| health evaluation of galapagos hawks (buteo galapagoensis) on santiago island, galapagos. | galapagos hawks (buteo galapagoensis), the only endemic, diurnal raptor species in galapagos, are currently distributed on eight galapagos islands having been extirpated from three of the human-inhabited islands. in january 2009, we performed health assessments of 89 galapagos hawks on santiago island, galapagos. four of the 89 galapagos hawks (4%) evaluated had physical abnormalities. blood parameters did not differ between males and females, except for aspartate transaminase values, which were ... | 2012 | 22247372 |
| island tameness: an altered cardiovascular stress response in galápagos marine iguanas. | island tameness is a widely documented phenomenon in which island species, particularly those that have evolved with no or few natural predators, show a greatly reduced behavioral response when faced with unfamiliar predators. this insufficient anti-predator response has led to widespread population declines among many island species exposed to novel predators, and has become a serious conservation problem. despite its prevalence, the underlying physiology of island tameness is not known. here w ... | 2010 | 20109476 |
| molecular and morphological divergence in a pair of bird species and their ectoparasites. | in an evolutionary context, parasites tend to be morphologically conservative relative to their hosts. however, the rate of neutral molecular evolution across many parasite lineages is faster than in their hosts. although this relationship is apparent at the macroevolutionary scale, insight into the processes underpinning it may be gained through investigations at the microevolutionary scale. birds and their ectoparasitic lice have served as important natural experiments in co-evolution. here, w ... | 2009 | 19655998 |
| cryptic host specificity of an avian skin mite (epidermoptidae) vectored by louseflies (hippoboscidae) associated with two endemic galapagos bird species. | host specificity of vectors is an important but understudied force shaping parasite evolution and the relationship between hosts and parasites. low vector specificity may allow a vectored parasite to invade new host species, whereas high specificity of vectors may reduce the host range of the parasite and favor specialization. the 'generalist' and widely distributed avian skin mite myialges caulotoon speiser (acari: epidermoptidae) is unusual because females require an insect vector to complete ... | 2006 | 17304798 |
| disease ecology in the galápagos hawk (buteo galapagoensis): host genetic diversity, parasite load and natural antibodies. | an increased susceptibility to disease is one hypothesis explaining how inbreeding hastens extinction in island endemics and threatened species. experimental studies show that disease resistance declines as inbreeding increases, but data from in situ wildlife systems are scarce. genetic diversity increases with island size across the entire range of an extremely inbred galápagos endemic bird, providing the context for a natural experiment examining the effects of inbreeding on disease susceptibi ... | 2006 | 16618672 |
| phylogeography of the galápagos hawk (buteo galapagoensis): a recent arrival to the galápagos islands. | galápagos hawks (buteo galapagoensis) are one of the most inbred bird species in the world, living in small, isolated island populations. we used mitochondrial sequence and nuclear minisatellite data to describe relationships among galápagos hawk populations and their colonization history. we sampled 10 populations (encompassing the entire current species range of nine islands and one extirpated population), as well as the galápagos hawk's closest mainland relative, the swainson's hawk (b. swain ... | 2006 | 16376110 |
| effects of host sociality on ectoparasite population biology. | theory predicts a positive relationship between parasite infection intensity and host density. however, this generalization is complicated in natural systems by differences in life history among parasite taxa, e.g., transmissibility. accordingly, predictions relating host density to parasite load should be specific to each parasite taxon. to illustrate this, we studied parasites that differed greatly in life history in the context of the galapagos hawk's (buteo galapagoensis) variably cooperativ ... | 2004 | 15562590 |
| differences in straggling rates between two genera of dove lice (insecta: phthiraptera) reinforce population genetic and cophylogenetic patterns. | differences in dispersal abilities have been implicated for causing disparate evolutionary patterns between columbicola and physconelloides lice (insecta: phthiraptera). however, no study has documented straggling (when lice are found on atypical hosts) rates within these lineages. we used the fact that the galapagos hawk, buteo galapagoensis (gould) (falconiformes) feeds on the galapagos dove zenaida galapagoensis gould (columbiformes) within an ecologically simplified setting. the galapagos do ... | 2004 | 15380682 |
| first record and morphology of myialges caulotoon (acari: epidermoptidae) from galapagos hosts. | hippoboscid flies were collected from wild birds on santiago and fernandina islands, galapagos, ecuador in august 1985. an epidermoptid mite, identified as myialges caulotoon, was found on icosta nigra from galapagos hawks and on olfersia sordida from brown pelicans and a flightless cormorant. this report is the first record of myialges from the 2 birds endemic to galapagos. it is also the first report to provide an identity of a species of myialges from galapagos hosts. | 1998 | 9488365 |