Faculty Publications

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Open Access
Areas of high habitat use from 1999-2010 for radio-collared Canada lynx reintroduced to Colorado
(Colorado State University. Libraries, 2011-03-31) Theobald, David M., author; Shenk, Tanya, author; Ivan, Jake, author; Lukacs, Paul, author; Rice, Mindy, author
Open Access
Behavioral responses associated with a human-mediated predator shelter
(Colorado State University. Libraries, 2014-04) Graeme, Shannon, author; Cordes, Line S., author; Hardy, Amanda R., author; Angeloni, Lisa M., author; Crooks, Kevin R., author; Public Library of Science, publisher
Human activities in protected areas can affect wildlife populations in a similar manner to predation risk, causing increases in movement and vigilance, shifts in habitat use and changes in group size. Nevertheless, recent evidence indicates that in certain situations ungulate species may actually utilize areas associated with higher levels of human presence as a potential refuge from disturbance-sensitive predators. We now use four-years of behavioral activity budget data collected from pronghorn (Antilocapra americana) and elk (Cervus elephus) in Grand Teton National Park, USA to test whether predictable patterns of human presence can provide a shelter from predatory risk. Daily behavioral scans were conducted along two parallel sections of road that differed in traffic volume - with the main Teton Park Road experiencing vehicle use that was approximately thirty-fold greater than the River Road. At the busier Teton Park Road, both species of ungulate engaged in higher levels of feeding (27% increase in the proportion of pronghorn feeding and 21% increase for elk), lower levels of alert behavior (18% decrease for pronghorn and 9% decrease for elk) and formed smaller groups. These responses are commonly associated with reduced predatory threat. Pronghorn also exhibited a 30% increase in the proportion of individuals moving at the River Road as would be expected under greater exposure to predation risk. Our findings concur with the 'predator shelter hypothesis', suggesting that ungulates in GTNP use human presence as a potential refuge from predation risk, adjusting their behavior accordingly. Human activity has the potential to alter predator-prey interactions and drive trophic-mediated effects that could ultimately impact ecosystem function and biodiversity.
Open Access
Characterising the impacts of emerging energy development on wildlife, with an eye towards mitigation
(Colorado State University. Libraries, 2012) Northrup, Joseph M., author; Wittemyer, George, author; Blackwell Publishing Ltd., publisher
Global demand for energy is projected to increase by 40% in the next 20 years, and largely will be met with alternative and unconventional sources. Development of these resources causes novel disturbances that strongly impact terrestrial ecosystems and wildlife. To effectively position ecologists to address this prevalent conservation challenge, we reviewed the literature on the ecological ramifications of this dominant driver of global land-use change, consolidated results for its mitigation and highlighted knowledge gaps. Impacts varied widely, underscoring the importance of area and species-specific studies. The most commonly reported impacts included behavioural responses and direct mortality. Examinations of mitigation were limited, but common easements included (1) reduction of the development footprint and human activity, (2) maintenance of undeveloped, 'refuge' habitat and (3) alteration of activity during sensitive periods. Problematically, the literature was primarily retrospective, focused on few species, countries, and ecoregions, and fraught with generalisations from weak inference. We advocate future studies take a comprehensive approach incorporating a mechanistic understanding of the interplay between development caused impacts and species ecology that will enable effective mitigation. Key areas for future research vital to securing a sustainable energy future in the face of development-related global change are outlined.
Open Access
Comparative demography of an at-risk African elephant population
(Colorado State University. Libraries, 2013) Wittemyer, George, author; Daballen, David, author; Douglas-Hamilton, Iain, author; Public Library of Science, publisher
Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human impacts (laying the foundation for modeling approaches), supporting predictions of evolutionary theory regarding demographic responses to ecological processes.
Open Access
Devastating decline of forest elephants in Central Africa
(Colorado State University. Libraries, 2013) Maisels, Fiona, author; Strindberg, Samantha, author; Blake, Stephen, author; Wittemyer, George, author; Hart, John, author; Williamson, Elizabeth A., author; Aba'a, Rostand, author; Abitsi, Gaspard, author; Ambahe, Ruffin D., author; Amsini, Fidèl, author; Bakabana, Parfait C., author; Hicks, Thurston Cleveland, author; Bayogo, Rosine E., author; Bechem, Martha, author; Beyers, Rene L., author; Bezangoye, Anicet N., author; Boundja, Patrick, author; Bout, Nicolas, author; Akou, Marc Ella, author; Bene, Lambert Bene, author; Fosso, Bernard, author; Greengrass, Elizabeth, author; Grossmann, Falk, author; Ikamba-Nkulu, Clement, author; Ilambu, Omari, author; Inogwabini, Bila-Isia, author; Iyenguet, Fortune, author; Kiminou, Franck, author; Kokangoye, Max, author; Kujirakwinja, Deo, author; Latour, Stephanie, author; Liengola, Innocent, author; Mackaya, Quevain, author; Madidi, Jacob, author; Madzoke, Bola, author; Makoumbou, Calixte, author; Malanda, Guy-Aimé, author; Malonga, Richard, author; Mbani, Olivier, author; Mbendzo, Valentin A., author; Ambassa, Edgar, author; Ekinde, Albert, author; Mihindou, Yves, author; Morgan, Bethan J., author; Motsaba, Prosper, author; Moukala, Gabin, author; Mounguengui, Anselme, author; Mowawa, Brice S., author; Ndzai, Christian, author; Nixon, Stuart, author; Nkumu, Pele, author; Nzolani, Fabian, author; Pintea, Lilian, author; Plumptre, Andrew, author; Rainey, Hugo, author; De Semboli, Bruno Bokoto, author; Serckx, Adeline, author; Stokes, Emma, author; Turkalo, Andrea, author; Vanleeuwe, Hilde, author; Vosper, Ashley, author; Warren, Ymke, author; Public Library of Science, publisher
African forest elephants - taxonomically and functionally unique - are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002-2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.
Open Access
Ecological effects of reservoir operations on Blue Mesa Reservoir
(Colorado State University. Libraries, 1998) Johnson, Brett M., author; Stockwell, Jason D., author; Department of Fishery and Wildlife Biology, Colorado State University, publisher
Annual progress report, May 1, 1997-April 30, 1998.
Open Access
Ecological effects of reservoir operations on Blue Mesa Reservoir
(Colorado State University. Libraries, 1997) Johnson, Brett M., author; Stockwell, Jason D., author; Bonfantine, Krista, author; Department of Fishery and Wildlife Biology, Colorado State University, publisher
Annual progress report, May 1, 1996-April 30, 1997.
Open Access
Ecological effects of reservoir operations on Blue Mesa Reservoir
(Colorado State University. Libraries, 1996) Johnson, Brett M., author; Wise, Michael J., author; Herwig, Brian, author; Szerlong, Glenn, author; Faber, Derrek, author; Byall, Blake, author; Department of Fishery and Wildlife Biology, Colorado State University, publisher
Annual progress report, May 1, 1995-April 30, 1996.
Open Access
Effects of recreation on animals revealed as widespread through a global systematic review
(Colorado State University. Libraries, 2016-12-08) Larson, Courtney L., author; Reed, Sarah E., author; Merenlender, Adina M., author; Crooks, Kevin R., author; PLOS ONE, publisher
Outdoor recreation is typically assumed to be compatible with biodiversity conservation and is permitted in most protected areas worldwide. However, increasing numbers of studies are discovering negative effects of recreation on animals. We conducted a systematic review of the scientific literature and analyzed 274 articles on the effects of non-consumptive recreation on animals, across all geographic areas, taxonomic groups, and recreation activities. We quantified trends in publication rates and outlets, identified knowledge gaps, and assessed evidence for effects of recreation. Although publication rates are low and knowledge gaps remain, the evidence was clear with over 93% of reviewed articles documenting at least one effect of recreation on animals, the majority of which (59%) were classified as negative effects. Most articles focused on mammals (42% of articles) or birds (37%), locations in North America (37.7%) or Europe (26.6%), and individual-level responses (49%). Meanwhile, studies of amphibians, reptiles, and fish, locations in South America, Asia, and Africa, and responses at the population and community levels are lacking. Although responses are likely to be species-specific in many cases, some taxonomic groups (e.g., raptors, shorebirds, ungulates, and corals) had greater evidence for an effect of recreation. Counter to public perception, non-motorized activities had more evidence for a negative effect of recreation than motorized activities, with effects observed 1.2 times more frequently. Snow-based activities had more evidence for an effect than other types of recreation, with effects observed 1.3 times more frequently. Protecting biodiversity from potentially harmful effects of recreation is a primary concern for conservation planners and land managers who face increases in park visitation rates; accordingly, there is demand for sciencebased information to help solve these dilemmas.
Open Access
Elk migration, habitat use and dispersal in the Upper Eagle Valley, Colorado: summary report 1986-1988
(Colorado State University. Libraries, 1989) de Vergie, William J., author; Alldredge, A. William, author
Open Access
Foraging ecology of black bears in urban environments: guidance for human-bear conflict mitigation
(Colorado State University. Libraries, 2015-08) Lewis, D. L., author; Baruch-Mordo, S., author; Wilson, K. R., author; Breck, S. W., author; Mao, J. S., author; Broderick, J., author; Ecological Society of America, publisher
Urban environments offer wildlife novel anthropogenic resources that vary spatiotemporally at fine scales. Property damage, economic losses, human injury, or other human-wildlife conflicts can occur when wildlife use these resources; however, few studies have examined urban wildlife resource selection at fine scales to guide conflict mitigation. We studied black bears (Ursus americanus) in the urban area of Aspen, Colorado, USA from 2007 to 2010 to quantify bear foraging on natural and anthropogenic resources and to model factors associated with anthropogenic feeding events. We collected fine-scale spatiotemporal data by tracking GPS-collared bears at 30-min intervals and backtracked to bear locations within 24 hours of use. We used discrete choice models to assess bears' resource selection, modeling anthropogenic feeding (use) and five associated random (availability) locations as a function of attributes related to temporally changing natural (e.g., ripe mast) and human (e.g., garbage) food resources, urban characteristics (e.g., housing density), and land cover characteristics (e.g., distance to riparian area). We backtracked to 2,675 locations used by 24 bears and classified 20% as foraging locations. We found that bears foraged on both natural and anthropogenic food sources in the urban environment, with 77% of feeding events being anthropogenic. We documented inter- and intra-annual foraging patterns in which bears foraged extensively in urban areas when natural food production was poor, then switched to natural food sources when available. These patterns suggest that bears balance energy budgets and individual safety when making foraging decisions. Overwhelmingly, garbage was the main anthropogenic food source that bears used. Selection of foraging sites was not only influenced by presence of garbage but also by proximity to riparian habitat and presence of ripe anthropogenic fruit trees. We found that while 76% of the garbage containers at random locations were bear-resistant, 57% of these bear-resistant containers were not properly secured. We recommend conflict mitigation focus on reducing available garbage and anthropogenic fruit trees, particularly near riparian areas, to make urban environments less energetically beneficial for foraging. Additionally, deploying bear-resistant containers is inadequate without education and proactive enforcement to change human behavior to properly secure garbage and ultimately reduce human-bear conflict.
Open Access
Refine modeling tools to forecast effects of dam operations on reservoir food webs
(Colorado State University. Libraries, 1998) Johnson, Brett M., author; Andre, Mary, author; Department of Fishery and Wildlife Biology, Colorado State University, publisher
Annual progress report, March 24 - August 1, 1998.
Open Access
Summary progress report on the Upper Eagle Valley elk study: the effects of ski area expansion on elk, accuracy of 2 telemetry systems in mountainous terrain, summer data - 1991
(Colorado State University. Libraries, 1992) Morrison, James R., author; Alldredge, A. William, author
Open Access
The use of on-animal acoustical recording devices for studying animal behavior
(Colorado State University. Libraries, 2013-07) Lynch, Emma, author; Angeloni, Lisa, author; Fristrup, Kurt, author; Joyce, Damon, author; Wittemyer, George, author; John Wiley and Sons, publisher
Audio recordings made from free-ranging animals can be used to investigate aspects of physiology, behavior, and ecology through acoustic signal processing. On-animal acoustical monitoring applications allow continuous remote data collection, and can serve to address questions across temporal and spatial scales. We report on the design of an inexpensive collar-mounted recording device and present data on the activity budget of wild mule deer (Odocoileus hemionus) derived from these devices applied for a 2-week period. Over 3300 h of acoustical recordings were collected from 10 deer on their winter range in a natural gas extraction field in northwestern Colorado. Analysis of a subset of the data indicated deer spent approximately 33.5% of their time browsing, 20.8% of their time processing food through mastication, and nearly 38.3% of their time digesting through rumination, with marked differences in diel patterning of these activities. Systematic auditory vigilance was a salient activity when masticating, and these data offer options for quantifying wildlife responses to varying listening conditions and predation risk. These results (validated using direct observation) demonstrate that acoustical monitoring is a viable and accurate method for characterizing individual time budgets and behaviors of ungulates, and may provide new insight into the ways external forces affect wildlife behavior.
Open Access
Upper Eagle River Valley elk study: progress report on 1996 activities, volume 1
(Colorado State University. Libraries, 1997-05-15) Phillips, Gregory E., author; Alldredge, A. William, author
Open Access
Will elephants soon disappear from West African savannahs?
(Colorado State University. Libraries, 2011) Bouché, Philippe, author; Douglas-Hamilton, Iain, author; Wittemyer, George, author; Nianogo, Aimé J., author; Doucet, Jean-Louis, author; Lejeune, Philippe, author; Vermeulen, Cédric, author; Public Library of Science, publisher
Precipitous declines in Africa's native fauna and flora are recognized, but few comprehensive records of these changes have been compiled. Here, we present population trends for African elephants in the 6,213,000 km2 Sudano-Sahelian range of West and Central Africa assessed through the analysis of aerial and ground surveys conducted over the past 4 decades. These surveys are focused on the best protected areas in the region, and therefore represent the best case scenario for the northern savanna elephants. A minimum of 7,745 elephants currently inhabit the entire region, representing a minimum decline of 50% from estimates four decades ago for these protected areas. Most of the historic range is now devoid of elephants and, therefore, was not surveyed. Of the 23 surveyed elephant populations, half are estimated to number less than 200 individuals. Historically, most populations numbering less than 200 individuals in the region were extirpated within a few decades. Declines differed by region, with Central African populations experiencing much higher declines (-76%) than those in West Africa (-33%). As a result, elephants in West Africa now account for 86% of the total surveyed. Range wide, two refuge zones retain elephants, one in West and the other in Central Africa. These zones are separated by a large distance (~900 km) of high density human land use, suggesting connectivity between the regions is permanently cut. Within each zone, however, sporadic contacts between populations remain. Retaining such connectivity should be a high priority for conservation of elephants in this region. Specific corridors designed to reduce the isolation of the surveyed populations are proposed. The strong commitment of governments, effective law enforcement to control the illegal ivory trade and the involvement of local communities and private partners are all critical to securing the future of elephants inhabiting Africa's northern savannas.

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