Characteristics of Central American brocket deer resting sites in a tropical mountain cloud forest in eastern Mexico

The Central American brocket deer is a vulnerable species. Geographically isolated populations have been affected by poaching and habitat fragmentation, leading to local extinctions. It is therefore important to understand this species’ habitat characteristics, particularly of resting sites, which play a crucial role in survival and fitness. We describe the characteristics and distribution patterns of Central American brocket deer resting sites at the microhabitat and landscape scales in San Bartolo Tutotepec, Hidalgo, México. We conducted eight bimonthly field surveys between November 2017 and March 2019, consisting of 32 transects of 500 m length to search for fecal pellets, footprints, scrapes, and browsed plants. At each resting site we identified, we measured canopy closure, horizontal thermal cover, protection from predators for fawns and adults, escape routes, slope from the ground, presence of scrapes, cumulative importance value of the edible plant species, and distance from the resting site to the nearest water resource to characterize the site at the microhabitat scale. At the landscape scale, we identified the type of biotope, elevation, aspect, and slope. We compared all of these parameters from resting sites with a paired randomly selected site to serve as a control. We performed a multiple logistic regression to identify the parameters associated with the resting sites and a point pattern analysis to describe their distribution. We characterized 43 resting sites and their corresponding control plots. At the microhabitat scale, resting sites were associated with higher vertical thermal cover, more concealment cover, more escape routes, more edible plant species, higher slope from the ground, and closer distance to water resources. At the landscape scale, resting sites were associated with beech forest, oak forest, secondary forest, and ravine biotopes and negatively associated with pine forest, houses, and roads. Resting sites had an aggregated spatial pattern from 0 to 900 m, but their distribution was completely random at larger scales. Our study revealed that Central American brocket deer selected places with specific characteristics to rest, at both microhabitat and landscape scales. We therefore suggest that existing habitat be increased by reforesting with native species—particularly Mexican beech forest and oak forest—to improve the deer’s conservation status in the study area.

OBTAINING OF COMPOSITE MATERIALS BY THERMAL SHOCK AND THEIR PROPERTIES

By the method of heat treatment, a mixture of graphite and salts was obtained from the foam graphite and the conditions for its effective production were determined. The composition of natural graphite of the GL-1 grade of the Russian deposit was determined. The study shows that the main element in graphite is a mixture of carbon and other elements. The analysis of energy dispersions showed the content of other elements in graphite. The content of Zn in the penografite obtained by elemental analysis was determined. In addition, the physicochemical properties of heat-treated graphite were investigated. Using IR spectroscopy, it was found that there are different groups on the surface of the penografite. Analysis of the CS-spectra of penografite allowed us to determine the structure of graphite and penografite. The conducted studies have shown that penografite differs depending on the forms of the spectrum, a set of spectral characteristics that allow us to quantify the degree of maturity of the crystal lattice and identify various defects. Raman spectroscopy for a full understanding of the results of the analysis, studies were carried out scanning electron microscopy (SEM) on a layered structure of penografia. The result of microanalysis and heat treatment shows that natural graphite has changed its composition and structure. It is established that the high-temperature thermal effect significantly changes the quantitative composition of the mixture and the content of various elements depends on the temperature of the thermal cover. The EDAX spectra of heat-treated graphite are shown.

Fawn Counts and Adult Female Site Use Are Mismatched Indicators of Habitat Quality in an Endangered Deer

Many ungulates are spotted as neonates. This trait is unique to individuals, making their identification feasible from remote cameras. Key deer (Odocoileus virginianus clavium) are an endangered subspecies of white-tailed deer endemic to the lower Florida Keys, U.S.A. Habitat loss and hunting were historical drivers of population decline but recent studies report positive associations of key deer with urbanization. Using opposing camera traps at 56 sites throughout the National Key Deer Refuge on Big Pine Key, we used spot patterns to uniquely identify and estimate fawn abundance with N-mixture models. We further compared those inferences to models informed by adult doe counts to see how well tracking adult females alone corresponded with fawn habitat associations. Our results indicated that fawn abundance was negatively associated with increasing elevation and human trails, contrary to models based on adult female observations alone. The lowest elevations where fawns were most abundant were associated with dense wetland plant communities, which were likely selected for thermal cover and warrant further investigation given that those areas are most vulnerable to sea-level rise. Our methods showcase the utility of identifying neonates from camera trap photos and draw attention to possible misaligned inferences when tracking adult females in isolation.

Prevention of corrosion fracture of agricultural equipment during storage

The aim of the study is to reduce metal losses of structural elements of agricultural machines caused by atmospheric corrosion. The presents the theoretical justification and practical implementation of method of storing agricultural machinery in an open area under an active thermal cover. The object of research is the experimental design of an active heat-reflecting screen equipped with heating elements that provide an infrared radiation flux in the mid-wave range of the spectrum with a wavelength of λ = 5-20 μm. A design feature of the heat-reflecting screen is the location of heating elements relative to the agricultural machine in it. The protective effect is achieved due to the fact that when the probability of dew drops increases, the elements heating the internal surface of the heat-reflecting screen and the surface of the machine are automatically switched on, while the air, which is an optically transparent medium, does not heat up, which creates conditions excluding dew. During the tests, it was found that the use of an active heat-reflecting screen allows to ensure reliable safety of the protected machine. The possibility of local heating of the inner surface of the heat-reflecting screen and the surface of the machine without heating the entire volume of air space inside the storehouse can reduce the cost of electric energy. There is no need to preheat the airspace inside the store due to the fact that the thermal effect from the heating elements is observed immediately after being switched on.

Observations of the use of buildings by free-ranging Elk, Cervus canadensis, in Prince Albert National Park, Saskatchewan

Elk (Cervus canadensis) are habituated to humans and associated buildings in many national parks in North America. During the summers of 2012–2014, observations were made of Elk standing on the decks of cabins and entering campground cook shelters in and around the town of Waskesiu in east-central Prince Albert National Park, Saskatchewan. These appear to be the first documented observations of Elk entering buildings intentionally. The reason for this behaviour is likely a combination of the animals seeking areas safe from wolves, thermal cover, and relief from biting insects.

The Influence of Thermal Protection on Winter Den Selection by Porcupines, Erethizon dorsatum, in Second-Growth Conifer Forests

I investigated den type selection by Porcupines (Erethizon dorsatum), in relation to the thermal cover provided by the den type, over a period of four winters. Porcupines used log dens, stump dens and rock dens in proportion to the thermal cover provided by each den type. Based on behavioural observations of Porcupines, I assumed that the lower critical temperature for porcupines in my study area was -4°C. Both stump and rock dens provided adequate thermal protection, under most ambient conditions, to allow Porcupines to maintain their body temperature, without increasing basal metabolic rate. In most cases rock and stump dens maintained den temperatures above -4°C until ambient temperatures reached -12°C or lower. In contrast log dens provided poor thermal protection, even in years of thick snowcover. When ambient temperatures dropped below -4°C, den temperatures within log dens were also recorded below -4°C. Log dens were used least often by Porcupines, whereas stump and rock dens were used most often. Despite the large number of potential dens available to Porcupines within the study area, den use was generally limited to three dens per porcupine per winter. The limited use of dens by an individual porcupine during winter may be related to the energetic cost of finding a new den or it may be related to specific selection criteria used by Porcupines.

The Influence of Temporal and Spatial Factors on Clearcut Use by White-Tailed Deer in Northern Idaho

Relatively little is known about the response of white-tailed deer (Odocoileus virginianus) to forest management practices currently used in northern Idaho. We used pellet group surveys and radiotelemetry to assess the influence of season, clearcut age, and clearcut size on deer use in the Priest Lake watershed of northern Idaho. Deer use of 14 clearcuts ranging from 1 to 25 yr in age and 4.05 to 14.75 ha in size was investigated. No association between pellet group density and clearcut size or age was found. Both pellet group and telemetry data, however, indicated seasonal shifts in white-tailed deer habitat use patterns. Deer displayed strong avoidance of nonforested sites during winter and concentrated on low elevation winter ranges characterized by dense overstories. With the advent of warm weather and reduced snow depths, nonforested sites received increasing use. Clearcut use peaked during early spring and declined with the onset of summer as deer migrated to higher elevations. Spring use of clearcuts was significantly higher than summer use on all sites sampled. Spring pellet group densities averaged 1.52 groups/plot, whereas summer densities averaged 0.50 groups/plot. In the Priest Lake drainage, cutting units should be restricted to less critical sites adjacent to wintering areas. Clearcuts within winter habitats will further fragment existing forested stands and will be at the expense of critical thermal cover. In other regions, vegetation structure and composition should not be the only criteria used to evaluate the influence of clearcutting on white-tailed deer habitat use. West. J. Appl. For. 14(4):177-182.