Population ecology, residents\u27 attitudes, hunter success, economic impact, modeling management options and retention time of Telazol of West Virginia black bears

The West Virginia Black Bear Research Project (WVBBRP) was initiated in 1972 to investigate population parameters, growth rates, home ranges, and habitat uses of a declining American black bear (Ursus americanus ) population. The West Virginia Division of Natural Resources (WVDNR) continued to monitor the black bear population and increased monitoring efforts and sample sizes in the 1990\u27s as the black bear population increased in size and expanded its range. As part of the WVBBRP, we investigated black bear population ecology. Our objectives were to estimate reproductive rates, estimate survival and cause-specific mortality rates, examine effects of special hunting seasons and food conditions on survival, estimate population growth rates, examine population growth sensitivity to differing demographic parameters.;Reproductive parameter estimates were similar for numerous methods and should provide managers with more cost efficient ways of gathering data. Population demographics were different between oak (Quercus spp.)-hickory (Carya spp.) forest and mixed-mesophytic forest associations. Extreme mast failures influenced the number of black bears surviving to 1 year. Survival estimates of black bears were influenced by hunting season structures and food conditions. Special black bear hunting seasons conducted by the WVDNR reduced female survival and apparently stabilized the population in southern West Virginia. Black bear population dynamics differed within West Virginia and even within study areas depending on capture locations of females. Population dynamics and growth rates were affected by early hunting seasons and protection from hunting through private sanctuaries of large (≥ 544 ha) tracts of land. Where we observed adequate hunting pressure, the 2-year running average of the black bear harvest was highly correlated to population estimates and provided managers with an index to population size when it was not feasible to gather specific demographic data.;Although understanding the population dynamics of an individual species is critical, biologists must also consider public opinion when setting hunting seasons. In November--December 2006, we conducted a telephone survey of 1,206 West Virginia residents to determine their opinions and attitudes toward black bear populations and hunting seasons and to help strengthen the state\u27s black bear management strategies. In general, most respondents supported black bear hunting if the population was carefully monitored, if they knew the population was stable, or both; however, a number of regional and sociodemographic characteristics appeared to influence public opinion on black bear hunting and hunting seasons in the state, and support for specific seasons varied considerably according to hunting method. Interestingly, our study found that, even among hunters, public opposition exceeded support for the current, year-round training season of black bear hunting dogs without harvesting animals in the state.;In addition to demographic data about wildlife populations and public opinion, hunter participation and success rates are vital for managers developing management programs and to evaluate current regulations and special seasons. We conducted a systematic random mail survey of hunters that purchased a black bear stamp in West Virginia in 2006 to determine effects of hunting seasons and the economic impact of black bear hunting. Hunters using dogs passed up more legal opportunities to harvest black bears than hunters using archery equipment or gun hunting without dogs. However, estimated harvests were similar because of the larger number of hunters that did not use dogs. The total economic impact of black bear hunting in West Virginia was {dollar}51,847,605.;The ability for managers to immobilize black bears for research projects and in nuisance situations is critical for a management agency. TelazolRTM (Fort Dodge Animal Health, Fort Dodge, IA) is an effective immobilization drug for black bears but concern exists regarding retention time of this drug in tissues relative to human consumption of bears. Therefore, we evaluated retention time of Telazol in captured American black bears immobilized with Telazol and held in captivity for 3 days, 7 days, 14 days, or 21 days. We detected Telazol in muscle and liver of one bear on day 7, in serum from 2 bears on day 7, and in urine of one bear each on day 3 and day 14. Our findings suggest Telazol is metabolized and eliminated quickly from the bear\u27s system and should allow managers additional flexibility in mark-recapture studies and nuisance situations. (Abstract shortened by UMI.)

Genetic Structure of the Rice Blast Pathogen (Magnaporthe oryzae) over a Decade in North Central California Rice Fields.

Rice blast, caused by the ascomycete Magnaporthe oryzae, is one of the most destructive rice diseases worldwide. Even though the disease has been present in California since 1996, there is no data for the pathogen population biology in the state. Using amplified fragment length polymorphisms and mating-type markers, the M. oryzae population diversity was investigated using isolates collected when the disease was first established in California and isolates collected a decade later. While in the 1990 samples, a single multilocus genotype (MLG) was identified (MLG1), over a decade later, we found 14 additional MLGs in the 2000 isolates. Some of these MLGs were found to infect the only rice blast-resistant cultivar (M-208) available for commercial production in California. The same samples also had a significant decrease of MLG1. MLG1 was found infecting the resistant rice cultivar M-208 on one occasion whereas MLG7 was the most common genotype infecting the M-208. MLG7 was identified in the 2000 samples, and it was not present in the M. oryzae population a decade earlier. Our results demonstrate a significant increase in genotypic diversity over time with no evidence of sexual reproduction and suggest a recent introduction of new virulent race(s) of the pathogen. In addition, our data could provide information regarding the durability of the Pi-z resistance gene of the M-208. This information will be critical to plant breeders in developing strategies for deployment of other rice blast resistance genes/cultivars in the future

Elevated organic carbon pulses persist in estuarine environment after major storm events

Estuaries regulate transport of dissolved organic carbon (DOC) from land to ocean. Export of terrestrial DOC from coastal watersheds is exacerbated by increasing major rainfall and storm events and human activities, leading to pulses of DOC that are shunted through rivers downstream to estuaries. Despite an upward trend of extreme events, the fate of the pulsed terrestrial DOC in estuaries remains unclear. We analyzed the effects of seven major tropical cyclones (TC) from 1999 to 2017 on the quantity and fate of DOC in the Neuse River Estuary (NC, USA). Significant TC-induced increases in DOC were observed throughout the estuary; the increase lasting from around 50 d at head-of-tide to over 6 months in lower estuary. Our results suggest that pulsed terrestrial DOC associated with TCs temporarily overwhelms the estuarine filter's abiotic and biotic degradation capacity under such high flow events, enhancing the shunt of terrestrial carbon to the coastal ocean.Non peer reviewe

Observational implications of lowering the LIGO-Virgo alert threshold

The recent detection of the binary-neutron-star merger associated with GW170817 by both the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo and the network of electromagnetic-spectrum observing facilities around the world has made the multi-messenger detection of gravitational-wave (GW) events a reality. These joint detections allow us to probe GW sources in greater detail and provide us with the possibility of confidently establishing events that would not have been detected in GW data alone. In this Letter, we explore the prospects of using the electromagnetic (EM) follow-up of low-significance GW event candidates to increase the sample of confident detections with EM counterparts. We find that the GW-alert threshold change that would roughly double the number of detectable astrophysical events would increase the false-alarm rate (FAR) by more than five orders of magnitude from 1 per 100 years to more than 1000 per year. We find that the localization costs of following up low-significance candidates are marginal, as the same changes to FAR only increase distance/area localizations by less than a factor of 2 and increase volume localization by less than a factor of 4. We argue that EM follow-up thresholds for low-significance candidates should be set on the basis of alert purity (P_(astro)) and not FAR. Ideally, such estimates of P_(astro) would be provided by LIGO-Virgo, but in their absence we provide estimates of the average purity of the GW candidate alerts issued by LIGO-Virgo as a function of FAR for various LIGO-Virgo observing epochs