Liberalized harvest regulations have not affected overabundant Snow Geese in Northern Manitoba

Large amounts of money are spent each year to control overabundant species that imperil biodiversity and ecosystem functioning across the globe. Lesser Snow Geese (Anser caerulescens caerulescens) are emblematic of this issue, as their overabundance has affected a whole suite of plant, insect, and bird communities via a trophic cascade that managers have attempted to stop before it spreads further across the North American (sub)Arctic. To achieve this goal, liberalized harvest measures designed to decrease Lesser Snow Goose survival and abundance were implemented almost 2 decades ago. Our previous quantitative assessment of management effectiveness indicated that the growing Lesser Snow Goose population quickly overwhelmed a satiated hunter population despite liberalized harvest regulations, eventually reducing the fraction of Lesser Snow Geese being harvested each year. Consistent with the philosophy of adaptive resource management, we apply improved methods to additional years of monitoring data to evaluate the ongoing impact of harvest conservation efforts on Lesser Snow Goose harvest rates. Our previous results suggested little effect of liberalized harvest regulations on harvest rates, but our new findings suggest even less of an impact. Harvest rates have recently stabilized at ~3%, the lowest levels observed over the last 48 yr of our study. Barring adverse effects of environmental change on natural mortality or reproductive success, additional measures will need to be taken to reduce Lesser Snow Goose overabundance and their ecosystem damage.

Impacts of Climate Change and Intensive Lesser Snow Goose (Chen caerulescens caerulescens) Activity on Surface Water in High Arctic Pond Complexes

Rapid increases in air temperature in Arctic and subarctic regions are driving significant changes to surface waters. These changes and their impacts are not well understood in sensitive high-Arctic ecosystems. This study explores changes in surface water in the high Arctic pond complexes of western Banks Island, Northwest Territories. Landsat imagery (1985–2015) was used to detect sub-pixel trends in surface water. Comparison of higher resolution aerial photographs (1958) and satellite imagery (2014) quantified changes in the size and distribution of waterbodies. Field sampling investigated factors contributing to the observed changes. The impact of expanding lesser snow goose populations and other biotic or abiotic factors on observed changes in surface water were also investigated using an information theoretic model selection approach. Our analyses show that the pond complexes of western Banks Island lost 7.9% of the surface water that existed in 1985. Drying disproportionately impacted smaller sized waterbodies, indicating that climate is the main driver. Model selection showed that intensive occupation by lesser snow geese was associated with more extensive drying and draining of waterbodies and suggests this intensive habitat use may reduce the resilience of pond complexes to climate warming. Changes in surface water are likely altering permafrost, vegetation, and the utility of these areas for animals and local land-users, and should be investigated further.