Dynamics of fat and protein reserves during winter and spring migration in greater snow geese

Abstract

We studied the dynamics of fat and protein reserves in greater snow geese (Chen caerulescens atlantica) during winter and spring migration, and examined the influence of a recent expansion of their staging grounds and change in habitat use on fat and protein storage. We collected 63 geese during the winter of 1989–1990 at Bombay Hook National Wildlife Refuge in Delaware, 158 geese in spring 1989 and 1990 at Lake Saint-Pierre and Cap-Saint-Ignace along the St. Lawrence River in southern Quebec, and 17 geese at the end of the 1990 migration on By lot Island, N.W.T. In both sexes, protein reserves did not change in winter but fat declined from a peak in December to a low point in early March, just before spring migration. Geese collected 3 weeks later at Lake Saint-Pierre (800 km north) had considerably larger fat reserves (90% larger in females and 40% in males). Geese accumulated large fat reserves at both sites along the St. Lawrence River. Although geese staged for a shorter period at Lake Saint-Pierre (a recently used area), males stored as much fat as those staging at Cap-Saint-Ignace and females only slightly less. A small amount of protein was stored between late winter and the end of staging. Spring conditioning of geese along the St. Lawrence River seems to have improved over the past decade. We found weak evidence that larger females stored more fat. The cost of migrating from the St. Lawrence to Arctic nesting grounds (2900 km) is considerable, as half of the fat reserves accumulated in spring were used for the migration. There is no evidence of fat or protein storage between the St. Lawrence estuary and the Arctic nesting grounds.

Manipulating individual state during migration provides evidence for carry-over effects modulated by environmental conditions

“…Twice a year, geese stage along the St Lawrence Valley of Quebec for six to eight weeks (late March to mid-late May in spring, late September to late November in autumn). This is their most important spring staging area where almost all their endogenous reserves are accumulated for the northward migration and subsequent reproduction [23]. During spring staging, geese feed both in tidal marshes along the St Lawrence River and in adjacent farmlands [20,22].…”

Determining the body condition of short-tailed shearwaters: implications for migratory flight ranges and starvation events

“…2. We used lipid stores to estimate flight ranges for short-tailed shearwaters; however, there is evidence that shorebirds and passerines also utilize protein stores while migrating (Piersma & Jukema 1990, JenniEiermann & Jenni 1991, Akesson et al 1992, Gauthier et al 1992. Nevertheless, it is unclear whether the use of protein stores during migration is devoted directly to increased flight costs, thus allowing an increase in flight range.…”

Estimation of Carcass Fat and Protein in Northern Pintails (Anas Acuta) During Spring Migration

“…We ground each lyophilized sample in a high-speed grinder and weighed 1 g duplicates using an analytical balance. We extracted lipids (total body fat [''carcass fat'']) following Gauthier et al (1992) using petroleum ether. Finally, we calculated dry lean mass (''carcass protein''): Carcass protein ϭ fatfree dry weight Ϫ mineral ash (obtained after incinerating the lyophilized sample at 550 C for 12 hr) (Miller, 1989;Dabbert et al, 1997).…”

“…This physiologic condition is partly a function of foraging in appropriate habitats (Gauthier et al, 1984;Whyte and Bolen, 1984); therefore spring staging areas may be important to allow birds to build energy reserves during and after migration to breeding areas (Olsen, 1994;Austin and Miller, 1995). Changes in body mass during spring or fall migration are common in many North American bird species (Dunn, 2001).…”

“…Lipids are the dominant fuel source during migratory flight in many bird species, and carcass fat has generally been determined by petroleum ether lipid extraction (Dobush et al, 1985;Johnson et al, 1985;Ringelman and Szymczak, 1985;Miller, 1989;Gauthier et al, 1992;Harder and Kirkpatrick, 1994;Dabbert et al, 1997). However, lipid extraction is both expensive and time consuming (Johnson et al, 1985).…”