Conference Posters Abstracts
Category 2 — Ecological Changes
Can Plains Rough Fescue Grasslands be Restored After Well Site and Pipeline Development?
Presenter: Mae E. Elsinger
Authors: Mae E. Elsinger; Dr. M. Anne Naeth
Rumsey Block is a remnant of plains rough fescue (Festuca hallii (Vasey) Piper) prairie in southern Alberta, Canada. Reclamation success of 17 pipelines and 36 well sites was assessed by comparing them to undisturbed prairie and determining the influences of age, construction and revegetation methods and cattle grazing. With few exceptions, these disturbances had different soil and plant community characteristics than undisturbed prairie. Reclamation success was more closely related to methods of construction and revegetation and grazing pressure than to age. Greater similarity between undisturbed prairie and well sites or pipelines were related to construction methods that leave sod and topsoil intact.
Revegetation by natural recovery resulted in a more diverse community than seeding either native or non native mixes but progress is slower on open soil disturbance than on minimal disturbance. In most cases increased grazing pressure was associated with lower reclamation success.
Revisiting the Nesting Ecology of Western Grebes After 40 Years Of Changes At Delta Marsh, Manitoba
Presenter: Nicholas La Porte
Authors: Nicholas La Porte; Dr. Nicola Koper
As one of the largest marshes on the Canadian prairies, Delta Marsh is a major nesting area for western grebes (Aechomophorus occidentalis) in Manitoba. Since the 1970s, artificially stabilized hydrology, the increased presence of common carp, and invasion by a cattail hybrid that is out competing native vegetation have significantly impacted Delta Marsh and may have severely impacted its western grebe population. To evaluate the impact of stressors within Delta Marsh on western grebes, and to facilitate comparisons across time, in 2009 we repeated surveys originally conducted by Neuchterlein (1975) on the nesting ecology of western grebes at Delta Marsh in 1973 and 1974. We calculated changes in the number of nests and colonies, nesting success and loss rates, chick-to-adult ratio, and habitat structure by comparing 2009-10 data with Nuechterlein’s (1975) data. In 2009, 49% of initial nests in the two largest colonies were successful, compared to 84% in the corresponding high-water year of 1974, and chick-to-adult ratio was 0.55, compared to 0.88 in 1974. In terms of nesting losses, 47% of nests in the two largest colonies were destroyed by wave action, compared to 22% in 1973-74. The increase in the proportion of nests destroyed by wave action and the significant structural changes in marsh vegetation used for nesting suggest that the breeding success of western grebes at Delta Marsh may have been negatively impacted. These data will help identify and prioritize actions to improve the management and conservation of western grebes in Delta Marsh and similar coastal marshes.
Deferring Grazing Has Immediate Nesting Success Benefit
Presenter: Laura Rogasky
Authors: Laura Rogasky;
Robert B. Emery
Grazing is a major land-use of Prairie grasslands but overgrazing can reduce range health and therefore the ability of a site to produce forage. The impact of heavy grazing on prairie wildlife, including waterfowl, is a concern. Preliminary results from Ducks Unlimited Canada (DUC)-supported research suggested that duck nesting productivity was higher in pastures that received moderate grazing pressure than in either idled or heavily grazed pastures. Using data collected during 2002-2008 by DUC’s Spatial and Temporal Variation in Nesting Success of Prairie Ducks study (SpATS) at 91-41 km2 study sites in Alberta, Saskatchewan, and Manitoba, we modeled the relationship between grazing pressure and duck nesting success to see if similar effects were evident at a broader spatial scale. SpATS is a long-term (10 year; 2002-2011) study examining how nesting success of prairie waterfowl varies in relation to landscape composition. We recorded grasslands as grazed or idled in both the previous year (Year 1) and current year of the study (Year 2). We found that duck nesting success in grasslands grazed in Year 1 and idled in Year 2 was higher (grazed-idled; 20.5%, 95% CI = 14.7 - 26.4%, n = 499 nests) than in grasslands idled in both years (idled-idled; 14.2%, 95% CI = 8.4% - 19.9%, n = 232) and in grasslands grazed in both years (grazed-grazed; 12.4%, 95% CI = 8.5 - 16.4%, n = 766). A lack of idled-grazed grasslands precluded nesting success estimates for this land-use type (n = 15 nests). As a proxy for grazing pressure, mean visual obstruction of vegetation (VOR) was 2.00 (SD = 1.50), 2.27 (SD = 1.61), and 2.59 (SD = 1.54) at nests in grazed-grazed, grazed-idled, and idled-idled grasslands, respectively. This work corroborates a link between good range management and the sustenance of prairie wildlife populations.
Effects of Bison and Cattle Grazing on Grassland Songbirds
Presenter: Maggi Sliwinski
Authors: Maggi Sliwinski; Dr. Nicola Koper
Grassland songbirds are experiencing significant declines, in part due to loss and degradation of habitat following transformation of many grasslands to agricultural lands. Grasslands were historically grazed by large, free-roaming herds of bison numbering in the millions, but bison have been largely replaced by fenced cattle. Research on grazing strategies, preferences, and behaviors of bison and cattle have shown that they are different and cause disparate effects on the landscape; they may, therefore, differ in their effects on songbird abundances. We conducted songbird surveys in Grasslands National Park of Canada (GNPC) in Saskatchewan to compare songbird abundance between habitat grazed by bison (West Block GNPC) and habitat grazed by cattle (East Block GNPC) in 2009. Site selection in both blocks was stratified across ungrazed (controls), medium, and heavily grazed sites. We used generalized linear models to determine whether there was an interaction between grazer species and grazing intensity. Western meadowlarks and Savannah sparrows responded differently to bison grazing intensity than to cattle grazing intensity, while Baird’s sparrow, chestnut-collared longspur, and Sprague’s pipit did not. This research will be continued for at least one additional year to decrease any effect of spurious results. Cattle may be an appropriate ecological substitute for bison for managing abundance of some songbird species, but not others.
Field evidence of non-target and secondary poisoning by strychnine and chlorophacinone used to control Richardson’s ground squirrels in southwest Saskatchewan
Presenter: Geoff Holroyd; Helen Trefry for Gilbert Proulx
Author: Gilbert Proulx
Richardson’s ground squirrels (Spermophilus richardsonii) are considered to be major pests in southwest Saskatchewan where recent population outbreaks caused damage to grasslands and pastures, and substantial losses to annual crops. Although it is known that the use of indiscriminate poisons poses potential threats to wildlife, since 2008, southwest Saskatchewan farmers have used large quantities of 0.4% strychnine (acute poison available as freshly mixed and ready-to-use baits ) and chlorophacinone (anticoagulant causing fatal hemorrhages) to control ground squirrel populations. In the last 2 years, I have gathered field evidence that both strychnine and chlorophacinone efficiently controlled ground squirrels but also killed a diversity of songbirds, small mammals (mice and voles), and predators including raptors, canids, American badger (Taxidea taxus),and long-tailed weasel (Mustela frenata). The purpose of this poster is to
- report primary poisoning of non-target species and secondary poisoning of predators in southwest Saskatchewan; and
- raise concerns about the negative impact of such poisoning on the survival of species at risk such as the burrowing owl (Athene cuniculari), the black-footed ferret (Mustela nigripes) and the swift fox (Vulpes velox), and of predators in general.
Diverse diet and high productivity show the adaptability of Swift Foxes in South-eastern Alberta to changing environments
Presenter: Helen Trefry
Authors: Helen Trefry;
Geoff Holroyd
Swift Foxes have been successfully reintroduced into Canada over the past 30 years and appear to be increasing at Onefour, Alberta, where we have documented them depredating Burrowing Owl nests. Little is known about their summer diet in Canada. In 2008 and 2009 we were able to monitor activity for 5 Swift Fox pairs with kits in south-eastern Alberta using motion-activated "Reconyx" cameras. Of 5 dens sites located, 2 were re-used the following year. Each swift fox pair had 3 or 4 kits emerge with high survival before dispersal. Dispersal occurred quickly in mid-August when all foxes disappeared from the burrow system and did not return the following month. Females were in attendance at the den burrow full time during the first half of the summer, and then spent less time as the kits grew and became more active. Prey were identified on the camera images and from feathers that we collected during camera changes. Reconyx cameras did not capture all food deliveries and prey items could not always be identified to species. However the prey deliveries captured reveal a diverse diet and indicates the importance of a healthy varied prairie ecosystem to conserve this fox. The diet of some pairs was predominantly ground squirrels while others ate primarily birds or sagebrush voles. The flexibility in prey bodes well for the success of these reintroduced predators in a changing landscape. The role of the much maligned and poisoned ground squirrel is especially important for some pairs. While no poisoning of ground squirrels occurred in our study area, the swift fox would be very vulnerable to secondary poisoning of this prey elsewhere.
PlantWatch Saskatchewan - Become a PlantWatch Volunteer and Help Track Climate Change
Presenter: Deanna Trowsdale-Mutafov
Author: Deanna Trowsdale-Mutafov
It is increasingly well documented that not only is climate change occurring, but it is due primarily to greater emissions in greenhouse gases over the last few decades. Higher temperatures, extended drought periods, greater air pollution, widespread habitat changes, more forest fires, and a prevalence of extreme weather provides evidence to this claim. Prairie ecosystems, and other ecosystems, are being impacted.
PlantWatch Saskatchewan is a volunteer monitoring program that has been designed to help identify changes that are affecting our environment. This program enables citizen scientists to contribute to an understanding of how and why the natural environment is changing. PlantWatch is an active phenology program which provides baseline data to document biological responses to climate change. Since plants flower largely in response to the amount of warmth they are exposed to, earlier flowering occurs after warmer winters, and later flowering occurs after colder winters. Because our climate is changing, winters are becoming warmer and Canadian PlantWatch data indicates that plants are blooming earlier in the spring. Analysis of this data also allows scientists to measure impacts of climate change on ecosystems, and on the plants and animals that inhabit them.
The PlantWatch program not only encourages volunteers to record blooming dates for 20 indicator plant species, but also provides plant watching and climate change information to participants and to the public. The message of plant watching and climate change has been presented to many schools through a PowerPoint presentation and PlantWatch materials over the past several years. Presentations are given to schools and groups on observation and appreciation of wild plants, responsible stewardship of our environment, and climate change and reduction of greenhouse gas emissions.
The very popular PlantWatch Saskatchewan poster was recently printed in both official languages. It is available to all interested individuals, schools and other groups.
The South Okanagan - Canada's Endangered Shrub-steppe Ecosystem
Presenter: William Preston
Author: William Preston
In Canada the Shrub-steppe Ecosystem occurs in the south Okanagan Valley from Penticton south to the International Boundary, a distance of approximately 60 kilometres, as well as in the adjacent Similkameen valley. This is the nearest to desert of anywhere in Canada and has been described as a northward extension of the Great Basin Desert of Washington, Oregon and Nevada. Due to current agricultural practices - mainly the wine industry - much of this ecosystem has been lost or badly fragmented. Another major threat is real estate development moving further and further into the surrounding hills. All of this has had an adverse effect on the unique wildlife of the valley, resulting in perhaps more endangered and threatened species than anywhere else in Canada. Many of these species occur nowhere else in Canada.
