Nesting and reproductive activities of Greater Sage-Grouse in a declining northern fringe population

In Canada, Greater Sage-Grouse (Centrocercus urophasianus) are at the north ern edge of their range, occurring only in southeastern Alberta and southwe stern Saskatchewan. The population in Canada has declined by 66% to 92% ove r the last 30 years. We used radio-telemetry to follow 20 female Greater Sa ge-Grouse and monitor productivity in southeastern Alberta, and to assess h abitat use at nesting and brood-rearing locations, All females attempted to nest. Mean clutch size (7.8 eggs per nest) was at the high end of the norm al range for sage-grouse (typically 6.6-8.2). Nest success (46%) and breedi ng success (55%) were within the range found for more southerly populations (15% to 86% and 15% to 70%, respectively). Thirty-six percent of unsuccess ful females attempted to renest. Fledging success was slightly lower than r eported in other studies. Thus, reproductive effort does not appear to be r elated to the population decline. However, chick survival to greater than o r equal to 50 days of age (mean = 18%) was only about half of that estimate d (35%) for a stable or slightly declining population, suggesting that chic k survival may be the most important factor reducing overall reproductive s uccess and contributing to the decline of Greater Sa.-e-Grouse in Canada.