Geology topics

Robert C. Boyd

Publications and source records attributed to Robert C. Boyd.

4 recordsLinked to original sources

USGS2017

Enhancing wind erosion monitoring and assessment for U.S. rangelands

On the Ground Wind erosion is a major resource concern for rangeland managers because it can impact soil health, ecosystem structure and function, hydrologic processes, agricultural production, and air quality. Despite its significance, little is known about which landscapes are eroding, by how much, and when. The National Wind Erosion Research Network was established in 2014 to develop tools for monitoring and assessing wind erosion and dust emissions across the United States. The Network, currently consisting of 13 sites, creates opportunities to enhance existing rangeland soil, vegetation, and air quality monitoring programs. Decision-support tools developed by the Network will improve the prediction and management of wind erosion across rangeland ecosystems.

Rangelands↗

USGS2011

Variation in spring harvest rates of male wild turkeys in New York, Ohio, and Pennsylvania

Spring harvest rates of male wild turkeys ( Meleagris gallapavo ) influence the number and proportion of adult males in the population and turkey population models have treated harvest as additive to other sources of mortality. Therefore, hunting regulations and their effect on spring harvest rates have direct implications for hunter satisfaction. We used tag recovery models to estimate survival rates, investigate spatial, temporal, and demographic variability in harvest rates, and assess how harvest rates may be related to management strategies and landscape characteristics. We banded 3,266 male wild turkeys throughout New York, Ohio, and Pennsylvania during 2006–2009. We found little evidence that harvest rates varied by year or management zone. The proportion of the landscape that was forested within 6.5 km of the capture location was negatively related to harvest rates; however, even though the proportion forested ranged from 0.008 to 0.96 across our study area, this corresponded to differences in harvest rates of only 2–5%. Annual survival was approximately twice as high for juveniles as adults . In turn, spring harvest rates for adult turkeys were greater for adults than juveniles . We estimated the population of male turkeys in New York and Pennsylvania ranged from 104,000 to 132,000 in all years and ranged from 63,000 to 75,000 in Ohio. Because of greater harvest rates for adult males, the proportion of adult males in the population was less than in the harvest and ranged from 0.40 to 0.81 among all states and years. The high harvest rates observed for adults may be offset by greater recruitment of juveniles into the adult age class the following year such that these states can sustain high harvest rates yet still maintain a relative high proportion of adult males in the harvest and population.

New York, Ohio, Pennsylvania↗

USGS2010

Loss of butt-end leg bands on male wild turkeys

We estimated loss of butt-end leg bands on male wild turkeys ( Meleagris gallapavo ) captured in New York, Ohio, and Pennsylvania (USA) during December–March, 2006–2008. We used aluminum rivet leg bands as permanent marks to estimate loss of regular aluminum, enameled aluminum, anodized aluminum, and stainless steel butt-end leg bands placed below the spur. We used band loss information from 887 turkeys recovered between 31 days and 570 days after release ( x¯ = 202 days). Band loss was greater for turkeys banded as adults (>1 yr old) than juveniles and was greater for aluminum than stainless steel bands. We estimated band retention was 79–96%, depending on age at banding and type of band, for turkeys recovered 3 months after release. Band retention was <50% for all age classes and band types 15 months after banding. We concluded that use of butt-end leg bands on male wild turkeys is inappropriate for use in mark–recapture studies.

New York, Ohio, Pennsylvania↗

USGS2004

From the field: Efficacy of detecting Chronic Wasting Disease via sampling hunter-killed white-tailed deer

Surveillance programs for Chronic Wasting Disease (CWD) in free-ranging cervids often use a standard of being able to detect 1% prevalence when determining minimum sample sizes. However, 1% prevalence may represent >10,000 infected animals in a population of 1 million, and most wildlife managers would prefer to detect the presence of CWD when far fewer infected animals exist. We wanted to detect the presence of CWD in white-tailed deer ( Odocoileus virginianus ) in Pennsylvania when the disease was present in only 1 of 21 wildlife management units (WMUs) statewide. We used computer simulation to estimate the probability of detecting CWD based on a sampling design to detect the presence of CWD at 0.1% and 1.0% prevalence (23-76 and 225-762 infected deer, respectively) using tissue samples collected from hunter-killed deer. The probability of detection at 0.1% prevalence was <30% with sample sizes of ???6,000 deer, and the probability of detection at 1.0% prevalence was 46-72% with statewide sample sizes of 2,000-6,000 deer. We believe that testing of hunter-killed deer is an essential part of any surveillance program for CWD, but our results demonstrated the importance of a multifaceted surveillance approach for CWD detection rather than sole reliance on testing hunter-killed deer.

Pennsylvania↗