Study of the impact of human disturbances on habitat selection and on calf survival for forest-dwelling caribou (Rangifer tarandus caribou)

2013

Date Source: 

Daniel Fortin of the Department of Biology at Université Laval.

Organizer: 

Thierry Duchesne at Université Laval.

Background

The population of forest-dwelling caribou has seriously declined over the last century, mostly due to timber harvest (Schaefer 2003). Other species, such as black bear (Ursus americanus), can benefit from recent cuts and regenerating forests, thereby increasing the predation risk for calf (Zager and Beecham 2006). Female caribou may modify their behaviour in response to human disturbances, which could in turn influence their own survival and that of their young, especially during calving (Vistnes and Nelleman 2001). Understanding how female caribou react to human disturbances and how this affects the survival of their calf is of primary importance in order to maintain forest harvesting without further endangering this species.
 

The study area of 5400 squared km was located about 100 km north of Québec City. Land cover was comprised of 18% mature conifer stands (dominant tree strata more than 60 years of age), 15% conifer stands (dominant tree strata 40-60 years of age), 9% mature mixed/deciduous stands (dominant tree strata more than 40 years of age), 20% regenerating conifer stands (dominant tree strata between 10 and 40 years of age), 11% regenerating mixed/deciduous stands (dominant tree strata between 10 and 40 years of age), non-regenerated areas (areas with dominant tree strata less than 10 years old), 4% recent cutovers (regeneration and soils that occurred at most within 5 years), 4% water bodies, 5% other land cover types.
 

The population investigated consisted of 23 adult female caribou that were equipped with Global Positioning System (GPS) telemetry collars. For each spring from 2004 to 2006, the location of each female was recorded every 6 hour from the time of the birth of their calf (or within 72 hours from birth) until the first of July 10 or death of the calf. To compare locations that were visited be the caribou to other locations within their respective home ranges, random locations were sampled within the home range of each caribou and land cover type characteristics were measured at these locations.
 

Research Question: 


Primary objective
 

The primary objective of this study is to assess whether the habitat selection strategy of adult female caribou (Rangifer tarandus caribou) is altered by human disturbances and, if so, whether this has an impact on the chances of survival of their calves.
 

Secondary objectives
 

The following questions are also of interest:

  1. Do adult female caribous select or avoid certain types of habitats? Is this selection homogeneous among all females?

Variables: 

 

The Excel file contains 5159 lines and 19 columns. Each line corresponds to either an observed or a random location. The columns contain the values of the following variables:

 

  • Column A: FEMALE_ID, the identification number of the female caribou
  • Column B: YEAR, Year of observation for observed locations (empty for random locations)
  • Column C: MONTH, Month (5 for May, 6 for June, etc.) of observation for observed locations (empty for random locations)
  • Column D: DAY, Day of the month of observation for observed locations (empty for random locations)
  • Column E: TIME(HOUR OF DAY), hour of day for observed locations (empty for random locations)
  • Column F: CALF_AGE(DAY), calf age in days for observed locations (empty for random locations)
  • Column G: CALF_DEAD, 0 if the calf is alive at time of observation, 1 if calf dead at time of observation (empty for random locations)
  • Column H: USE1_AVAILABLE0, 0 for random locations, 1 for observed locations
  • Column I: Proportion_Water, proportion of water bodies within a circle of radius 220 m around the location
  • Column J: Proportion_50_yr-oldConifer, proportion of conifer stands within a circle of radius 220 m around the location
  • Column K: Proportion_MautreConifer, proportion of mature conifer stands within a circle of radius 220 m around the location
  • Column L: Proportion_MatureMixedDeciduous, proportion of mature mixed/deciduous stands within a circle of radius 220 m around the location
  • Column M: Proportion_RecentCutovers: proportion of recent cutovers within a circle of radius 220 m around the location
  • Column N: Proportion_Non-regenerated: proportion of non-regenerated areas within a circle of radius 220 m around the location
  • Column O: Proportion_RegeneratingMixedDeciduous: proportion of regenerating mixed/deciduous stands within a circle of radius 220 m around the location
  • Column P: Proportion_RegeneratingConifer: proportion of regenerating conifer stands within a circle of radius 220 m around the location
  • Column Q: Proportion_Others: proportion of the circle of radius 220 m around the location comprised of other land cover types
  • Column R: TPI_UpperSlope: 1 if the location is at the top of a hill, 0 otherwise
  • Column S: Road_Density (km•km-2): density of roads in the circle of radius 220 m around the location
     

Data Files: 

References: 

  1. Schaefer, J. A. 2003 Long-term range recession and the persistence of caribou in the taiga. Conserv. Biol. 17, 1435–1439. (doi:10.1046/j.1523-1739.2003.02288.x)
  2. Vistnes, I. & Nelleman, C. 2001 Avoidance of cabins, roads, and power lines by reindeer during calving. J. Wildl Manag. 55, 915–925. (doi:10.2307/3803040)
  3. Zager, P. & Beecham, J. 2006 The role of American black bears and brown bears as predators on ungulates in North America. Ursus 17, 95–108. (doi:10.2192/1537-6176(2006)17[95:troabb]2.0.co;2)