Estimating population size and forager movement in a tropical subterraneantermite (Isoptera : Rhinotermitidae)

Colony population size of Coptotermes acinaciformis (Froggatt), a species o f mound-building, wood-eating, subterranean termite from tropical Australia , was estimated using a market-recapture protocol and by direct counts of i ndividuals collected from mounds. The mark-recapture estimates varied widel y within and between colonies (0.4-19.1 million),depending on definitions o f recaptures (intensity of color), and could be 10 times larger than the di rect counts (1.2-1.6 million). Assumptions of the mark-recapture protocol w ere shown to be violated in field and laboratory tests. Nile blue A, a fat- stain marker, did not persist and was transferred by cannibalism. Marked in dividuals did not mix uniformly with unmarked individuals; instead, forager s displayed feeding-site fidelity. The likelihood of recapture differed bet ween castes and instars, there was a higher recapture rate of large workers and soldiers relative to small workers. These violations would increase po pulation estimates from mark-recapture protocols. These results agree with those found for temperate species, suggesting that the difficulties with ma rk-recapture protocols are not limited to 1 habitat type or species, and th at mark-recapture protocols do not estimate population size accurately.