The absence of concordant population genetic structure in the black‐tailed prairie dog and the flea,Oropsylla hirsuta,with implications for the spread of Yersinia pestis

The black‐tailed prairie dog (Cynomys ludovicianus) is a keystone species on the mid‐ and short‐grass prairies of North America. The species has suffered extensive colony extirpations and isolation as a result of human activity including the introduction of an exotic pathogen, Yersinia pestis, the causative agent of sylvatic plague. The prairie dog flea, Oropsylla hirsuta, is the most common flea on our study colonies in north‐central Montana and it has been shown to carry Y. pestis. We used microsatellite markers to estimate the level of population genetic concordance between black‐tailed prairie dogs and O. hirsuta in order to determine the extent to which prairie dogs are responsible for dispersing this potential plague vector among prairie dog colonies. We sampled fleas and prairie dogs from six prairie dog colonies in two regions separated by about 46 km. These colonies were extirpated by a plague epizootic that began months after our sampling was completed in 2005. Prairie dogs showed significant isolation‐by‐distance and a tendency toward genetic structure on the regional scale that the fleas did not. Fleas exhibited higher estimated rates of gene flow among prairie dog colonies than the prairie dogs sampled from the same colonies. While the findings suggested black‐tailed prairie dogs may have contributed to flea dispersal, we attributed the lack of concordance between the population genetic structures of host and ectoparasite to additional flea dispersal that was mediated by mammals other than prairie dogs that were present in the prairie system.     

Characterization of 14 polymorphic microsatellite markers for the black‐tailed prairie dog (Cynomys ludovicianus)

We report the development of 14 polymorphic microsatellite markers for the black‐tailed prairie dog, Cynomys ludovicianus. The number of alleles per locus ranges from three to 11, and the observed heterozygosity ranges from 0.37500 to 1.0000. These markers will benefit studies of landscape effects on prairie dog migration, disease dynamics, and conservation efforts.     

Field evaluation of imidacloprid as a systemic approach to flea control in black‐tailed prairie dogs,Cynomys ludovicianus

Epizootic outbreaks of sylvatic plague have dramatically influenced prairie dog (Cynomys sp.) populations across North America. While a great deal of debate surrounds the cause and persistence of plague, flea control can stop the spread of plague epizootic outbreaks and even increase prairie dog survival under non‐epizootic conditions. We investigated a newly‐developed imidacloprid‐treated grain bait that could potentially reduce flea infestations and mitigate the effects of plague on black‐tailed prairie dogs (C. ludovicianus). We used a study design involving randomly assigned experimental and control study plots to assess the effectiveness of the systemic flea control product. We observed a significant difference in flea prevalence and abundance between experimental and control sites on three of the four sites treated with a single application of imidacloprid‐treated grain bait for up to 90 days post‐treatment. We observed an even greater reduction in flea infestations following the double application of treatment bait on two of three additional experimental sites. While we were unable to reduce flea infestations to the extent reported for more commonly used topical insecticides containing deltamethrin, imidacloprid might still be effective at reducing the risk of plague and halting epizootics. In addition, this systemic product can be more rapidly applied than topical insecticides, providing managers with a tool to quickly reduce flea infestations. Future research is needed to evaluate the effectiveness of different application timing and rates, the utility of the product in limiting plague, and the potential effects on non‐target species that might also consume the treated bait.     

Climate change impacts on the conservation outlook of populations on the poleward periphery of species ranges: A case study of Canadian black‐tailed prairie dogs (Cynomys ludovicianus)

Given climate change, species' climatically suitable habitats are increasingly expected to shift poleward. Some imperilled populations towards the poleward edge of their species' range might therefore conceivably benefit from climate change. Interactions between climate and population dynamics may be complex, however, with climate exerting effects both indirectly via influence over food availability and more directly, via effects on physiology and its implications for survival and reproduction. A thorough understanding of these interactions is critical for effective conservation management. We therefore examine the relationship between climate, survival and reproduction in Canadian black‐tailed prairie dogs, a threatened keystone species in an imperilled ecosystem at the northern edge of the species' range. Our analyses considered 8 years of annual mark–recapture data (2007–2014) in relation to growing degree days, precipitation, drought status and winter severity, as well as year, sex, age and body mass. Survival was strongly influenced by the interaction of drought and body mass class, and winter temperature severity. Female reproductive status was associated with the interaction of growing degree days and growing season precipitation, with spring precipitation and with winter temperature severity. Results related to body mass suggested that climatic variables exerted their effects via regulation of food availability with potential linked effects of food quality, immunological and behavioural implications, and predation risk. Predictions of future increases in drought conditions in North America's grassland ecosystems have raised concerns for the outlook of Canadian black‐tailed prairie dogs. Insights gained from the analyses, however, point to mitigating species management options targeted at decoupling the mechanisms by which climate exerts its negative influence. Our approach highlights the importance of understanding the interaction between climate and population dynamics in peripheral populations whose viability might ultimately determine their species' ability to track climatically suitable space.     

Grooming behaviors of black‐tailed prairie dogs are influenced by flea parasitism,conspecifics, and proximity to refuge

Grooming is a common animal behavior that aids in ectoparasite defense. Ectoparasites can stimulate grooming, and natural selection can also favor endogenous mechanisms that evoke periodic bouts of “programmed” grooming to dislodge or kill ectoparasites before they bite or feed. Moreover, grooming can function as a displacement or communication behavior. We compared the grooming behaviors of adult female black‐tailed prairie dogs (Cynomys ludovicianus) on colonies with or without flea control via pulicide dust. Roughly 91% of the prairie dogs sampled on the non‐dusted colony carried at least one flea, whereas we did not find fleas on two dusted colonies. During focal observations, prairie dogs on the non‐dusted colony groomed at higher frequencies and for longer durations than prairie dogs on the dusted colonies, lending support to the hypothesis that fleas stimulated grooming. However, the reduced amount of time spent grooming on the dusted colonies suggested that approximately 25% of grooming might be attributed to factors other than direct stimulation from ectoparasites. Non‐dusted colony prairie dogs rarely autogroomed when near each other. Dusted colony prairie dogs autogroomed for shorter durations when far from a burrow opening (refuge), suggesting a trade‐off between self‐grooming and antipredator defense. Allogrooming was detected only on the non‐dusted colony and was limited to adult females grooming young pups. Grooming appears to serve an antiparasitic function in C. ludovicianus. Antiparasitic grooming might aid in defense against fleas that transmit the plague bacterium Yersinia pestis. Plague was introduced to North America ca. 1900 and now has a strong influence on most prairie dog populations, suggesting a magnified effect of grooming on prairie dog fitness.     

Seasonal and among‐site variation in the occurrence and abundance of fleas on California ground squirrels (Otospermophilus beecheyi)

An improved understanding of the ecology of fleas on California ground squirrels, Otospermophilus beecheyi, is warranted given the role of fleas in the transmission, and perhaps persistence, of the plague‐causing bacterium Yersinia pestis. We sampled O. beecheyi on a seasonal basis from three study sites, each representing a different land use type (preserve, pasture, and agriculture) in the San Joaquin Valley, CA. Overall, the abundance of fleas on squirrels was greatest in spring at the preserve site, in summer at the agriculture and pasture sites, and in winter at the pasture site. Hoplopsyllus anomalus, the species most frequently found on squirrels, was most abundant in spring at the preserve site and in summer at the agriculture and pasture sites. Oropsylla montana was most abundant in winter at the pasture site and on adult squirrels. Echidnophaga gallinacea was most abundant in fall on juvenile squirrels at the preserve site. All three flea species we encountered are known to be potential vectors of Y. pestis. Future efforts to predict flea species occurrence and abundance (and plague risk) at sites of concern should consider seasonal microclimatic conditions and the potential influence of human land use practices.     

Population genomic evidence for multiple Pliocene refugia in a montane‐restricted harvestman (Arachnida,Opiliones, Sclerobunus robustus) from the southwestern United States

The integration of ecological niche modelling into phylogeographic analyses has allowed for the identification and testing of potential refugia under a hypothesis‐based framework, where the expected patterns of higher genetic diversity in refugial populations and evidence of range expansion of nonrefugial populations are corroborated with empirical data. In this study, we focus on a montane‐restricted cryophilic harvestman, Sclerobunus robustus, distributed throughout the heterogeneous Southern Rocky Mountains and Intermontane Plateau of southwestern North America. We identified hypothetical refugia using ecological niche models (ENMs) across three time periods, corroborated these refugia with population genetic methods using double‐digest RAD‐seq data and conducted population‐level phylogenetic and divergence dating analyses. ENMs identify two large temporally persistent regions in the mid‐latitude highlands. Genetic patterns support these two hypothesized refugia with higher genetic diversity within refugial populations and evidence for range expansion in populations found outside hypothesized refugia. Phylogenetic analyses identify five to six genetically divergent, geographically cohesive clades of S. robustus. Divergence dating analyses suggest that these separate refugia date to the Pliocene and that divergence between clades pre‐dates the late Pleistocene glacial cycles, while diversification within clades was likely driven by these cycles. Population genetic analyses reveal effects of both isolation by distance (IBD) and isolation by environment (IBE), with IBD more important in the continuous mountainous portion of the distribution, while IBE was stronger in the populations inhabiting the isolated sky islands of the south. Using model‐based coalescent approaches, we find support for postdivergence migration between clades from separate refugia.     

Complete mitochondrial genome of the black‐tailed hornet,Vespa ducalis (Hymenoptera: Vespidae): Genomic comparisons in Vespoidea

We sequenced the complete mitochondrial genome (mitogenome) of the black‐tailed hornet, Vespa ducalis (Hymenoptera: Vespidae). The genome was 15,779‐bp long and contained typical sets of genes [13 protein‐coding genes (PCGs), 22 tRNAs, and 2 rRNAs]. The V. ducalis A + T‐rich region was 166‐bp long and was the shortest of all sequenced Vespoidea genomes, including Vespa. The genome was highly biased toward A/T nucleotides—80.1 % in the whole genome, 77.8 % in PCGs, 83.4–85.6 % in RNAs, and 92.8 % in the A + T‐rich region. These values are well within the typical range for genes and regions of Vespoidea mitogenomes. Start and stop codons in several Vespa species—including V. ducalis—were diversified, despite these species belonging to the same genus. In comparison with the ancestral mitogenomes, Vespa mitogenomes—including that of V. ducalis—showed substantial gene rearrangement; however, we detected no gene rearrangement among Vespa species. We conducted phylogenetic reconstruction based on concatenated sequences of 13 PCGs and two rRNAs (12,755 bp ) in available species of Vespoidea—21 species in six subfamilies in two families (Vespidae and Formicidae). The Bayesian inference and maximum likelihood (ML) methods revealed that each family formed strong monophyletic groups [Bayesian posterior probability (BPP) = 1; ML, 100 %]. Moreover, V. ducalis and V. mandarinia formed a strong sister group (BPP = 1; ML, 94 %).     

Females are the ecological sex: Sex‐specific body mass ecogeography in wild sifaka populations (Propithecus spp.)

Previous work in primates has shown that body size often covaries with ecological parameters related to resource or energy availability in the environment. This relationship may differ for males and females as access to resources has greater importance for reproductive success in females. We test the hypotheses that (1) female body mass may be more tightly constrained than male body mass by ecological variables, and (2) female body mass may respond more strongly than male body mass to changes in ecological variables (i.e., population‐specific female mass may vary more across an ecological gradient than male mass). Specifically, we investigate the relationship between climatic variables and sex‐specific body mass in Propithecus, a genus in which species‐specific body mass has already been demonstrated to covary significantly with climatic variables. Data from 733 wild sifakas are used to identify sex‐specific body mass for 27 populations representing all nine described sifaka species, and climatic data for each population are derived from the WorldClim database. We use phylogenetic generalized least squares models to demonstrate that body mass in both sexes is significantly correlated with annual rainfall and number of dry months. Furthermore, coefficients of determination are always higher for female models, and coefficients for each climatic variable are higher for females in all significant models. These results support the two hypotheses tested, indicating that ecological forces can have a greater impact on female mass than on male mass in primates. Am J Phys Anthropol 151:77–87, 2013. © 2013 Wiley Periodicals, Inc.     

Land‐cover/use transitions in the binational Tijuana River watershed during a period of rapid industrialization

Question: How do differing social and economic systems affect the dynamics and trajectory of land cover / land use change on similar, neighbouring ecosystems in a time span when an economic industrialization program was enforced? Location: Tijuana River watershed, located on the border between Baja California, Mexico and California, United States. Methods: We quantified land use changes between 1970 and 1994 in the Tijuana River watershed. Using aerial photographs and geographic information systems, we elaborated land‐cover/use maps and calculated transition probability matrices to describe natural land‐cover changes at the landscape level on both sides of the border. Results: Land cover / land use transitions are mainly driven by urban development on both sides of the border, but exhibit different patterns in each country. The processes seem to be more complex in the Mexican part of the basin, where itinerant land use may revert induced grasslands and rain‐fed agriculture into natural communities, than on the US side, where the transition pathways are few and unidirectional. Conclusions: Despite the need for an integrated planning and management of binational basins and shared water resources, in practice, these goals may be hampered by different economic and social factors triggering land use change within each country.     

Scorched mussels (Brachidontes spp., Bivalvia: Mytilidae) from the tropical and warm‐temperate southwestern Atlantic: the role of the Amazon River in their speciation

Antitropicality is a distribution pattern where closely related taxa are separated by an intertropical latitudinal gap. Two potential examples include Brachidontes darwinianus (south eastern Brazil to Uruguay), considered by some authors as a synonym of B. exustus (Gulf of Mexico and the Caribbean), and B. solisianus, distributed along the Brazilian coast with dubious records north of the intertropical zone. Using two nuclear (18S and 28S rDNA) and one mitochondrial gene (mtDNA COI), we aimed to elucidate the phylogeographic and phylogenetic relationships among the scorched mussels present in the warm‐temperate region of the southwest Atlantic. We evaluated a divergence process mediated by the tropical zone over alternative phylogeographic hypotheses. Brachidontes solisianus was closely related to B. exustus I, a species with which it exhibits an antitropical distribution. Their divergence time was approximately 2.6 Ma, consistent with the intensification of Amazon River flow. Brachidontes darwinianus, an estuarine species is shown here not to be related to this B. exustus complex. We suspect ancestral forms may have dispersed from the Caribbean to the Atlantic coast via the Trans‐Amazonian seaway (Miocene). The third species, B rodriguezii is presumed to have a long history in the region with related fossil forms going back to the Miocene. Although scorched mussels are very similar in appearance, their evolutionary histories are very different, involving major historical contingencies as the formation of the Amazon River, the Panama Isthmus, and the last marine transgression.     

Yield of willow (Salix spp.) grown in short rotation coppice mixtures in a long‐term trial

Salix spp. genotypes were grown in random intimate mixtures comprising 5, 10, 15 and 20 components at 3 planting densities (10 000, 15 000 and 20 000 cuttings ha^?1). Planted in 1994/95, plots were harvested every 3 years in 1998/99 (previously reported), 2001/02, 2004/05 and 2007/08. Each individual stool in both mono‐ and mixture plots was weighed. The total yield from mixture plots was consistently higher than the mean of the components in mono‐plots and with only limited exceptions higher than the yield of any of the individual components grown in mono‐plots. This occurred despite the loss of a number of disease‐susceptible genotypes. When a stool died the remaining plants were able to colonise the vacant space and compensate for the loss. There was no clear benefit in increasing the number of components from 10 to 15 or 20 although host diversity is considered to be an important contributor to the effectiveness of a mixture both in disease reduction and yield enhancement. It is argued that the use of Salix spp. mixtures is highly advantageous, even in the absence of any disease pressure, and that mixtures increase the sustainability of a willow plantation.     

Vegetation structure and ground cover attributes describe the occurrence of a newly discovered carnivorous marsupial on the Tweed Shield Volcano caldera,the endangered black‐tailed dusky antechinus (Antechinus arktos)

The black‐tailed dusky antechinus (Antechinus arktos) is a recently discovered, endangered, carnivorous marsupial mammal endemic to the Tweed Shield Volcano caldera, straddling the border between Queensland and New South Wales in eastern Australia. The species' preference for cool, high‐altitude habitats makes it particularly vulnerable to a shifting climate as these habitats recede. Aside from basic breeding and dietary patterns, the species' ecology is largely unknown. Understanding fine‐scale habitat attributes preferred by this endangered mammal is critical to employ successful conservation management. Here, we assess vegetation attributes of known habitats over three sites at Springbrook and Border Ranges National Parks, including detailed structure data and broad floristic assessment. Floristic compositional assessment of the high‐altitude cloud rainforest indicated broad similarities. However, only 22% of plant species were shared between all sites indicating a high level of local endemism. This suggests a diverse assemblage of vegetation across A. arktos habitats. Habitat characteristics were related to capture records of A. arktos to determine potential fine‐scale structural habitat requirements. Percentage of rock cover and leaf litter were the strongest predictors of A. arktos captures across survey sites, suggesting a need for foraging substrate and cover. Habitat characteristics described here will inform predictive species distribution models of this federally endangered species and are applicable to other mammal conservation programs.     

A case report of ovotesticular disorder of sex development (OT‐DSD) in a baboon (Papio spp.) and a brief review of the non‐human primate literature

Disorders of sexual development are rare in non‐human primates. We report a case of true hermaphroditism in a 19‐year‐old, nulliparous, female baboon (Papio spp.). At necropsy, the animal was obese with adequate muscle mass and hydration. Reproductive organs appeared normal with the exception of 2 firm nodular structures in the myometrium (1‐1.5 cm diameter) and a thickened, dark endocervical mucosa. Histologically, both gonads were ovotestes and contained discrete areas of ovarian and testicular tissue. There were follicles in various stages of development surrounded by ovarian stroma. Other areas contained hypoplastic seminiferous tubules lined by Sertoli cells, but lacked germ cells and spermatozoa. The uterine lesions were consistent with adenomyosis and cystic endometrial hyperplasia. Cervical lesions were consistent with atypical glandular hyperplasia and squamous metaplasia with dysplasia. We report the first case of ovotesticular disorder of sexual development (OT‐DSD), or true hermaphroditism in a baboon.