Minke whale (Balaenoptera acutorostrata) and white-beaked dolphin (Lagenorhynchus albirostris) feeding behaviour in Faxaflói bay, south-west Iceland

• Main Author: Bertulli, Chiara Giulia
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2010
• Subjects: Líffræði; Hnýðingur; Hrefna; Fæðuöflun dýra; Faxaflói; Garður; Balaenoptera acutorostrata; Iceland; Lagenorhynchus albirostris; minke whale; White-beaked dolphin
• Online Access: http://hdl.handle.net/1946/6216

Faxaflói bay is known to be exploited by migratory species such as minke whales (Balaenoptera acutorostrata) and white-beaked dolphins (Lagenorhynchus albirostris) which are however resident in Icelandic waters. The aim of this study was to examine feeding behaviour utilized by both species and their feeding association with seabird species. There seem to be preferable feeding grounds for B. acutorostrata and L. albirostris in Faxaflói bay, located approximately 10-12 nm west from Kollafjörður and the Garður area where both species were sighted especially during spring months. Minke whales display a wide range of well-known engulfment and entrapment feeding manoeuvres, although the first where more easily observed (2008: n=137; 2009: n=132). Additionally, a novel feeding manoeuvre termed ‘sharking’ was first time described in 2008 (1.5%, n=2) whose occurrence increase in 2009 (7.6%, n=10). L. albirostris foraging behaviour (2008: n=39; 2009: n=23) was found to be composed of a wide range of aerial behaviours among which most common were ‘noisy leaps’ (i.e. leaping, breaching, back-breaching, tail-slapping). L. albirostris foraging behaviour was primarily observed in multi-species groups of all occurring in particular in presence of humpback whales (2008-2009: 30%, n=7, <5m) and minke whales (2008-2009: 13%, n=3, <100m). Significant correlations were found for minke whales and white-beaked dolphins recorded in association with different seabird species during feeding bouts. Last, the first minke whales ID-Catalogue was established in the area counting 311 identifiable individuals. In all 245 white-beaked dolphins were also identified. Both species showed a low re-sighting rate (Ba: 14.5%; La: 11.4%). Faxaflói er nýttur af hvaltegundunum hrefnu (Balaenoptera acutorostrata) og hnýðingi (Lagenorhynchus albirostris), en síðarnefnda tegundin er líklega er staðbundin á Íslandsmiðum. Markmið rannsóknanna var að kanna fæðuatferli hrefnu og hnýðings, og tengsl fæðuatferlis þeirra við útbreiðslu og fæðuatferli ...