A Comparison of the Breeding Biology of the Welcome Swallow in Australia and Recently Colonized New Zealand

Abstract

A comparison is made of breeding by Welcome Swallows Hirundo neoxena in eastern and western Australia and nestlings in recently colonised New Zealand. In all areas only the female incubated and brooded but the male helped feed the chicks and took away more faecal sacs than the female. Growth rates and pterylosis are described. Clutch sizes averaged 4.5 in New Zealand, 3.7 in eastern Australia and 3.2 in Western Australia and most hatched over a two day period. Average New Zealand incubation took 16.7 days and in eastern Australia took 16.0 days. Average nestling period in New Zealand of 21.5 days was significantly longer than the average Australian time of 18.9 days. The most productive clutch size produced: 5.0 fledglings (C/6) in New Zealand, 4.2 fledglings ((216) in eastern Australia and 3.3 fledglings (C/4) in Western Australia. Although the species is new to New Zealand and has a larger clutch size there, total breeding success was not greater than that of Australian birds.