Individual strategies, group dynamics and population regulation in cooperative breeders
with Tim Clutton-Brock & Tim Coulson (2011)
In my recent postdoctoral position at the University of Cambridge, I am investigating the population and group dynamic consequences of cooperative breeding and the evolution of alternative social strategies. Using long-term individual-based data on meerkats from southern Kalahari, I will address questions regarding the social mechanisms regulating group size, the relationship between group size and reproductive strategies, and the relative costs and benefits of alternative reproductive strategies in different group sizes. Eventually, I will use individul-based demographic models to assess the influence of social behaviour on population dynamics and the effects of group-level dynamics on demography at the population-level.
You can find more info on the Kalahari meerkat project here.
Individual differences and the dynamics of animal populations
with Tim Coulson, Shiprad Tuljapurkar & Tim Benton (2008)
Understanding population dynamics in a variable environment necessitates understanding the link between life histories and environment. Most studies investigate the interaction between age/stage structured demography and environment, but often ignore individual differences in phenotypic traits. Yet, individuals vary in quality, and such variation can influence their survival and reproduction, and in turn, population dynamics. Recent research highlights the influence of micro-evolutionary change in trait distributions on population dynamics. In this study, we are investigating the links between phenotypic trait distributions, environment and population dynamics by considering demography as a phenotype-by-environment interaction:
– How do changes in trait distributions influence demography and population dynamics?
– How do population dynamics feedback on the distributions of phenotypic traits?
– How does environmental variation influence the relationship between trait and population dynamics?
My research utilizes four contrasting systems (Soay sheep, yellow-bellied marmots, meerkats, silvereyes, and soil mites) and combines statistical analysis of existing data, with the development of new theory and models specific to each system.
Effect of upper respiratory tract disease on the population dynamics of gopher tortoises
with Madan Oli, Mary Brown, Lori Wendland & Caro Perez-Heydrich (2006)
Emerging infectious diseases (EIDs) have played an important role in shaping the human history, and their roles in influencing global biodiversity is being increasingly recognized. EIDs have been implicated in population declines or local extinction of several species. However, studies investigating the impact of infectious diseases on free-ranging wildlife populations, other than those of economic or public health significance, have been rare. Upper respiratory tract disease (URTD), an infectious disease caused byMycoplasma agassizii, has been associated with the decline of several tortoise populations, and it has been detected in gopher tortoise (Gopherus polyphemus) populations in Florida. However, the rate of transmission of URTD, and its effects on vital demographic rates in free-ranging populations of gopher tortoises remain unknown. In this study, we are investigating the effect of URTD on gopher tortoise population dynamics.
Metapopulation dynamics of yellow-bellied marmots
with Madan Oli, Ken Armitage, Dan Blumstein & Dirk Van Vuren (2001)
Spatial heterogeneity is a common characteristic of wildlife populations, and an important factor influencing population dynamics. However, very few empirical studies on long-lived vertebrates have thoroughly investigated the effect of spatial heterogeneity on population dynamics. The yellow-bellied marmot metapopulation nearby Rocky Mountain Biological Laboratory (Gothic, Colorado) is distributed into distinct colonies that interact via dispersal, providing an adequate patchy distribution for studying spatiotemporal patterns in local population dynamics. Using long-term mark-recapture data, we investigate the factors and processes that influence the dynamics of the yellow-bellied marmot metapopulation. We address a variety of questions: (1) the relative influence of particular sites on metapopulation dynamics; (2) the spatiotemporal variation in demographic rates and their influences on local population dynamics; (3) the demographic causes of the spatial variation in local population dynamics, and (4) the relative influence of within path and between patch processes on regional population dynamics. Ultimately, this study aims to provide a better understanding of the yellow-bellied marmot population dynamics, and the predictive powers of spatially explicit demographic models.
You can find more info on the long-term marmot study here.
Effect of disturbance on population dynamics of box turtles
with Ken Dodd & Madan Oli (2004)
Disturbances have the potential to cause long-term effects to ecosystem structure and function. Long-lived vertebrates such as turtles may be at risk from major environmental disturbances as their life histories preclude rapid recovery from extensive mortality events. Using mark–recapture data, we investigated disturbance effects on a population of Florida box turtles (Terrapene carolina bauri) on Egmont Key, Florida. Near the midpoint of the study, a series of physical disturbances affected the island, from salt water overwash associated with several tropical storms to extensive removal of nonindigenous vegetation. These disturbances allowed us to examine the demographic responses of the turtle population and to determine if they affected dispersal behavior throughout the island.
Small mammal population fluctuations
with Lowell Getz & Madan Oli (2002)
Many populations of microtine rodents undergo large-scale, multiannual fluctuations in abundance. Causes of these population fluctuations have been an ecological puzzle and a subject of debate among ecologists since the publication of Elton’s influential paper in the 1920s. In this study, we performed a thorough analysis of long-term mark-recapture data collected from a prairie vole (Microtus ochrogaster) population in Illinois. We investigated the temporal variation in demographic rates such as stage-specific survival, maturation, fecundity, age-at-maturity and lifespan, and studied their effect on the observed fluctuations in population density.
You can find more info on the long-term vole study here.
Ecology and conservation of cave-dwelling bats in Northwestern Turkey
with Andrzej Furman, Rasit Bilgin & Emrah Coraman (1998)
I studied the community ecology of cave-dwelling bats during my undergraduate and MSc years in Bosphorus University. My colleagues and I conducted two consecutive research projects:
In this project, we investigated population distribution and conservation status of cave-dwelling bats in Bosphorus area, a transition region between southeastern Europe and Asia Minor. We studied the distribution of eight cave-dwelling bat species and their seasonal use of 14 underground roosts. Consequently, each species and roost’s conservation status was derived for the region, and specific management strategies were recommended. As a part of the project, an amateur bat research group was established among Turkish cavers, which would continue the regular monitoring and the conservation effort in the region. We have also given numerous seminars and slide shows for a wide spectrum of audience in order to raise public awareness on bats and their conservation. This project received theThreatened Species Category Award from BP Conservation Program
This project was a follow-up to the project “ Eurasian Bridge ”, and it covered a much larger spatial scale. In this study, we investigated 50 natural caves in Turkish Thrace, which was the only part of Europe where population distribution of bats was not studied yet. We investigated the population distribution of 13 cave-dwelling bats, and their seasonal use of 50 underground roosts. The outcomes of this project highlighted the significant priority of the region for the conservation of the European bats. Outcomes of these two research projects are gathered in one report and two peer-reviewed manuscripts. This project received the Rufford Conservation Grant from Whitley Awards Foundation