Portal to the Lesser White-fronted Goose

Literature type: Scientific

Journal: Journal of Ornithology

Volume: 155 , Pages: 707-712.

DOI: 10.1007/s10336-014-1056-6

Language: English

Full reference: Wang, X, Fox, A.D., Zhuang, X., Cao, L., Meng, F. & Cong, P. 2014. Shifting to an energy-poor diet for nitrogen? Not the case for wintering herbivorous Lesser White-fronted Geese in China Journal of Ornithology 155: 707-712. https://www.dx.doi.org/10.1007/s10336-014-1056-6

Keywords: East Dongting Lake, Energy budget, foraging decisions, Nitrogen budget, Recessional grasslands, Uric acid

Abstract:

Geese often forage on mid-winter foods that fail to satisfy daily energy needs, but they may do so to acquire other nutrients, such as nitrogen. We tested thishypothesis by evaluating nitrogen budgets, namely thebalance of nitrogen income against expenditure, of winteringLesser White-fronted Geese Anser erythropus feedingat two sites within East Dongting Lake, China, where they could and could not balance daily energy budgets.Geese could balance nitrogen budgets in energy-rich habitats but were less able to do so in habitats where they failed to balance energy budgets. This study presents the first full nitrogen budget for a wintering goose species, and suggests that, rather than acting as a source of nitrogen, use of energy-poor but undisturbed habitats may represent a refuge from human disturbance at other habitats.

Literature type: Scientific

Journal: Journal of Ornithology

, Pages: online June 2013.

DOI: 10.1007/s10336-013-0979-7

Language: English

Full reference: Wang, X., Zhang, Y., Zhao, M. Cao, L. & Fox, A.D. 2013. The benefits of being big: effects of body size on energy budgets of three wintering goose species grazing Carex beds in the Yangtze River floodplain, China. Journal of Ornithology : online June 2013. https://www.dx.doi.org/10.1007/s10336-013-0979-7

Keywords: energy budget, Yangtze River floodplain, erythropus, fabalis, serrirostris, Albifrons, wintering

Abstract:

Herbivores of different body size vary in food selection because of their different metabolic requirements and abilities to harvest and digest food. Compared with smaller grazers, larger ones require higher food quantity but can tolerate poorer quality. This divergence may also explain habitat partitioning in the distribution of closely related species. By estimating daily energy expenditure (based on observed activity budgets) and energy intake (using the indigestible marker method in food and faeces), we compared the field energy budgets of three wintering herbivorous goose species differing in body size feeding on the same Carex meadows. Throughout the winter, the larger Bean Geese Anser fabalis serrirostris and Greater White-fronted Geese Anser albifrons maintained positive energy budgets grazing lower quality Carex, in contrast to the smaller Lesser White-fronted Geese Anser erythropus which failed to do so and could only maintain positive energy budgets by grazing high-quality Alopecurus, Cynodon and Eleocharis. However, all three species failed to maintain positive energy balance and lost mass in midwinter. These results have important implications for explaining the divergent distribution patterns of these species on their wintering grounds in China.

Literature type: Scientific

Journal: Ibis

Volume: 155 , Pages: 576–592.

DOI: 10.1111/ibi.12039

Language: English

External Link:

Full reference: Wang, W., Fox, A.D., Cong, P. & Cao, L. 2013. Food constraints explain the restricted distribution of wintering Lesser White-fronted Geese Anser erythropus in China. Ibis 155: 576–592. https://www.dx.doi.org/10.1111/ibi.12039

Keywords: food, China, management, East Dongting Lake, energy budget, goose foraging,

Abstract:

More than 90% of the Lesser White-fronted Geese Anser erythropus in the Eastern Palearctic flyway population winter at East Dongting Lake, China. To explain this restricted distribution and to understand better the winter feeding ecology and habitat requirements of this poorly known species, we assessed their food availability, diet and energy budgets at this site through two winters. Lesser White-fronted Geese maintained a positive energy budget when feeding on above-ground green production of Eleocharis and Alopecurus in recessional grasslands in autumn and spring to accumulate fat stores. Such food was severely depleted by late November and showed no growth in mid-winter. Geese fed on more extensive old-growth Carex sedge meadows in mid-winter where they were in energy deficit and depleted endogenous fat stores. Geese failed to accumulate autumn fat stores in one year when high water levels prevented the Geese from using recessional grassland feeding areas. Fat stores remained lower throughout that winter and Geese left for breeding areas later in spring than in the previous year, perhaps reflecting the need to gain threshold fat stores for migration. Sedge meadows are widespread at other Yangtze River floodplain wetlands, but recessional grasslands are rare and perhaps restricted to parts of East Dongting Lake, which would explain the highly localized distribution of Lesser White-fronted Geese in China and their heavy use of these habitats at this site. Sympathetic management of water tables is essential to maintain the recessional grasslands in the best condition for Geese. Regular depletion of fat stores whilst grazing sedge meadows in mid-winter also underlines the need to protect the species from unnecessary anthropogenic disturbances that enhance energy expenditure. The specialized diet of the Lesser White-fronted Goose may explain its highly restricted winter distribution and global rarity.