Linnet Breeding Biology on Hawaii

Abstract

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.A study of the Linnet (Carpodacus mexicanus frontalis) was conducted on the island of Hawaii from 1969 through 1973. Pair bond formation commences in early spring with a characteristic male courting behavior. Both native and introduced trees are utilized as nesting sites and there appears to be a direct correlation between nest height and total height of the tree. Favored areas of placement were found to be in the lower inside region of the tree, with a possible shift occurring to the outer forks. Nest construction--primarily by the female--takes from six to 11 days. The measurements of a number of nests are given with the types of materials utilized. Clutch size was found to be 3.9 ± 0.7 eggs and the mean weight of the eggs was 1.5 ± 0.2 grams. Incubation period was 13 to 14 days and the nestling period varied from 14 to 17 days. The breeding season of the Linnet in Hawaii extends from early March through late July. It appears that in the past 100 years the breeding biology of the Linnet in Hawaii has changed little from that of the birds in western North America.Research was supported in part by the International Council for Bird Preservation, the McInerny Foundation, the Hawaii Audubon Society and the ISLAND ECOSYSTEMS Integrated Research Program of the US/IBP