Geology topics

David J. Vales

Publications and source records attributed to David J. Vales.

5 recordsLinked to original sources

USGS2015

Elk monitoring in Mount Rainier and Olympic national parks: 2008-2011 synthesis report

In 2008, the USGS collaborated with the NPS, the Muckleshoot and Puyallup Indian Tribes, and WDFW to develop a protocol tor monitor changes in abundance, population composition, and spatial distribution of elk on summer ranges in MORA and OLYM and winter ranges in OLYM. We developed double-observer sightability (DO-S) models that adjusted raw counts of elk as a function of factors influencing detection probabilities from the air, e.g. vegetation, elk group size, light, elk activity, and pilot experience. We plan to develop DO-S models for both MORA and OLYM summer ranges, but due to radiotelemetry collar failures in OLYM, we do not yet have enough data to model detection probabilities in OLYM. We analyzed results of the first 4 years of elk monitoring conducted under the new protocol from 2008-2011. Objectives of this first synthetic analysis are to: • update the DO-S model for MORA aerial survey results • examine abundance, composition, and distribution of elk trends in MORA summer ranges • establish a baseline of counts, population composition, and distribution of elk in OLYM summer ranges • examine trends in counts and distribution of elk in OLYM low-elevation winter ranges during early spring • determine environmental factors influencing abundance and composition of elk in selected MORA summer ranges and unadjusted counts of elk on selected OLYM winter ranges • review progress in developing a DO-S model for OLYM elk surveys • examine aerial survey operations and provide suggestions for future surveys. There was no trend in elk numbers in the N. Rainier TCA from 2008-2011; the trend in the S. Rainier TCA was not statistically significant but increased 3.3%/year. Maximum counts increased in the N. Rainier TCA ~6%/year. Maximum counts in the S. Rainier TCA increased at a rate of 17% annually. Due to failed radiocollars, weather, and other problems, we completed surveys in 2 of 5 OLYM summer range TCAs; no trend data are available. In OLYM winter ranges, we surveyed the Hoh TCA during early spring 2008-10 and of the S. Fork Hoh and Queets in 2008 and 2010. No surveys were done for early-spring counts in 2011 and 2012 due to high snowfall and lack of funding. Legacy early-spring surveys in OLYM since 1985 allowed us to assess trends in counts in the early-spring TCAs from 1985-2010. Counts of elk in the early-spring TCAs declined: 63% in the S. Fork Hoh, 18% in the Hoh, and 22% in the Queets Valley. We continue to develop and improve the DO-S model for application to OLYM summer surveys. In the next synthesis report, we will update findings with additional data following the 2015 field season, based on 8 years of survey results; it will be a more complete analysis of elk population trends.

Washington↗

USGS2013

A hybrid double-observer sightability model for aerial surveys

Raw counts from aerial surveys make no correction for undetected animals and provide no estimate of precision with which to judge the utility of the counts. Sightability modeling and double-observer (DO) modeling are 2 commonly used approaches to account for detection bias and to estimate precision in aerial surveys. We developed a hybrid DO sightability model (model M H ) that uses the strength of each approach to overcome the weakness in the other, for aerial surveys of elk (Cervus elaphus). The hybrid approach uses detection patterns of 2 independent observer pairs in a helicopter and telemetry-based detections of collared elk groups. Candidate M H models reflected hypotheses about effects of recorded covariates and unmodeled heterogeneity on the separate front-seat observer pair and back-seat observer pair detection probabilities. Group size and concealing vegetation cover strongly influenced detection probabilities. The pilot's previous experience participating in aerial surveys influenced detection by the front pair of observers if the elk group was on the pilot's side of the helicopter flight path. In 9 surveys in Mount Rainier National Park, the raw number of elk counted was approximately 80–93% of the abundance estimated by model M H . Uncorrected ratios of bulls per 100 cows generally were low compared to estimates adjusted for detection bias, but ratios of calves per 100 cows were comparable whether based on raw survey counts or adjusted estimates. The hybrid method was an improvement over commonly used alternatives, with improved precision compared to sightability modeling and reduced bias compared to DO modeling.

Washington↗

USGS2013

Mount Rainier National Park and Olympic National Park elk monitoring program annual report 2011

Fiscal year 2011 was the first year of implementing an approved elk monitoring protocol in Mount Rainier (MORA) and Olympic (OLYM) National Parks in the North Coast and Cascades Network (NCCN) (Griffin et al. 2012). However, it was the fourth and second year of gathering data according to protocol in MORA and OLYM respectively; data gathered during the protocol development phase followed procedures that are laid out in the protocol. Elk monitoring in these large wilderness parks relies on aerial surveys from a helicopter. Summer surveys are intended to provide quantitative estimates of abundance, sex and age composition, and distribution of migratory elk in high elevation trend count areas. An unknown number of elk is not detected during surveys; however the protocol estimates the number of missed elk by applying a model that accounts for detection bias. Detection bias in elk surveys in MORA is estimated using a double-observer sightability model that was developed using survey data from 2008-2010 (Griffin et al. 2012). That model was developed using elk that were previously equipped with radio collars by cooperating tribes. At the onset of protocol development in OLYM there were no existing radio-collars on elk. Consequently the majority of the effort in OLYM in the past 4 years has been focused on capturing and radio-collaring elk and conducting sightability trials needed to develop a double-observer sightability model in OLYM. In this annual report we provide estimates of abundance and composition for MORA elk, raw counts of elk made in OLYM, and describe sightability trials conducted in OLYM. At MORA the North trend count area was surveyed twice and the South once (North Rainier herd, and South Rainier herd). We counted 373 and 267 elk during two replicate surveys of the North Rainier herd, and 535 elk in the South Rainier herd. Using the model, we estimated that 413 and 320 elk were in the North and 652 elk were in the South trend count areas during the time of the respective surveys. At OLYM, the Core and Northwest trend count areas were completely surveyed, as were portions of the Quinault. In addition, we surveyed 10 survey units specifically to get resight data. Two-hundred and forty eight elk were counted in the Core, 19 in the Northwest, and 169 in the Quinault. We conducted double-observer sightability trials associated with 14 collared elk groups for use in developing the double-observer sightability model for OLYM.

Washington↗

USGS2010

Revisions of rump fat and body scoring indices for deer, elk, and moose

Because they do not require sacrificing animals, body condition scores (BCS), thickness of rump fat (MAXFAT), and other similar predictors of body fat have advanced estimating nutritional condition of ungulates and their use has proliferated in North America in the last decade. However, initial testing of these predictors was too limited to assess their reliability among diverse habitats, ecotypes, subspecies, and populations across the continent. With data collected from mule deer ( Odocoileus hemionus ), elk ( Cervus elaphus ), and moose ( Alces alces ) during initial model development and data collected subsequently from free-ranging mule deer and elk herds across much of the western United States, we evaluated reliability across a broader range of conditions than were initially available. First, to more rigorously test reliability of the MAXFAT index, we evaluated its robustness across the 3 species, using an allometric scaling function to adjust for differences in animal size. We then evaluated MAXFAT, rump body condition score (rBCS), rLIVINDEX (an arithmetic combination of MAXFAT and rBCS), and our new allometrically scaled rump-fat thickness index using data from 815 free-ranging female Roosevelt and Rocky Mountain elk ( C. e. roosevelti and C. e. nelsoni ) from 19 populations encompassing 4 geographic regions and 250 free-ranging female mule deer from 7 populations and 2 regions. We tested for effects of subspecies, geographic region, and captive versus free-ranging existence. Rump-fat thickness, when scaled allometrically with body mass, was related to ingesta-free body fat over a 38–522-kg range of body mass ( r 2 = 0.87; P < 0.001), indicating the technique is remarkably robust among at least the 3 cervid species of our analysis. However, we found an underscoring bias with the rBCS for elk that had >12% body fat. This bias translated into a difference between subspecies, because Rocky Mountain elk tended to be fatter than Roosevelt elk in our sample. Effects of observer error with the rBCS also existed for mule deer with moderate to high levels of body fat, and deer body size significantly affected accuracy of the MAXFAT predictor. Our analyses confirm robustness of the rump-fat index for these 3 species but highlight the potential for bias due to differences in body size and to observer error with BCS scoring. We present alternative LIVINDEX equations where potential bias from rBCS and bias due to body size are eliminated or reduced. These modifications improve the accuracy of estimating body fat for projects intended to monitor nutritional status of herds or to evaluate nutrition's influence on population demographics.

Journal of Wildlife Diseases↗

USGS2010

Mount Rainier National Park and Olympic National Park Elk Monitoring Program Annual Report 2010

Fiscal year 2010 was the third year of gathering data needed for protocol development while simultaneously implementing what is expected to be the elk monitoring protocol at Mount Rainier (MORA) and Olympic (OLYM) national parks in the North Coast and Cascades Network (NCCN). Elk monitoring in these large wilderness parks relies on aerial surveys from a helicopter. Summer surveys are planned for both parks and are intended to provide quantitative estimates of abundance, sex and age composition, and distribution of migratory elk in high elevation trend count areas. Spring surveys are planned at Olympic National Park and are intended to provide quantitative estimates of abundance of resident and migratory elk on low-elevation winter ranges within surveyed trend count areas. An unknown number of elk is not detected during surveys. The protocol under development aims to estimate the number of missed elk by applying a model that accounts for detection bias. Detection bias in elk surveys in MORA will be estimated using a double-observer sightability model that was developed based on data from surveys conducted in 2008-2010. The model was developed using elk that were previously equipped with radio collars by cooperating tribes. That model is currently in peer review. At the onset of protocol development in OLYM there were no existing radio- collars on elk. Consequently double-observer sightability models have not yet been developed for elk surveys in OLYM; the majority of the effort in OLYM has been focused on capturing and radio collaring elk to permit the development of sightability models for application in OLYM. As a result, no estimates of abundance or composition are included in this annual report, only raw counts of the numbers of elk seen in surveys. At MORA each of the two trend count areas (North Rainier herd, and South Rainier herd) were surveyed twice. 290 and 380 elk were counted on the two replicates in the North Rainier herd, and 621 and 327 elk counted on the two replicate South Rainier counts. At Olympic National Park, each of three spring trend count areas was surveyed once in March 2010. 27 elk were observed in the South Fork Hoh trend count area, 137 elk were observed in the Hoh trend count area, and 131 elk were observed in the Queets trend count area. In September 2010, 18 elk were captured and fitted with radio collars as part of a contracted animal capture, eradication and tagging of animals (ACETA) operation. These animals will be available to contribute double-observer sightability data in future spring and summer surveys. There were no summer surveys for elk in OLYM in 2010.

Washington↗