My project involves working with CWS and its partners to determine how hydroelectric development in the West Kootenays may be impacting marsh bird populations. The Canadian Wildlife Service has been surveying marsh bird species in BC’s Southern Interior Mountains since 2010. These surveys focus on marsh bird species that tend to be more secretive in nature, therefore harder to observe and study. In the West Kootenay region, significant sections of the Columbia and Kootenay Rivers and their tributaries have been impounded or otherwise altered by hydroelectric projects. These projects alter the landscape and ecosystem processes in a variety of ways, altering vegetation communities, flood regimes, and nutrient cycling just to name a few. Additionally, large sections of the Creston Valley floodplain have been altered by agricultural development and diking. In 2016, surveys began in the Columbia Wetlands region of the East Kootenays. These wetlands are relatively unaltered and one of the longest intact wetland complexes in North America.
To get a better sense of how differences between regions relate to marsh bird populations, complementary habitat surveys at each survey station have been collected through the years. These surveys consider critical elements of the area which could influence whether birds are present, such as how much of the area is open water versus emergent vegetation. Finally, in 2018 aquatic invertebrate samples were collected at most survey stations. Ideally, these samples will provide a sense of how much food is available, either for the birds directly or generally within the base levels of the food web.
Field work always comes with its own challenges, especially when you are not familiar with your study areas. Invertebrate collection at several survey stations was difficult, as stations were not originally selected for that kind of sampling. Knowledge from those working locally who had been involved with the project for years was invaluable in my planning, as many stations were not safe or feasible to sample for invertebrates. Ultimately, I collected samples where it was possible and was able to get good overall representation of the regions. Early analyses are already showing that certain aspects of the habitat are more important than others, and this varies between species. These initial results are maybe not surprising but having a better understanding about how marsh bird populations and critical aspects of the ecosystem (vegetation communities, invertebrates, etc.) have been impacted can allow us to better tailor restoration efforts to support these species.