Information on the breeding of greenfinches (Carduelis chloris) was collected over three breeding seasons (1979-1981) in Hawke’s Bay from 104 nests, 78 clutches and 31 broods. The laying season lasted from mid-October to early February. The average clutch size was 4.60 eggs (n= 55 clutches). Sixty percent of completed clutches consisted of 5 eggs and 35% of 4 eggs. Twenty-seven percent of 297 eggs in 78 clutches resulted in young that flew. Predators removed 40 % of eggs and 31% of young. Comparisons were made with 191 greenfinch nest record cards collected over 47 years by the Ornithological Society of New Zealand and with data from Britain. Clutch sizes and brood sizes of greenfinches in New Zealand were significantly smaller than in Britain.
This paper presents, as well as some earlier data, the results of a study of the burrowing petrels of the Crozet Islands (South Indian Ocean) made during the East Island expedition of September 1981 to February 1982. The 16 petrels are discussed and analysed in the following taxonomic groups: 4 gadfly petrels, 5 prions, 2 Procellaria petrels, 3 storm petrels and 2 diving petrels. For each group, biometric data and the breeding biology of each species are given. The timing of events (first return to land, laying, hatching, fledging), nest reoccupation, incubation schedule, chick growth and chick-feeding pattern were the main study topics. Abundance cycles during pairing, temporary egg desertions, nest selection, comparison with other localities and particularly ecological segregation of the petrels are discussed.
Experiments were undertaken to identify the animals responsible for attacks on nests of greenfinches (Carduelis chloris) on a mixed farm in Hawke’s Bay. Nests encased in wiremesh, which excluded all potential predators except mice, suffered no egg losses. Tracking papers placed on wooden poles leading to nests were marked by rats twice. Two ship rats (Rattus rattus) were killed at nests with eggs injected with strychnine. Mustelids destroyed one clutch of eggs and were probably responsible for most of the predations on young. The experiments did not test whether harriers (Circus approximans) or other birds were involved.