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The survival of parasites is threatened directly by environmental alteration and indirectly by all the threats acting upon their hosts, facing coextinction. The fate of Darwin's finches and their native ectoparasites in the Galapagos Islands is uncertain because of an introduced avian parasitic fly, Philornis downsi, which could potentially drive them to extinction. We documented all known native ectoparasites of Darwin's finches. Thirteen species have been found: nine feather mites, three feather lice and one nest mite. No ticks or fleas have been recorded from them yet. Management options being considered to control P. downsi include the use of the insecticide permethrin in bird nests which would not only kill the invasive fly larvae but the birds’ native ectoparasites too. Parasites should be targeted for conservation in a manner equal to that of their hosts. We recommend steps to consider if permethrin-treated cotton stations are to be deployed in the Galapagos archipelago to manage P. downsi.

Parasite host range can be influenced by physiological, behavioral, and ecological factors. Combining data sets on host-parasite associations with phylogenetic information of the hosts and the parasites involved can generate evolutionary hypotheses about the selective forces shaping host range. Here, we analyzed associations between the nest-parasitic flies in the genus Philornis and their host birds on Trinidad. Four of ten Philornis species were only reared from one species of bird. Of the parasite species with more than one host bird species, P. falsificus was the least specific and P. deceptivus the most specific attacking only Passeriformes. Philornis flies in Trinidad thus include both specialists and generalists, with varying degrees of specificity within the generalists. We used three quantities to more formally compare the host range of Philornis flies: the number of bird species attacked by each species of Philornis, a phylogenetically informed host specificity index (Poulin and Mouillot's S TD), and a branch length-based S TD. We then assessed the phylogenetic signal of these measures of host range for 29 bird species. None of these measures showed significant phylogenetic signal, suggesting that clades of Philornis did not differ significantly in their ability to exploit hosts. We also calculated two quantities of parasite species load for the birds - the parasite species richness, and a variant of the S TD index based on nodes rather than on taxonomic levels - and assessed the signal of these measures on the bird phylogeny. We did not find significant phylogenetic signal for the parasite species load or the node-based S TD index. Finally, we calculated the parasite associations for all bird pairs using the Jaccard index and regressed these similarity values against the number of nodes in the phylogeny separating bird pairs. This analysis showed that Philornis on Trinidad tend to feed on closely related bird species more often than expected by chance.

Aim Species’ responses to climate change are likely to depend on their ability to overcome abiotic constraints as well as on the suite of species with which they interact. Responses to past climate change leave genetic signatures of range expansions and shifts, allowing inferences to be made about species’ distributions in the past, which can improve our ability to predict the future. We tested a hypothesis of ongoing range shifting associated with climate change and involving interactions of two species inferred to exclude each other via competition. Location New Zealand. Methods The distributions of two tree weta species (Hemideina crassidens and H. thoracica) were mapped using locality records. We inferred the likely modern distribution of each species in the absence of congeneric competitors with the software Maxent. Range interaction between the two species on an elevational gradient was quantified by transect sampling. Patterns of genetic diversity were investigated using mitochondrial DNA, and hypotheses of range shifts were tested with population genetic metrics. Results The realized ranges of H. thoracica and H. crassidens were narrower than their potential ranges, probably due to competitive interactions. Upper and lower elevational limits on Mount Taranaki over 15 years revealed expansion up the mountain for H. thoracica and a matching contraction of the low elevation limits of the range of H. crassidens. The observed nucleotide diversity in H. thoracica was consistent with a species that persisted in northern areas during Pleistocene glacial periods, from where it expanded at warmer times. In contrast, a two-tailed distribution of nucleotide diversity in H. crassidens was as expected for a species that expanded northwards during glacials and southwards during interglacials.

Hypoxia is a key factor determining survival, and haemoglobins are targets of selection in species native to high-altitude regions. We studied population genetic structure and evaluated evidence for local adaptation in the crested duck (Lophonetta specularioides). Differentiation, gene flow and time since divergence between highland and lowland populations were assessed for three haemoglobin genes (α(A) , α(D) , β(A) ) and compared to seven reference loci (six autosomal introns and mtDNA). Four derived amino acid replacements were found in the globin genes that had elevated Φ(ST) values between the Andean highlands and Patagonian lowlands. A single β(A) -globin polymorphism at a site known to influence O(2) affinity was fixed for different alleles in the two populations, whereas three α(A) - and α(D) -globin polymorphisms exhibited high heterozygosity in the highlands but not in the lowlands. Coalescent analyses supported restricted gene flow for haemoglobin alleles and mitochondrial DNA but nonzero gene flow for the introns. Simulating genetic data under a drift-migration model of selective neutrality, the β(A) -globin fell outside the 95% confidence limit of simulated data, suggesting that directional selection is maintaining different variants in the contrasting elevational environments, thereby restricting migration of β(A) -globin alleles. The α(A) - and α(D) -globins, by contrast, did not differ from the simulated values, suggesting that variants in these genes are either selectively neutral, or that the effects of selection could not be differentiated from background levels of population structure and linkage disequilibrium. This study illustrates the combined effects of selection and population history on inferring levels of population divergence for a species distributed across an altitudinal gradient in which selection for hypoxia resistance has likely played an important role.

We studied the phylogenetic relationships of four duck genera endemic to South America: Brazilian teal Amazonetta brasiliensis, spectacled duck Speculanas specularis, crested duck Lophonetta specularioides, and four species of steamer ducks Tachyerespatachonicus, T. leucocephalus, T. pteneres, T. brachypterus. Genetic divergence within and among species was compared using population-level sampling of the mitochondrial DNA (mtDNA) control region, supplemented with three additional mtDNA genes and six independent nuclear loci from one individual of each species and a variety of outgroup taxa. The monophyly of these four morphologically divergent South American genera was strongly supported. Within this clade, Amazonetta and Speculanas were supported as sister species in all analyses, but different gene regions yielded conflicting or ambiguous results for Lophonetta and Tachyeres. This lack of resolution resulted from little informative variation in nuclear loci and high levels of homoplasy in the mtDNA control region. Control region sequences from the four Tachyeres species fell into two distinct clades. In one clade, T. patachonicus and T. leucocephalus share a set of closely related haplotypes (≤0.6% sequence divergence); while no identical haplotypes were shared between species, the control region phylogeny was insufficiently resolved to either support or reject reciprocal monophyly. The second clade, ~1.7% divergent from the first, comprised haplotypes of the Falkland Islands species T. brachypterus and a captive individual of T. pteneres. These distinctive South American ducks likely experienced two bouts of rapid diversification, thus making analysis of their phylogenetic relationships difficult. Incomplete lineage sorting, founder effects, and perhaps introgression likely have contributed to obscuring the relationships among steamer ducks.

Premise of the study: Microsatellite markers were developed for Arthropodium cirratum (Asparagaceae) to study population genetic structure and translocation of this species. These markers were tested for cross-amplification in two other Arthropodium species. Methods and Results: Sixteen microsatellite markers were developed from a genomic library and tested in three populations of A. cirratum. The loci exhibited one to five alleles per locus, with private alleles present in each of the populations. Cross-amplification tests in the two other New Zealand Arthropodium species revealed that many of the loci amplify and demonstrate polymorphism in A. bifurcatum. Conclusions: These markers will be useful for determining genetic structure in A. cirratum and for determining the origins of translocated populations of this species.