I tested a prevalent assumption in glucocorticoid research that states that each species has a dominant glucocorticoid, and cortisol and corticosterone are interchangeable steroids. A comprehensive analysis of historical and current data failed to support this assumption and revealed evidence of drift away from exploration of cortisol and corticosterone as dual, important adrenal products to the exclusive quantification of one, dominant glucocorticoid. Originating approximately 30 years ago, the dominant glucocorticoid/ interchangeability assumption is now portrayed in textbook images used to represent adrenal steroid biosynthesis and is widespread throughout empirical research. Less than 1% of over 50,000 published papers relating to the glucocorticoids have considered the potential for independence in glucocorticoid signaling by quantifying both cortisol and corticosterone within a sample. A dispersed literature shows independent regulation of cortisol and corticosterone, extensive inter-species variation in glucocorticoid concentrations and cortisol: corticosterone ratios and adrenal synthesis of the non-dominant glucocorticoid during early development. We hypothesize that there is a functional duality in glucocorticoid signaling and use mass spectrometry to explore the glucocorticoid profile of the full-term human (n = 125) and guinea pig (n = 28) fetus (both cortisol-dominant species). The sample preparation method yielded poor steroid recoveries (~ 4-28%), which made quantification by mass spectrometry challenging, but in both species corticosterone concentrations were significantly higher in fetal blood compared to umbilical venous or umbilical mixed blood (p < 0.0001), suggesting fetal corticosterone enrichment. Within an individual, cortisol was not an accurate predictor of corticosterone for either species (human, r = 0.001, p > 0.05; guinea pig, r = 0.14, p > 0.05) and our data suggests independent glucocorticoid responses; in humans, cortisol was significantly higher in vaginal deliveries relative to elective Caesarian sections (p < 0.0001) but corticosterone was unaffected. Guinea pig fetal corticosterone was not affected by daily maternal stress during gestation but cortisol was significantly lower in stressed fetuses (p < 0.05). While these preliminary data require further investigation, we conclude that fetuses from the human and guinea pig actively secrete the non-dominant glucocorticoid in late gestation and suggest that there is a functional duality in glucocorticoid signaling. / Thesis (Master, Biology) -- Queen's University, 2010-01-25 10:28:26.307

Almost half of the world�s mammal extinctions in the last two hundred years have occurred in Australia (Short and Smith 1994). The western barred bandicoot Perameles bougainville is one of a suite of species that is currently threatened with extinction, surviving only on two islands in Shark Bay, Western Australia. Reintroduction has been used as a tool in conservation biology to assist in the recovery of threatened species, such as the western barred bandicoot. The aims of this project were to 1) successfully reintroduce and establish a free-ranging mainland population of the western barred bandicoot at Heirisson Prong, Shark Bay, 2) contribute information on the biology of the species, its interactions with introduced species, and its likelihood of persistence as a reintroduced population in the longer-term, and 3) to provide recommendations to assist future reintroductions of the species. The first reintroduction of the western barred bandicoot from surviving remnant island populations to the mainland, some 60 years after its apparent mainland extinction, was from Dorre Island to Heirisson Prong in 1995. Animals were translocated initially to a predator-free refuge on Heirisson Prong, and then subsequently released to the 12 km2 peninsula where introduced predators (foxes Vulpes vulpes and feral cats Felis catus) had been controlled, but European rabbits Oryctolagus cuniculus had not. Despite a small founder number and high mortality of free-range bandicoots in the presence of a low-density feral cat population, the bandicoot population successfully established. The reintroduced population of western barred bandicoots provided an opportunity to study the biology of the species, and to compare it with the remnant island populations and other species of Australian bandicoot. Many population parameters were similar between the island and mainland western barred bandicoot populations, as well as between the western barred bandicoot and other bandicoot species, suggesting that the habitat at the reintroduction site is suitable for long-term persistence of the population. However, there were some notable differences. The western barred bandicoot is the smallest extant species of bandicoot, with fewer young per litter than recorded for other bandicoot species, adult sex ratios were closer to parity, animals reached sexual maturity later, and it is the only species of bandicoot where females are larger than males. Home range size is larger also than recorded for other species. Some of these differences may be explained in part by trade-offs between island dwarfism, lactational pressures, and nest defence. The nesting biology of the western barred bandicoot was studied at Heirisson Prong, including during periods of high and low densities of rabbits. Individuals of the species constructed and utilised nests in a similar fashion to other species of Australian bandicoot, nesting amongst litter underneath shrubs. The western barred bandicoot appeared to favour particular shrub species, especially when vegetation condition was poor due to rabbit damage, but displayed flexibility in being able to construct nests under a variety of shrub species where at least some surface litter was present. Grasses were used in nest construction only when rabbit density was low. Nests appear important for protection against temperature extremes and diurnal predators. Vegetation exclosures around three of the shrub species most commonly used by the western barred bandicoot for nest sites (Acacia ligulata, A. tetragonophylla and Melaleuca cardiophylla) were used to examine the impact of rabbits on vegetation on Heirisson Prong. A high-density rabbit population over the summer of 1997/98 caused in a decrease in canopy cover and the death of mature A. ligulata. Subsequent rainfall and low-density rabbit populations allowed A. tetragonophylla shrubs to recover their former structure, and M. cardiophylla to recover, but not to the same degree. The flexibility of western barred bandicoots in use of nest materials and their omnivorous diet may enable the species to survive in the face of habitat modification by rabbits. Population viability analysis was used to examine future options for the recovery of the endangered western barred bandicoot. Biological data from the Dorre Island and Heirisson Prong populations were input to the computer simulation program VORTEX. The western barred bandicoot populations were modelled under a variety of scenarios to examine the possible effects of changes in carrying capacity, founder population size, inbreeding depression, and the occurrence of drought and cat predation as catastrophes, on the probability of population extinction. This analysis highlighted the need for eradication of feral cats, above all other management actions. Cat predation was particularly potent when it acted through high loss of juveniles, as well as adult bandicoots. Predator control is considered critical for the long-term persistence of reintroduced populations of the western barred bandicoot. This study documents the first reintroduction of the endangered western barred bandicoot to mainland Australia. The population had been extant for four years at the completion of data collection for this thesis, in late 1999 and for over eight years at the finalisation of this thesis in July 2004. The knowledge gained from the reintroduction was used to discuss management recommendations and future options for the recovery of the species. The primary concern for reintroductions of this, and other species of bandicoots, remains the control of introduced predators. For long-term persistence of small, isolated populations, such as those of the western barred bandicoot at Heirisson Prong and the Arid Recovery Project at Roxby Downs in South Australia, and the eastern barred bandicoot Perameles gunnii at a range of sites in Victoria, the complete eradication of introduced predators is essential.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 146-157).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. Vita. With this is bound: Tracking of fisher and marten / by A. de Vos. From Sylva, vol. 7 (1951), p. 15-20. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 200-203).

Thesis (doctoral)--Wageningen University and Research Centre, 2000. / Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes Bibliographical References. Also available via the Internet.

Thesis (M. Sc.)--Laurentian University, 2000. / Includes bibliographical references (leaves 49-62).

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2005. / Appendix includes reproductions of six papers and manuscripts co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix of papers.

Invasive plant species have widespread effects on the ecosystems they inhabit. Extensive research has been done on the economic and ecological impact of invasive species in relation to native plant species, but little is known about the effect of these species on native fauna. My study examined the impact of an invasive plant species Elaeagnus umbellata (autumn olive) on small mammals populations in southern Illinois. Elaeagnus umbellata is a native shrub of southeast Asia and was introduced to the United States in the 1830s. It is now the fifth most abundant invasive plant species in the state of Illinois. To determine the impact of this invasive shrub on small mammal populations, Sherman traps were set up in six separate trapping webs, three in upland forests with heavy E. umbellata cover and three in upland forests with little to no E. umbellata cover (control). Trapping spanned three seasons from March-August 2013. Through the use of capture and release methods, individuals were measured, weighed, and marked for possible recapture. Beginning in season 3, Cuterebra fontinella (bot fly) abundance in small mammals was also assessed. Differences in relative abundance of small mammal populations were determined using a repeated measures ANOVA with a Tukey test. T-tests were used to determine any significant difference among small mammals between forest types. Very little difference was found among the measured variables between the invaded and control forest sites. Prevalance of C. fontinella was also similar, but the resulting percentage of infection was much higher when compared to other studies in the literature. These results indicate there is little effect of E. umbellata on small mammal populations, although the long-term impacts of this invasive species may need further research.

To address my first objective, I opportunistically collected road-killed bobcats (n=44) throughout Illinois during 2013-2014, and analyzed their liver tissue for the presence of PCBs, PBDEs, and various other alternative halogenated flame retardants. Concentrations of ∑PCBs ranged from 76.4 ng/g lw to 3782 ng/g lw (median 562.97 ng/g lw). Male bobcats had significantly higher concentrations of PCBs than females (p = 0.04). Concentrations of ∑PBDEs (including all detectable PBDE congeners) ranged from 8.3 to 1920 ng/g lipid weight (median: 50.3 ng/g lw). Among the alternative flame retardants screened, Dechloranes (including anti- and syn-Dechlorane Plus and Dechlorane-602, 603, and 604), tetrabromo-o-chlorotoluene (TBCT), and hexabromocyclododecane (HBCD) were also detected frequently, with median concentrations of 28.7, 5.2, and 11.8 ng/g lw, respectively. Dechlorane analogue compositions in bobcats were different from that reported in other studies, suggesting species- or analogue-dependent bioaccumulation, biomagnification, or metabolism of Dechlorane chemicals in different food webs. My findings, along with previously reported food web models, suggest Dechloranes may possess substantial bioaccumulation and biomagnification potencies in terrestrial mammalian food webs. Thus, attention should be given to these highly bioavailable flame retardants in future environmental biomonitoring and risk assessments in a post-PBDE era. To address my second objective I collected raccoons (n=32) from various sites across Illinois and Missouri during 2013-2015. Liver tissues were analyzed for the presence of PBDEs and Dechloranes. ∑PBDE concentrations ranged from 19.1 ng/g lw to 2124 ng/g lw (median = 98.0 ng/g lw) and did not differ between gender or age of raccoon. Although nonsignificant (p=0.06), adult raccoons appeared to have greater PBDE concentration loads compared to juveniles. These nonsignificant differences are likely due to large variation in contaminant concentrations, possibly reflecting differences in individual raccoon diet and behavior. This is the first study reporting bioaccumulation of halogenated flame retardants in a wild felid in North America, and also the first report of PBDE accumulation in North American raccoons. The wide detection of Dechloranes, HBCD and TBCT in bobcats suggests a broad exposure of these alternative flame retardants in terrestrial apex predators in terrestrial ecosystems. The comparatively high levels of PBDEs in raccoons also suggest that biota in terrestrial habitats are still widely exposed to and susceptible to the bioaccumulation of these flame retardants.