The winter fattening model: a test at low latitude using the Clamorous Reed Warbler
Article first published online: 22 JUN 2005
Volume 147, Issue 4, pages 680–687, October 2005
How to Cite
MEROM, K., QUADER, S. and YOM-TOV, Y. (2005), The winter fattening model: a test at low latitude using the Clamorous Reed Warbler. Ibis, 147: 680–687. doi: 10.1111/j.1474-919X.2005.00444.x
- Issue published online: 10 AUG 2005
- Article first published online: 22 JUN 2005
- Received 7 May 2004; revision accepted 18 March 2005.
Small birds at high latitudes accumulate fat during the day so that they can survive long and cold winter nights. The winter fattening model suggests that birds increase their minimum (morning) mass in cold weather, build up their mass during the day, and then rely on the energy reserves so accumulated until the morning. While data from mid and high latitudes support this model, little is known about the strategies of birds inhabiting lower latitudes (< 40°N). We use an 18-year data set to investigate whether the winter fattening model holds in a mid-latitude (32°N) population of the Clamorous Reed Warbler Acrocephalus stentoreus. We show that morning mass and fat score vary as predicted by the winter fattening model. In addition, adults appear to be better adapted to long and cold winter nights than first-year birds. A long-term trend of increased body mass may be attributable to character release following reduced interspecific competition.