Inland pastures are an appropriate alternative for salt-marshes as a feeding area for spring-fattening Dark-bellied Brent Geese Branta bernicla

Citation
B. Spaans et P. Postma, Inland pastures are an appropriate alternative for salt-marshes as a feeding area for spring-fattening Dark-bellied Brent Geese Branta bernicla, ARDEA-T NED, 89(3), 2001, pp. 427-440
Citations number
20
Categorie Soggetti
Animal Sciences
Journal title
ARDEA
ISSN journal
03732266 → ACNP
Volume
89
Issue
3
Year of publication
2001
Pages
427 - 440
Database
ISI
SICI code
0373-2266(2001)89:3<427:IPAAAA>2.0.ZU;2-#
Abstract
On the Dutch Wadden Sea island Texel, spring-fattening Dark-bellied Brent G eese Branta bernicla fed almost exclusively inland on improved grasslands, whereas the remainder of the flyway population utilised coastal saltmarshes elsewhere in the Wadden Sea. There are indications that inland pastures ar e 'second choice habitat' during this important period. During spring-fatte ning, salt-marsh food plants just started to grow, offering the geese high quality food, while the growth of grasses on the inland pastures started ea rlier in the season, so that the nutritional value of inland grasses declin ed in the course of the spring-fattening period. This paper describes the h abitat use of spring-fattening Dark-bellied Brent Geese on Texel and compar es the reproductive output of pasture feeding and salt-marsh feeding geese. Dark-bellied Brent Geese on Texel overcame the problem of declining grass quality on inland pastures by tuning their grazing pressure to the plant pr oduction in such a manner that they kept the grass in the young, protein ri ch phase. Observations of individually marked Dark-bellied Brent Geese reve aled the site-fidelity of spring-fattening geese on Texel. The annual survi val of a sample of Texel geese (89%) was slightly higher than published val ues for the whole population (86%). Between 1982 and 1993, Dark-bellied Bre nt Geese successfully bred in six years, while the reproductive success of inland pasture feeders and salt-marsh feeders was similar. The calculated l ifetime reproduction of Dark-bellied Brent Geese spring-fattening on Texel amounted to 1.39 offspring per goose, which was in accordance with overall population trends during the period concerned. The results show that an imp roved grassland reserve can be an appropriate alternative for salt marshes for spring-fattening Brent Geese.