Some predators face the problem of locating and
capturing foods while at the same time avoiding
a number of environmental hazards and even
predation on themselves. These challenges can
be more extreme for some species than for others
(Raubenheimer 2010). For example, a number
the air-water interface (Thewissen & Nummela
2008). The need to function in both media imposes
2001). These animals include penguins, which also
success (Wilson 2003).
Australasian gannets (Morus serrator; hereafter
et al.et al. 2012). Diving
often occurs in multi-species-feeding associations
(MSFA) that involve high densities of marine
( et al. 2011 a, b). Gannets
et al. 2011b;
et al. 2012). We were therefore
Notornis, 2013, Vol. 60: 255-257
Received 8 Mar 2013; accepted 17 May 2013
Can gannets (Morus serrator) select their diving prole prior to
is determined prior to submergence, or whether it
phase of the dive.
of aerial video footage of gannet dive behaviour was
Lagenorhynchus obscurus) feeding
underwater housing (for more details see Vaughn et
al. 2007; 2008). The dolphin feeding bout occurred
underwater momentum of the plunge and are short
in duration were categorised as V-shaped whereas
et al. (2011b). The angle
dives in the plane perpendicular to the camera
optical axis, using the water surface as the horizontal
version 11.0.2. For statistical comparisons, data
were tested using a t- test in PAWS Statistics version
18. We report data as mean ± SD.
water for a total of 25 dives showed that during
than during V-shaped dives (53.70 ± 7.30 degrees;
t-test, t = -3.84, df = 23, P < 0.001, Fig. 1). These
before the birds had entered the water, suggesting
that gannets might predict their dive performance
the aerial phase of the plunge dive as suggested
et al. (2009). Among seabirds,
et al. 1996;
dives in gentoo penguins (Pygoscelis papua) are used
to forage in suitable habitats, whereas V-shaped
decisions that enable them to maximise the time
foraging (Aidala et al. 2012). Although gannets are
et al. 2012) that are able to see in the
et al. 2011c), it is still unclear how their
the air. Further studies are needed to understand the
in complex marine environments.
Department of Wildlife and Fisheries Sciences, Texas A&M
Marlborough District Council. D.R. and G.M.C. are
Aidala, J.; Fidler,
M. G.; Talaba,
lineages: paleognaths, parrots, and songbirds. Journal
of Comparative Physiology A 198: 495-510.
Fig. 1. Dive angles relative to the horizon during V-shaped
Australasian gannets (Morus
and error bars, which represent standard deviations.
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obscurus) feeding tactics and multi-species associations.
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Keywords seabirds; Morus serrator; dive behaviour; dive