Katharine T. Yagi

8Trees Inc.

We examined the effect of body size on locomotor performance and movement behavior in early postmetamorphic toadlets of Fowler's Toad (Anaxyrus fowleri). Dispersal, if strictly density dependent, should be favored among the relatively small toadlets that emerge from crowded growth conditions, but not among the relatively large toadlets that result...

Density-dependent growth has ordinarily been studied in aquatic ecosystems by varying the abundance of animals in mesocosms of equal volume. Aside from the unequal sample sizes involved with using this abundance-limited method, confounding factors potentially associated with levels of social interactions may also be introduced. The alternative, vol...

Body temperature has a major influence on the physiological processes, growth, reproductive output, and overall survival of ectotherms. When a habitat is altered as a result of natural or anthropogenic influences, the available temperatures in the habitat can change, thus affecting an animal’s ability to thermoregulate. We studied thermoregulation...

Many studies have focused on the effects of anthropogenic habitat alterations on animals, but little attention has been given to the effects of natural changes in habitat. The purpose of our study was to examine the effects of flooding caused by Beaver (Castor canadensis) dams on the spatial ecology of the federally endangered Spotted Turtle (Clemm...

Thermal biology research compares field with laboratory data to elucidate the evolution of temperature-sensitive traits in ectotherms. The hidden challenge of many of these studies is discerning whether animals actively thermoregulate, since motivation is not typically assessed. By studying the behaviours involved in thermoregulation, we can better...

Temperate snakes occupy overwintering sites for most of their annual life cycle. Microhabitat characteristics of the hibernaculum are largely undescribed yet are paramount in ensuring snake overwintering survival. We hypothesized that snakes survive hibernation within a vertical subterranean space that we termed a “life zone” (LZ), that is aerobic,...

We used radio-tracking to investigate movement patterns and habitat use of Fowler’s Toads (Anaxyrus fowleri) during late summer and early fall in a relatively undisturbed lakeshore dune and beach habitat at Long Point, Ontario. Small radio transmitters were fitted to 11 adult toads with an external harness made from fine surgical plastic tubing wra...

Carry-over effects, which occur when an animal's early life experience has lasting effects on its later life, may be manifested in an animal's behavior, growth, and fitness, and are often overlooked as contributing factors to such aspects of animal ecology. Metamorphosis is a process that can produce such effects in animals with complex life histor...

A summary of the preliminary results from a toadlet jumping performance test and how it relates to their tadpole density conditions.

This presentation showed preliminary results depicting juvenile toad displacement as a result of their tadpole density conditions.

Preliminary results of a common-garden experiment looking for carry-over effects by examining activity level in density-treated tadpoles and toadlets.

A summary of tadpole density-dependent growth, and behaviour (activity level) compared to growth and behaviour at the toadlet (post-metamorphosis) life stage. Toadlet data analysis was preliminary.

Preliminary results for the Fowler’s toad tadpole density growth trials in 2013. These results are part of Chapter 1 of my Doctorate thesis.

Preliminary results for movement patterns and habitat selection analysis of adult Fowler’s toads in Long Point, Ontario, using data from 2008.

A summary of my Master’s thesis chapter 2: Temperature selection in Spotted turtles.

A summary of the final results of Spotted Turtle habitat selection in a partially-mined bog in southern Ontario (Master’s thesis, Chapter 1).

A summary of preliminary analyses on Spotted turtle habitat selection and thermal preferences using radio telemetry and a grid of environmental temperature loggers in a partially-mined bog in Southern Ontario.