Oetelaar G.A.,University of Calgary |
Beaudoin A.B.,Royal Alberta Museum
Quaternary International | Year: 2016
In a series of papers, we adopted a regional perspective to explore the short and long-term impacts of the Mount Mazama eruption on the plant and animal communities of the northwestern Plains and later developed a model to explain human responses to this natural disaster. The model assumed the convergence of natural disasters which forced the local bison hunters to abandon the impacted zone and to seek refuge among their distant relatives living beyond the eastern limits of their homeland. Together, the refugees and their hosts intensified their subsistence strategies and adapted or developed new methods of food preparation to accommodate the increased pressure on the local resource base. Throughout their stay, the groups continued to monitor the rebirth of their traditional homeland and eventually returned to the places occupied by their ancestors. Upon their return, the groups continued to hunt bison but adapted the stone boiling technology to produce bone grease and pemmican. This nutritious, storable and transportable food source alleviated the concerns about long-term shortages and became an important product in the regional exchange networks. The primary objective of this paper is to test this model using sedimentary, pedological and archaeological data recovered from two deeply stratified sites with evidence of human occupations before and after the eruption of Mount Mazama. © 2014 Elsevier Ltd and INQUA.
Edwards M.A.,Royal Alberta Museum |
Edwards M.A.,University of Alberta |
Derocher A.E.,University of Alberta |
Nagy J.A.,University of Alberta
PLoS ONE | Year: 2013
The area traversed in pursuit of resources defines the size of an animal's home range. For females, the home range is presumed to be a function of forage availability. However, the presence of offspring may also influence home range size due to reduced mobility, increased nutritional need, and behavioral adaptations of mothers to increase offspring survival. Here, we examine the relationship between resource use and variation in home range size for female barren-ground grizzly bears (Ursus arctos) of the Mackenzie Delta region in Arctic Canada. We develop methods to test hypotheses of home range size that address selection of cover where cover heterogeneity is low, using generalized linear mixed-effects models and an information-theoretic approach. We found that the reproductive status of female grizzlies affected home range size but individually-based spatial availability of highly selected cover in spring and early summer was a stronger correlate. If these preferred covers in spring and early summer, a period of low resource availability for grizzly bears following den-emergence, were patchy and highly dispersed, females travelled farther regardless of the presence or absence of offspring. Increased movement to preferred covers, however, may result in greater risk to the individual or family. © 2013 Edwards et al.
Weiss S.L.,Duke University |
Weiss S.L.,Arizona State University |
Foerster K.,Max Planck Institute for Ornithology (Seewiesen) |
Foerster K.,University of Tubingen |
Hudon J.,Royal Alberta Museum
Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology | Year: 2012
Indicator models of sexual selection suggest that signal honesty is maintained via costs of ornament expression. Carotenoid-based visual signals are a well-studied example, as carotenoids may be environmentally limited and impact signaler health. However, not all bright yellow, orange and red ornaments found in vertebrates are carotenoid-based; pteridine pigments may also produce these colors. We examine the contribution of carotenoid and pteridine pigments to the orange reproductive color of female striped plateau lizards (Sceloporus virgatus). This color ornament reliably indicates female mate quality, yet costs maintaining signal honesty are currently unknown. Dietary carotenoid manipulations did not affect orange color, and orange skin differed from surrounding white skin in drosopterin, not carotenoid, content. Further, orange color positively correlated with drosopterin, not carotenoid, concentration. Drosopterin-based female ornaments avoid the direct trade-offs of using carotenoids for ornament production vs egg production, thus may relax counter-selection against color ornament exaggeration in females. Direct experimentation is needed to determine the actual costs of pteridine-based ornaments. Like carotenoids, pteridines influence important biological processes, including immune and antioxidant function; predation and social costs may also be relevant. © 2011 Elsevier Inc.
Brink J.W.,Royal Alberta Museum
Quaternary International | Year: 2013
Pronghorn (Antilocapra Americana) were communally hunted over much of western North America. Typically, this was done using V-shaped containment structures of wood and brush leading to an enclosure, pit, or other type of kill site. Such traps are best known in the Great Basin, but less so on the Great Plains. Only one pronghorn drive that utilized lines of stones as the animal-guiding mechanism has been recorded in the latter region. This paper reports on a second occurrence, the Barnett site in southeastern Alberta, Canada. Here, two converging lines of stone form the drive funnel. Rocks are preferentially loaded towards the narrow end, where greatest control was needed. A pit may have been located at the end of the drive, where sharp angles in the stone lines may have been places for archers to station themselves. A review of pronghorn behaviour focuses on their innate curiosity and how this trait was manipulated by knowledgeable hunters. Shamans, or antelope charmers, were key figures in the communal hunts for their role in summoning pronghorn to the traps. It is argued that pronghorn were primarily lured to the Barnett site at which point they were driven down the stone lines.When he [Old Man] was in the mountains, he made the antelope out of dirt, and turned it lose, to see how it would go. It ran so fast that it fell over some rocks and hurt itself. He saw that this would not do, and took the antelope down on the prairie, and turned it lose; and it ran away fast and gracefully, and he said, " This is what you are suited to" (Blackfoot Lodge Tales, Grinnell, 1962, pp. 138). © 2013 .
Beaulieu F.,University of Queensland |
Walter D.E.,Royal Alberta Museum |
Walter D.E.,University of Alberta |
Proctor H.C.,University of Alberta |
Kitching R.L.,Griffith University
Biotropica | Year: 2010
Suspended soils in forest canopies are thought to harbor a substantial fraction of canopy biomass and many arboreal specialists, but do forest floor generalist predators with high vagility also use this habitat? We tested the hypothesis of no difference between forest floor and suspended-soil predatory mite faunas (Acari: Mesostigmata) in an Australian rain forest. Our results show that instead of being habitat generalists, many predatory mites partition soil into two main strata: soil suspended aboveground irrespective of height (0.5-20m) and soil on the ground. Of 53 species of Mesostigmata in suspended soil, 53 percent (28 species) were absent from or rarely found on the ground. This increased to 60 percent (15/25 species) if only common species are considered. Among these 15 'suspended-soil specialists', all but the three least abundant were found throughout the arboreal strata. Moreover, ten species also occurred in litter accumulated on the surface of decaying logs or boulders close to the forest floor. Thus, although the arboreal predatory mite fauna is distinct from that on the forest floor, it is not restricted to the high canopy: even slightly elevated substrate appears acceptable as habitat for these suspended-soil specialists. Our data suggest that a substantial portion of a rain forest's soil and litter fauna is held above the forest floor. © 2010 The Author(s). Journal compilation © 2010 by The Association for Tropical Biology and Conservation.