Kirk A. Olson
Smithsonian Conservation Biology Institute
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Featured researches published by Kirk A. Olson.
BioScience | 2011
Julie K. Young; Kirk A. Olson; Richard P. Reading; Sukh Amgalanbaatar; Joel Berger
In human-populated landscapes, dogs (Canis familiaris) are often the most abundant terrestrial carnivore. However, dogs can significantly disrupt or modify intact ecosystems well beyond the areas occupied by people. Few studies have directly quantified the environmental or economic effects of free-roaming and feral dogs. Here, we review wildlife-dog interactions and provide a case study that focuses on interactions documented from our research in Mongolia to underscore the need for studies designed to best determine how dogs affect native wildlife and especially imperiled populations. We suggest additional research, public awareness campaigns, and the exclusion of dogs from critical wildlife habitat. The application of scientific findings to management and enhanced public outreach programs will not only facilitate recovery and maintenance of wildlife populations globally but also has the potential to reduce economic losses.
The American Naturalist | 2014
Chris H. Fleming; Justin M. Calabrese; Thomas Mueller; Kirk A. Olson; Peter Leimgruber; William F. Fagan
Understanding animal movement is a key challenge in ecology and conservation biology. Relocation data often represent a complex mixture of different movement behaviors, and reliably decomposing this mix into its component parts is an unresolved problem in movement ecology. Traditional approaches, such as composite random walk models, require that the timescales characterizing the movement are all similar to the usually arbitrary data-sampling rate. Movement behaviors such as long-distance searching and fine-scale foraging, however, are often intermixed but operate on vastly different spatial and temporal scales. An approach that integrates the full sweep of movement behaviors across scales is currently lacking. Here we show how the semivariance function (SVF) of a stochastic movement process can both identify multiple movement modes and solve the sampling rate problem. We express a broad range of continuous-space, continuous-time stochastic movement models in terms of their SVFs, connect them to relocation data via variogram regression, and compare them using standard model selection techniques. We illustrate our approach using Mongolian gazelle relocation data and show that gazelle movement is characterized by ballistic foraging movements on a 6-h timescale, fast diffusive searching with a 10-week timescale, and asymptotic diffusion over longer timescales.
Oryx | 2005
Kirk A. Olson; Todd K. Fuller; George B. Schaller; Daria Odonkhuu; Martyn G. Murray
in autumn, with total population estimates of 803,820 (483,790–1,330,100 95% confidence interval) and 870,625 (499,432–1,491,278 95% confidence interval), respectively. Confidence limits were wide, and to obtain a coefficient of variation of 20%, transect lengths would need to be extended three- to four-fold. Until more efficient means for conducting population surveys can be implemented, driving long-distance transects, combined with distance analysis, seem to provide the best quantitative estimate of Mongolian gazelle populations.
Oryx | 2009
Kirk A. Olson; Thomas Mueller; Sanjaa Bolortsetseg; Peter Leimgruber; William F. Fagan; Todd K. Fuller
In September 2007 unusual precipitation patterns created conditions in the eastern steppe of Mongolia (drought conditions in many places and wet conditions in one area) that led to the observation of a historically large Mongolian gazelle Procapra gutturosa herd (. 200,000). A model developed to predict gazelle occurrence based on satellite imagery of vegetation productivity correctly identified the region where the mega-herd was located. Additionally, few gazelles were observed in large portions of adjacent, suitable habitat that either had intense insect activity or were undergoing intensive oil development. Because Mongolian gazelles appear to undertake long-distance nomadic movements to cope with a highly variable environment and food availability, development activities that discourage use of limited suitable habitat may ultimately reduce gazelle fecundity or increase mortality. Landscape level conservation strategies that prevent habitat loss and allow access to all of the grasslands seem preferable to strategies that focus on enhancing a handful of protected areas.
Journal of Zoology | 2005
Kirk A. Olson; Todd K. Fuller; George B. Schaller; B. Lhagvasuren; Daria Odonkhuu
Mongolian gazelles Procapra gutturosa were observed, hand-captured and radio-monitored in the eastern steppe of Mongolia during 1998–2003 to understand better their reproduction and survival. During early June, 92% (range = 87–96%) of adult (≥ 2 years old) females observed (mean n = 735/year) were pregnant, and nearly all gave birth during a 10-day interval (24 June–3 July) each year. Mean mass of neonate (1–2 days old) calves (mean n = 47/year) was greater for males than for females, and masses were directly correlated with mean monthly temperatures the previous winter (December–April). Survival during the first 10 days of life for 111 radio-marked neonate calves monitored during 2000–03 (n = 9–55/year) was 0.83 and did not seem to vary with birth weight. Also, deaths owing to hypothermia, abandonment, or unknown causes (interval cause-specific mortality rate = 0.16) outnumbered deaths owing to predation (0.02) during this interval. Survival rates were similar during the rest of the year (0.86 for 355 days) when most mortalities were owing to predation (interval mortality rate = 0.12 vs 0.01). Annual survival of calves was 0.71 (95% CI = 0.61–0.82). Gazelle births are highly synchronous, probably to take most advantage of the short summer growing season, and perhaps to avoid deleterious spring weather and to minimize predation. High fecundity and relatively high calf survival, especially during the first weeks of life, support the notion that gazelle populations can recover fairly quickly from demographic catastrophes.
Journal of Morphology | 2008
Roland Frey; Alban Gebler; Kirk A. Olson; Daria Odonkhuu; Guido Fritsch; Nyamsuren Batsaikhan; Ingo W. Stuermer
This study provides the first evidence of pronounced temporary laryngeal descent in a bovid species. An elaborate acoustic display is prominent in male courtship behavior of polygynous Mongolian gazelle. During rut, rounding up of females is accompanied by continuous head‐up barking by dominant males. Throughout the rut their evolutionarily enlarged larynx descends to a low mid‐neck resting position. In the course of each bark the larynx is additionally retracted toward the sternum by 30% of the resting vocal tract length. A geometric model of active larynx movements was constructed by combining results of video documentation, dissection, skeletonization, and behavioral observation. The considerable distance between resting position and maximal laryngeal descent suggests a backward tilting of the hyoid apparatus and an extension of the thyrohyoid connection during the retraction phase. Return to the resting position is effected by strap muscles and by the elastic recoil of the pharynx and the thyrohyoid connection. An intrapharyngeal inflation of the peculiar palatinal pharyngeal pouch of adult males is inferred from a short‐time expansion of the ventral neck region rostral to the laryngeal prominence. The neck of adult dominant males is accentuated by long gray guard hairs during the rut. The passive swinging of the heavy larynx of adult males during locomotion gives the impression of a handicap imposed on rutting males. Apparently, this disadvantage becomes outweighed by the profits for reproductive success. J. Morphol., 2008.
Methods in Ecology and Evolution | 2014
Christian H. Fleming; Justin M. Calabrese; Thomas Mueller; Kirk A. Olson; Peter Leimgruber; William F. Fagan
Summary By viewing animal movement paths as realizations of a continuous stochastic process, we introduce a rigorous likelihood method for estimating the statistical parameters of movement processes. This method makes no assumption of a hidden Markov property, places no special emphasis on the sampling rate, is insensitive to irregular sampling and data gaps, can produce reasonable estimates with limited sample sizes and can be used to assign AIC values to a vast array of qualitatively different models of animal movement at the individual and population levels. To develop our approach, we consider the likelihood of the first two cumulants of stochastic processes, the mean and autocorrelation functions. Together, these measures provide a considerable degree of information regarding searching, foraging, migration and other aspects of animal movement. As a specific example, we develop the likelihood analyses necessary to contrast performance of animal movement models based on Brownian motion, the Ornstein–Uhlenbeck process and a generalization of the Ornstein–Uhlenbeck process that includes ballistic bouts. We then show how our framework also provides a new and more accurate approach to home-range estimation when compared to estimators that neglect autocorrelation in the movement path. We apply our methods to a data set on Mongolian gazelles (Procapra gutturosa) to identify the movement behaviours and their associated time and length scales that characterize the movement of each individual. Additionally, we show that gazelle annual ranges are vastly larger than those of other non-migratory ungulates.
PLOS Biology | 2016
John D. C. Linnell; Arie Trouwborst; Luigi Boitani; Petra Kaczensky; Djuro Huber; Slaven Reljić; Josip Kusak; Aleksandra Majić; Tomaz Skrbinsek; Hubert Potočnik; Matt W. Hayward; E. J. Milner-Gulland; Bayarbaatar Buuveibaatar; Kirk A. Olson; Lkhagvasuren Badamjav; Richard Bischof; Steffen Zuther; Urs Breitenmoser
The ongoing refugee crisis in Europe has seen many countries rush to construct border security fencing to divert or control the flow of people. This follows a trend of border fence construction across Eurasia during the post-9/11 era. This development has gone largely unnoticed by conservation biologists during an era in which, ironically, transboundary cooperation has emerged as a conservation paradigm. These fences represent a major threat to wildlife because they can cause mortality, obstruct access to seasonally important resources, and reduce effective population size. We summarise the extent of the issue and propose concrete mitigation measures.
Conservation Biology | 2014
Nyamsuren Batsaikhan; Bayarbaatar Buuveibaatar; Bazaar Chimed; Oidov Enkhtuya; Davaa Galbrakh; Oyunsaikhan Ganbaatar; Badamjav Lkhagvasuren; Dejid Nandintsetseg; Joel Berger; Justin M. Calabrese; Ann E. Edwards; William F. Fagan; Todd K. Fuller; Michael Heiner; Takehiko Y. Ito; Petra Kaczensky; Peter Leimgruber; A. A. Lushchekina; E. J. Milner-Gulland; Thomas Mueller; Martyn G. Murray; Kirk A. Olson; Richard P. Reading; George B. Schaller; Annagret Stubbe; Michael Stubbe; Chris Walzer; Henrik von Wehrden; Tony Whitten
Department of Zoology, School of Biology and Biotechnology, National University of Mongolia, University Avenue-1, Ulaanbaatar,Mongolia†Mongolia Program, Wildlife Conservation Society, Amar Street-3, “Internom” Bookstore Building, 3rd Floor, Ulaanbaatar, Mongolia‡Ochir-WWF Mongolia Program, Amar Street-4, P.O. Box 115, PO-20A, Ulaanbaatar, Mongolia§The Nature Conservancy Mongolia Program Office, Amar Street-4, 2nd floor, Ulaanbaatar, Mongolia¶Protected Areas Administration, Mongolia, Great Gobi B Strictly Protected Area, Khovd, Mongolia
Ecology | 2015
Chris H. Fleming; William F. Fagan; Thomas Mueller; Kirk A. Olson; Peter Leimgruber; Justin M. Calabrese
An animals trajectory is a fundamental object of interest in movement ecology, as it directly informs a range of topics from resource selection to energy expenditure and behavioral states. Optimally inferring the mostly unobserved movement path and its dynamics from a limited sample of telemetry observations is a key unsolved problem, however. The field of geostatistics has focused significant attention on a mathematically analogous problem that has a statistically optimal solution coined after its inventor, Krige. Kriging revolutionized geostatistics and is now the gold standard for interpolating between a limited number of autocorrelated spatial point observations. Here we translate Kriging for use with animal movement data. Our Kriging formalism encompasses previous methods to estimate animals trajectories--the Brownian bridge and continuous-time correlated random walk library--as special cases, informs users as to when these previous methods are appropriate, and provides a more general method when they are not. We demonstrate the capabilities of Kriging on a case study with Mongolian gazelles where, compared to the Brownian bridge, Kriging with a more optimal model was 10% more precise in interpolating locations and 500% more precise in estimating occurrence areas.