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Objective: We used environmental DNA (eDNA) sampling methods to determine the possibility of Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix (hereafter, bigheaded carp) range expansion above barriers to fish movement in two tributaries of the Missouri River in eastern South Dakota. Methods: We collected water samples above and below two perceived barriers to fish movement: a natural chain of waterfalls in the Big Sioux River and a spillway at the downstream end of a man‐made reservoir in the Vermillion River. We used filtration methods to collect bigheaded carp eDNA from water samples and implemented real‐time quantitative polymerase chain reaction techniques to quantify the amount of eDNA in each sample. A total of 198 water samples and 35 field blanks were collected over 2 years (2021 and 2022). Result: We detected bigheaded carp eDNA below both barriers in 2021 and 2022 and above the barrier in the Vermillion River during 2022. The median posterior prediction value for detecting eDNA below both barriers was 75.3% (95% credible interval [CrI] = 73.2–77.2%) for Bighead Carp eDNA and 54.2% (95% CrI = 51.5–56.4%) for Silver Carp eDNA. The probability of detecting eDNA above the barriers was significantly smaller: 1% (95% CrI = 0.01–1.10%) in the Big Sioux River and 1% (95% CrI = 0.01–1.30%) in the Vermillion River. Conclusion: The detection of positive samples above the spillway barrier in the Vermillion River provides the first evidence that bigheaded carp may have expanded their range to habitats upstream of their documented range in eastern South Dakota. Impact statementThis study demonstrates the utility of using environmental DNA sampling methods to detect bigheaded carp in areas of both known and unknown bigheaded carp presence in smaller tributary streams to the Missouri River. [ABSTRACT FROM AUTHOR]

Agricultural development may produce highly fragmented landscapes, which can influence population genetic structure for organisms restricted to insularized breeding habitats. Common Nighthawks (Chordeiles minor) in agriculturally dominated landscapes nest on urban gravel rooftop and might be subject to reduced gene flow among isolated urban sites. We conducted an analysis of the genetic variability and population genetic structure of Common Nighthawks nesting on rooftops in four towns in southeastern South Dakota, an area that has experienced extreme conversion of native prairie to agriculture. Using sequence data from a 725 bp region of the cytochrome b (cytb) mitochondrial gene sampled from 37 individuals representing a total of 30 different nests collected in summers 2014-2016, we found evidence of a recent population bottleneck and reduced mtDNA variability. The spatial dispersion of the 14 detected haplotypes and the presence of nine haplotypes unique to one of the four sampled towns further suggested a lack of panmixia among these nighthawks. These data are consistent with a hypothesis of habitat fragmentation due to agricultural expansion resulting in population isolation within this species of conservation concern., INTRODUCTIONSince the 1980s aerial insectivorous birds have experienced one of the most prominent population declines of any bird guild (Sauer et al., 2007; Nebel et al., 2010). This decline may [...]

The presence of extra-pair fertilizations (EPF) in a dense breeding population of Sandhill Cranes (Grus canadensis) was examined using six microsatellite DNA markers. In this long-lived species that maintains long-term pair bonds, 4.4%-11% of 45 chicks were not genetically related to one social parent, and extra-pair chicks were present in 5.6%-22% of 18 family groups. Two confirmed extra-pair chicks were from different broods of the same pair that was socially bonded for a minimum of 12 years. The social male was rejected as the genetic father of both of these chicks. Three other potential cases of EPF (two cases in which the social male was rejected as the genetic parent, one in which the social female was rejected) could also have resulted from mate replacement prior to sampling. The range of EPF in this population of Sandhill Cranes is similar to that of other species with similar mating systems. In the confirmed cases of EPF, the female was able to increase her individual reproductive success without losing her territory. Key words: extra-pair fertilization, Grus canadensis, microsatellites, monogamy, Sandhill Crane. La presencia de fertilizacion extra-pareja (FEP) en una poblacion reproductiva numerosa de Grus canadensis rue analizada usando seis marcadores microsatelitales de ADN. En esta especie longeva que mantiene vinculos de pareja a largo plazo, entre el 4.4% y el 11% de 45 polluelos no se relacionaron geneticamente a uno de sus padres sociales, y los polluelos extra-pareja estuvieron presentes en el 5.6% al 22%, de 18 grupos familiares. Dos pollos extra-pareja de diferentes camadas pertenecieron a una pareja que ha estado socialmente vinculada por un periodo minimo de 12 anos. El macho social fue rechazado como el padre genetico en ambos casos. Los otros tres casos posibles de FEP (dos casos en los que el macho social fue rechazado como el padre genetico, uno en el que la hembra social fue rechazada) podrian deberse al reemplazo de la pareja antes del muestreo. El rango de FEP para esta poblacion de G. canadensis se aproxima al de otras especies con sistemas de apareamiento similar. En los casos confirmados de FEP. la hembra fue capaz de incrementar su exito reproductivo sin perder su territorio.

Maintenance of sylvatic plague in prairie dogs ( Cynomis spp.) was once thought unlikely due to high mortality rates; yet more recent findings indicate that low-level enzootic plague may be maintained in susceptible prairie dog populations. Another hypothesis for the maintenance of sylvatic plague involves small mammals, other than prairie dogs, as an alternative reservoir in the sylvatic plague system. These hypotheses, however, are not mutually exclusive, as both prairie dogs and small mammals could together be driving sylvatic cycles of plague. The concept of a bridging vector has been used to explain the transmission of pathogens from one host species to another. In the case of sylvatic plague, this would require overlap in fleas between small mammals and prairie dogs, and potentially other species such as carnivores. Our goal was to evaluate the level of flea sharing between black-tailed prairie dogs ( Cynomis ludovicianus) and other small mammals in a mixed-grass prairie in South Dakota. We investigated the species richness of small mammals and small-mammal fleas in a mixed-grass prairie system and compared findings with previous studies from a short-grass ecosystem in Colorado. Over the summer field seasons 2014-2016 we live-trapped small mammals, collected fleas, and showed differences between both the flea and small mammal composition of the two systems. We also recorded higher densities of deer mice and lower densities of northern grasshopper mice in mixed versus shortgrass prairies. We confirmed, as is the case in shortgrass prairies, a lack of substantial flea species overlap on small mammal hosts and fleas from prairie dogs and their burrows. Moreover this study demonstrates that although small mammals may not play a large part in interepizootic plague cycling in shortgrass prairie ecosystems, their role in mixed-grass prairies requires further evaluation. [ABSTRACT FROM AUTHOR]

Sylvatic plague is one of the major impediments to the recovery of the black-footed ferret ( Mustela nigripes) because it decimates their primary prey species, prairie dogs ( Cynomys spp.), and directly causes mortality in ferrets. Fleas are the primary vector of Yersinia pestis, the causative agent of sylvatic plague. The goal of this research was to better understand the flea fauna of ferrets and the factors that might influence flea abundance on ferrets. Fleas from ferrets were tested for Y. pestis in a post hoc assessment to investigate the plausibility that some ferrets could act as incidental transporter hosts of fleas infected with Y. pestis. Fleas were collected from ferrets captured on the Lower Brule Indian Reservation in central South Dakota, US from 2009 to 2012. A total of 528 fleas collected from 67 individual ferrets were identified and tested for the presence of Y. pestis with a nested PCR assay. The predominant flea recovered from ferrets was Oropsylla hirsuta, a species that comprises 70-100% of the fleas recovered from prairie dogs and their burrows in the study area. Yersinia pestis was detected at low levels in fleas collected from ferrets with prevalence ranging from 0% to 2.9%; male ferrets harbored significantly more fleas than female ferrets. Six of 67 ferrets vaccinated against plague carried fleas that tested positive for Y. pestis, which suggests ferrets vaccinated against plague could inadvertently act as incidental transporter hosts of Y. pestis-positive fleas. [ABSTRACT FROM AUTHOR]

We examined fleas collected from black-tailed prairie dog ( Cynomys ludovicianus) burrows from 2009 through 2011 in five national park units east of the known distribution of active plague across the northern Great Plains for the presence of Yersinia pestis. Across all national park units, Oropsylla tuberculata and Oropsylla hirsuta were the most common fleas collected from prairie dog burrows, 42.4% and 56.9%, respectively, of the 3964 fleas collected from burrow swabbing. Using a nested PCR assay, we detected 200 Y. pestis-positive fleas from 3117 assays. In total, 6.4% of assayed fleas were Y. pestis positive and 13.9% of prairie dog burrows swabbed contained Y. pestis-positive fleas. Evidence of the presence of Y. pestis was observed at all national park units except Devils Tower National Monument in Wyoming. We detected the presence of Y. pestis without large die-offs, i.e., enzootic sylvatic plague, east of the known distribution of active plague and near the eastern edge of the present distribution of black-tailed prairie dogs. This study, in combination with previous work suggests that sylvatic plague likely occurs across the range of black-tailed prairie dogs and should now be treated as endemic across this range. [ABSTRACT FROM AUTHOR]