Upper Therien Lake

Survey Citation:
Prescott, D. R. C., J. Unruh, S. Morris-Yasinski, and M. Wells. 2018. Distribution and abundance of the western grebe (Aechmophorus occidentalis) in Alberta: an update. Alberta Environment and Sustainable Resource Development, Fish and Wildlife Policy Branch, Alberta Species at Risk Report No. 160, Edmonton, AB. 23 pp.

• Type
  boat
• Time period
  1981, 2016
• Source
  Report
• Both Western and Clarks?
  N

Count Type	Range	Max	Year
Max Adults	1 to 100	presence	1981, 1993
Most Recent Adults	0	0	2016
Max Nests	1 to 100	presence	1993
Most Recent Nests	0	0	2016
Max Chicks	1 to 100	presence?	1993
Most Recent Chicks	0	0	2016

Comments:

Sources are FWMIS (Accessed Nov 2015 including field surveys from 2015 and 2016) and Erickson 2010. This report is an update of Western grebe distribution in Alberta based on previous provincial status reports, additional breeding records (between May 1 to August 31) through end of 2014 from new sources. Lakes were visited in 2015 and 2016 for occupancy and habitat conditions. In a given year, if there are multiple sources of data, the highest count was given. From the Appendix, I entered only lakes (67) with evidence of breeding (either chicks or nests, but doesn't specify which and no nest nor chick numbers provided). Otherwise, 318 lakes supported adult grebe populations. This report compiled a list of 35 priority lakes for grebe surveys and management actions through the provincial recovery plan based on high population and habitat scores. New lakes with breeding reveal a changing system of lake occupancy and possibly higher populations than previously thought in Alberta.