The breeding biology and behaviour of the yellow-breasted tit (Petroica macrocephala macrocephala).
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
The breeding biology, territorial behaviour, movements of banded birds, nest sites and nests, feeding biology and vocalizations of a population of Yellow-breasted tits (Petroica macrocephala macrocephala) were studied in Mount Fitzgerald Scenic Reserve, Banks Peninsula, during 1977-1979. Pairs of Yellow-breasted tits remained on a territory throughout the year. Territorial advertisement and defence were at a peak during the late prebreeding season and breeding season. Boundaries were maintained through vocalizations, body-feather and wing displays, chases and, more rarely, fights. The territorial nature of, and the intolerance towards, other tits were seen developing while fledglings were still being fed by their parents. Shortly after independence, some juvenile males and females set up small subterritories on the peripheries of adult territories. A synchronous movement by some juveniles away from adult territories occurred five to six weeks after independence. Breeding activities commenced in early September in all pairs and continued to late February for some pairs. The cupular nests were built in four site-types in my study area. A maximum of three broods per pair was raised to independence per season, but one or two was more usua1. Brood size varied between three and five. The female renested within two to three days of the previous brood fledging, while the male continued to feed the fledglings. Circumstantial evidence suggested that up to six eggs per clutch could be laid. The behaviour of tits of all ages throughout the breeding season is described. A wide range of invertebrate prey was taken. Berries may also have been eaten. Prey were captured using the "watch and wait" technique. No active foraging was observed. Four methods were employed to capture the prey. The song of the adult male was the most distinctive vocalization of a wide range of calls given by Yellow-breasted tits of all ages. Sonagrams were produced to show and compare the structures of different calls. The developmental stages of male song are also described. Neighbouring males tended to have very similar songs. A dialect may have evolved within Mount Fitzgerald Scenic Reserve. Possible factors causing the patchy distribution of tits within the Reserve are discussed. This habitat may be supporting the maximum number of tits possible.