Monday, November 2, 2015
Alexej Siren of the University of Massachusetts was recently invited to a Canada lynx (Lynx canadensis) expert elicitation workshop in Bloomington, Minnesota.
Alexej Siren was asked to summarize the potential threats of climate change on lynx populations in the contiguous US with specific attention paid to the uncertainty of the climate modeling predictions.
The workshop was organized by the US Fish and Wildlife Service (USFWS) to inform its Species Status Assessment for lynx, which is listed as threatened under the Endangered Species Act. The intent of this workshop was to provide the USFWS with the latest knowledge, best professional judgments and opinions of lynx experts regarding the current status of, threats to, and likely future viability of the distinct population segment (DPS) of lynx in the US. The DPS includes lynx populations in north central Washington, northwestern Montana and northeastern Idaho, the Greater Yellowstone Area of southwestern Montana and northwestern Wyoming, western Colorado, northeastern Minnesota, and northern New England (primarily Maine). There are many facets of lynx biology and population dynamics for which empirical data are lacking, but lynx researchers and resource managers at the workshop were able to contribute their expert opinion with the latest knowledge to develop the assessment at this workshop.
Lynx are highly adapted for hunting snowshoe hares (Lepus americanus) in areas with deep, persistent powdery snow. Alexej provided information on the recent trends and predictions of winter temperature and precipitation, and snowpack in the DPS regions. Overall, lynx populations in this range are likely to experience warmer winters with more precipitation during the 21st century. Importantly, most predictions indicate that a higher proportion of the precipitation will occur as rain rather than snow. In combination, these changes are forecasted to increase crusting conditions, reduce snowfall and depth, and reduce the length of the snow season. At higher elevations, these predictions are thought to be less pronounced, and lynx and its prey may not be as heavily impacted by the changing climate. However, populations in the eastern US lack the elevational refugia available to lynx in the western US and will likely experience rainy and mild winters, with the possible exception of the Minnesota population benefiting from a deeper snowpack due to lake-effect snow until mid-century.
The workshop lasted for three days and included long hours of presentations, deliberations, and elicitation activities designed to extract the most relevant information on the lynx DPS. Other researchers provided the USFWS staff and the lynx expert panelists information on broader topics that may influence DPS populations, such as genetics, predator-prey dynamics, climate change, and regulatory mechanisms and conservation efforts specific to the DPS. After presentations concluded, the workshop shifted emphasis towards utilizing the best available information to identify and rank current and future threats. By the time the workshop concluded, species experts had filled an entire wall of figures and diagrams that detailed the probability of persistence of each DPS population under a suite of potential threats (e.g., climate change, habitat alteration, and stochastic and catastrophic events). Thankfully, there was also a team of fastidious note takers that documented the entire process. The comprehensive biological and ecological information and current threat assessment gathered at the workshop will be reviewed for accuracy and used to determine lynx status since it’s listing in 2000.