Friday, February 5, 2010   Lecture Theatre 7-152     3:30 - 4:30 pm

Dr. Mark Shrimpton, Ecosystem Science & Management Program, UNBC

Should I stray or should I go home?

Selection of suitable sites for spawning is critical because the highest rates of mortality in salmonids generally occur during the incubation period and mortality is closely related to features of the spawning/incubation site.  For Pacific salmon, the downstream migration to exploit the nutrient rich resources of the ocean favours the development of large body size, but necessitates a return migration and the ability to find suitable habitat for spawning.  Our understanding has been that Pacific salmon “home” to the location where they were spawned.  There is considerable support for this paradigm as reproductive isolation due to homing behaviour and spawning site fidelity creates genetic divergence and we can identify genetically distinct popula­tions.  Recent studies, however, have demonstrated that the proportion of fish that do not return to their natal streams is appreciable and fish may stray long distances to spawn in locations that differ from their parents.  A number of factors may contribute to higher rates of long-distance dispersal; availability of new habitat, disturbance, and population size.  The use of genetic markers and elemental signatures in bone has provided us with clear evidence that straying from natal streams occurs.  Such low levels of gene flow may be particularly important for small populations as they can elevate effective population size and preserve genetic variability.  So how do Pacific salmon know where to spawn if they do not go home?

Friday, February 12, 2010   Lecture Theatre 7-152     3:30 - 4:30 pm

Roy V. Rea, Ecosystem Science & Management Program, UNBC

YouTube™ Insights into Moose-Train Interactions

To gain a better understanding of the behavioral aspects of moose-train encounters, we reviewed videos of ungulate-train interactions available on YouTube™ and from train operators.  Video footage viewed included: moose (47.4%), cattle (15.8%), deer (10.5%), elk (10.5%), camels (10.5%) and sheep (5.3%), 46% of which were adults.  Although footage of ungulates in general was recorded predominantly in snow-free conditions, most of the recorded moose-train interactions were taken in winter when moose appeared to be “trapped” by deep snow on either side of the rail bed.  In fact, when under chase by trains, moose, elk and deer all ran within ~50-60 cm of track center and ran less than ~30 cm outside of the steel rails where snow was restricting mobility.  Escapes from train chases in winter occurred where a discontinuity in the habitat/setting was encountered by moose and where the speed of train enabled them time to escape.  Ungulates in groups displayed social behaviors in response to group leadership that generally elicited escapes; although one cow-calf moose pair was struck as was a domestic livestock calf when attempting to follow the herd across the track in front of an oncoming train.  Most ungulates were killed on straight stretches of track.  We determined that videos are a valuable resource for trying to understand reactions of ungulates to trains.  We suggest that videos continue to be filmed and be posted on open source databases such as YouTube™ for use by biologists attempting to understand the dynamics of collisions for mitigation.