Levin I.I.,University of Missouri-St. Louis |
Parker P.G.,University of Missouri-St. Louis |
Parker P.G.,WildCare Institute
Molecular Ecology | Year: 2014
Haemosporidian parasites, which require both a vertebrate and invertebrate host, are most commonly studied in the life stages occurring in the vertebrate. However, aspects of the vector's behaviour and biology can have profound effects on parasite dynamics. We explored the effects of a haemosporidian parasite, Haemoproteus iwa, on a hippoboscid fly vector, Olfersia spinifera. Olfersia spinifera is an obligate ectoparasite of the great frigatebird, Fregata minor, living among bird feathers for all of its adult life. This study examined the movements of O. spinifera between great frigatebird hosts. Movement, or host switching, was inferred by identifying host (frigatebird) microsatellite genotypes from fly bloodmeals that did not match the host from which the fly was collected. Such host switches were analysed using a logistic regression model, and the best-fit model included the H. iwa infection status of the fly and the bird host sex. Uninfected flies were more likely to have a bird genotype in their bloodmeal that was different from their current host's genotype (i.e. to have switched hosts) than infected flies. Flies collected from female birds were more likely to have switched hosts than those collected on males. Reduced movement of infected flies suggests that there may be a cost of parasitism for the fly. The effect of host sex is probably driven by differences in the sex ratio of bird hosts available to moving flies. See also the Perspective by Waite © 2013 John Wiley & Sons Ltd.
Ettling J.A.,WildCare Institute |
Aghasyan A.L.,Armenian National Academy of Sciences |
Aghasyan L.A.,Armenian National Academy of Sciences
International Zoo Yearbook | Year: 2015
The Caucasus is classified as one of the world's 35 'Biodiversity Hotspots', owing to the high level of endemism. Armenia is situated in the middle of the Caucasus hotspot and its reptilian fauna is considered to be one of the most interesting in the region. There are four species of viper occurring in Armenia: Blunt-nosed viper Macrovipera lebetina obtusa, Armenian viper Montivipera raddei, Darevsky's viper Pelias darevskii and Armenian Steppe viper Pelias eriwanensis. The latter three species are classified by the International Union for Conservation of Nature Red List as Near Threatened, Critically Endangered and Vulnerable, respectively. This paper provides insight into the factors that are threatening the existence of these vipers and describes what has been learned about their biology, and outlines the conservation actions that are being taken to secure their future. © 2014 The Zoological Society of London.
Santiago-Alarcon D.,Institute Ecologia AC |
Santiago-Alarcon D.,University of Missouri-St. Louis |
Rodriguez-Ferraro A.,Simon Bolivar University of Venezuela |
Parker P.G.,University of Missouri-St. Louis |
And 2 more authors.
Parasites and Vectors | Year: 2014
Background: Previous studies have shown that haemosporidian parasites (Haemoproteus (Parahaemoproteus) and Plasmodium) infecting passerine birds have an evolutionary history of host switching with little cospeciation, in particular at low taxonomic levels (e.g., below the family level), which is suggested as the main speciation mechanism of this group of parasites. Recent studies have characterized diverse clades of haemosporidian parasites (H. (Haemoproteus) and H. (Parahaemoproteus)) infecting non-passerine birds (e.g., Columbiformes, Pelecaniiformes). Here, we explore the cospeciation history of H. (Haemoproteus) and H. (Parahaemoproteus) parasites with their non-passerine hosts. Methods. We sequenced the mtDNA cyt b gene of both haemosporidian parasites and their avian non-passerine hosts. We built Bayesian phylogenetic hypotheses and created concensus phylograms that were subsequently used to conduct cospeciation analyses. We used both a global cospeciation test, PACo, and an event-cost algorithm implemented in CoRe-PA. Results: The global test suggests that H. (Haemoproteus) and H. (Parahaemoproteus) parasites have a diversification history dominated by cospeciation events particularly at the family level. Host-parasite links from the PACo analysis show that host switching events are common within families (i.e., among genera and among species within genera), and occasionally across different orders (e.g., Columbiformes to Pelecaniiformes). Event-cost analyses show that haemosporidian coevolutionary history is dominated by host switching and some codivergence, but with duplication events also present. Genetic lineages unique to raptor species (e.g., FALC11) commonly switch between Falconiformes and Strigiformes. Conclusions: Our results corroborate previous findings that have detected a global cospeciation signal at the family taxonomic level, and they also support a history of frequent switching closer to the tips of the host phylogeny, which seems to be the main diversification mechanism of haemosporidians. Such dynamic host-parasite associations are relevant to the epidemiology of emerging diseases because low parasite host specificity is a prerequisite for the emergence of novel diseases. The evidence on host distributions suggests that haemosporidian parasites have the potential to rapidly develop novel host-associations. This pattern has also been recorded in fish-monogenean interactions, suggesting a general diversification mechanism for parasites when host choice is not restricted by ecological barriers. © 2014 Santiago-Alarcon et al.; licensee BioMed Central Ltd.
Chaves J.A.,University of California at Los Angeles |
Parker P.G.,University of Missouri-St. Louis |
Parker P.G.,WildCare Institute |
Smith T.B.,University of California at Los Angeles
Journal of Evolutionary Biology | Year: 2012
The faunas associated with oceanic islands provide exceptional examples with which to examine the dispersal abilities of different taxa and test the relative contribution of selective and neutral processes in evolution. We examine the patterns of recent differentiation and the relative roles of gene flow and selection in genetic and morphological variation in the yellow warbler (Dendroica petechia aureola) from the Galápagos and Cocos Islands. Our analyses suggest aureola diverged from Central American lineages colonizing the Galápagos and Cocos Islands recently, likely less than 300000years ago. Within the Galápagos, patterns of genetic variation in microsatellite and mitochondrial markers suggest early stages of diversification. No intra-island patterns of morphological variation were found, even across steep ecological gradients, suggesting that either (i) high levels of gene flow may be homogenizing the effects of selection, (ii) populations may not have had enough time to accumulate the differences in morphological traits, or (iii) yellow warblers show lower levels of 'evolvability' than some other Galápagos species. By examining genetic data and morphological variation, our results provide new insight into the microevolutionary processes driving the patterns of variation. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.
Yackulic C.B.,Columbia University |
Yackulic C.B.,Princeton University |
Blake S.,Wildlife Conservation Society |
Blake S.,Max Planck Institute for Ornithology (Radolfzell) |
And 5 more authors.
Journal of Animal Ecology | Year: 2011
Large data sets containing precise movement data from free-roaming animals are now becoming commonplace. One means of analysing individual movement data is through discrete, random walk-based models. Random walk models are easily modified to incorporate common features of animal movement, and the ways that these modifications affect the scaling of net displacement are well studied. Recently, ecologists have begun to explore more complex statistical models with multiple latent states, each of which are characterized by a distribution of step lengths and have their own unimodal distribution of turning angles centred on one type of turn (e.g. reversals). Here, we introduce the compound wrapped Cauchy distribution, which allows for multimodal distributions of turning angles within a single state. When used as a single state model, the parameters provide a straightforward summary of the relative contributions of different turn types. The compound wrapped Cauchy distribution can also be used to build multiple state models. We hypothesize that a multiple state model with unimodal distributions of turning angles will best describe movement at finer resolutions, while a multiple state model using our multimodal distribution will better describe movement at intermediate temporal resolutions. At coarser temporal resolutions, a single state model using our multimodal distribution should be sufficient. We parameterize and compare the performance of these models at four different temporal resolutions (1, 4, 12 and 24h) using data from eight individuals of Loxodonta cyclotis and find support for our hypotheses. We assess the efficacy of the different models in extrapolating to coarser temporal resolution by comparing properties of data simulated from the different models to the properties of the observed data. At coarser resolutions, simulated data sets recreate many aspects of the observed data; however, only one of the models accurately predicts step length, and all models underestimate the frequency of reversals. The single state model we introduce may be adequate to describe movement data at many resolutions and can be interpreted easily. Multiscalar analyses of movement such as the ones presented here are a useful means of identifying inconsistencies in our understanding of movement. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.