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Bear damage to western larch trees on intensively managed public and private forest lands of the Intermountain West continues to be a problem for forest managers. Bark stripping and subsequent cambium feeding by bears commences upon den emergence in the spring, when foraging options are most restrictive. Various damage reduction methods are often controversial (snaring, hunting, supplemental feeding), or do not always adequately resolve the problem (silvicultural strategies); hence, a need exists for the development of alternative nonlethal techniques to reduce damage. We tested the efficacy of three candidate repellents (Hot Sauce®, Tree Guard™, and grizzly bear feces) to reduce spring/summer bear damage to western larch trees on reforestation units in northern Idaho. Plots were laid out and treated in early June and examined for damage four months later. Thirty-four of 300 (11.3%) treated trees were damaged by black bears. Of the newly damaged trees, the highest damage rates were on the control plots: 15 of 75 (20%) trees. Damage levels to trees on treatment plots were 8-9.3%. Mean area of damage, or bark removal, on newly damaged trees only, was 452.8 cm2. Almost half (47%) of the bear-damaged trees were completely girdled. Chi-square contingency table analysis showed that the damage rate of treated trees was less than of control trees. No difference in mean surface area of damage was detected among treatments. Further testing is necessary to reveal the true potential of chemical repellents for reducing black bear damage to conifers in the spring. A wide array of chemicals should be evaluated for their potential.

Additional methods and integrated strategies to reduce damage by voles and other small rodents are needed, especially where rodenticides cannot be readily used. This field study examined if fields vegetated with endophytic grasses (i.e., grasses infected with the fungi, Acremonium spp. or Neotyphodium spp.) which produce alkaloids that impair herbivory, resulted in lower abundance or impaired reproduction of small mammals. We also determined if small mammals inhabiting fields with endophytic grasses had impaired capabilities (i.e., smaller body size and body condition). A lower abundance of small mammals in fields of endophytic grasses was evident. However, there appeared to be very little difference in the size, body condition, and pregnancy rates of small mammals from either field type. These results suggested that endophytic varieties of grasses could be used reduce population numbers of rodents, thereby reducing human-wildlife conflicts resulting from overabundance of rodents.

Many fossorial species of wildlife cause damage in a variety of land-use settings. Research of these species is challenging because of the complications associated with working underground. Traditional methods of conducting research on fossorial rodents in their natural environments are expensive, labor intensive, and invasive on the landscape. More innovative and effective methods of doing research underground are needed. We evaluated a burrow-probe camera for viewing inside the burrows of California ground squirrels (Spermophilus beecheyi) as part of an anticoagulant baiting study. It was useful for locating carcasses as well as for collecting information on live squirrels and non-target species. We also used burrow cameras to aid in on-going studies of black-tailed prairie dogs (Cynomys ludovicianus) and evaluated their utility in the burrows and dens of other mammals along the front range of Colorado. We will discuss our evaluations of burrow cameras and applications for their use in wildlife damage research.

Trapping is an integral tool in research and control of damage caused by pocket gophers (Thomomys spp.). We evaluated three types of traps (Macabee®, Cinch, Blackhole® Rodent) in a California field trial by comparing the number of captures to activity at the sets (capture efficiency) and separately, the duration of time from first to last capture (time efficiency). On each of six study plots established on irrigated agriculture fields, 60 trap stations were established at locations of gopher mounds. One trap type was used per station and traplines were run continuously for about four days. We captured a total of 256 gophers. Overall, the Cinch trap had the highest capture efficiency (41.7%), followed by the Macabee® trap (27.7%) and the Blackhole® trap (18.3%). The Cinch trap had a significantly greater (P=0.003) capture efficiency than either of the other two trap types, which did not differ (P>0.05). From a time efficiency standpoint, the Cinch trap also ranked first (0.046), the Macabee® trap second at 0.036 and the Blackhole® trap last (0.032), though the differences were not significant (P=0.693). We conclude that the Cinch trap was the most efficient of the three trap types for capturing gophers in this study. Its chief drawback is that the large baseplate makes it more time-consuming to set. The Blackhole® Rodent trap was the least efficient for capturing gophers, and very time-consuming to set and check. Furthermore, the floor of the trap (solid plastic) may have induced trap shyness, even when covered by soil. The Macabee® ranked intermediate in both capture efficiency and time efficiency. Due to its small size and ease to set and check, it will probably remain a popular alternative for capturing pocket gophers. An integrated pest management approach is recommended for the most effective control of pocket gophers.

Porcupines (Erethizon dorsatum) rely on trees and shrubs for winter food and can cause serious, localized damage to conifers. Twenty-two percent of ponderosa trees (Pinus ponderosa) examined in southeastern Washington were damaged by porcupines. Most damage involved complete girdling of the mid- to upper boles of the larger trees (12 to 30 cm dbh) in the stand. Preliminary repellent trials with captive porcupines suggested that several materials might reduce tree damage, especially predator-associated odors. Field trials are needed to assess efficacy and duration of protection under ambient winter conditions.

From 2011 to 2017, 4,534 serum samples from 13 wildlife species collected across the US and in one territory (US Virgin Islands) were tested for exposure to Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. Of 1,759 canids, 1,043 cervids, 23 small Indian mongooses ( Herpestes auropunctatus), 1,704 raccoons ( Procyon lotor), and five striped skunks ( Mephitis mephitis), 27.0, 44.4, 30.4, 40.8, and 60%, respectively, were antibody positive for any of the six serovars. The most commonly detected serovars across all species were Bratislava and Grippotyphosa. Our results indicate that Leptospira titers are very common in a wide variety of wildlife species. These species may act as important reservoirs in the epidemiological cycle of the pathogen. Additional studies to determine the relationship between serologic evidence and shedding of the pathogen by wildlife are necessary to better understand the risk. [ABSTRACT FROM AUTHOR]

The article presents a surveillance study on the distribution and prevalence of raccoon roundworm Baylisascaris procyonis in raccoons in Wyoming. It discusses findings based on necropsy and fecal examination of collected animals on the prevalence and worm burdens in highly populated and rural areas. It also explores association between prevalence of B. procyonis and zoonotic risk and potential risks of raccoon roundworm infection for humans and animals.