Stable Isotope Analysis Of Two Mephitidae Species Reflects Population Trends And Landscape Structure

The eastern spotted skunk (Spilogale putorius) is a small omnivorous Carnivora similar in much of its natural history to the commonly found striped skunk (Mephitis mephitis). Spilogale putorius has experienced drastic population declines over a large portion of its geographic range. Many hypotheses for the decline of S. putorius have been proposed. δ13C and δ15N isotope analysis provides a unique opportunity to examine diet over an expanded time span. Thus was used on hair sampled from natural history collections, teaching collections, and road kills to examine dietary change for both S. putorius and M. mephitis from 1852 to 2012. Because stable isotope values of hair reflect the diet at the time the hair was grown, knowledge of molting patters is necessary when using hair in stable isotope studies. I determined molting patterns in S. putorius were similar to M. mephitis. When compared to M. mephitis molting patterns in S. putorius were delayed by approximately a month. Long-term farm and crop trends have not been examined in Kansas. I examined trends in average farm size, percent of land in farms, number of farms, number of irrigated farms, hectares of woodland, and hectares of17 different crops across Kansas from 1880 to 2007. Trends were observed in most crop types and provided support for a slow transition from small diversely planted farms to large scale monoculture in Kansas. I analyzed Kansas fur harvest trends for M. mephitis and S. putorius and detected corresponding declines in Kansas for both species. These declines were correlated with a reduction of maize in the landscape and agricultural intensification. Studies indicate the presence of melanin in colored feathers affects the δ13C and δ15N values of feather samples. I examined the effect of melanin on δ13C and δ15N values of hair from 8 mammal species but detected no effect. The effects of preservation techniques on δ13C and δ15N values of mammalian samples are also not well understood. I examined the effect of tanning as a preparation technique on δ13C and δ15N values of M. mephitis. Tanned hides were depleted in both stable isotopes compared to non-tanned hides. Diet of S. putorius and M. mephitis was related to landscape structure. Maize composed the highest proportion of the diet for both S. putorius and M. mephitis and has experienced change in the diet of S. putorius over time. In addition, increased δ15N variability was observed over time in these species, potentially suggesting decline of or exclusion from historical diet sources. This research provided useful insights into the effects of landscape structure on a declining mesocarnivore, and provided additional support for dietary change as a contributing factor to the decline of S. putorius. When combined, these data potentially provide evidence for a decline in S. putorius based in part on a reduction in the amount of maize in the landscape and agricultural intensification

Separating Proactive Conservation from Species Listing Decisions

Proactive Conservation is a paradigm of natural resource management in the United States that encourages voluntary, collaborative efforts to restore species before they need to be protected through government regulations. This paradigm is widely used to conserve at-risk species today, and when used in conjunction with the Policy for Evaluation of Conservation Efforts (PECE), it allows for successful conservation actions to preclude listing of species under the Endangered Species Act (ESA). Despite the popularity of this paradigm, and recent flagship examples of its use (e.g., greater sage grouse, Centrocercus urophasianus), critical assessments of the outcomes of Proactive Conservation are lacking from the standpoint of species status and recovery metrics. Here, we provide such an evaluation, using the New England cottontail (Sylvilagus transitionalis), heralded as a success of Proactive Conservation efforts in the northeastern United States, as a case study. We review the history and current status of the species, based on the state of the science, in the context of the Conservation Initiative, and the 2015 PECE decision not to the list the species under the ESA. In addition to the impacts of the PECE decision on the New England cottontail conservation specifically, our review also evaluates the benefits and limits of the Proactive Conservation paradigm more broadly, and we make recommendations for its role in relation to ESA implementation for the future of at-risk species management. We find that the status and assurances for recovery under the PECE policy, presented at the time of the New England cottontail listing decision, were overly optimistic, and the status of the species has worsened in subsequent years. We suggest that use of PECE to avoid listing may occur because of the perception of the ESA as a punitive law and a misconception that it is a failure, although very few listed species have gone extinct. Redefining recovery to decouple it from delisting and instead link it to probability of persistence under recommended conservation measures would remove some of the stigma of listing, and it would strengthen the role of Species Status Assessments in endangered species conservation

Data from: Competition alters seasonal resource selection and promotes use of invasive shrubs by an imperiled native cottontail

1. Many ecosystems face multiple invaders, and interactions among invasive and native species may complicate conservation efforts for imperiled species. Examination of fine-scale resource selection can be used to detect patterns in habitat selection resulting from species interactions and assess the value of specific resources, including invasive plants, to wildlife. 2. We used animal location data with mixed-effects resource selection models to examine seasonal competitive interactions and species-specific selection for forage and cover resources by an imperiled native lagomorph, the New England cottontail Sylvilagus transitionalis and its non-native competitor, the eastern cottontail S. floridanus in the eastern Hudson Valley, NY. 3. We found evidence that resource selection by New England cottontails depended on the relative prevalence of eastern cottontails to New England cottontails. Where eastern cottontails were less prevalent New England cottontail selected for resources characteristic of early-successional shrublands. Where eastern cottontails were more prevalent, New England cottontails selected for resources characteristic of later-successional shrublands. 4. New England cottontail use of certain invasive shrubs depended on the prevalence of eastern cottontails relative to New England cottontails, suggesting response to invasive plants is confounded by interactions with a non-native competitor. 5. Our results further emphasize the need for conservation efforts to consider invasive management within the ecosystem context. We demonstrate the utility of resource selection studies to assist in this regard by exploring competitive interactions in the absence of removal studies, while simultaneously assessing the impact of habitat components such as invasive vegetation on species of conservation concern. 6. Synthesis and applications Resource selection studies can be directly applied to inform ongoing species conservation where multiple invaders are present or where species interactions influence resource selection. Fine-scale assessments of resource selection, similar to those presented here, can be used to selectively manage habitat to benefit desired species within the ecosystem context

Habitat Management to Reduce Competitive Interactions: Case Study of Native and Invading Cottontails

Habitat management recommendations are often based on best available science determined through retroductive and inductive hypotheses. Such recommendations are not frequently tested, potentially resulting in the implementation of unreliable practices for management of imperiled species. The New England cottontail (Sylvilagus transitionalis) is an imperiled shrubland‐obligate species whose recovery efforts include habitat management and restoration. Researchers suggest former best management practices for the species may result in ecological traps and new recommendations have been developed. We evaluated these newly revised best management practices designed to retain higher tree canopy closure to promote New England cottontails without encouraging eastern cottontails (Sylvilagus floridanus). We compared New England and eastern cottontail density between management plots (tree canopy thinned with all downed trees left on the ground, with or without invasive shrub treatment) and control plots (unmanaged) and examined the influence of management on resource selection and survival. Management strategies retaining higher canopy closure promoted stronger selection by New England cottontails than by eastern cottontails. Catch per unit effort of New England cottontails was greater than for eastern cottontails in management plots (P = 0.002). For both species, the proportion of the 95% home range overlapping managed areas was greater than the proportion of managed area in the habitat patch; however, for the 50% core area of the home range, this was only true for New England cottontails. When post‐treatment canopy cover was \u3e75%, New England cottontails selected canopy‐thinning treatments without invasive shrub removal over unmanaged areas, but selection by eastern cottontails was unaffected by management treatment or canopy cover. Survival probability of both species was high and uncorrelated with time spent in management areas. Survival probability decreased as the average distance a rabbit moved in a 7‐day period increased. Our results illustrate the need to revise management strategies that emphasize eliminating canopy cover when improving New England cottontail habitat is an objective, particularly where they are sympatric with eastern cottontails

Behavior as a rapid indicator of reintroduction and translocation success for a cryptic mammal, the New England Cottontail (Sylvilagus transitionalis)

Interactions between animals and their environments are reflected in behavior, which is an indicator of perceived risk and habitat quality. Behavioral studies can therefore provide a rapid assessment of conservation actions. We evaluated the behavior of reintroduced and translocated New England cottontails (Sylvilagus transitionalis)– a species for which the benefits of habitat management, reintroductions, and translocations have been difficult to demonstrate via demographic studies. We first used a random forests model to create a behavioral library for the species using triaxial accelerometers deployed on captive animals that were also monitored with video. We then applied our library to compare time-activity budgets among wild catch-and-release rabbits, wild-caught translocated rabbits, and rabbits introduced into the wild from a captive population. Our library included six behaviors (feeding, grooming, vigilant, movement, resting, and investigating) with an overall classification accuracy of 96.63% and class error rates \u3c14%. For all three groups of rabbits, resting, vigilance, and grooming were the most frequent behaviors; however, captive-bred and translocated rabbits spent significantly more time vigilant and moving than did catch-and-release rabbits. The results raise concern that time spent exploring a new environment may make reintroduced and translocated New England cottontails more vulnerable to predation than local wild rabbits and contribute to low survival rates in reintroduction programs. Our approach shows promise for developing behavioral studies as a rapid indicator of response to conservation efforts for cryptic mammals

Aurora A kinase phosphorylates Hec1 to regulate metaphase kinetochore-microtubule dynamics

Precise regulation of kinetochore-microtubule attachments is essential for successful chromosome segregation. Central to this regulation is Aurora B kinase, which phosphorylates kinetochore substrates to promote microtubule turnover. A critical target of Aurora B is the N-terminal "tail" domain of Hec1, which is a component of the NDC80 complex, a force-transducing link between kinetochores and microtubules. Although Aurora B is regarded as the "master regulator" of kinetochore-microtubule attachment, other mitotic kinases likely contribute to Hec1 phosphorylation. In this study, we demonstrate that Aurora A kinase regulates kinetochore-microtubule dynamics of metaphase chromosomes, and we identify Hec1 S69, a previously uncharacterized phosphorylation target site in the Hec1 tail, as a critical Aurora A substrate for this regulation. Additionally, we demonstrate that Aurora A kinase associates with inner centromere protein (INC ENP) during mitosis and that INC ENP is competent to drive accumulation of the kinase to the centromere region of mitotic chromosomes. These findings reveal that both Aurora A and B contribute to kinetochore-microtubule attachment dynamics, and they uncover an unexpected role for Aurora A in late mitosis

Cnn1 inhibits the interactions between the KMN complexes of the yeast kinetochore

El pdf del artículo es la versión de autor.-- et al.Kinetochores attach the replicated chromosomes to the mitotic spindle and orchestrate their transmission to the daughter cells. Kinetochore-spindle binding and chromosome segregation are mediated by the multi-copy KNL1 Spc105, MIS12 Mtw1 and NDC80 Ndc80 complexes that form the so-called KMN network. KMN-spindle attachment is regulated by the AuroraB Ipl1 and MPS1 Mps1 kinases. It is unclear whether other mechanisms exist that support KMN activity during the cell cycle. Using budding yeast, we show that kinetochore protein Cnn1 localizes to the base of the Ndc80 complex and promotes a functionally competent configuration of the KMN network. Cnn1 regulates KMN activity in a spatiotemporal manner by inhibiting the interaction between its complexes. Cnn1 activity peaks in anaphase and is driven by the Cdc28, Mps1 and Ipl1 kinases. © 2012 Macmillan Publishers Limited. All rights reserved.P.D.W. acknowledges financial support from the Italian Association for Cancer Research (grant 8840). T.R.H. recognizes support from the N.I.H. (grant GM087461) and the American Cancer Society (grant IRG 58-006-50). T.U.T. acknowledges a Cancer Research U.K. senior fellowship and Wellcome Trust program grant. L.J.B. acknowledges a doctoral fellowship from the European School of Molecular Medicine.Peer Reviewe