Geese Staging Research Articles

Expensive Traditions: Energy Expenditure of Aleutian Geese in Traditional and Recently Colonized Habitats

ABSTRACT In an effort to reduce goose depredation at a traditional spring migratory stopover site, private landowners implemented a coordinated hazing plan to scare Aleutian cackling geese (Branta hutchinsii leucopareia) from private lands to adjacent public pastures that were cultivated and set aside specifically for geese. Coincidentally, some Aleutian geese began using a new stopover site 150 km farther south in their spring migratory range; numbers at the new site continue to increase. We tested the idea that when their ability to acquire resources deteriorates geese are likely to seek improved foraging conditions, especially during spring migration when individuals strive to maximize nutrient stores and minimize energy expenditure. We quantified measures of goose foraging performance in traditional and new spring staging sites by calculating foraging opportunity, foraging effort, body condition, and daily energy expenditure. Geese staging at the site with higher levels of human disturbance had less foraging opportunity and, despite increased foraging effort and more nutritious food‐plants at the site, birds there experienced an elevated energy expenditure and poorer body condition than birds at the new stopover site. Reduced foraging time and increased energy expenditure at the traditional spring staging site may have triggered the colonization process. Suitability assessment of habitat for migratory geese should include measures of foraging opportunity, disturbance risks, and daily energy expenditure in addition to quantity and quality of foods.

Staging, Migration, and Winter Distribution of Canada and Cackling Geese Staging in Interior Alaska

The breeding stock composition and ecology of Canada (Branta canadensis) and cackling (B. hutchinsii) geese, collectively white-cheeked geese, staging in interior Alaska and wintering in the Pacific Northwest is poorly understood. We captured, measured, and applied neck collars to white-cheeked geese during spring and fall staging near Fairbanks and Delta Junction, Alaska, USA, to study their breeding stock composition, migration, and winter distribution. We measured exposed culmen, flattened wing chord, total tarsus, and body length of geese staging in interior Alaska to assist with determination of breeding stock. The first principal components, as well as a univariate measurement of exposed culmen, indicated geese trapped in Fairbanks in the fall were larger on average than geese trapped in Delta Junction in either spring or fall. We observed or recovered most of the banded geese detected in fall and winter in central British Columbia, Canada, central Washington, USA, and north-central Oregon, USA, east of the Cascade Mountains, with relatively few observations in western British Columbia, Washington, and Oregon. We found no evidence of movement between wintering areas on the east and west sides of the Cascade Mountains. Geese that we trapped during spring staging in Delta Junction were more often observed on the west side of the Cascade Mountains than geese trapped during fall staging in Fairbanks. Most (93%) geese trapped during fall staging in both Fairbanks and Delta Junction, however, wintered east of the Cascade Mountains. After-hatch-year (AHY) geese from interior Alaska staging areas observed on the west side of the Cascade Mountains were structurally smaller on average than AHY geese observed on the east side of the Cascade Mountains. Our results indicate fall staging white-cheeked geese in Fairbanks were predominantly 1 breeding stock of white-cheeked geese, while fall and spring staging white-cheeked geese in Delta Junction comprised at least 2 stocks of white-cheeked geese. Based on our findings, we recommend separate harvest and management strategies be considered for small white-cheeked geese migrating through coastal and central British Columbia and wintering east and west of the Cascade Mountains in Washington and Oregon to avoid potential overharvest of independent breeding stocks.

Autumn Diet of Lesser Snow Geese Staging in Northeastern Alaska

The coastal plain of the Arctic National Wildlife Refuge (ANWR) is used by lesser snow geese (Chen caerulescens caerulescens) in autumn for premigratory staging. To better understand the potential impacts of human disturbance on lesser snow geese, we investigated species composition of, and temporal and age-related variation in, their diet during staging. Depending on age and time of collection, between 35.2 and 94.1% of the diet (aggregate percent wet mass, n = 75) consisted of 2 species of plants; underground stems of tall cotton-grass (Eriophorum angustifolium), and aerial shoots of northern scouring-rush (Equisetum variegatum)

Comparison of daily energy expenditure of greater snow geese between two habitats

We estimated the daily energy expenditure (DEE) of greater snow geese (Anser caerulescens atlanticus) on their St. Lawrence River estuary spring staging ground using time budget data. We compared DEE between two habitats: the traditionally occupied freshwater Scirpus-dominated marsh (SCI), and the recently invaded Spartina-dominated salt marsh (SPA). As greater snow geese staging at SCI have been found to accumulate larger fat reserves in the spring than those staging at SPA, we sought to explain these differences in diverging DEE patterns between the two habitats. We found that geese spent 42% more time (and energy) feeding in the marsh at SCI, but spent 61% less energy feeding in the field than at SPA. The energy spent in other activities was similar in both habitats. However, during the 6-week staging period, DEE was lower by only 4.7% at SPA (1613 kJ/day; 2.3 × basal metabolic rate (BMR) when compared with SCI (1689 kJ/day; 2.5 × BMR). This difference in DEE cannot account for the habitat-based differences in prebreeding fattening, and alternative hypotheses are examined.

Nutrient reserve dynamics of lesser snow geese staging at James Bay, Ontario

We compared mean body weights, nutrient reserves (fat and protein), and an index of feeding of lesser snow geese arriving at and leaving southern James Bay in spring and fall 1976. Feeding increased in spring and decreased in fall. Body weight and protein of adults increased in spring, and fat reserves were maintained. The protein increase of adult females was equivalent to the protein in one egg. Ovarian follicular development in adult females appeared to proceed as reserves became available. Juvenile males had completed body growth by the end of the fall staging period but juvenile females had not. Fat and protein reserves of adults arriving on James Bay in the fall were significantly larger than those of adults after wing molt on the breeding grounds. Fat reserves of adults and juveniles increased significantly during the fall; body weight of juvenile females increased also. The fat gain greatly increases the theoretical maximum flight range of the geese and we suggest it is an important determinant of normal fall migration.