Conference Posters Abstracts
Category 3 — Changes in the Physical Environment
How Does Petroleum Development Affect Burrowing Owl Nocturnal Space-Use?
Presenter: Corey Scobie
Authors: Corey Scobie;
Troy Wellicome;
Erin Bayne;
Alan Marsh
The Burrowing owl is a federally listed endangered species that continues to decline throughout its Canadian range. The prairies have seen a steady increase in petroleum development, raising concerns about potential impacts to species at risk, such as the burrowing owl. A risk to burrowing owls from petroleum development is changes to habitat and the introduction of sensory disturbances that might alter nocturnal space-use while foraging at night. The female owls incubate and brood chicks while the male flies as far as 4 km from the nest to hunt prey. Some habitat features may present increased mortality risk if owls are attracted to them (e.g. roads), or other features may increase overall home-range size if they are avoided (e.g. compressor stations) and thus influence prey delivery and associated fledging rate. We predicted that owls will avoid auditory disturbances, such as compressor stations and oil wells, but will be attracted to perches from which they can hunt (gas wells) and to areas of lush vegetation (road ditches). We tracked 57 adult male burrowing owls with miniature GPS dataloggers, in Alberta and Saskatchewan. Their nests were surrounded by varying amounts of petroleum development and maintenance. Sound was measured from sound-producing structures within owl home ranges, and traffic data was collected with pneumatic-tube traffic counters from 53 roads near nests, concurrent with owl tracking. Anthropogenic features (roads, gas and oil wells, buildings, etc.) and habitat types were classified and recorded around all nests. A resource selection function was used to evaluate owl use of habitat features and areas with anthropogenic disturbances. We show whether adult male burrowing owls are influenced by anthropogenic features and sensory disturbance while travelling at night. In the future, we will explore how these movements may influence owl survival, nest success, and fledging rate.
Benefits of crop conversion programs for prairie species restoration
Presenter: Holly L. Hennin
Authors: Holly L. Hennin; Ray G. Poulin; Christopher M. Somers
Agriculture has caused the loss of more than 80% of native grasslands across North America, resulting in large-scale declines of associated animal species. As a means of restoring or maintaining grassland biodiversity, some organizations employ crop-conversion programs (converting cropland into non-native grassland) as a conservation tool. The effectiveness of these crop conversion programs and their benefits to endangered species and native biodiversity has not been adequately assessed. We compared the abundances of four taxa: (1) raptors; (2) small mammals; (3) grasshoppers; and (4) fossorial mammals (e.g. ground squirrels, badgers) on three different habitat types: (1) crop conversion (non-native grassland; N=33), (2) native prairie (N=33), and (3) cropland (N=33) across much of Southern Saskatchewan. To determine species density and diversity we used various standardized surveying and sampling techniques. We analyzed these data using multivariate statistics paired with AIC to model which vegetative and landscape factors influence each taxa most. We suggest how to improve crop conversions programs to enhance native species diversity and abundances on the Prairies of North America.
The Effects of Hydrology on the Plant Community Structure of the Tallgrass Prairie
Presenter: Ryan Sheffield
Authors: Ryan Sheffield; Dr. John Markham
The distribution and abundance of tallgrass prairie plant species shifts in both space and time. Heterogeneity also exists in the environmental factors of a prairie such as soil water conditions, nutrient availability, fire history and soil biota. My research investigates whether the changes in the environment correspond to the differences in the plant community. Recent literature has found strong trends between grassland plant species distribution and soil water conditions. At the scale of tens of meters we hypothesize that soil water is the dominant environmental factor controlling the spatial differences in the plant community. Water availability can limit plant growth and survival in two ways: flooding creates anaerobic soil conditions and dry soils create water limitation. The Tall Grass Prairie Preserve in Southern Manitoba is a predominantly lowland tallgrass prairie and we have found water logged conditions to be more prevalent than water limitation. Thirty permanent 1m2 plots were set up at each of three different locations at the Tall Grass Prairie Preserve. Soil water content, depth of aerobic soil and depth to water table were measured on a weekly basis throughout the past two growing seasons. Vegetation assessments surveying the presence and abundance of the plant species in each plot were completed in both seasons and the maximum cover value for each species was analyzed. One analysis providing evidence for correspondence between the plant community and the environment was when the plots were grouped according to vegetation data with a cluster analysis. Imposing these groups onto the environmental data and then performing an ANOVA test, the groups created by the vegetation data also showed significant environmental differences. Analyzing the water conditions over time with a regression equation elucidates trends not found in the spatial analysis previously mentioned. Soil water conditions have proven to affect the plant community structure in the tallgrass prairie and further analysis may reveal a stronger control of the environment on the vegetation in this ecosystem.
Determining Critical Habitat for the Northern Prairie Skink: Ground truthing a GIS Mapping Method
Presenter: Pamela Rutherford
Authors: Pamela Rutherford; William McFadden; James Duncan; Nicole Firlotte
In Canada, the Northern Prairie Skink (Plestiodon septentrionalis) is limited to a small area of sandy soils in southwestern Manitoba. This species was listed as Endangered by COSEWIC in 2004. The primary conservation issue for the Prairie Skink is habitat loss, which is occurring at their primary and secondary locations (Carberry and Lauder Sandhills, respectively). As in the rest of North America, the amount of mixed grass prairie habitat has declined as a result of numerous factors: cultivation, urbanization, road construction, fire suppression, and the invasion of the exotic Leafy Spurge. In February 2009, a Prairie Skink Recovery Team working group developed and applied a GIS protocol to delineate suitable (aka “proposed critical habitat”) and recovery habitat for the northern prairie skink. Using ArcView 3.2a, the group mapped two polygons around all skink capture sites in Spruce Woods Provincial Park: 1) recovery habitat -100 m radius circle around the capture location based on knowledge of their movement patterns, and 2) suitable habitat - all known suitable habitat, e.g. grassland, low shrub, and sand within the 100 m radius recovery habitat polygon. Recovery and suitable habitat polygons were mapped using the best available orthophotos, and current knowledge of Prairie Skink biology. In summer 2009, GIS mapped suitable habitat polygons were ground truthed in the field by walking within their perimeters while recording actual suitable habitat polygons in ArcPad on a handheld PDA. In addition, orthophotos were taken using an UAV (unmanned aerial vehicle) at one site. The degrees of overlap between the 3 methods were mapped and compared in ArcMap 9.3. The degree of overlap between the orthophoto and ground truthed polygons ranged from 27-94% (N=12 sites). There was more overlap between the ground truthed and UAV polygons, than between the ground truthed and orthophoto polygons (5% vs 86%).
