Assessing the impact of lesser snow goose and cackling goose competition on breeding Atlantic brant

• Main Author: Nissley, Clark
• Format: Thesis
• Language: unknown
• Published: University of Delaware 2016
• Subjects: Brant > Nunavut > Southampton Island; Snow goose > Nunavut > Southampton Island; Cackling goose > Nunavut > Southampton Island; Bird populations > Nunavut > Southampton Island; Nunavut; Foxe Basin; Southampton Island; East Bay; Brant
• Online Access: http://udspace.udel.edu/handle/19716/21431

Population estimates from Mid-Winter Survey Counts over the last half century show that Atlantic brant numbers have fluctuated over the course of this time period; however, between 2000 – 2016 the population has been showing a slow decline of ~20%. Additionally, the Mid-Winter Surveys (MWS) indicate a low percentage of young in flocks in recent years (<10% between 2013–2015), indicating breeding ground limitations in those years. Southampton Island’s East Bay (located on the southern end of the Foxe Basin), supported a historic nesting colony of brant as well as a significant population of lesser snow geese (Chen caerulescens caerulescens) and a small population of cackling geese (Branta hutchinsii). However, range-wide, lesser snow geese populations have increased from a few million to ~15 million in the last few decades with consequences that resonate throughout the ecosystem, affecting other species sharing that ecosystem. Additionally, the MWS indicates the range-wide cackling goose population has also increased from ~400,000 to ~700,000 in the last 3 decades. ☐ While East Bay historically supported a large nesting colony of Atlantic brant. Research crews in 2010 found that a local decline in brant nesting had occurred, though reasons for the decline were not resolved. The aim of my study was to begin to decipher the keys to understanding why a localized decline is occurring and to provide an update of the status of nesting Atlantic brant at East Bay. By means of nest searching, the careful observation of brant pairs during incubation, and collection of habitat and nest site selection data, we now believe we have a better grasp on some of the factors limiting brant success at East Bay, Southampton Island. ☐ Snow geese and cackling geese arrived 25 May 2014 and 21– 22 (respectively) May 2015. Brant arrived on 9 June in summer 2014 and 8 June in summer 2015. Snow melt in 2014 occurred much faster than snow melt in 2015. In 2014, snow cover reached 0% by 12 June, while in 2015 snow cover did not reach 0% ...