Feather Mites Are Positively Associated with Daily Survival in Cliff Swallows

Feather mites (Acari: Astigmata) have been reported to be parasitic, commensal, and even mutualis-tic on the birds that serve as their hosts. We investigated whether there was a relationship between number of feather mites (Pteronyssoides obscurus (Berlese, 1885)) on the wing and daily survival of cliff swallows (Petrochelidon pyrrhonota (Vieillot, 1817)) during the breeding season at 12 nesting colonies in Nebraska in 2005. Survival of birds with known mite loads was monitored by mark–recapture, and survival models with and without a linear effect of mites were compared with the program MARK. For adult swallows, mites were positively associated with daily survival at six colonies, negatively associated at two colonies, and there was no relationship at four colonies. For recently fledged juveniles studied at two colonies, survival varied positively with mite load at one, while the other showed no relationship. Feather mites may provide direct benefits to cliff swallows by consuming old oil, pollen, fungi, and harmful bacteria on the feathers or by preempting resources used by deleterious fungi or bacteria. The data do not support a truly parasitic relationship in which mites are costly to cliff swallows; these particular feather mites may be beneficial mutualists. Les acariens des plumes (Acari : Astigmata) sont connus pour être des parasites, des commensaux et même des symbiotes des oiseaux qui leur servent d’hôtes. Nous avons vérifié s’il existe une relation entre le nombre d’acariens des plumes (Pteronyssoides obscurus (Berlese, 1885)) sur les ailes et la survie journalière des hirondelles à front blanc (Petrochelidon pyrrhonota (Vieillot, 1817)) durant la saison de reproduction dans 12 colonies de nidification au Nebraska en 2005. Nous avons suivi la survie d’oiseaux avec une charge d’acariens connue par marquage et recapture; nous avons comparé au moyen du programme MARK les modèles de survie avec et sans effet linéaire des acariens. Chez les hirondelles adultes, il y a une association positive entre les acariens et la survie journalière à six des colonies, une association négative à deux colonies et aucune association aux quatre colonies. Chez les jeunes qui viennent de prendre leur envol étudiés à deux colonies, la survie varie positivement en fonction de la charge d’acariens dans une colonie, mais à l’autre il n’y a pas de relation. Les acari-ens des plumes fournissent peut-être des bénéfices directs aux hirondelles à front blanc en consom-mant le vieux mazout, le pollen, les champignons et les bactéries nuisibles sur les plumes ou alors en accaparant les ressources utilisées par les champignons et bactéries délétères. Nos données n’ap-puient pas l’existence d’une relation vraiment parasitaire qui pourrait être coûteuse aux hirondelles à front blanc; dans ce casci, les acariens des plumes sont vraisemblablement des symbiotes bénéfiques

Winter Ecology of Buggy Creek Virus (Togaviridae, \u3ci\u3eAlphavirus\u3c/i\u3e) in the Central Great Plains

A largely unanswered question in the study of arboviruses is the extent to which virus can overwinter in adult vectors during the cold winter months and resume the transmission cycle in summer. Buggy Creek virus (BCRV; Togaviridae, Alphavirus) is an unusual arbovirus that is vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) and amplified by the ectoparasitic bug’s main avian hosts, the migratory cliff swallow (Petrochelidon pyrrhonota) and resident house sparrow (Passer domesticus). Bugs are sedentary and overwinter in the swallows’ mud nests. We evaluated the prevalence of BCRV and extent of infection in swallow bugs collected at different times in winter (October–early April) in Nebraska and explored other ecological aspects of this virus’s overwintering. BCRV was detected in 17% of bug pools sampled in winter. Virus prevalence in bugs in winter at a site was significantly correlated with virus prevalence at that site the previous summer, but winter prevalence did not predict BCRV prevalence there the following summer. Prevalence was higher in bugs taken from house sparrow nests in winter and (in April) at colony sites where sparrows had been present all winter. Virus detected by reverse transcription (RT)-polymerase chain reaction in winter was less cytopathic than in summer, but viral RNA concentrations of samples in winter were not significantly different from those in summer. Both of the BCRV lineages (A, B) overwintered successfully, with lineage A more common at sites with house sparrows and (in contrast to summer) generally more prevalent in winter than lineage B. BCRV’s ability to overwinter in its adult vector probably reflects its adaptation to the sedentary, long-lived bug and the ecology of the cliff swallow and swallow bug host–parasite system. Its overwintering mechanisms may provide insight into those of other alphaviruses of public health significance for which such mechanisms are poorly known

Winter Ecology of Buggy Creek Virus (Togaviridae, \u3ci\u3eAlphavirus\u3c/i\u3e) in the Central Great Plains

A largely unanswered question in the study of arboviruses is the extent to which virus can overwinter in adult vectors during the cold winter months and resume the transmission cycle in summer. Buggy Creek virus (BCRV; Togaviridae, Alphavirus) is an unusual arbovirus that is vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) and amplified by the ectoparasitic bug’s main avian hosts, the migratory cliff swallow (Petrochelidon pyrrhonota) and resident house sparrow (Passer domesticus). Bugs are sedentary and overwinter in the swallows’ mud nests. We evaluated the prevalence of BCRV and extent of infection in swallow bugs collected at different times in winter (October–early April) in Nebraska and explored other ecological aspects of this virus’s overwintering. BCRV was detected in 17% of bug pools sampled in winter. Virus prevalence in bugs in winter at a site was significantly correlated with virus prevalence at that site the previous summer, but winter prevalence did not predict BCRV prevalence there the following summer. Prevalence was higher in bugs taken from house sparrow nests in winter and (in April) at colony sites where sparrows had been present all winter. Virus detected by reverse transcription (RT)-polymerase chain reaction in winter was less cytopathic than in summer, but viral RNA concentrations of samples in winter were not significantly different from those in summer. Both of the BCRV lineages (A, B) overwintered successfully, with lineage A more common at sites with house sparrows and (in contrast to summer) generally more prevalent in winter than lineage B. BCRV’s ability to overwinter in its adult vector probably reflects its adaptation to the sedentary, long-lived bug and the ecology of the cliff swallow and swallow bug host–parasite system. Its overwintering mechanisms may provide insight into those of other alphaviruses of public health significance for which such mechanisms are poorly known

Phylogeographical Structure and Evolutionary History of Two Buggy Creek Virus Lineages in the Western Great Plains of North America

Buggy Creek virus (BCRV) is an unusual arbovirus within the western equine encephalitis complex of alphaviruses. Associated with cimicid swallow bugs (Oeciacus vicarius) as its vector and the cliff swallow (Petrochelidon pyrrhonota) and house sparrow (Passer domesticus) as its amplifying hosts, this virus is found primarily in the western Great Plains of North America at spatially discrete swallow nesting colonies. For 342 isolates collected in Oklahoma, Nebraska, Colorado, and North Dakota, from 1974 to 2007, we sequenced a 2076 bp region of the 26S subgenomic RNA structural glycoprotein coding region, and analyzed phylogenetic relationships, rates of evolution, demographical histories and temporal genetic structure of the two BCRV lineages found in the Great Plains. The two lineages showed distinct phylogeographical structure: one lineage was found in the southern Great Plains and the other in the northern Great Plains, and both occurred in Nebraska and Colorado. Within each lineage, there was additional latitudinal division into three distinct sublineages. One lineage is showing a long-term population decline. In comparing sequences taken from the same sites 8–30 years apart, in one case one lineage had been replaced by the other, and in the other cases there was little evidence of the same haplotypes persisting over time. The evolutionary rate of BCRV is in the order of 1.6–3.6 × 10–4 substitutions per site per year, similar to that estimated for other temperate-latitude alphaviruses. The phylogeography and evolution of BCRV could be better understood once we determine the nature of the ecological differences between the lineages

Phylogeographical Structure and Evolutionary History of Two Buggy Creek Virus Lineages in the Western Great Plains of North America

Buggy Creek virus (BCRV) is an unusual arbovirus within the western equine encephalitis complex of alphaviruses. Associated with cimicid swallow bugs (Oeciacus vicarius) as its vector and the cliff swallow (Petrochelidon pyrrhonota) and house sparrow (Passer domesticus) as its amplifying hosts, this virus is found primarily in the western Great Plains of North America at spatially discrete swallow nesting colonies. For 342 isolates collected in Oklahoma, Nebraska, Colorado, and North Dakota, from 1974 to 2007, we sequenced a 2076 bp region of the 26S subgenomic RNA structural glycoprotein coding region, and analyzed phylogenetic relationships, rates of evolution, demographical histories and temporal genetic structure of the two BCRV lineages found in the Great Plains. The two lineages showed distinct phylogeographical structure: one lineage was found in the southern Great Plains and the other in the northern Great Plains, and both occurred in Nebraska and Colorado. Within each lineage, there was additional latitudinal division into three distinct sublineages. One lineage is showing a long-term population decline. In comparing sequences taken from the same sites 8–30 years apart, in one case one lineage had been replaced by the other, and in the other cases there was little evidence of the same haplotypes persisting over time. The evolutionary rate of BCRV is in the order of 1.6–3.6 × 10–4 substitutions per site per year, similar to that estimated for other temperate-latitude alphaviruses. The phylogeography and evolution of BCRV could be better understood once we determine the nature of the ecological differences between the lineages

Multidimensional signals and analytic flexibility: Estimating degrees of freedom in human speech analyses

Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis which can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling, but also from decisions regarding the quantification of the measured behavior. In the present study, we gave the same speech production data set to 46 teams of researchers and asked them to answer the same research question, resulting insubstantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further find little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system and calibrate their (un)certainty in their conclusions

Data for Dugas et al. O. pumilio begging

Each analysis in the manuscript is on its own tab in this file

Data from: Tadpole begging reveals high quality

Parents can benefit from allocating limited resources non-randomly among offspring, and offspring solicitation (i.e., begging) is often hypothesized to evolve because it contains information valuable to choosy parents. We tested the diagnostic predictions of three ‘honest begging’ hypotheses –Signal of Need, Signal of Quality, and Signal of Hunger – in the tadpoles of a terrestrial frog (Oophaga pumilio). In this frog, mothers provision tadpoles with trophic eggs, and when mothers visit, tadpoles perform a putative begging signal by stiffening their bodies and vibrating rapidly. We assessed the information content of intense tadpole begging with an experimental manipulation of tadpole condition (need/quality) and food-deprivation (hunger). This experiment revealed patterns consistent with the Signal of Quality hypothesis and directly counter to predictions of Signal of Need and Signal of Hunger. Begging effort and performance were higher in more developed and higher condition tadpoles and declined with food-deprivation. Free-living mothers were unlikely to feed tadpoles of a non-begging species experimentally cross-fostered with their own, and allocated larger meals to more developed tadpoles and those that vibrated at higher speed. Mother O. pumilio favour their high quality young, and because their concurrent offspring are reared in separate nurseries, must do so by making active allocation decisions. Our results suggest that these maternal choices are based at least in part on offspring signals, indicating that offspring solicitation can evolve to signal high quality

AcornAntThermalTolerance

Acorn ant thermal tolerances (upper and lower) from urban and rural sites in Cleveland Ohio USA. Column header descriptions: ColonyID = unique identifier for each ant colony; latitude = decimal degrees latitude for collection site; longitude = decimal degrees longitude for collection site; ISA = percent developed impervious surface of collection site; UR = whether the habitat is considered urban or rural; Individual = unique identifier for each individual; Genus/Species = latin binomial for study organism; Caste = whether the individual is a worker, alate or queen; WhenTol = when the tolerances were assessed, post.cg is post-common garden; Treatment = temperature treatment, daytime_nighttime; DateIn = date put in temperature treatment; DateTol = date thermal tolerance assessed; TrtDays = number of days in the temperature treatment; Tolerance = thermal tolerance estimate; TolType = maximum or minimum tolerance assessed; TolRamp = rate of temperature increase degreesC_per number of minute

Data from: Rapid evolution of ant thermal tolerance across an urban-rural temperature cline

Rates of urbanization are accelerating worldwide. The increases in temperature associated with ‘urban heat island’ effects provide both an ecological imperative and a unique opportunity to explore the ecological and evolutionary mechanisms that underlie organismal responses to rapid environmental change. We used the acorn ant, Temnothorax curvispinosus (Mayr 1866), to compare shifts in thermal tolerance of ants from rural and urban habitats throughout Cleveland, USA. Urban warming in the region has been ongoing for the past century which translates to 20 or fewer acorn ant generations. Using a common garden experiment, we found gains in the ability to withstand high temperatures and losses in the ability to withstand cool temperatures among ants in urban habitats. Owing to the greater magnitude of phenotypic change in lower compared with upper tolerances, tolerance breadth decreased in urban habitats. Mechanistically, these shifts in thermal tolerance under urbanization reflected both evolutionary change and phenotypic plasticity, as ants from urban areas exhibited higher thermal tolerances compared with ants from rural areas regardless of rearing temperature, and ants reared in the warmer temperature treatment exhibited higher tolerances than ants reared in the cooler temperature treatment. We also found evidence of evolved plasticity as the slope of the response to warmer and colder rearing environments differed significantly among rural and urban populations. While much of the ecological forecasting literature focuses on plastic responses to environmental change, our study provides evidence of rapid evolution of thermal tolerances, and suggests the importance of including evolutionary responses in forecasts of organismal responses to climatic change