Mammal Capture Success of Scent Stations and Remote Cameras in Prairie and Forest Habitat

Two common noninvasive (i.e., no stress to the animal) methods used to survey mammals include track stations (i.e., track captures of mammals) and remote camera-traps (i.e., photo-captures of mammals). Our objectives were to compare capture effectiveness of both track stations and remote cameras in both forested and prairie habitats. This project was conducted on 4 study sires (2 forested sires and 2 prairie sites) located in Fayette County, Iowa. Each study site had 6 trapping stations 2:: 100 m apart. We monitored traps for a total of 216 trap nights and we recorded a total of 368 captures composed of 19 different mammal species. We found that in forest habitat remote camera-traps captured significantly more mammals compared to track stations (n = 53) (P\u3c0.01; df = 1) while in prairie habitat we found no significant difference in the number of mammals captured between trap sires (P=0.27; df = 1). We recommend the use of digital remote cameras with no glow infrared technology in combination with the monitoring of mammal tracks to maximize mammal capture effectiveness

Use of Soil Chemical Analysis to Detect Commercial Wildlife Game Baits

Hunters and poachers often use commercially-available, nutrient-rich baits to attract wildlife game animals. We used atomic absorption spectroscopy and ion selective electrochemical analysis techniques to determine whether two common proprietary baits (Deer Cane and Acorn Rage) would leave detectable chemical signatures in soil (i.e., Na+, Cl-, and Ca+2). Our goal was to evaluate low cost tests which could be replicated by wildlife conservation officers in the field. To complete the evaluation we randomly placed two commercial baits on 3 sites in The Millersville University Biological Preserve in Millersville, PA. We collected soils samples from each site over the course of 35 days after bait placement to conduct our soil chemical analysis. We found that baited soils consistently exhibited higher concentrations of Na+ and Cl- compared to control soils. The levels of Na+ on baited soils for the first 3 weeks for both bait sites averaged 3,209 ppm and 4,056 ppm and these levels were substantially higher than average and median concentrations of Na+ found on wild natural lick sites in North America. The simple low-cost techniques we used to test baited soils, NaCl Insta-TEST strips and ‘Acetic Acid’ test, proved effective in detecting the higher concentrations of Na+ and Cl-. These inexpensive field tests may provide wildlife conservation officers a simple tool to verify the use of commercial wildlife baits in areas under investigation for illegal baiting. We recommend that future evaluations of commercial wildlife baits in soils include data on heavy rainfall events, soil type, bait placement and duration

A Method for Determining Asymptotes of Home-Range Area Curves

Home-range area curves are used to estimate the number of locations needed to accurately estimate home range size based on the asymptote of the curve. However, the current methodology used to identify asymptotes for home-range area curves is largely subjective and varies between studies. Our objective was to evaluate the use of exponential, Gompertz, logistic, and reciprocal function models as a means for identifying asymptotes of home-range area curves. We radio monitored northern bobwhite (Colinus virginianus) coveys during mid-September through November 2001-2002 in Jim Hogg County, Texas. We calculated home-range size of radiomarked coveys using the 95% fixed kernel with least squares cross validation and minimum convex polygon estimators. We fitted area observations and coefficient of variation to the number of locations using exponential, Gompertz, logistic, and reciprocal function models to estimate the minimum number of locations necessary to obtain a representative home range size for each home range estimator. The various function models consistently provided a relatively good fit for home range area curves and coefficient of variation curves (0.58 ≤ R2 0.99; P \u3c 0.05) for both home range estimators. We used an information-theoretic framework (AICC) to select the best model to estimate area-curve asymptotes. The use of function models appears to provide a structured and useful approach for calculating area-curve asymptotes. We propose that researchers consider the use of such models when determining asymptotes for home-range area curves and that more research be conducted to validate the strength of this method

Non-native insects dominate daytime pollination in a high-elevation Hawaiian dryland ecosystem

PREMISE OF THE STUDY: Over one-third of the native flowering plant species in the Hawaiian Islands are listed as federally threatened or endangered. Lack of sufficient pollination could contribute to reductions in populations, reproduction, and genetic diversity among these species but has been little studied. METHODS: We used systematic observations and manual flower treatments to quantify flower visitation and outcrossing dependency of eight native (including four endangered) plant species in a dryland ecosystem in Hawaii: Argemone glauca, Bidens menziesii, Dubautia linearis, Haplostachys haplostachya, Sida fallax, Silene lanceolata, Stenogyne angustifolia, and Tetramolopium arenarium. KEY RESULTS: During 576.36 h of flower observations, only insects visited the flowers. Out of all recorded flower visits, 85% were performed by non-native species, particularly the honeybee (Apis mellifera) and flies in the family Syrphidae. Some plant species received little visitation (e.g., S. angustifolia received one visit in 120 h of observation), whereas others were visited by a wide diversity of insects. The endangered plant species were visited by fewer visitor taxa than were the common native plant species. For six of the focal plant species, bagging of flowers to exclude pollinators resulted in significant reductions in seed set. CONCLUSIONS: The flower visitor community in this system, although heavily dominated by non-native insects, appears to be facilitating pollination for multiple plant species. Non-native insects may thus be sustaining biotic interactions otherwise threatened with disruption in this island ecosystem. This may be particularly important for the studied endangered plant species, which exhibit fewer partners than the more common plant species

Absence of native flower visitors for the endangered Hawaiian mint \u3ci\u3eStenogyne angustifolia\u3c/i\u3e: Impending ecological extinction?

If an organism becomes rare enough that it no longer participates in certain interspecific interactions, it can be said to have become ecologically extinct, even though it is still present. This form of extinction is much less recognized than global extinctions, although it may have ramifications for ecological community function. Here, we describe a case of possible or pending ecological extinction of an endemic Hawaiian plant. We performed over 120 h of systematic flower visitation observations of the endangered Hawaiian mint, Stenogyne angustifolia, in its wild habitat. The robust size and open shape of S. angustifolia flowers, along with their high accessibility, visibility, and nectar content, suggest that they are adapted to animal-mediated pollination. However, only one flower visitor was observed at our focal high-elevation study site: an individual of the non-native bee species Lasioglossum impavidum. Experimental pollination treatments indicate that S. angustifolia is self-compatible and demonstrates some autogamy, setting fruit and seed in the absence of pollinators. However, experimental additions of pollen increased fruit production, indicating that plants are pollen-limited and that lack of pollinators carries a reproductive cost for this species. Ecological communities throughout Hawaii are highly modified, and the distribution and diversity of the native pollinator community that occurred with S. angustifolia prior to these changes are wholly unknown. Nevertheless, the lack of visitation by native pollinators and extremely rare visitation by non-native pollinators suggest that this plant is today contributing little to pollination networks in its high-elevation habitat

Operationalizing resilience for conservation objectives: the 4S’s

Although resilience thinking is increasingly popular and attractive among restoration practitioners, it carries an abstract quality that hinders effective application. Because resilience and its components are defined differently in social and ecological contexts, individual managers or stakeholders may disagree on the definition of a system’s state, occurrence of a state change, preferred state characteristics, and appropriate methods to achieve success. Nevertheless, incentives and mandates often force managers to demonstrate how their work enhances resilience. Unclear or conflicting definitions can lead to ineffective or even detrimental decision-making in the name of resilience; essentially, any convenient action can be touted as resilience-enhancing in this case. We contend that any successful resilience management project must clearly identify up-front the stressors of concern, state traits, scales of appropriate management, and success indicators (the 4S’s) relevant to the management targets. We propose a deliberate process for determining these components in advance of resilience management for conservation. Our recommendations were inspired and informed by two case studies wherein different definitions of stressors, state, scales, and success would result in very different management choices, with potentially serious consequences for biodiversity targets

Invasive predators affect community-wide pollinator visitation

Disruption of plant–pollinator interactions by invasive predators is poorly understood but may pose a critical threat for native ecosystems. In a multiyear field experiment in Hawai’i, we suppressed abundances of globally invasive predators and then observed insect visitation to flowers of six native plant species. Three plant species are federally endangered (Haplostachys haplostachya, Silene lanceolata, Tetramolopium arenarium) and three are common throughout their range (Bidens menziesii, Dubautia linearis, Sida fallax). Insect visitors were primarily generalist pollinators, including taxa that occur worldwide such as solitary bees (e.g., Lasioglossum impavidum), social bees (e.g., Apis mellifera), and syrphid flies (e.g., Allograpta exotica). We found that suppressing invasive rats (Rattus rattus), mice (Mus musculus), ants (Linepithema humile, Tapinoma melanocephalum), and yellowjacket wasps (Vespula pensylvanica) had positive effects on pollinator visitation to plants in 16 of 19 significant predator–pollinator–plant interactions. We found only positive effects of suppressing rats and ants, and both positive and negative effects of suppressing mice and yellowjacket wasps, on the frequency of interactions between pollinators and plants. Model results predicted that predator eradication could increase the frequency of insect visitation to flowering species, in some cases by more than 90%. Previous results from the system showed that these flowering species produced significantly more seed when flowers were allowed to outcross than when flowers were bagged to exclude pollinators, indicating limited autogamy. Our findings highlight the potential benefits of suppression or eradication of invasive rodents, ants, and yellowjackets to reverse pollination disruption, particularly in locations with high numbers of at-risk plant species or already imperiled pollinator populations

The Variation of the Galaxy Luminosity Function with Group Properties

We explore the shape of the galaxy luminosity function (LF) in groups of different mass by creating composite LFs over large numbers of groups. Following previous work using total group luminosity as the mass indicator, here we split our groups by multiplicity and by estimated virial (group halo) mass, and consider red (passive) and blue (star forming) galaxies separately. In addition we utilise two different group catalogues (2PIGG and Yang et al.) in order to ascertain the impact of the specific grouping algorithm and further investigate the environmental effects via variations in the LF with position in groups. Our main results are that LFs show a steepening faint end for early type galaxies as a function of group mass/ multiplicity, with a much suppressed trend (evident only in high mass groups) for late type galaxies. Variations between LFs as a function of group mass are robust irrespective of which grouping catalogue is used, and broadly speaking what method for determining group `mass' is used. We find in particular that there is a significant deficit of low-mass passive galaxies in low multiplicity groups, as seen in high redshift clusters. Further to this, the variation in the LF appears to only occur in the central regions of systems, and in fact seems to be most strongly dependent on the position in the group relative to the virial radius. Finally, distance-rank magnitude relations were considered. Only the Yang groups demonstrated any evidence of a correlation between a galaxy's position relative to the brightest group member and its luminosity. 2PIGG possessed no such gradient, the conclusion being the FOF algorithm suppresses the signal for weak luminosity--position trends and the Yang grouping algorithm naturally enhances it.Comment: 20 pages, 29 figures, accepted for submission to MNRA

Achieving the Millennium Development Goals: Does Mental Health Play a Role?

Miranda and Patel argue that mental disorders are among the most important causes of disability and premature mortality in developing countries