Current graduate students:
Krista Shofstall (University of Manitoba, PhD): Reproductive skew in female Cape ground squirrels
BS in Wildlife Biology from Humboldt State University, Arcata California
MSc in Biology, Ecology & Evolution from Laurentian University, Sudbury Ontario
My PhD research is going to take an integrative approach using behavior, ecology, and genetics to study the reproductive skew of female Cape ground squirrels (Xerus inauris). The objective of my research is look at potential reasons why female squirrels fail to wean offspring. First, I will be looking at the selection pressures and the possibility of reproductive suppression that these squirrels may experience. Second, I will be looking at resource limitation by looking at precipitation over time and by conducting supplemental feeding experiments using automated feeders. Third, I will determine the influence of maternal and alloparental care on the survival and condition of the offspring. This research will allow a greater understanding of the factors influencing reproductive success in this ecologically important and valuable species
BS in Wildlife Biology from Humboldt State University, Arcata California
MSc in Biology, Ecology & Evolution from Laurentian University, Sudbury Ontario
My PhD research is going to take an integrative approach using behavior, ecology, and genetics to study the reproductive skew of female Cape ground squirrels (Xerus inauris). The objective of my research is look at potential reasons why female squirrels fail to wean offspring. First, I will be looking at the selection pressures and the possibility of reproductive suppression that these squirrels may experience. Second, I will be looking at resource limitation by looking at precipitation over time and by conducting supplemental feeding experiments using automated feeders. Third, I will determine the influence of maternal and alloparental care on the survival and condition of the offspring. This research will allow a greater understanding of the factors influencing reproductive success in this ecologically important and valuable species
Riley Jellicoe (University of Manitoba, MSc): What makes a male a stud?
BSc in Biology from the University of Saskatchewan
Riley is examining the reproductive success of male Cape ground squirrels using our long-term datasets. He is testing hypotheses on how factors such as alternative reproductive tactic, age, tenure as a breeding male, and body condition influence reproductive success in this long-lived ground squirrel. His second objective is to examine the variance in survival among these males to better understand the costs and benefits of early vs late dispersal.
BSc in Biology from the University of Saskatchewan
Riley is examining the reproductive success of male Cape ground squirrels using our long-term datasets. He is testing hypotheses on how factors such as alternative reproductive tactic, age, tenure as a breeding male, and body condition influence reproductive success in this long-lived ground squirrel. His second objective is to examine the variance in survival among these males to better understand the costs and benefits of early vs late dispersal.
Fall 2022: More to come on new members of the lab!
Past graduate students:
Rebecca Lem (University of Manitoba, MSc): Kin Selection using temporal-spatial factors
Rebecca examined the spatial patterns of kin groups in Cape ground squirrels. She hypothesized that if there is a spatial pattern due to kin selection, groups that share related squirrels will be found close together, and home range overlap will be high. Her second objective was to understand how the within group spatial patterns increase fitness and influence group splitting using our long-term behavioural database (and kinship data) as well as her own detailed behavioural data.
Philip Shimel (University of Manitoba, MSc):
My research has focused on the fitness consequences of social network position in Cape ground squirrels, specifically how female social network position influences longevity or fitness in this non-aggressive species. The objective of my research is to answer whether Cape ground squirrels share affiliative interactions preferentially with closer kin. A second objective is to answer whether Cape ground squirrels have higher reproductive success with higher rates of affiliative interactions. A third objective is to answer whether Cape ground squirrels have higher reproductive success with more central positions in their social networks. These objectives will indicate 1) whether Cape ground squirrels discriminate their behavioural interactions based on kin within their social groups, 2) whether their affiliative interactions are objects of natural selection, and 3) whether social networks drive natural selection in ways that are undetectable at simpler scales of measurement.
Annemarie van der Marel (University of Manitoba, PhD): Evolution of sociality in ground squirrels
My name is Annemarie and I'm from The Netherlands. The objective of my thesis is to investigate the evolution of sociality using ground squirrels of the family Sciuridae as model group. First, I will make a comparative interspecific analysis of habitat structure and predation pressure on sociality in ground-dwelling sciurids, controlling for phylogeny. Secondly, I will perform an intraspecific analysis to test the influence that environmental factors may have on the sociality of a southern African ground squirrel, the Cape ground squirrel (Xerus inauris). Furthermore, I will focus on understanding the plasticity of sociality by examining the social system of a northern African ground squirrel, the Barbary ground squirrel (Atlantoxerus getulus). First, how grouping is influenced by kinship and social structure (kin and non-kin), which will be studied using social network analysis. Secondly, how their reproductive success is maximised by studying the mating system and different mating strategies by both males and females. Finally, I will experimentally test hypotheses on anti-predator behaviour as an evolutionary force promoting sociality in the Barbary ground squirrel by studying their sentinel and alarm calling behaviours.
Elaine Anjos (University of Manitoba, PhD): Sperm competition in ground-dwelling squirrels
[email protected] MSc Degree in Ecology and Conservation from Federal University of South Mato Grosso, Brazil
For my PhD at University of Manitoba, my research interest was to investigate sperm competition in mammals, specifically in ground squirrels. It is important to recognize which traits influence the fertilizing efficiency of males and how different species maximize their reproductive success through post-copulatory sexual selection. I examined sperm in three different species, Richardson's ground squirrels (Urocitellus richardsoni) from Winnipeg, Cape Ground Squirrels (Xerus inauris) from South Africa and Barbary Ground Squirrels (Atlantoxerus getulus) from Fuerteventura Island, Spain.
Paige Bissonnette (University of Manitoba, MSc): Understanding the energetic costs of social play in polar bears (Ursus maritimus) using body condition measures and thermal-imagery technology.
Jennifer Sojka (University of Manitoba, MSc): The effects of consistent individual differences and behavioural syndromes on reproductive success in female Cape ground squirrels.
Jen Sojka investigated how consistent individual differences, or animal personality, affects reproductive success in female Cape ground squirrels. By measuring traits such as boldness and exploration, she explored why some females are more successful than others in a species where aggression is rare.
Kelsey O'Brien (University of Manitoba, MSc. 2015): Trade-offs among immunity, hormones and alternative reproductive tactics of male Cape ground squirrels (Xerus inauris).
Kelsey studied hormonal and immunological trade-offs made by male Cape ground squirrels, including testosterone-immunity-cortisol interactions. She has examined these trade-offs in males that stayed in their family groups (some for up to 6 years) compared to those that dispersed.
Molly Phillips (University of Manitoba, MSc. 2012): Anti-predator behaviours in the Cape ground squirrel.
I studied anti-predator behaviours in the Cape ground squirrel, investigating variation in snake mobbing responses among individual squirrels and with different predator species. I also examined venom resistance in Cape ground squirrels and the ability of the squirrels to detect the odour of potential predators.
Mary Beth Manjerovic (University of Central Florida, PhD 2010): elective factors that influence male mating strategies and population genetics in Cape ground squirrels.
My research investigated the mating system and reproduction of the Cape ground squirrel (Xerus inauris) of southern Africa. This species is extremely social but unlike other species with similar levels of sociality, they lack aggression and territoriality. They also stand apart due to the male’s rather generous endowment which, combined with their unique behaviours, suggests an extraordinary level of sperm competition. My primary goal was to link male mating behaviours to paternity while further exploring the overall population structure. I was also interested in male dispersal given the propensity for adult males to remain within their natal social group.
Danielle Eisenberg (University of Central Florida, MS. 2008): Status survey of Big Cypress fox squirrel in order to evaluate the conservation status of this species.
The Big Cypress Fox Squirrel is a subspecies endemic to the South Florida Ecosystem; averaging 28-38cm. in length and a life span of 7-10 years (Koprowski et al. 1988). Since 1990 it has been listed as threatened by the Florida Fish and Wildlife Conservation Commission, and recently the subspecies was reviewed by the U.S. Fish and Wildlife Service for possible listing as an endangered species. The decline of the Big Cypress fox squirrel mirrors the decline in its preferred habitats as South Florida has been increasingly transformed by human activities. My project involved a status survey to determine the distribution, abundance, and habitat use of Big Cypress fox squirrels (Sciurus niger avicennia). This study documented the historic and current distribution of the BCFS by obtaining and mapping occurrence records from the U.S. Fish and Wildlife Service, Florida Natural Areas Inventory, Florida Museum of Natural History, and other sources, and through interviews with biologists and other field personnel of public land-managing agencies. We assessed habitat variables in areas that support Big Cypress fox squirrels so that habitat management guidelines can be developed and suitable areas can be protected to ensure the persistence of this rare subspecies.
Carlos J. R. Anderson (University of Central Florida, MS. 2007): Computational and mathematical approaches to biological problems: automated identification of individual polar bears
Efficient use of a computer requires good problem solving skills and years of experience, although many simple problems can be solved by anyone. As a computer scientist, I became interested in applying my skills and experience to solving problems in science. I am developed a computer-aided identification system for polar bears based on their unique whisker spot patterns and have expanded this program to work with other species.
Beth Pettitt (University of Central Florida, MS. 2006): Reproductive suppression and hormone cycles of Cape ground squirrels
I am interested in a diversity of questions in evolution, behavioural ecology and reproductive endocrinology. My research interests are generally concerned with the study of environmental and ecological influences on sociality. My Master’s research focused on the parameters influencing the age of sexual maturity in the African Cape ground squirrel (Xerus inauris), a cooperative breeder. I found the age of female sexual maturity was primarily influenced by social structure, with age of sexual maturity increasing with both number of adult breeding females and adult related males.
Melissa Hillegass (University of Central Florida, MS. 2006): Importance of parasitism on social structure and behaviour of Cape ground squirrels.
Melissa’s research examined sex biases in parasite loads and the impact of parasites on the reproductive success of female Cape ground squirrels. She tested the impact of parasites by effectively removing both ecto and endoparasites from the squirrels and recording their behavioural, physiological and reproductive responses to the removal
Doug Skurski (University of Central Florida, MS. 2006): Monitoring a potentially stressful situation in captive western lowland gorillas (Gorilla gorilla gorilla) through analysis of behaviour and urinary cortisol
Gillian Eckhardt (University of Central Florida, MS. 2005): The effects of ecotourism on polar bear behaviour
Lynette Bouchie (University of Central Florida, MS. 2004): Ovulation in the Cape ground squirrel (Xerus inauris)
Barbara Fields (University of Central Florida, MS. 2004): Behaviour of captive Florida manatees, Trichechus manatus latirostris
Carolyn Unck (University of Pretoria,MSc. 2004): Does kin selection influence anti predator vigilance in Cape ground squirrels (Xerus inauris)?
Ali Rabatsky (University of Central Florida, MS. 2003): Caudal luring and defensive tail display in the dusky pigmy rattlesnake, Sistrurus miliarius barbouri, with comments on ontogeny and evolution
Rebecca Sellin (University of Central Florida, MS 2003): Influence of hormones and sexual swellings on social interactions in female mandrills (Mandrillus spinx)
Rebecca Lem (University of Manitoba, MSc): Kin Selection using temporal-spatial factors
Rebecca examined the spatial patterns of kin groups in Cape ground squirrels. She hypothesized that if there is a spatial pattern due to kin selection, groups that share related squirrels will be found close together, and home range overlap will be high. Her second objective was to understand how the within group spatial patterns increase fitness and influence group splitting using our long-term behavioural database (and kinship data) as well as her own detailed behavioural data.
Philip Shimel (University of Manitoba, MSc):
My research has focused on the fitness consequences of social network position in Cape ground squirrels, specifically how female social network position influences longevity or fitness in this non-aggressive species. The objective of my research is to answer whether Cape ground squirrels share affiliative interactions preferentially with closer kin. A second objective is to answer whether Cape ground squirrels have higher reproductive success with higher rates of affiliative interactions. A third objective is to answer whether Cape ground squirrels have higher reproductive success with more central positions in their social networks. These objectives will indicate 1) whether Cape ground squirrels discriminate their behavioural interactions based on kin within their social groups, 2) whether their affiliative interactions are objects of natural selection, and 3) whether social networks drive natural selection in ways that are undetectable at simpler scales of measurement.
Annemarie van der Marel (University of Manitoba, PhD): Evolution of sociality in ground squirrels
My name is Annemarie and I'm from The Netherlands. The objective of my thesis is to investigate the evolution of sociality using ground squirrels of the family Sciuridae as model group. First, I will make a comparative interspecific analysis of habitat structure and predation pressure on sociality in ground-dwelling sciurids, controlling for phylogeny. Secondly, I will perform an intraspecific analysis to test the influence that environmental factors may have on the sociality of a southern African ground squirrel, the Cape ground squirrel (Xerus inauris). Furthermore, I will focus on understanding the plasticity of sociality by examining the social system of a northern African ground squirrel, the Barbary ground squirrel (Atlantoxerus getulus). First, how grouping is influenced by kinship and social structure (kin and non-kin), which will be studied using social network analysis. Secondly, how their reproductive success is maximised by studying the mating system and different mating strategies by both males and females. Finally, I will experimentally test hypotheses on anti-predator behaviour as an evolutionary force promoting sociality in the Barbary ground squirrel by studying their sentinel and alarm calling behaviours.
Elaine Anjos (University of Manitoba, PhD): Sperm competition in ground-dwelling squirrels
[email protected] MSc Degree in Ecology and Conservation from Federal University of South Mato Grosso, Brazil
For my PhD at University of Manitoba, my research interest was to investigate sperm competition in mammals, specifically in ground squirrels. It is important to recognize which traits influence the fertilizing efficiency of males and how different species maximize their reproductive success through post-copulatory sexual selection. I examined sperm in three different species, Richardson's ground squirrels (Urocitellus richardsoni) from Winnipeg, Cape Ground Squirrels (Xerus inauris) from South Africa and Barbary Ground Squirrels (Atlantoxerus getulus) from Fuerteventura Island, Spain.
Paige Bissonnette (University of Manitoba, MSc): Understanding the energetic costs of social play in polar bears (Ursus maritimus) using body condition measures and thermal-imagery technology.
Jennifer Sojka (University of Manitoba, MSc): The effects of consistent individual differences and behavioural syndromes on reproductive success in female Cape ground squirrels.
Jen Sojka investigated how consistent individual differences, or animal personality, affects reproductive success in female Cape ground squirrels. By measuring traits such as boldness and exploration, she explored why some females are more successful than others in a species where aggression is rare.
Kelsey O'Brien (University of Manitoba, MSc. 2015): Trade-offs among immunity, hormones and alternative reproductive tactics of male Cape ground squirrels (Xerus inauris).
Kelsey studied hormonal and immunological trade-offs made by male Cape ground squirrels, including testosterone-immunity-cortisol interactions. She has examined these trade-offs in males that stayed in their family groups (some for up to 6 years) compared to those that dispersed.
Molly Phillips (University of Manitoba, MSc. 2012): Anti-predator behaviours in the Cape ground squirrel.
I studied anti-predator behaviours in the Cape ground squirrel, investigating variation in snake mobbing responses among individual squirrels and with different predator species. I also examined venom resistance in Cape ground squirrels and the ability of the squirrels to detect the odour of potential predators.
Mary Beth Manjerovic (University of Central Florida, PhD 2010): elective factors that influence male mating strategies and population genetics in Cape ground squirrels.
My research investigated the mating system and reproduction of the Cape ground squirrel (Xerus inauris) of southern Africa. This species is extremely social but unlike other species with similar levels of sociality, they lack aggression and territoriality. They also stand apart due to the male’s rather generous endowment which, combined with their unique behaviours, suggests an extraordinary level of sperm competition. My primary goal was to link male mating behaviours to paternity while further exploring the overall population structure. I was also interested in male dispersal given the propensity for adult males to remain within their natal social group.
Danielle Eisenberg (University of Central Florida, MS. 2008): Status survey of Big Cypress fox squirrel in order to evaluate the conservation status of this species.
The Big Cypress Fox Squirrel is a subspecies endemic to the South Florida Ecosystem; averaging 28-38cm. in length and a life span of 7-10 years (Koprowski et al. 1988). Since 1990 it has been listed as threatened by the Florida Fish and Wildlife Conservation Commission, and recently the subspecies was reviewed by the U.S. Fish and Wildlife Service for possible listing as an endangered species. The decline of the Big Cypress fox squirrel mirrors the decline in its preferred habitats as South Florida has been increasingly transformed by human activities. My project involved a status survey to determine the distribution, abundance, and habitat use of Big Cypress fox squirrels (Sciurus niger avicennia). This study documented the historic and current distribution of the BCFS by obtaining and mapping occurrence records from the U.S. Fish and Wildlife Service, Florida Natural Areas Inventory, Florida Museum of Natural History, and other sources, and through interviews with biologists and other field personnel of public land-managing agencies. We assessed habitat variables in areas that support Big Cypress fox squirrels so that habitat management guidelines can be developed and suitable areas can be protected to ensure the persistence of this rare subspecies.
Carlos J. R. Anderson (University of Central Florida, MS. 2007): Computational and mathematical approaches to biological problems: automated identification of individual polar bears
Efficient use of a computer requires good problem solving skills and years of experience, although many simple problems can be solved by anyone. As a computer scientist, I became interested in applying my skills and experience to solving problems in science. I am developed a computer-aided identification system for polar bears based on their unique whisker spot patterns and have expanded this program to work with other species.
Beth Pettitt (University of Central Florida, MS. 2006): Reproductive suppression and hormone cycles of Cape ground squirrels
I am interested in a diversity of questions in evolution, behavioural ecology and reproductive endocrinology. My research interests are generally concerned with the study of environmental and ecological influences on sociality. My Master’s research focused on the parameters influencing the age of sexual maturity in the African Cape ground squirrel (Xerus inauris), a cooperative breeder. I found the age of female sexual maturity was primarily influenced by social structure, with age of sexual maturity increasing with both number of adult breeding females and adult related males.
Melissa Hillegass (University of Central Florida, MS. 2006): Importance of parasitism on social structure and behaviour of Cape ground squirrels.
Melissa’s research examined sex biases in parasite loads and the impact of parasites on the reproductive success of female Cape ground squirrels. She tested the impact of parasites by effectively removing both ecto and endoparasites from the squirrels and recording their behavioural, physiological and reproductive responses to the removal
Doug Skurski (University of Central Florida, MS. 2006): Monitoring a potentially stressful situation in captive western lowland gorillas (Gorilla gorilla gorilla) through analysis of behaviour and urinary cortisol
Gillian Eckhardt (University of Central Florida, MS. 2005): The effects of ecotourism on polar bear behaviour
Lynette Bouchie (University of Central Florida, MS. 2004): Ovulation in the Cape ground squirrel (Xerus inauris)
Barbara Fields (University of Central Florida, MS. 2004): Behaviour of captive Florida manatees, Trichechus manatus latirostris
Carolyn Unck (University of Pretoria,MSc. 2004): Does kin selection influence anti predator vigilance in Cape ground squirrels (Xerus inauris)?
Ali Rabatsky (University of Central Florida, MS. 2003): Caudal luring and defensive tail display in the dusky pigmy rattlesnake, Sistrurus miliarius barbouri, with comments on ontogeny and evolution
Rebecca Sellin (University of Central Florida, MS 2003): Influence of hormones and sexual swellings on social interactions in female mandrills (Mandrillus spinx)