SUMMARYWOINARSKI, J.C.Z. and C. BULMAN, 1985. Ecology and breeding biology of the Forty-spotted Pardalote and other pardalotes on North Bruny Island. Emu 85: 106–120.The second largest known colony of the rare Forty-spotted PardalotePardalotus quadragintusis on North Bruny Island (Tas). We spent from September to December 1983 at this colony. There were 86 breeding adults on a 55 ha study site (with c. 50 and 22 individuals for the co-existing StriatedP. striatusand SpottedP. punctatusPardalotes respectively).P. punctatusheld large (= 3.4 ha) non-overlapping territories.P. quadragintusheld small (= 0.7 ha) territories with little overlap.P. striatusdid not defend territories. Bothpunctatus(males) andquadragintus(males, but also some females) responded vigorously to playbacks of recorded calls of their own species, but there was little evidence of interspecific territoriality. Bothquadragintusandstriatushad a somewhat clumped dispersion of nests. The choice of nest-site differed between species, with mostquadragintusnests (N = 24) in hollows in dead wood (especially cut-off stumps),striatusnests (N = 15) in hollows of living timber or in tunnels on the ground andpunctatusnests (N = 5) only in ground tunnels. Most nests were apparently successful.P. striatusstarted nesting later than the other species. All species had some clutches. Predation of nest contents was rare.P. quadragintus, at least, may show strong nest-site fidelity.All pardalote species, but particularlyquadragintus, foraged disproportionately inEucalyptus viminalis.Foliage of that species was comparatively rich in arthropods and, more critically, in the exudate, manna. This was a major diet item for all pardalotes (and particularly forquadragintusandpunctatus). There was some interspecific aggression associated with foraging, with a distinct dominance hierarchy from Black-headed HoneyeaterMelithreptus affinis(weight = 16.4 g) toquadragintus(10.7 g) tostriatus(13.6 g) topunctatus(9.2 g).P. quadragintusindividuals averaged onlyc.5 mins/day in these interspecific encounters.The survival of this colony may be jeopardized by habitat modification, through either change in fire regime or further clearing and fragmentation. This would affect not only availability of nest-sites but also potential for local post- breeding dispersal. The latter may be critical because of a presumed winter decline and unpredictability of food resources and becausequadragintushas a wing shape which appears to be unsuited for dispersal over long distances.