Introduction and Background
Despite some rebounds, the deer population in the traditional territory of the St’at’imc Nation, in British Columbia, has decrease since the early 1990’s and the population size stays still below the levels observed in the 1960s and 1970s. This decreasing trend is likely resulting from different factors that remain unclear. However it is certain that hydroelectric and timber projects negatively impacted and probably still impact the deer population. Those considerations were addressed in a previous two years study concerning the female portion of the deer population in the St’at’imc Nation.
Objectives of the research project
The objectives of this project is to study the buck portion of the deer population on the basis of the results and data of the previous research focusing on the females. The research will aim to collect data on habitat use and migration ecology of the mule deer bucks in order to improve stewardship of the mule deer habitat in the Bridge River drainage. Eight long-term goals have been described : determine residency status (resident or migratory), habitat particularities of seasonal ranges, migration patterns and the reasons behind seasonal habitat selection, report daily habitat use and movement patterns between November 10 and December 31, verify the validity of predictions obtained by the model by comparison with buck winter ranges observed in the field, evaluate the variation of the parameters across the years and understand the reasons of those variations and finally provide appropriate and efficient recommendations. Short-term goals were also described. First, radio-collars must be collected and spatial data must be recovered. Second, the first data analysis must be done.
Methods, Materials and Study Area
The studied area is located in the St’at’imc Nation territory at the north of Carpenter Lake and include the BC Hydro Bridge River Complex.
The first step of the method was realized in 2011. Nine bucks were captured. Radio-collars were fixed and set up to save localization data during one year and at a higher frequency during forecast migration periods. The mortality and location of the buck were documented. In 2012, bucks were recaptured to retrieve the collars and collected data. Data were transferred in a program that enables visual analysis.
Results of the Study
Thanks to high quality data, 47 locations were determined for the nine bucks surveyed. 33.3% died due to human activities and 78% were assessed as migratory. The migratory patterns of these mule deer bucks were established. They mostly migrated from east (spring and winter ranges) to west (summer ranges) on the south side of the mountains just North of Carpenter Lake. Spring ranges were located at lower elevation than summer and winter ranges. During the rut period, mule deer bucks were located at close proximity to Carpenter lake. On average the spring migration began on May 6 and ended on June 4 for a travelled distance of 29,5 km. However the departure date was potentially biased due to the capture of two bucks during this period. On average, the fall migration began October 21, bucks travelled 29.4 km and reached the winter range on November 22. For two of these migratory bucks their rutting area was different than their winter area and they first travelled to their rutting range before to reach their winter area. The size of those different seasonal areas varied according to season and individual.
The results presented here emanated from the first on-the-ground study concerning mule deer bucks habitat. As these results might be influenced by varying environment factors, most of the interpretations and discussion will be done following the second data collection. The analysis showed surprising migration patterns. However, those patterns were comparable with those observed for female mule deer in the same area in 2009.
As the results were only preliminary, the main recommendation of this report was to implement a second sampling session based on the same method of capture-radio collar-recapture. The comparison of these results and those to come will supply information about migration and habitat use variation across the years.
- Source Chris Procter & Francis Iredale. March 2013. Mule Deer Buck Migrations and Habitat Use in the Bridge River, British Columbia: Preliminary Results (FWCP Project # 12.W.BRG.03). Prepared by Ministry of Forests, Lands & Natural Resource Operations, Fish & Wildlife, for Fish & Wildlife Compensation Program-Coastal. Available at : https://a100.gov.bc.ca/pub/acat/documents/r37960/12.W.BRG.03_finalreport2012_13_mule_1378215957484_4304516039bb99bff7c79c07312a33c1dfa0e26f480ada9ac9cf542ce2f02e69.pdf [Accessed 03/2021].