative phylogeography techniques to examine the pattern and history of divergence in 11 endemic birds representing potential within-island speciation events. Haplotype and allele networks from mitochondrial ND2 and nuclear intron loci reveal a consistent pattern: phylogeographic divergence within or between closely related species is correlated with the likely distribution of ancient sea barriers that once divided Hispaniola into several smaller paleo-islands. Coalescent and mitochondrial clock dating of divergences indicate species-specific response to different geological events over the wide span of the island's history. We found no evidence that ecological or topographical complexity generated diversity, either by creating open niches or by restricting long-term gene flow. Thus, no true within-island speciation appears to have occurred among the species sampled on Hispaniola. Divergence events predating the merging of Hispaniola's paleo-island blocks cannot be considered in situ divergence, and postmerging divergence in response to episodic island segmentation by marine flooding probably represents in situ vicariance or interarchipelago speciation by dispersal. Our work highlights the necessity of considering island geologic history while investigating the speciation-area relationship in birds and other taxa. © 2011 Blackwell Publishing Ltd.

Tinoco B.A.,State University of New York at Stony Brook | Astudillo P.X.,University of Azuay | Latta S.C.,National Aviary | Strubbe D.,University of Antwerp | Graham C.H.,State University of New York at Stony Brook
Biotropica | Year: 2013

Human-induced alteration of habitat is a major threat to biodiversity worldwide, especially in areas of high biological diversity and endemism. Polylepis (Rosaceae) forest, a unique forest habitat in the high Andes of South America, presently occurs as small and isolated patches in grassland dominated landscapes. We examine how the avian community is likely influenced by patch characteristics (i.e., area, plant species composition) and connectivity in a landscape composed of patches of Polylepis forest surrounded by páramo grasslands in Cajas National Park in the Andes of southern Ecuador. We used generalized linear mixed models and an information-theoretic approach to identify the most important variables probably influencing birds inhabiting 26 forest patches. Our results indicated that species richness was associated with area of a patch and floristic composition, particularly the presence of Gynoxys (Asteraceae). However, connectivity of patches probably influenced the abundance of forest and generalists species. Elsewhere, it has been proposed that effective management plans for birds using Polylepis should promote the conservation of mature Polylepis patches. Our results not only suggest this but also show that there are additional factors, such as the presence of Gynoxys plants, which will probably play a role in conservation of birds. More generally, these findings show that while easily measured attributes of the patch and landscape may provide some insights into what influences patch use by birds, knowledge of other factors, such as plant species composition, is essential for better understanding the distribution of birds in fragmented landscapes. © 2013 Association for Tropical Biology and Conservation Inc.

Latta S.C.,National Aviary | Latta K.N.,University of Wyoming
Wilson Journal of Ornithology | Year: 2015

Ground-nesting Common Nighthawks (Chordeiles minor), adapted to living and reproducing in North American cities, nest on flat-topped gravel roofs. But populations of Common Nighthawks have declined in recent years throughout their range. One hypothesis to explain these declines is that American Crows (Corvus brachyrhynchos), which have increased dramatically in numbers in urban areas in recent years, may be depredating nighthawk nests. If urban crows are a factor in nighthawk declines, we predicted there would be higher rates of predation on nests in urban areas than in rural areas. We tested this hypothesis by placing and monitoring artificial nests containing Coturnix quail eggs in both urban and rural settings. Depredation of experimental clutches was significantly lower in rural, natural habitats than in the urban environment. The type of substrate on urban roofs may also be important in influencing rates of depredation, as egg-loss was more common at experimental nests on roofs with a small pea gravel substrate than on roofs covered in larger river stone. In all cases, identified predators were American Crows. While experimental predation rates may not represent actual levels of predation on natural nests, these relative differences in rates of predation suggest that urban crows may be an important contributor to declining populations of Common Nighthawks. © 2015 The Wilson Ornithological Society.

Ricklefs R.E.,University of Missouri-St. Louis | Dodge Gray J.,University of Missouri-St. Louis | Latta S.C.,National Aviary | Svensson-Coelho M.,University of Missouri-St. Louis
Journal of Avian Biology | Year: 2011

We compared the haemosporidian parasite faunas (Plasmodium and Haemoproteus) of small land birds on the islands of St Lucia, St Vincent and Grenada in the southern Lesser Antilles. The islands differ in distance from the South American source of colonists, proximity to each other, and similarity of their avifaunas. On each island, we obtained 419-572 blood samples from 22-25 of the 34-41 resident species. We detected parasite infection by PCR and identified parasite lineages by sequencing a portion of the mitochondrial cytochrome b gene. Parasite prevalence varied from 31% on St Lucia to 22% on St Vincent and 18% on Grenada. Abundant parasite lineages differed between the three islands in spite of the similarity in host species. As in other studies, the geographic distributions of the individual parasite lineages varied widely between local endemism and broad distribution within the West Indies, including cases of long-distance disjunction. St Vincent was unusual in the near absence of Plasmodium parasites, which accorded with low numbers of suitable mosquito vectors reported from the island. Parasites on St Vincent also tended to be host specialists compared to those on St Lucia and Grenada. Similarity in parasite assemblages among the three islands varied in parallel with host assemblage similarity (but not similarity of infected hosts) and with geographic proximity. Parasite prevalence increased with host abundance on both St Lucia and St Vincent, but not on Grenada; prevalence did not vary between endemic and more widespread host species. In addition, the endemic host species harbored parasites that were recovered from a variety of non-endemic species as well. These results support the individualistic nature of haemosporidian parasite assemblages in evolutionarily independent host populations. © 2011 The Authors.

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