Tyler Flockhart

Tyler Flockhart

PhD

About

76
Publications
14,877
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,227
Citations
Additional affiliations
December 2013 - June 2015
University of Guelph
Position
  • PostDoc Position
September 2004 - October 2007
University of Saskatchewan
Position
  • Master's Student
Education
September 2009 - November 2013
University of Guelph
Field of study
  • Population Ecology
September 2004 - October 2007
University of Saskatchewan
Field of study
  • Evolutionary Ecology
September 1997 - December 2001
University of Alberta
Field of study
  • Environmental and Conservation Sciences

Publications

Publications (76)
Article
Translocation is a common tool for managing nuisance Canada geese (Branta canadensis) in urban areas across North America. However, no previous research has assessed how translocation affects survival and philopatry at donor and release sites. Such information is required for managers to decide if translocation is a suitable intervention to reach t...
Article
Full-text available
Background Selective pressures that occur during long-distance migration can influence morphological traits across a range of taxa. In flying insects, selection should favour individuals that have wing morphologies that increase energy efficiency and survival. In monarch butterflies, differences in wing morphology between migratory and resident pop...
Article
Addressing population declines of migratory insects requires linking populations across different portions of the annual cycle and understanding the effects of variation in weather and climate on productivity, recruitment, and patterns of long-distance movement. We used stable H and C isotopes and geospatial modeling to estimate the natal origin of...
Article
Full-text available
Successful conservation of migratory birds demands we understand how habitat factors on the breeding grounds influences breeding success. Multiple factors are known to directly influence breeding success in territorial songbirds. For example, greater food availability and fewer predators can have direct effects on breeding success. However, many of...
Article
Although free-roaming cats can have a significant impact on the environment, and substantial resources have been invested to find humane alternatives for managing free-roaming cat populations, there are no empirical estimates of free-roaming cat population size in medium to large cities. In addition, little is known about factors limiting free-roam...
Article
Accurate information about the number of cats living outdoors and how they respond to different kinds of management are necessary to quell debates about outdoor cat policy. The DC Cat Count will develop the tools and methodologies needed to realize this possibility and make them available for broader use. This three-year initiative represents a maj...
Preprint
Animal shelters address animal welfare in communities through the intake and outcome of companion animals, but these efforts affect population dynamics of companion animals based on the distance animals are moved and the factors that underlie intake and outcome. Using data from an animal shelter in Washington, D.C., we analyzed cat intakes and outc...
Article
The ecological impact of free-roaming domestic cats (Felis catus) is well-studied. However, despite receiving considerable attention in both the scientific and popular literature, predation behavior is rarely an explicit consideration when developing cat population management plans. We used motion-activated wildlife cameras to document predation ev...
Article
Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) have shown promise for tracing the geographic origin of animal tissues because they have high‐resolution and show discrete spatial patterns independent and complementary to those of light isotopes. In this study, we provide a complete quantitative framework to apply ⁸⁷Sr/⁸⁶Sr for tracking migratory animals using...
Article
1. Neonicotinoid insecticides are the most widely used class of insecticides in the world and can have both lethal and sub‐lethal effects on non‐target organisms in agricultural areas. Monarch butterflies (Danaus plexippus) have experienced dramatic declines in recent decades and, given that a large proportion of milkweed on the landscape grows in...
Article
Full-text available
Urbanization is increasing globally, fragmenting habitats and prompting human–wildlife conflict. Urban wildlife research is concurrently expanding, but sampling methods are often biased towards large and intact habitats in public green spaces, neglecting the far more abundant, but degraded, habitats in the urban matrix. Here, we introduce the Five...
Article
Full-text available
Survival probability is fundamental for understanding population dynamics. Methods for estimating survival probability from field data typically require marking individuals, but marking methods are not possible for arthropod species that molt their exoskeleton between life stages. We developed a novel Bayesian state‐space model to estimate arthropo...
Article
Full-text available
Pollution is a pervasive, albeit often invisible, threat to biodiversity in Canada. Currently, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) relies on expert opinion to assess the scope (i.e., the proportion of a species’ population that may be affected) of pollution to species at risk. Here, we describe a spatially explici...
Article
Insects represent the most diverse and functionally important group of flying migratory animals around the globe, yet their small size makes tracking even large migratory species challenging. We attached miniaturized radio transmitters (less than 300 mg) to monarch butterflies ( Danaus plexippus) and common green darner dragonflies ( Anax junius) a...
Article
Full-text available
Monarch butterflies (Danaus plexippus, Linnaeus, 1758) are comprised of two migratory populations separated by the Rocky Mountains and are renowned for their long-distance movements among the United States, Canada, and Mexico. Both populations have declined over several decades across North America prompting all three countries to evaluate conserva...
Article
Full-text available
The eastern North American migratory population of monarch butterflies (Danaus plexippus) has declined precipitously due, in part, to the widespread decline of its obligate host plant, milkweed (Asclepias spp.). Linear right-of-ways (e.g. roadsides, power line corridors) are believed to be a significant source of milkweed and represent a valuable t...
Article
Full-text available
The migratory monarch butterflies (Danaus plexippus) of eastern North America have undergone large-scale declines, which may be attributable to a variety of underlying causes. The uncertainty about the primary cause of declines and whether individual threats are likely to increase in the future presents challenges for developing effective conservat...
Article
Full-text available
Current conservation templates prioritize biogeographic regions with high intensity ecosystem values, such as exceptional species richness or threat. Intensity-based targets are an important consideration in global efforts, but they do not capture all available opportunities to conserve ecosystem values, including those that accrue in low intensity...
Article
In 2014, 116 Guelph residents were surveyed to investigate attitudes about community cats and preferences for population management. There are an estimated 29 579 owned cats in Guelph, an estimated 40% of residents allow outdoor access to their cat(s), and 8054 households (15%) feed community cats. Participants reported more concern with community...
Article
Implementation of cat population management strategies that are effective and supported by the community requires knowledge of local contexts, public values, and preferences. From 2014 to 2015 the Guelph Cat Population Taskforce surveyed Guelph, Ontario residents to investigate attitudes and values concerning community cats and preferences for cat...
Article
Full-text available
Alternative life history strategies are mechanisms by which organisms are able to maximize fitness across a range of environmental conditions. Fitness is maximized by different strategies depending on context, resulting in trade-offs between life history strategies. Monarch butterflies (Danaus plexippus) employ both migratory and resident life hist...
Article
Monarch butterflies ( Danaus plexippus (Linnaeus) (Lepidoptera: Nymphalidae)) in eastern North America migrate each year from overwintering areas in Mexico to cover a large breeding distribution across the United States of America and southern Canada. In 2012, monarch butterflies migrated well beyond their usual range, resulting in an extended bree...
Article
Full-text available
From butterflies to elephants, the rapidly developing science of movement ecology is providing increasingly detailed spatio-temporal data on a wide array of mobile animals. Thus, this discipline also holds great promise for improving the conservation of wildlife. To measure progress toward this promise, we investigated the degree to which movement...
Article
Determining habitat attributes used by animals of conservation concern at different spatial scales is a key aspect of developing effective recovery plans. Managers must know whether forest songbirds choose habitat based on selection of specific plant species or on structural features shared by different plant species. Coarse-scale habitat features...
Article
Environmental change induces some wildlife populations to shift from migratory to resident behaviours. Newly formed resident populations could influence the health and behaviour of remaining migrants. We investigated migrant-resident interactions among monarch butterflies and consequences for life history and parasitism. Eastern North American mona...
Article
Full-text available
Surgical sterilization programs for dogs have been proposed as interventions to control dog population size. Models can be used to help identify the long-term impact of reproduction control interventions for dogs. The objective of this study was to determine the projected impact of surgical sterilization interventions on the owned dog population si...
Data
Empirical data from Villa de Tezontepec, Hidalgo, Mexico, 2015, used to determine parameter values for the individual-base model. (DOCX)
Data
Table A. Difference in mean population size between mixed age surgical sterilization and young age surgical sterilization interventions within the same level of surgical capacity. Level 1 represents a surgical capacity of 21 surgeries per month, Level 2 represents 42 surgeries per month, and Level 3 represents 84 surgeries per month. Percentages in...
Data
Figure A. Comparison of the impact of increasing the annual risk of non-age related mortality for adult confined dogs from 1.5% to 7.5% for the mixed age sterilization interventions at the lowest level of surgical capacity. Model outcomes demonstrated increased variability as the adult mortality rate increased. Figure B. Comparison of the impact of...
Article
Full-text available
Migratory species are rapidly declining but we rarely know which periods of the annual cycle are limiting for most species. This knowledge is needed to effectively allocate conservation resources to the periods of the annual cycle that best promote species recovery. We examined demographic trends and response to human footprint for Canada warblers...
Article
Full-text available
Concerns over cat homelessness, over-taxed animal shelters, public health risks, and environmental impacts has raised attention on urban-cat populations. To truly understand cat population dynamics, the collective population of owned cats, unowned cats, and cats in the shelter system must be considered simultaneously because each subpopulation cont...
Data
Free-roaming and feral cat population density records from published literature. (CSV)
Article
Many metrics exist for quantifying the relative value of habitats and pathways used by highly mobile species. Properly selecting and applying such metrics requires substantial background in mathematics and understanding the relevant management arena. To address this multidimensional challenge, we demonstrate and compare three measurements of habita...
Article
In recent years, there has been a growing concern regarding populations of cats who are homeless. Shelters are constantly overwhelmed by the influx of cats without caregivers and are seeking solutions to enhance positive outcomes for them. In 2014, the Guelph Humane Society implemented a population management program to expedite the movement of cat...
Article
Full-text available
Variation in movement across time and space fundamentally shapes the abundance and distribution of populations. Although a variety of approaches model structured population dynamics, they are limited to specific types of spatially structured populations and lack a unifying framework. Here, we propose a unified network-based framework sufficiently n...
Article
Full-text available
There is a strong need for animal shelters to determine strategies to decrease the incidence of healthy animals being euthanized due to a lack of space. Thus, the Capacity for Care program was implemented at the Guelph Humane Society during August 2014. One objective of the Capacity for Care program is to decrease length of stay of cats within the...
Article
Full-text available
Migratory behaviour can result in reduced prevalence of pathogens in host populations. Two hypotheses have been proposed to explain this relationship: (i) ‘migratory escape’, where migrants benefit from escaping pathogen accumulation in contaminated environments; and (ii) ‘migratory culling’, where the selective removal of infected individuals occu...
Article
In July 2014, the U.S. Fish and Wildlife Service and National Marine Fisheries Service announced a new policy interpretation for the Endangered Species Act. According to the Act, a species must be listed as threatened or endangered if it is determined to be threatened or endangered in a significant portion of its range. The 1973 law does not define...
Article
Dog overpopulation in developing countries has negative implications for the health and safety of people, including the transmission of zoonotic diseases, physical attacks and intimidation to humans and animals, as well as impacts on canine welfare. Understanding the ecology and demographic characteristics of a dog population can help in the planni...
Article
Full-text available
Strontium isotopes ((87)Sr/(86)Sr) can be useful biological markers for a wide range of forensic science applications, including wildlife tracking. However, one of the main advantages of using (87)Sr/(86)Sr values, that there is no fractionation from geological bedrock sources through the food web, also happens to be a critical assumption that has...
Article
Full-text available
Understanding factors that influence the survival of endangered migratory species is critical for making informed management decisions, yet this understanding relies on long-term recapture datasets for species that are, by definition, rare. Using 3 geographically widespread (Saskatchewan, Alberta, and Manitoba, Canada) and long-term (615 yr) mark-r...
Article
Full-text available
Threats to migratory animals can occur at multiple periods of the annual cycle that are separated by thousands of kilometers and span international borders. Populations of the iconic monarch butterfly (Danaus plexippus) of eastern North America have declined over the last 21 years. Three hypotheses have been posed to explain the decline: habitat lo...
Thesis
Full-text available
The population dynamics of migratory animals requires understanding how individuals move, survive, and reproduce throughout the year. How sequential life history events interact to influence population abundance depends upon how populations are spatially connected, termed their migratory connectivity. Developing predictive models of population dyna...
Article
Full-text available
Surprisingly, little is known about how the environment influences the production of the iconic Orange coloration of the monarch butterfly (Danaus plexippus). Previous research under controlled laboratory conditions has shown that the temperature during larval development influences the color of monarch wings, where females raised in warm condition...
Conference Paper
Background/Question/Methods Conserving migratory animals requires understanding population dynamics that link how individuals move, survive and reproduce throughout the annual cycle. Monarch butterflies (Danaus plexippus) in eastern North America are famous for their long-distance migration and unique life-history but they face multiple threats a...
Article
Full-text available
Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the b...
Article
Full-text available
A comprehensive understanding of how natural and anthropogenic variation in habitat influences populations requires long-term information on how such variation affects survival and dispersal throughout the annual cycle. Gray jays Perisoreus canadensis are widespread boreal resident passerines that use cached food to survive over the winter and to b...
Article
Full-text available
A central goal of population ecology is to identify the factors that regulate population growth. Monarch butterflies (Danaus plexippus) in eastern North America re-colonize the breeding range over several generations that result in population densities that vary across space and time during the breeding season. We used laboratory experiments to mea...
Article
We assessed age-dependent survival, site-fidelity, and, together with data on prey and reproduction, trends in the population of ferruginous hawks (Buteo regalis) breeding in western Canada. Our analysis included 7,129 ferruginous hawks banded near Hanna, Alberta, and Kindersley-Alsask, Saskatchewan, from 1972 to 2003. We estimated annual adult sur...
Article
On the breeding grounds, migratory birds have limited time to breed and molt before autumn migration. However, few studies of long-distance migrants have examined the phenology of these events to determine what life-history trade-offs might result if these activities overlap. From 2000 to 2007, I used banding data to determine the timing of migrati...
Article
Full-text available
Dos subespecies de Colaptes auratus, C. a. auratus y C. a. cafer, forman una zona de hibridación que cubre toda la longitud de Norte América y es aparentemente estable. La hipótesis más ampliamente aceptada para esta zona, la de la superioridad limitada de los híbridos, predice que la adecuación de los híbridos debería ser igual o mayor a la de los...
Article
Full-text available
Fitness in a hybrid zone is determined both by the reproductive success and the survival of phenotypes. The hybrid zone of Northern Flickers (Colaptes auratus), a common woodpecker, is one of the largest and most well-known hybrid zones in North America. Bounded-hybrid superiority, the most widely accepted hypothesis for the persistence of the zone...