Effects of Large Scale Climate Patterns (PDO, ENSO, AO) on Calving Ground Location, Forage Availability, and Calf Survival of the Porcupine Caribou Herd
June 2016 - October 2019
- Science Support Program (SSP) FWS
Our goal is to develop a mechanistic understanding of why Concentrated Calving Areas (CCAs) of the Porcupine Caribou Herd (PCH) were located predominantly in the Yukon Territory, 2000-2013, after a 17 year period (1983-1999) of being located predominantly in Alaska and the 1002 Area (Fig. 1 a,b). This goal addresses whether or not the eastward shift in concentrated calving, 2000-2013 is “permanent” or may be one phase of a cyclic phenomenon. The working hypothesis is that PCH caribou shifted calving eastward, 2000-2013, because the Pacific Decadal Oscillation (PDO) shifted to a negative phase and affected the location of high quality/high quantity forage in relation to predation risk (i.e., cows continued to find the best place to calve in a variable and cyclic climate). When the PDO shifts back to a predominantly positive phase, we expect calving to shift back to the Alaska Coastal Plain.