Monday, October 18, 2021

Clutch sizes and hatching success of Canada geese nesting in Canterbury, New Zealand

TitleClutch sizes and hatching success of Canada geese nesting in Canterbury, New Zealand
Publication TypeJournal Article
Year of Publication2021
AuthorsAdams, JS, Williams, M
JournalNotornis
Volume68
Issue1
Pagination13-25
KeywordsBranta canadensis, Canada goose, clutch size, hatching success, nesting, New Zealand
Abstract

 

Nesting outcomes of Canada geese (Branta canadensis maxima) in Canterbury, New Zealand were recorded from a sedentary population nesting at coastal Lake Forsyth (1967–70) and from a seasonally migratory population nesting in headwater valleys of the Waimakariri River (1966–80). Mean clutch size in 462 Lake Forsyth nests was 5.3 (sd = 1.3) eggs, with clutches of 4, 5, and 6 eggs comprising 17%, 30% and 30% respectively of the total. Goslings hatched from 67.4% of 1,602 eggs in 298 monitored nests, and the entire clutch hatched successfully in 42.6% of the monitored nests. Mean productivity at hatching was 3.6 (sd = 2.3) goslings per nest. Mean clutch size in 1,211 Waimakariri River headwaters nests was 4.5 (sd = 1.3), with clutches of 4, 5, and 6 eggs comprising 25%, 32%, and 20% respectively of the total. Goslings hatched from 63.3% of 3,952 eggs in 871 monitored nests, and the entire clutch hatched successfully in 30.5% of the monitored nests. Mean productivity at hatching was 2.9 (sd = 1.9) goslings per nest. Relative to Canada geese in their native North American range, geese nesting at Lake Forsyth laid clutches of similar size, had similar hatching success but higher nest success whereas geese nesting in the Waimakariri River headwaters laid, on average, conspicuously smaller clutches, had similar hatching success, but higher nest success.

 

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