Incorporating nocturnal activity of wintering Atlantic brant (Branta bernicla hrota) into 24 hour time-activity and daily energy expenditure models

• Main Author: Heise, Jeremiah
• Format: Thesis
• Language: unknown
• Published: University of Delaware 2012
• Subjects: Brant > Wintering > New Jersey; Arctic; Brant; Branta bernicla
• Online Access: http://udspace.udel.edu/handle/19716/11791

The Arctic Goose Joint Venture has established numerous priority areas of research for Atlantic brant (Branta bernicla hrota). Several of these priorities focus on the wintering grounds, as the wintering period is often a limiting time for many species, especially migratory waterfowl. Addressing these areas of research often centers on behavioral observations to construct subsequent time-energy models. While waterfowl have qualitatively been shown to be active nocturnally, limited research has addressed incorporating this activity into time-activity and daily energy expenditure models. Thus, popular assumption promotes that observed diurnal behavior is representative of 24 hrs. As a result, my objectives were to 1) directly quantify the behavioral dynamics of wintering Atlantic brant within the 24 hr period inclusive of morning crepuscular, diurnal, evening crepuscular, and nocturnal periods along southern coastal New Jersey, USA, 2) determine if environmental variability (e.g. freezing temperatures, wind, snow cover, ice cover, etc.), or anthropogenic pressure (e.g. hunting disturbance) affect time spent in different behaviors across the 24 hr period, and 3) evaluate the effect of hunting and non-hunting areas on brant behavior both during and outside the Coastal Zone waterfowl hunting seasons. I observed brant during October-February 2009–2010 and 2010–2011, across their main wintering grounds along the Great Bay estuary of southeastern coastal New Jersey. I conducted behavioral observations using an instantaneous scan method across two different combinations of 6 hr observation periods, effectively covering the 24 hrs of a day. These observations were paired across either a diurnal and nocturnal period or morning and evening period inclusive the respective crepuscular periods, thus effectively being matched over a given day’s tide cycle. Explanatory environmental variables, as well as hunting location and season data, were also collected to model against the collected behavior data. During two years of ...