Determinants of a Quality Wild Turkey Hunting Season

According to the National Wild Turkey Federation, there has been a 450% increase in the number of licensed wild turkey hunters since 1973. Unfortunately, there is a paucity of research articles focusing specifically on turkey hunting. Most human dimensions of wildlife research have focused on either deer or waterfowl hunting. In this study, dimensions of hunting quality, days afield, and harvest were examined among a sample of 739 Virginia fall turkey hunters. Quality of a hunting season, rather than a specific hunt, was examined. Principal components analysis (PCA) revealed five domains of attributes of a high-quality turkey-hunting season: wildlife interaction, education, being away, social interaction, and hunting skills. The domains of hunting quality revealed by the PCA are similar to domains found previously for spring turkey hunters as well as other types of hunters. Also examined were hunter perceptions of overall hunting quality, the number of days spent hunting turkeys during the fall season, and harvest success. For comparative purposes and agency needs, hunters were segmented into three categories based on days spent hunting: low frequency (1 to 2 days), medium frequency (3 to 4 days), and high frequency (≥5 days). The influence of these variables to respondents’ perceptions of overall quality was examined using a series of regression models. Variables found to be significant predictors of quality were wildlife interaction and harvest success. Hunters who killed a turkey reported a significantly higher quality season than those who did not kill a turkey.     

A Comparison of Protocols and Observer Precision for Measuring Physical Stream Attributes1

Abstract: Stream monitoring programs commonly measure physical attributes to assess the effect of land management on stream habitat. Variability associated with the measurement of these attributes has been linked to a number of factors, but few studies have evaluated variability due to differences in protocols. We compared six protocols, five used by the U.S. Department of Agriculture Forest Service and one by the U.S. Environmental Protection Agency, on six streams in Oregon and Idaho to determine whether differences in protocol affect values for 10 physical stream attributes. Results from Oregon and Idaho were combined for groups participating in both states, with significant differences in attribute means for 9 out of the 10 stream attributes. Significant differences occurred in 5 of 10 in Idaho, and 10 of 10 in Oregon. Coefficients of variation, signal‐to‐noise ratio, and root mean square error were used to evaluate measurement precision. There were differences among protocols for all attributes when states were analyzed separately and as a combined dataset. Measurement differences were influenced by choice of instruments, measurement method, measurement location, attribute definitions, and training approach. Comparison of data gathered by observers using different protocols will be difficult unless a core set of protocols for commonly measured stream attributes can be standardized among monitoring programs.     

Pulling up roots in the 1990s: Who's willing to relocate?

The purpose of this study was to develop a profile of employees in Fortune 500 companies who are willing to relocate. The profile was developed on a demographically diverse random sample of 827 employees from 20 Fortune 500 corporations, all of whom had moved at least once for their current employer. Employees who were most willing to relocate were younger, their incomes were lower, their career ambitions higher, and their spouses more willing than those who were less willing to relocate. These employees could be found in sales/marketing and production functions. Their attitudes toward moving were also favorable. The single most important predictor of willingness to relocate was spouse willingness to relocate. This result suggests strongly that in the 1990s, corporations are going to have to address the concerns of spouses, if married employees are going to remain mobile. The study also cautions corporations about the shortsightedness of thinking of spouse and dual career issues as ’women's issues‘ and assuming that females and minorities are unwilling to relocate.     

Cowbird removals unexpectedly increase productivity of a brood parasite and the songbird host

Generalist brood parasites reduce productivity and population growth of avian hosts and have been implicated in population declines of several songbirds of conservation concern. To estimate the demographic effects of brood parasitism on Bell's Vireos (Vireo bellii), we removed Brown-headed Cowbirds (Molothrus ater) in a replicated switchback experimental design. Cowbird removals decreased parasitism frequency from 77% and 85% at unmanipulated plots to 58% and 47% at removal plots in 2004 and 2005, respectively. Vireo productivity per pair was higher at cowbird removal plots when years were pooled (mean = 2.6 +/- 0.2 [SE] young per pair) compared to unmanipulated plots (1.2 +/- 0.1). Nest desertion frequency was lower at cowbird removal plots (35% of parasitized nests) compared to unmanipulated plots (69%) because removal of host eggs was the proximate cue for nest desertion, and vireos experienced lower rates of egg loss at cowbird removal plots. Nest success was higher among unparasitized than parasitized nests, and parasitized nests at cowbird removal plots had a higher probability of success than parasitized nests at unmanipulated plots. Unexpectedly, cowbird productivity from vireo pairs was higher at cowbird removal plots (mean = 0.3 +/- 0.06 young per pair) than at unmanipulated plots (0.1 +/- 0.03) because fewer parasitized nests were deserted and the probability of nest success was higher. Our study provides the first evidence that increases in cowbird productivity may be an unintended consequence of cowbird control programs, especially during the initial years of trapping when parasitism may only be moderately reduced. Thus, understanding the demographic impacts of cowbird removals requires an informed understanding of the behavioral ecology of host-parasite interactions.     

Using circuit theory to model connectivity in ecology, evolution, and conservation

Connectivity among populations and habitats is important for a wide range of ecological processes. Understanding, preserving, and restoring connectivity in complex landscapes requires connectivity models and metrics that are reliable, efficient, and process based. We introduce a new class of ecological connectivity models based in electrical circuit theory. Although they have been applied in other disciplines, circuit-theoretic connectivity models are new to ecology. They offer distinct advantages over common analytic connectivity models, including a theoretical basis in random walk theory and an ability to evaluate contributions of multiple dispersal pathways. Resistance, current, and voltage calculated across graphs or raster grids can be related to ecological processes (such as individual movement and gene flow) that occur across large population networks or landscapes. Efficient algorithms can quickly solve networks with millions of nodes, or landscapes with millions of raster cells. Here we review basic circuit theory, discuss relationships between circuit and random walk theories, and describe applications in ecology, evolution, and conservation. We provide examples of how circuit models can be used to predict movement patterns and fates of random walkers in complex landscapes and to identify important habitat patches and movement corridors for conservation planning.     

Marine protected areas for deepwater fish populations: an evaluation of their effects in Hawai’i

The success of marine protected areas (MPAs) as a tool for conservation and fisheries management has been well documented. However, these results have typically been seen in shallow water systems and questions remain whether this management strategy could be successfully applied to deepwater ecosystems. Our objectives were to determine the efficacy of four deepwater MPAs called bottomfish restricted fishing areas (BRFAs), with various time spans of protection, monitored at depths between 90 and 310 m from 2007 to 2011 for six species of deepwater snapper and one grouper harvested in the Main Hawaiian Islands. Our results suggested that the duration of protection influenced reserve effects, particularly for target species. Mean fish length, and in some cases abundance, increased for one or more of the most economically important target species inside nearly all tested BRFAs. In addition, more mature fish were seen inside the BRFA with the longest duration of protection (~14 years); species richness increased outside this area while inside it remained the same. Here, we provide the first evidence that deepwater MPAs can have positive effects on deepwater species and that many protection effects were consistent with results found in shallow water ecosystems. While these findings are novel, additional data over greater temporal scales will be necessary to determine whether these trends will continue and if others will become important over time.     

Comparison of heavy metal loads in stormwater runoff from major and minor urban roads using pollutant yield rating curves

Trace metal export by stormwater runoff from a major road and local street in urban Sydney, Australia, is compared using pollutant yield rating curves derived from intensive sampling data. The event loads of copper, lead and zinc are well approximated by logarithmic relationships with respect to total event discharge owing to the reliable appearance of a first flush in pollutant mass loading from urban roads. Comparisons of the yield rating curves for these three metals show that copper and zinc export rates from the local street are comparable with that of the major road, while lead export from the local street is much higher, despite a 45-fold difference in traffic volume. The yield rating curve approach allows problematic environmental data to be presented in a simple yet meaningful manner with less information loss.     

Comment on “A Reanalysis of Long-Term Surface Air Temperature Trends in New Zealand”

de Freitas et al. (2015) (henceforth dFDB) report a trend of 0.28 °C per century over the period 1909–2009 for New Zealand land surface temperatures, from their reanalysis of a composite of seven long-term records. This is much lower than the warming trend of about 0.9 °C per century reported previously by other researchers and much smaller than trends estimated from independent sea surface temperature data from the surrounding region. We show these differences result primarily from the way inhomogeneities in temperature time series at individual stations due to site or instrument changes are identified and adjusted for in the dFDB paper. The adjustments reported in that paper are based on a method designed by one of us (Salinger), but use only a short (1–2-year) overlap period with comparison stations and consider only inhomogeneities in monthly mean (rather than monthly maximum and minimum) temperatures. This leads to underestimates of the statistical significance of individual temperature discontinuities and hence rejection of many valid adjustments. Since there was a systematic tendency for the seven-station sites to be relocated to colder locations as the early half of the twentieth century progressed, this rejection of valid adjustments produces an artificially low rate of warming. We therefore disagree with the trend calculations in the dFDB paper and consider there is no reason to reject the previous estimates of around 0.9 °C warming per century.     

Demonstrating the In Situ Biodegradation Potential of Phenol Using Bio‐Sep® Bio‐Traps® and Stable Isotope Probing

The effect of phenol concentration on phenol biodegradation at an industrial site in the south of Wales, United Kingdom, was investigated using standard Bio‐Sep^® Bio‐Traps^® and Bio‐Traps^® coupled with stable isotope probing (SIP). Unlike many ¹³C‐amendments used in SIP studies (such as hydrocarbons) that physically and reversibly adsorb to the activated carbon component of the Bio‐Sep^® beads, phenol is known to irreversibly chemisorb to activated carbon. Bio‐Traps^® were deployed for 32 days in nine site groundwater monitoring wells representing a wide range of phenol concentrations. Bio‐Traps^® amended with ¹³C‐phenol were deployed together with non‐amended Bio‐Traps® in three wells. Quantitative polymerase chain reaction (qPCR) analysis of Bio‐Traps^® post‐deployment indicated an inhibitory effect of increasing phenol concentration on both total eubacteria and aerobic phenol‐utilizing bacteria as represented by the concentration of phenol hydroxylase gene. Despite the chemisorption of phenol to the Bio‐Sep^® beads, activated carbon stable isotope analysis showed incorporation of ¹³C into biomass and dissolved inorganic carbon (DIC) in each SIP Bio‐Trap^® indicating that chemisorbed amendments are bioavailable. However, there was a clear effect of phenol concentration on ¹³C incorporation in both biomass and DIC confirming phenol inhibition. These results suggest that physical reductions of the phenol concentrations in some areas of the plume will be required before biodegradation of phenol can proceed at a reasonable rate. © 2013 Wiley Periodicals, Inc.