Mark K. Johnson

FACTORS ASSOCIATED WITH PATHOGEN SEROPREVALENCE AND INFECTION IN ROCKY MOUNTAIN COUGARS

Serological and genetic material collected over 15 years (1990–2004) from 207 cougars (Puma concolor) in four populations in the Rocky Mountains were examined for evidence of current or prior exposure to feline immunodeficiency virus (FIV), feline parvovirus (FPV), feline coronavirus (FCoV), feline calicivirus (FCV), canine distemper virus (CDV), feline herpesvirus (FHV), and Yersinia pestis. Serologic data were analyzed for annual variation in seroconversions to assess whether these pathogens are epidemic or endemic in cougars, and to determine whether family membership, age, sex, or location influence risk of exposure. FIV and FPV were clearly endemic in the studied populations, whereas exposure to FCoV, FCV, CDV, and Y. pestis was more sporadic. No evidence was found for FHV. Age was the most consistent predictor of increased exposure risk, often with no other important factors emerging. Evidence for transmission within family groups was limited to FIV and FCoV, whereas some indication for host sex affecting exposure probability was found for FIV and Y. pestis. Overall, cougar populations exhibited few differences in terms of pathogen presence and prevalence, suggesting the presence of similar risk factors throughout the study region.

Abortion Caused by Brucella abortus Biovar 1 in a Free-ranging Bison (Bison bison) from Yellowstone National Park

A near-term aborted bison (Bison bison) fetus was collected near Old Faithful geyser in Yellowstone National Park, Wyoming (USA). On necropsy, the fetus liver had a small capsular tear, and there was a small quantity of blood in the peritoneal cavity. Microscopic lesions included mild, purulent bronchopneumonia and mild, multifocal, interstitial pneumonia. Brucella abortus biovar 1 was isolated from fetal abomasal contents, lung, and heart blood.

Estimating coyote food intake from undigested residues in scats

Average dry weights per occurrence in a coyote (Canis latrans) scat were determined for undigested fractions of mammals, birds, reptiles, arthropods, plants and seeds. Dry weights of these items are useful for estimating biomass originally ingested. Normalizing data produce an estimate of the coyote dietary. If coyote population densities and food intake rates were known, estimates of relative biomass taken from each prey population could be obtained.

Effects of Birth Date and Body Mass at Birth on Adult Body Mass of Male White-Tailed Deer

We examined relationships of birth date and body mass at birth with body mass at mature ages (≥1.5 years) of captive, male white-tailed deer ( Odocoileus virginianus ). Birth date was not associated with body mass at birth ( P = 0.862) and had no effect on body mass at the 1.5-, 2.0-, and 2.5-year age classes ( P ≥ 0.379). Males with greater body mass at birth added more body mass between birth and the 1.5-year age class ( P < 0.001) and had greater body mass at the 1.5-, 2.0-, and 2.5-year age classes ( P < 0.001). Body mass of male white-tailed deer at birth may influence body mass at mature ages.

Frequency Sampling for Microscopic Analysis of Botanical Compositions

There is confusion in the literature as to the underlying basis for quantifying botanical mixtures microhistologically. The relationship between particle density and frequency of occurrence is useful for estimating numbers of individuals contained in a large number of sampling units. Applied studies do not adequately report the mathematical rationale behind estimation procedures. This paper explains why certain sampling and quantification procedures are useful when applied to microscope analysis of herbivore diet samples. Recently, Havstad and Donart (1978) published a paper discussing-certain assumptions of the microhistological technique for diet analysis. They said that acceptance of underlying assumptions was important for utilizing the technique. However, before any method can be utilized correctly, investigators should understand the assumptions. The papers of Sparks and Malechek (1968), Cavender and Hansen (1970) and Havstad and Donart (1978) all explain certain practical aspects of quantifying diets using a microscope technique but none of the papers contains a complete description of the mathematical basis for the sampling procedure. While investigators have described variations of the microhistological technique and reported components of error, no one has yet provided a detailed treatment of the mathematical relationshipsinvolved when frequency sampling is employed as the quantification procedure. Presumably this was neglected because the procedure is relatively easy to understand for persons with a great deal of mathematical training. This note is intended as a clarification and is directed towards persons without the background needed for deriving these relationships by themselves. Sparks and Malechek (1968) validated the frequency sampling method reported by Fracker and Brischle (1944) for use with a microscope technique for identifying plant taxa (Baumgartner and Martin 1939). Their method treated each microscope field as a sampling unit and certain assumptions were made: (1) Microfragments of plants were randomly distributed on microscope slides, (2) Microfragments from different plant taxa were the same average size, (3) Dry weight bulk densities of different plant taxa were the same. Assumptions 1 and 2 are valid since the distribution and average number of fragments per microscope field is controlled in slide making. The relationship between frequency of occurrence and the number of individuals per observation (particle density) has great value for improvement of sampling efficiency. Application allows the replacement of exhaustive enumeration of individuals with a much quicker determination of presence or absence within quadrats. This results in a large savings of time and effort for a given sample size. Conversely, for a given amount of time and effort, a much larger number of samples can be inspected. In order to explain the relationship between particle density and frequency of occurrence, we must examine the occupancy of cells by randomly assigned objects. The argument is based on a finite number of plant fragments of any species distributed at random over k microscope fields. If an individual is randomly located in one of k microscope fields so that each cell is equally likely to be assigned the object, the probability of occurrence (p) of the object in any specific field is 1 /k. The corresponding probability of nonoccurrence is given by l-l / k. Furthermore, if n such objects are Author is associate professor, School of Forestry and Wildlife Management, Louisiana State University, Baton Rouge 70803. The author thanks Richard Hansen, George Van Dyne, and David Guynn for initial review of this paper. This work is Mississippi Agr. and Forestry Exp. Sta. Contribution No. 3960. independently, randomly assigned, the probability that none occur in the specified field is ( I-1 / kp. Now consider the random variable xi, which is an indicator of occupancy of the fh field: xi = 1 if field i is occupied and xi = 0 if field i is not. Then y = C xi is a random variable specifying the number of occupied fields. The average number of occupied fields is given by the expected value of y.

Differentiating mountain lion and bobcat scats

La chromatographie en phase gazeuse des acides biliaires des feces est a preferer a la chromatographie en couche mince pour distinguer Felis concolor de Felis rufus pour diverses etudes etho-ecologiques

Esophageal, fecal and exclosure estimates of cattle diets on a longleaf pine-bluestem range.

Microhistological analysis of esophageal or fecal materials provides an accurate and efficient method for evaluating botanical compositions of cattle diets on native longleaf pine-bluestem range. For practical purposes fecal analysis is the preferred method. Plant species that were most important to cattle during the present study were the bluestems and panicums. Southern pine ecosystems serve as range for livestock and wildlife. These forest ranges have potential for high production of red meat with minimum inputs (Pearson and Whitaker 1974; Pearson 1975; Sternitzke and Pearson 1975). Cattle impact on ecosystems is related to the animal’s dietary needs, preferences, and available forage. The purpose of this study was to estimate cattle diets on longleaf pine-bluestem range. Specific objectives were to contrast cattle diets estimated from esophageal and fecal samples with estimates obtained from exclosures. Study Areas

Disappearance Rates for Deer Pellets in the Southeast

In xeric regions fecal pellets may last for years, and thus are useful for estimating relative population sizes and diets of herbivores (Eberhart and Van Etten 1956, Wallmo et al. 1962, Flinders and Crawford 1977). Data on survivorship of white-tailed deer (Odocoileus virginianus) pellets in the mesic southeastern United States (Downing et al. 1965) are limited. The purpose of our study was to determine disappearance rates for fecal pellets of white-tailed deer in the Southeast, and to identify possible environmental correlates.

Foods of primary consumers on cold desert shrub-steppe of southcentral Idaho.

Trophic relationships of rabbits, black-tailed jack rabbits, pronghorn, sheep, and cattle were examined on the Idaho National Engineering Laboratory Site in southcentral Idaho. Grasses were the most important foods of lagomorphs and livestock. Pronghorn depended mostly on basin big sagebrush, common winterfat, and saltbushes. If jack rabbits increase in the future, severe competition for forage with livestock may result. Large portions of the shrub-steppe of Idaho are winter grazed by sheep (Ovis ah-es), cattle (Bos tuurus), and native wild herbivores. Unregulated grazing can lead to poor range condition, poor condition of wild herbivores, and poor livestock performance. Range managers must assess quantitatively the combined impacts of different herbivores on range resources before planning grazing operations. The Idaho National Engineering Laboratory (INEL) Site in southcentral Idaho is managed by the U.S. Department of Energy and the U.S. Bureau of Land Management lets grazing leases for about 60% of the area (Johnson 1978). Sheep and cattle use these areas and each grazes in common with wild herbivores but the domestic animals do not use the same areas. The most important wild herbivores on the site are pronghorn (Antelocapra americana) and rabbits (Sylvilagus spp). Blacktailed jack rabbit (Lepus calijornicus) populations may become periodically important. During the present study jack rabbit population densities were extremely low on the study area. The purpose of this paper is to report potential levels of diet competition between herbivores which use the INEL Site. Since the study area is typical of the shrub-steppe of southern Idaho, the results of this study have potential for guiding range management over wide areas of the northern Great Basin area.

Use of artificial mineral licks by white-tailed deer in Louisiana.

We examined white-tailed deer (Odocoileus virginianus) use of artificial mineral licks on 3 properties in southcentral Louisiana. High deer use of licks extended longer into summer and fall than reported for areas in more northern latitudes. Estimated monthly mineral consumption averaged 538.0 g/deer (SE = 70.8) and was associated with total moisture and crude protein reported for native plants on forest range in central Louisiana. Consumption from individual licks was positively associated with adjacent soil P concentration (P < 0.001).