Bias associated with baited camera sites for assessing population characteristics of deer

Camera surveys often involve placing bait in front of the camera to capture animals more frequently, which could introduce biases in parameter estimates. From September 2008 to March 2009, we monitored cameras placed at random, along game trails, and at feed stations to determine if camera placement influenced measures of population demographics in a herd of white-tailed deer (Odocoileus virginianus). There was no time period in which cameras placed at feed stations provided sex ratio and recruitment estimates similar to those acquired from randomly placed cameras. Trail-based camera surveys provided population estimates similar to those from random sites and may provide a feasible alternative to using baited camera stations. © 2011 The Wildlife Society.     

Efficiency of time-lapse intervals and simple baits for camera surveys of wild pigs

Growing concerns surrounding established and expanding populations of wild pigs (Sus scrofa) have created the need for rapid and accurate surveys of these populations. We conducted surveys of a portion of the wild pig population on Fort Benning, Georgia, to determine if a longer time-lapse interval than had been previously used in surveys of wild pigs would generate similar detection results. We concurrently examined whether use of soured corn at camera sites affected the time necessary for pigs to locate a new camera site or the time pigs remained at a site. Our results suggest that a 9-min time-lapse interval generated dependable detection results for pigs and that soured corn neither attracted pigs to a site any quicker than plain, dry, whole-kernel corn, nor held them at a site longer. Maximization of time-lapse interval should decrease data and processing loads, and use of a simple, available bait should decrease cost and effort associated with more complicated baits; combination of these concepts should increase efficiency of wild pig surveys. © 2011 The Wildlife Society.     

BaitsTools: Software for hybridization capture bait design

Nucleic acid hybridization capture is a principal technology in molecular ecology and genomics. Bait design, however, is a nontrivial task and few resources currently exist to automate the process. Here, I present baitstools , an open‐source, user‐friendly software package to facilitate the design of nucleic acid baits for hybridization capture.     

An approach for identifying the influence of carcass type and environmental features on sarcosaprophagous Diptera communities

Summary. Since the entomosarcosaprophagous community is affected by environmental variables, it needs to be studied under different environmental conditions. In addition, because most studies are usually conducted with biomodels rather than human corpses, it is necessary to verify whether or not the type of decomposing animal matter affects the decomposition process itself, as well as the related fauna. For this reason, a study was conducted on the sarcosaprophagous Diptera community in two different environments of the Region of Murcia (SE Spain), using piglet and chicken carcasses, and Schoenly traps as collecting devices. To analyse possible differences regarding faunal composition among samples, a one-way Permutational Multivariate Analysis of Variance (PERMANOVA) was applied. The results indicate significant differences concerning the bait. In this sense, Calliphoridae, Muscidae, Fanniidae and Sarcophagidae families are the main groups responsible for such differences. In terms of environment-related differences, the only species that contribute are those of the dominant families, Calliphoridae and Muscidae.     

Patterns of feeding behaviour in adult male riodinid butterflies and their relationship to morphology and ecology

Adult butterflies are known to visit a wide variety of food substrates, but, with the exception of flower visitation, little is known about what substances are being sought or what determines substrate choice. This is especially true for the Riodinidae, a large family [c. 1300 spp.) of almost exclusively Neotropical butterflies. We present adult male feeding records for 124 species in 41 genera of Riodinidae (out of a total of 441 species in 85 genera collected in the study), based on ten months sampling in Ecuador. Records of food substrates visited in this study include flowers, damp sand or mud (‘puddling’) and rotting carrion. Rotting carrion placed in traps was the most frequently recorded food source in terms of numbers of individuals and taxa, attracting 89 species from 32 genera. A correlation is found between food substrate choice and morphology, specifically wing area to thoracic volume ratio (WA: TV ratio). Our data suggest the possible existence of two adaptive syndromes whose species have significantly different mean WA:TV ratios and differing suites of accompanying ecological traits, with lower ratios being significantiy correlated with species that were recorded feeding. Among species recorded feeding, carrion feeders and puddlers have significantly lower mean WA:TV ratios than flower nectarers, and carrion feeders have a lower mean WA:TV ratio than species not recorded on this food source, a correlation that is significant across all tribes and within some tribes (Riodinini and Saratoni). We reanalyse previously published data on flight and morphology for species in other butterfly and moth families and show mat the ratio of wing area to thoracic mass is significantly negatively correlated with flight speed and oxygen consumption (a direct indicator of metabolic rate). We suggest that adult male riodinids may puddle and feed at rotting carrion to supplement nutrient stores from larval feeding, not only to increase reproductive success, but also to provide the necessary nutrients to maintain high metabolic rates during rapid flight.     

Management of a German cockroach population with a juvenoid bait formulation: an experiment in residential buildings

Baits including 0.1% of ethyl 2-(4-((1,4-dioxaspiro [4.5]dec-6-yl) methyl) phenoxy) ethylcarbamate were applied in two buildings containing 46 apartments with various degrees of infestation of the German cockroach, Blattella germanica (L.). During a yearly experiment, generally 8 baits were placed in each apartment and replenished monthly at which time cockroach population density, demographic structure, and percentage of morphologically deformed adults were determined from specimens captured by stickytrap sampling. Initial growth of the cockroach population observed during the first two months after deposition of the baits was followed by an asymptotical decrease. Only 2.5% of the initial population remained at the end of the experiment. Although adults with twisted wings (sterile) constituted only 70% of the total adult catches, the decrease of the nymph/adult ratio from 2.9 to 0.7 indicated a far more profound inhibitory effect on cockroach reproduction. This study shows that baits might be an efficient alternative to juvenoid formulations currently in use for control of the German cockroach.     

Estimation of foraging territories of Reticulitermes grassei through mark–release–recapture

Subterranean termites have highly cryptic life habits and their foraging activities are as a rule confined to below-ground level gallery systems. Mark–release–recapture (MRR) using fat-soluble histological dyes is a candidate method for the study of foraging dynamics and territories, but has not hitherto been standardized experimentally. A wide range of dye types and concentrations is reported in the literature. In this study, six potential dyes were evaluated at different concentrations for marking workers of Reticulitermes grassei (Clément) (Isoptera: Rhinotermitidae), under laboratory and simulated field conditions. Neutral red (1% wt/wt) was considered the most effective while showing acceptably low toxicity. In a subsequent field trial using dye impregnated into a wooden bait, the MMR procedure was used to map the foraging territory perimeter of a single colony. Assumptions inherent in the interpretation of MMR data are reviewed. To map the foraging territory perimeter by this method, two theoretical approaches are defined (a conservative and a non-conservative hypothesis). We show that the approach adopted may affect the estimate obtained by as much as 100%. Results are discussed in the context of the ecology and behaviour of subterranean termite colonies.     

Invasive Snake Activity Before and After Automated Aerial Baiting

Aerially delivered toxic baits have proven effective for landscape-level control of numerous invasive vertebrate populations with major benefits for conservation and ecosystem function, but this technique has not been broadly adapted for control of invasive reptiles. Nonnative brown treesnakes (Boiga irregularis) on the Pacific island of Guam have caused severe ecological and economic damage and pose an invasion risk on other islands, making them a high-profile candidate for application of aerial baiting methods. Although terrestrial applications of traps, toxicants, and hand-removal are standard brown treesnake management practices, these methods are not cost-effective for control in the island's large tracts of remote, rugged forest. In 2016, the first major in situ evaluation of a helicopter-borne automated aerial bait delivery system applied snake-targeted toxic baits at an effective rate of approximately 120 baits/ha over a 110-ha forested test plot on Guam. We evaluated the extent and duration of the suppressive effect of this toxic bait application on brown treesnakes by measuring nontoxic bait take rates as a proxy index of relative snake abundance before and after toxic bait application in a treatment plot and surrounding reference area. We placed 4,420 nontoxic baits in random transects at georeferenced locations, from 1 month before until nearly 12 months after toxic bait application, allowing temporal analysis of the suppressive effect and spatial analysis of treatment plot reinvasion. Over the first 30 days after toxic bait application, average nontoxic bait take rate in the treatment plot was 41.2% lower than the pre-application rate, and there was no immediate decrease in bait take in the reference area. Reduced snake activity was still evident nearly 12 months after bait application. Roads forming a portion of the treatment boundary appeared to slow snake movement between treated area and surrounding untreated area. Trail cameras monitoring a subset of bait tubes showed that 97.5% of baits removed were taken by snakes rather than nontarget species. We indexed rodent abundance in the treatment plot and reference area, and found no indication of a rodent population increase following toxic bait application. Our results show that automated aerial bait applications can suppress brown treesnake abundance over a large area and that reinvasion from surrounding untreated habitat occurs over several months. We anticipate that repeated bait applications could achieve and maintain greatly reduced brown treesnake abundance on a landscape scale, potentially improving biosecurity and enabling experimental reintroduction of native birds extirpated by brown treesnake predation. Published 2019. This article is a U.S. Government work and is in the public domain in the USA. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

Resource choice in orchard populations of Drosophila

Three capture-recapture experiments were performed on natural populations of Drosophila from orchards in California. Two of the experiments investigated choice between known breeding substrates: oranges v. grapefruits and figs v. peaches. The third involved choice between citrus baits in a citrus orchard and both banana and citrus baits in an adjacent almond orchard. Drosophila pseudoobscura showed no fidelity to the bait or area of initial capture. However, a statistically significant but low level of resource fidelity was displayed by D. melanogaster/D. simulans. An index of differential choice is used to compare our results to those of previous studies. Possible biological bases of choice behaviour are discussed.     

基于GC-IMS技术的不同红火蚁监测诱饵的风味成分分析

探讨不同红火蚁Solenopsis invicta Buren监测诱饵的风味成分,以期获得优化诱饵配方的科学依据。本文采用顶空气相色谱-离子迁移谱法分析不同红火蚁监测诱饵在60℃下的气味指纹图谱,并通过主成分分析法分析其风味物质的差异。结果共鉴定出93个信号峰和87种挥发性化合物,载体物质（CK）中具有较高强度峰的化合物包括3种苯、2种醇、3种酮、2种酯、4种醛、1种呋喃和1种烯;自主配制的诱饵（JR、ZR、JZ）的风味组成相似,较高强度峰的化合物包括2种醇、1种酸、12种醛和1-8桉叶素等;市售火腿肠（HT）中的3种烯、10种酮、1种苯、5种醛、1种呋喃、3种醚、7种醇和4种酯是具有较高强度峰的化合物。主成分分析表明,CK、HT与自主研发的诱饵聚集距离较远,三者均单独聚为一类,相互风味成分区别较大。综上所述,JR、ZR和JZ诱饵中醛类物质较多,而HT中酮类与醇类物质较为丰富。上述诱饵的风味成分分析结果能为研发精准高效的红火蚁监测专用诱饵提供重要信息。