Rn. Holdaway et Th. Worthy, DIET AND BIOLOGY OF THE LAUGHING OWL SCELOGLAUX-ALBIFACIES (AVES, STRIGIDAE) ON TAKAKA HILL, NELSON, NEW-ZEALAND, Journal of zoology, 239, 1996, pp. 545-572
The faunal composition of two Holocene fossil deposits of small verteb
rates provided new information on the diet and biology of Sceloglaux a
lbifacies, a strigid owl endemic to New Zealand. The taxonomic composi
tion and several measures of diversity of the prey accumulation are gi
ven. Most taxa in the deposit had a mass of 50-150 g, but species up t
o 400 g were also present. The owl was a generalist feeder, but the pr
ey biomass distribution showed that a few taxa provided most of its en
ergy requirements. Changes in the diet appeared to coincide with the a
ppearance of Rattus exulans, the Polynesian rat, and the consequent de
cline or extinction of several prey. The ecologies of extant taxa repr
esented in the deposit suggest that the owl was primarily a nocturnal
forest species. Many prey taxa were terrestrial. Species richness was
higher for both diurnal (by 50%) and nocturnal (by 63%) vertebrates in
the deposit than in the present fauna around the site. Analysis of po
ssible guilds in the pre-human and present faunas of Takaka Hill sugge
sts that ground-frequenting taxa were most severely affected by extinc
tions; three guilds vanished entirely.