Web spider's dilemma: a risky move or site dependent growth.

Nephila clavipes inhabiting adjacent habitats showed differences in rate and ratio of growth. Spiders inside the forest fed less, grew slower and stayed smaller than those at the forest edge, a richer environment. The mortality rate in this habitat was about 1% per day, the mortality of vagrant males was even higher. Experimentally fed spiders did not shift their webs readily, even starving individuals stayed much longer than expected. The spiders avoided frequent moves and in a poor site grew more slowly and in smaller size increments. It seems that the costs of small adult size are less than the risks of active foraging.