Blog Post 3: Ongoing Field Observations

Between March 17 and June 2, 2019, I made 9 visits to my study area, totaling 14.75 hours of field observation and 188 data points with associated covariates; 159 of which were indicative of terrestrial vertebrates.  Where possible, photographs of wildlife or indicators of their presence were taken and stamped with UTM locations, or identified visually or by song.  I was using a cell phone camera and am a poor photographer so frequently I was unable to capture images of animals I observed.  I decided to end my investigations on June 2, given that a significant increase in observed industrial (e.g., water withdrawal and nearby industrial noise, scheduled changes to river flow regime), recreational (e.g., human presence and deposition of wildlife attractants) and transit activity (e.g., off-road vehicles, boating) which had the potential to affect wildlife activity in the direct vicinity of my study area.  This seemed a reasonable if not necessary place to end my field observations.

As I collected data over time (e.g., prior do, during and after spring freshet), the edges of the floodplain and riparian areas became clearly defined and the terrestrial vertebrate community structure within each emerged as evidenced by sightings, audible calls, observations of tracks, animal sign as well as active nests, dams and dens.  Despite the changing seasonal conditions, habitat use by certain species and classes of vertebrates remained relatively consistent in the riparian area and floodplain as well as in and above the open water.  For example, Tundra Swans were only observed in open-water on the Halfway River while Geese were observed everywhere but open-water on the Halfway river (i.e., floodplain, riparian area and open-water on the Peace River); dabbling ducks were only observed on open-water in the Peace River.   Western Toad tadpoles were only observed in pools on the floodplain while both grouse species I observed were in the riparian area.  All of the carnivorous species I observed were on the floodplain.

Given that my study location is at the confluence of a regulated and a non-regulated river, the Peace River and Halfway Rivers respectively, I was presented with a unique opportunity to examine how regulation of river level and discharge could be related to vertebrate habitat use and community structure.  Both rivers are influenced similarly at the confluence by local snow and ice melt, but only the Peace River is regulated by upstream hydroelectric infrastructure.  The area most affected by rising water level and flow rate or discharge is the floodplain, given large areas of it are inundated daily due to fluctuating river level.

Thus, the biological attribute I am interested in examining is vertebrate community structure in discrete areas (i.e., riparian, floodplain, and open-water areas) at the confluence of the Peace and Halfway Rivers.

My hypothesis is that short-term fluctuations in river level and/or discharge affect terrestrial vertebrate habitat use, and thus the community structure of riparian, floodplain and open-water areas of the Peace and Halfway Rivers deferentially.

If the community structure of terrestrial vertebrates is affected by short term fluctuations in river level and discharge, I predict that the species richness and diversity of the floodplain will fluctuate to a greater degree than the riparian and open-water areas relative to hydro metric conditions.

Response Variable: Species diversity; continuous

Explanatory Variable I: River level; continuous

Explanatory Variable II: Area; categorical

Note: UTM extraction is proving to take much longer than I had anticipated and will be included at a later time for anyone interested!