Abstracts below
Wiley, D, C Ware, A Bocconcelli, D Cholewiak, A Friedlaender, M
Thompson & M Weinrich (2011) Underwater components of humpback
whale bubble-net feeding behaviour. Behaviour 148: 575-602.
Robillard, T & L Desutter-Grandcolas (2011) Evolution of calling
songs as multicomponent signals in crickets (Orthoptera: Grylloidea:
Eneopterinae). Behaviour 148: 627-672.
Price, JJ & DH Yuan (2011) Song-type sharing and matching in a
bird with very large song repertoires, the tropical mockingbird.
Behaviour 148: 673-689.
Abstracts:
Wiley, D, C Ware, A Bocconcelli, D Cholewiak, A Friedlaender, M
Thompson & M Weinrich (2011) Underwater components of humpback
whale bubble-net feeding behaviour. Behaviour 148: 575-602.
Humpback whales (Megaptera novaeangliae) employ a unique and
complex foraging behaviour — bubble-netting — that involves
expelling air underwater to form a vertical cylinder-ring of bubbles
around prey. We used digital suction cup tags (DTAGs) that
concurrently measure pitch, roll, heading, depth and sound (96 kHz
sampling rate), to provide the first depiction of the underwater
behaviours in which humpback whales engage during bubble-net
feeding. Body mechanics and swim paths were analysed using custom
visualization software that animates the underwater track of the
whale and quantifies tag sensor values. Bubble production was
identified aurally and through spectrographic analysis of tag audio
records. We identified two classes of behaviour (upward-spiral; 6
animals, 118 events and double-loop; 3 animals, 182 events) that
whales used to create bubble nets. Specifically, we show the actual
swim path of the whales (e.g., number of revolutions, turning rate,
depth interval of spiral), when and where in the process bubbles
were expelled and the pattern of bubble expulsion used by the
animals. Relative to other baleanopterids, bubble-netting humpbacks
demonstrate increased manoeuvrability probably aided by a unique
hydrodynamicly enhanced body form. We identified an approximately 20
m depth or depth interval limit to the use of bubble nets and
suggest that this limit is due to the physics of bubble dispersal to
which humpback whales have behaviourally adapted. All animals were
feeding with at least one untagged animal and we use our data to
speculate that reciprocity or by-product mutualism best explain
coordinated feeding behaviour in humpbacks.
Robillard, T & L Desutter-Grandcolas (2011) Evolution of calling
songs as multicomponent signals in crickets (Orthoptera: Grylloidea:
Eneopterinae). Behaviour 148: 627-672.
Calling songs of crickets are multi-component signals that serve
several purposes in the species biology. The multiple functions of
calling songs reflect the multiple selective forces shaping signal
parameters. We test several predictions about signal evolution at a
phylogenetic scale, taking into account the way signals are produced
and used. We addressed these predictions in a diverse cricket clade,
the Eneopterinae subfamily, using an independently derived
phylogeny. Acoustic analyses of the calling songs of 24 eneopterine
species permitted the definition of 35 acoustic characters
describing the spectral and temporal properties of the songs. These
characters proved informative for their phylogenetic content. Our
main conclusions were that eneopterine calling songs have evolved as
multiple independent characters (atomised evolution hypothesis),
although they partly depended on the influence of emitting
structures. They experienced a general tendency toward more
information delivered per unit time and were driven toward
equivalent temporal patterns through the combined action of
inheritance from ancestors, parallelism and character convergence.
Price, JJ & DH Yuan (2011) Song-type sharing and matching in a
bird with very large song repertoires, the tropical mockingbird.
Behaviour 148: 673-689.
Song-type matching, a behaviour of some songbirds in which one
individual replies to another's song with a matching song type, has
been studied primarily in birds that have small to moderately sized
song repertoires (<15 song types) and that share only a
few song types with neighbours. Few previous studies have examined
song-type matching in species with very large song repertoires, in
which birds can share larger numbers of songs with neighbours and
matching particular song types might be more challenging. Here we
describe frequent and rapid song-type matching in a population of
tropical mockingbirds, Mimus gilvus. Males had repertoire
sizes of about 133 distinct song types on average which were
delivered with high versatility. Territorial neighbours shared
significantly more song types than did non-neighbours, and
neighbouring males matched each other's songs frequently and often
with surprising speed. Overlapping of songs occurred at
approximately chance levels. Song-type matching in these birds could
indicate more than just aggressive intentions, which is the presumed
function of this behaviour in species with smaller repertoires. In
tropical mockingbirds, rapidly matching the songs of neighbours
could provide information to listeners about a singer's experience
or abilities.
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