Walker's Mammals of the World, 4th Edition, Ronald M. Nowak, John L. Paradiso. The Johns Hopkins University Press, Baltimore, Maryland (1983), 1xi, +1-568 (Vol. I), xxv+569-1362 (Vol. II). Price $65.00

Maximum entropy (Maxent) modeling has great potential for identifying distributions and habitat selection of wildlife given its reliance on only presence locations. Recent studies indicate Maxent is relatively insensitive to spatial errors associated with location data, requires few locations to construct useful models, and performs better than other presence-only modeling approaches. Further advances are needed to better define model thresholds, to test model significance, and to address model selection. Additionally, development of modeling approaches is needed when using repeated sampling of known individuals to assess habitat selection. These advancements would strengthen the utility of Maxent for wildlife research and management.

https://www.mdpi.com/1099-4300/11/4/854/pdf

Use of Maximum Entropy Modeling in Wildlife Research

Camera Traps in Animal Ecology

Groundwater is considered as the most important natural resources in arid and semi-arid regions. In this study, the application of random forest (RF) and maximum entropy (ME) models for groundwater potential mapping is investigated at Mehran Region, Iran. Although the RF and ME models have been applied widely to environmental and ecological modeling, their applicability to other kinds of predictive modeling such as groundwater potential mapping has not yet been investigated. About 163 groundwater data with high potential yield values of ≥ 11 m 3 /h were obtained from Iranian Department of Water Resources Management (IDWRM). Further, these selected wells were randomly divided into a dataset 70% (114 wells) for training and the remaining 30% (49 wells) was applied for validation purposes. In total, ten groundwater conditioning factors that affect the storage of groundwater occurrences (e.g. altitude, slope percent, slope aspect, plan curvature, drainage density, distance from rivers, topographic wetness index (TWI), landuse, lithology, and soil texture) were used as input to the models. Subsequently, the RF and ME models were applied to generate the groundwater potential maps (GPMs). Moreover, a sensitivity analysis was used to identify the impact of variable uncertainties on the produced GPMs. Finally, the results of the GPMs were quantitatively validated using observed groundwater dataset and the receiver operating characteristic (ROC) method. Area under ROC curve (AUC) was used to compare the performance of RF with ME. The uncertainty on the preparation of conditioning factors was taken in account to enhance the model. The validation results showed that the AUC for success rate of RF and ME models was 86.5 and 91%, respectively. In contrast, the AUC for prediction rate of RF and ME methods was obtained 83.1 and 87.7%, respectively. Therefore, RF and ME were found to be effective models for groundwater potential mapping.

Application of GIS-based data driven random forest and maximum entropy models for groundwater potential mapping: A case study at Mehran Region, Iran

Increase in food production is the prime-most objective of all countries, as world population is expected to grow to nearly 10 billion by 2050 Based on evidence, world population is increasing by an estimated 97 million per year (Saravi and Shokrzadeh, 2011) The Food and Agricultural Organization (FAO) of the United Nations has in-fact issued a sobering forecast that world food production needs to increase by 70%, in order to keep pace with the demand of growing population However, increase in food production is faced with the ever-growing challenges especially the new area that can be increased for cultivation purposes is very limited (Saravi and Shokrzadeh, 2011) The increasing world population has therefore put a tremen‐ dous amount of pressure on the existing agricultural system so that food needs can be met from the same current resources like land, water etc In the process of increasing crop pro‐ duction, herbicides, insecticides, fungicides, nematicides, fertilizers and soil amendments are now being used in higher quantities than in the past These chemicals have mainly come into the picture since the introduction of synthetic insecticides in 1940, when organochlorine (OCl) insecticides were first used for pest management Before this introduction, most weeds, pests, insects and diseases were controlled using sustainable practices such as cultural, mechanical, and physical control strategies

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Pesticides: Environmental Impacts and Management Strategies

Developing an effective strategy for indexing roof rat abundance in citrus orchards

Many wildlife populations are expanding both their range and population densities given effective management practices. This wildlife expansion, combined with concomitant human expansion, has led to increased human-wildlife conflict in many parts of North America. Managing these conflicts has become more difficult given increased regulation on many management tools, leading to a need for new, effective strategies for mitigating these conflict situations, as well as a clearer understanding of how current management practices influence both target and non-target wildlife. A greater and more focused effort on education and outreach is needed to clearly inform all parties about true versus perceived risks associated with controversial management strategies given that the general populace will likely drive most future wildlife damage management regulation. As wildlife scientists, our goal should be to allow society to make management decisions that are based on sound science rather than on limited data sets, or worse yet, conjecture or social dogma. Such a strategy would allow for management programs that are both socially acceptable and effective in minimizing human-wildlife conflict.

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Challenges and Opportunities for the Wildlife Damage Management Profession in the Face of Expanding Wildlife Populations : An Extension Perspective

Author(s): Baldwin, Roger A.; Halbritter, Heather; Meinerz, Ryan; Snell, Laura K.; Abbo, Benjamin G.; Goldade, David A. A.; Orloff, Steve B. | Abstract: Belding’s ground squirrels (Urocitellus beldingi) cause extensive damage in alfalfa and other hay crops throughout substantial portions of the Intermountain West. Recent management efforts have largely focused on shooting, burrow fumigation, and occasionally grain baits. However, these tools are often either too costly to implement or ineffective. In 2015, the California Department of Pesticide Regulation approved a Special Local Needs permit to use zinc phosphide-coated cabbage for managing Belding’s ground squirrels in Siskiyou, Modoc, and Lassen Counties. This baiting strategy could provide a cost effective and efficacious management approach, although efficacy data were lacking. Therefore, we established a study to assess the importance of spatial variability of location sites, prebaiting, and ground squirrel density on efficacy of zinc phosphide-coated cabbage for Belding’s ground squirrel management across impacted hay-growing regions in northeastern CA. We also assessed potential differences in bait mixing strategies (in a tub via hand mixing vs. the use of a commercial-style cement mixer) on targeted zinc phosphide concentrations, as well as the degradation rate of zinc phosphide and moisture content of cabbage under environmental conditions. We did not detect a significant difference between hand and mechanical mixing. However, mechanical mixing was closer to the target level (mean = 101% vs. 115% for mechanical and hand mixing, respectively), was more precise, and allowed for the mixing of larger batches. As such, mechanical mixing was the strategy we used for field application. Furthermore, both moisture content (0.29% loss per hour) and zinc phosphide concentration (31% loss in 48 hours) steadily declined during a three-day observation period, indicating a fairly minimal window of exposure for nontarget species. See Baldwin et al. (2018) for additional details on lab testing of mixing methods and residual zinc phosphide levels associated with cabbage bait. During field trials, we found that prebaiting increased overall efficacy by approximately 18%, with efficacy 23% greater in the western (eastern Siskiyou and western Modoc Counties) vs. eastern portions (south-central Modoc County) of the study area. The tested bait was also substantially more efficacious when initial ground squirrel populations were larger, presumably due to a greater need for forage at high densities. Ground squirrel activity was relatively consistent throughout the day, although peaks were noted from 09:00 to 11:00 and from 13:00 to 15:00. Consumption of cabbage bait diminished throughout the day after initial application. Consumption was again high the following morning, but again diminished throughout the remainder of the day. Ideal times for bait application were likely before 09:00 and again before 13:00, although ground squirrels continued to feed on bait throughout the day. Zinc phosphide-coated cabbage bait appears to be an effective management option when prebaiting is used in Siskiyou County and in western portions of Modoc County. Additional research is needed to determine methods to increase efficacy in central and eastern Modoc County. See Baldwin et al. (2019) for additional details on this study.

/pdf/zinc-phosphide-coated-cabbage-for-managing-belding-s-ground-2itrrevuvb.pdf

Zinc Phosphide-coated Cabbage for Managing Belding’s Ground Squirrels (Abstract)

Author(s): Baldwin, Roger A.; Meinerz, Ryan; Witmer, Gary W.; Werner, Scott J. | Abstract: California voles cause extensive damage to tree crops through girdling of young stems. Recent laboratory trials have indicated substantial repellency (up to 84%) of anthraquinone (a post-ingestive repellent) to voles on treated grain. Given these lab results, we established a field study to test the efficacy of anthraquinone applications to tree stems to reduce girdling damage from voles. We also assessed the impact of vegetation around the base of trees to determine the impact of cover on girdling activity. In Fresno County, CA, during summer 2016 and spring 2017, we established twenty 3.35 × 2.44-m bins (hereafter mesocosms) where we evenly spaced eight 1-yr-old clementine orange trees. Cover crops including various grasses and forbs were planted on randomly-selected halves of each mesocosm. All trees were treated with anthraquinone in half of the mesocosms; trees were left untreated in the remaining half. We captured 40 voles and released two individuals into each mesocosm and tracked girdling damage once weekly for five weeks during summer and six weeks during spring. We observed a significant reduction in girdling damage on anthraquinone-treated trees. The removal of vegetation around the base of trees completely eliminated girdling damage for anthraquinone-treated trees during summer, although vegetation did not significantly impact damage for untreated trees during summer, nor for either anthraquinone-treated or untreated trees during spring. We did not observe an increase in damage over time in anthraquinone-treated mesocosms, indicating that anthraquinone maintained its repellency during the duration of this study. Anthraquinone appears to be highly repellent to voles, and it is worthy of field study in other mammalian species as well.

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Anthraquinone as a Vole Repellent: Not Just for the Birds?

Author(s): Meinerz, Ryan; Kavermann, Matthew; Orloff, Steve B.; Baldwin, Roger A. | Abstract: Pocket gophers and ground squirrels cause extensive damage to many crops. Pressurized exhaust injection devices are increasingly used for managing these rodents, although no data were available to support their use. Therefore, we established a study to: 1) determine the efficacy of pressurized exhaust machines for pocket gopher and ground squirrel management, 2) compare these results to other burrow fumigant options, and 3) compare their cost effectiveness. Specifically, we tested two different pressurized exhaust machines for both ground squirrels and pocket gophers: Pressurized Exhaust Rodent Controller (PERC), and 2) Cheetah rodent control machine. For California ground squirrels, efficacy for the PERC machine was greater in moist soils (mean = 100%) than in drier soils (mean = 66%). Initial treatments using the PERC machine were more expensive than other burrow fumigation options, given the large cost of the machine. However, costs quickly dropped below that of gas cartridges (~44 days), and eventually dropped below that of aluminum phosphide if used extensively (~830 days). Efficacy for the Cheetah rodent control machine was far less encouraging for California ground squirrels, with results showing increased squirrel numbers at treatment sites (mean = +115%) post-treatment. For pocket gophers, aluminum phosphide (mean = 86%) and trapping (mean = 81%) proved to be more effective than PERC applications (mean = 56%) in heavy organic soils. We observed somewhat greater PERC efficacy in mineral soils (mean = 68%), suggesting potential variability in efficacy across soil types. At this point, the use of the PERC machine appears to be a viable option for inclusion into Integrated Pest Management programs for burrowing rodents where alternative options are limited; the Cheetah rodent control machine showed no utility for ground squirrel management in our study. More extensive testing of pressurized exhaust devices in differing soil types and under variable moisture levels is needed to determine their utility across a broader spectrum of treatment situations.

/pdf/fumigation-of-burrowing-rodents-with-carbon-monoxide-a-2t9i4x4qll.pdf

Roger A. Baldwin

Papers

Developing an effective strategy for indexing roof rat abundance in citrus orchards

Challenges and Opportunities for the Wildlife Damage Management Profession in the Face of Expanding Wildlife Populations : An Extension Perspective

Zinc Phosphide-coated Cabbage for Managing Belding’s Ground Squirrels (Abstract)

Anthraquinone as a Vole Repellent: Not Just for the Birds?

Fumigation of Burrowing Rodents with Carbon Monoxide: A Comparison to Alternative Management Options