We have numerous ongoing research projects. Most address prairie conservation, avian conservation (mostly passerines but also some waterbirds), conservation biology, grassland ecology and/or landscape ecology. Below we highlight some of these projects.
Effects of cattle stocking rate on prairie heterogeneity
Mixed-grass prairies in North America evolved under the influence of disturbances, such as grazing by native ungulates, and fire. However, large bison herds have been removed from the landscape, and fires are suppressed to the extent possible. Cattle may play an important role in this altered landscape by returning a source of disturbance to this ecosystem. Grasslands National Park is using cattle and bison to restore ecological integrity to its mixed-grass prairies. We are helping to evaluate effects of ungulate grazing on diversity of plant and avian communities, particularly focusing on effects of grazing intensity. This research will help us manage and conserve Grasslands National Park, but will also help us understand, manage and conserve northern mixed-grass prairies throughout the northern Great Plains.
This project represents one of the largest manipulative cattle grazing experiments in North America. It also has the unique feature that it is being conducted on lands previously ungrazed for more than 15 years; as such, we have full ecological surveys of plant and avian communities before grazing was introduced, which will be compared with conditions in the same sites after grazing has been introduced. Unique features include, (1) 300ha pastures, (2) 900ha of ungrazed controls, 30x more than any other mixed-grass grazing experiment, (3) equal proportions of uplands, lowlands, riparian and stream habitats in each replicate pasture, (4) surveys of soil conditions, plant, avian, grasshopper and carabid beetle communities. For more information, contact Dr. Koper, or see www.grazingbiodiversity.org.
Effects of habitat loss and fragmentation on tall-grass prairie conservation
More than 99% of tall-grass prairies in Manitoba have been lost through habitat conversion. This has left fragments of dispersed prairie remnants throughout southern Manitoba. We are interested in the effects of this fragmentation on prairie plants and birds. In particular, we are evaluating effects of the habitat matrix surrounding the prairie, size of prairies, management of prairies and prairie quality, on the species that can inhabit tall-grass prairie remnants.
Behavioural ecology and conservation
The presence of conspecifics (individuals of the same species) may be an important indicator of habitat quality for birds prospecting for future territories and may significantly influence avian settlement patterns. Because small patches of habitat are more likely to undergo local population extinction, they are less likely to remain populated if conspecific attraction influences a species’ territory selection (because of an absence of conspecifics to encourage re-settlement following a local extinction). This phenomenon may be occurring in the songbird populations of Manitoba’s tall-grass prairie, which has been drastically reduced and fragmented: several of its bird species tend to exhibit area sensitivity – that is, they avoid small prairie patches and occur at higher densities in larger patches. We are conducting behavioural experiments to assess the extent to which conspecific attraction mediates effects of patch size on prairie birds.
Conservation and nesting ecology of western grebes
Delta Marsh is a marsh of international significance under the RAMSAR Convention and has undergone major changes to the marsh ecosystem over the last 40 years. Using baseline data from Gary Nuechterlein’s (1975) seminal study on Western Grebe nesting ecology, we have linked significant decreases in reproductive success to an increase in the abundance of the invasive fish species common carp, artificially stabilized high water levels, and changes to the plant community. As a flagship species that can draw attention to the conservation and eco-tourism opportunities of Delta Marsh, the benefits of its conservation and management go far beyond the benefits to this species alone.
Effects of shallow gas and oil development on grassland songbirds
Shallow gas development and oil is increasing rapidly in Alberta and Saskatchewan, but their potential effects on grassland songbirds is unknown. We are conducting research in Alberta, concurrently with Dr. Stephen Davis’s research group, who is primarily studying this issue in Saskatchewan.
Any economically viable land use, such as cattle ranching or natural resources extraction, may help conserve prairies and prairie birds, if it helps to protect native prairies from habitat conversion for agricultural purposes. Of course, this is only effective if anthropogenic land uses are, in fact, compatible with conservation. It is, therefore, of great interest to our lab to identify human land uses of prairies that have few or no negative impacts on the species that inhabit these landscapes.
It is as yet unclear whether shallow gas development has a significant effect on songbirds. Much of the associated infrastructure has a relatively small footprint, and as such, it is possible that its activities are compatible with conservation of prairie songbirds, including species at risk. However, it is not known whether birds avoid areas with more shallow gas development, or whether they have unknown and unpredictable effects on nesting success or reproduction of songbirds. We are evaluating these effects and hope we will be able to identify intensities of land use at which songbirds can be conserved while maintaining economic returns.
Oil extraction differs from shallow gas extraction in that infrastructure for oil development is noisy, and the footprint on the landscape is generally much larger than the footprint associated with shallow-gas infrastructure. We are also studying the effects of oil extraction infrastructure on prairie birds, and we are evaluating whether replacing commonly used infrastructure, such as pump-jacks, with quieter infrastructure would mitigate effects of oil development on grassland birds.
Effects of rotational grazing on grassland songbirds
While the bulk of our research is field-based, we also encounter problems, or “challenges”, when analyzing data collected in the field. Rather than adapting traditional or inadequate methods for these purposes, our research group regularly contributes to enhancing statistical, analytical, and study design methodologies. There are many opportunities for progress in ecological statistics. Recent projects have included evaluating the use of generalized estimating equations and generalized linear mixed-effects models for developing resource selection functions, evaluating our ability to disentangle effects of habitat loss and habitat fragmentation using available statistical methods (see Awards), and maximizing statistical power in grazing experiments.