|SREL Reprint #1050|
Loss, Tail Color, and Predator Escape in Eumeces (Lacertilia: Scincidae):
Age-specific Differences in Costs and Benefits
J. Vitt and William E. Cooper, Jr.
The tail loss adaptation in Eumeces of the
southeastern United States is complex. Juveniles
possess tails that are colored differently from those of adults and apparently
distract the attention of potential predators from the body to the tail.
Adult tails are cryptically colored.
Frequency of tail loss is high across size groups.
Experiments on growth of tailed and tailless juveniles suggest no effect
of tail loss on growth and, thus, there may be little cost of tail loss to
juveniles other than the temporary loss of the autotomy adaptation.
Lipids in adult tails constitute nearly 50% of total standing lipids and
are reduced during reproduction similar to other lipid reserves.
This suggests that tail loss in adults is expensive, particularly prior
to or during the breeding season. We
suggest that the high costs of tail loss in Eumerces are offset by the
increased probability of predator escape via tail loss.
Tail loss data are minimal estimates of escape via distraction of a
predatorís attack to the tail as indicated by predation experiments.
The presence, coloration, and behaviors of the tail may result in a high
proportion of predation attempts being redirected to the tail followed by total
SREL Reprint #1050
Vitt, L.J. and W.E. Cooper Jr. 1986. Tail loss, tail color
and predator escape in Eumeces (Lacertilia: Scincidae): age
specific differences in costs and benefits. Canadian Journal of