Projects‎ > ‎

Limiting Factors Analysis

In March 2009 the PIF implementation and science committees were asked by Joint Ventures to identify factors limiting populations to help determine where habitat conservation will be most effective for declining species. The WWG dove in, discussions ensued at the Penticton meeting in April 2009, and continued in Forest Grove.  In a breakout session in Forest Grove a work group discussed the first steps, i.e. initiating analyses for a species or two to demonstrate our ability to consider full life cycle factors that limit populations of high priority species.  After much discussion, RUHU, YWAR (riparian), WIWA (forest), SWTH (winter info), WETA and LAZB (molt migrants), BRSP and GRSP (grassland), WIFL were chosen (western and tri-national in range).  This group also developed a matrix of species by available data that will inform these analyses.  The group discussed traditional analyses (that use productivity, survivorship, and recruitment to identify factors that limit population growth for a species), and alternative approaches, motivated by Matt Betts’ presentation (at the Forest Grove meeting) of his thresholds analysis, through which he inferred that amounts of young hardwoods on the landscape are limiting some species that are declining based on BBS, such as RUHU and OCWA, in the Pacific Northwest.

The Draft Matrix (dated 11/13/2009) is attached
This new initiative for the WWG is in its infancy.
Mike Green,
Feb 3, 2010, 2:00 AM