(Abstracts below)
Bioacoustic papers in Behaviour 147-9
http://www.ingentaconnect.com/content/brill/beh/2010/00000147/00000009
Marquez, R, J Bosch & X Eekhout (2010) Intensity of female
preference for call source level in midwife toads Alytes cisternasii
and A. obstetricans. Behaviour 147: 1185-1199.
Digweed, SM & D Rendall (2010) Are the alarm calls of North
American red squirrels (Tamiasciurus hudsonicus) functionally
referential?
Behaviour
147: 1201-1218.
Bioacoustic papers in Behaviour 147-10
http://www.ingentaconnect.com/content/brill/beh/2010/00000147/00000010
Foote, JR, LP Fitzsimmons, DJ Mennill & LM Ratcliffe (2010)
Black-capped chickadee dawn choruses are interactive communication
networks. Behaviour
147: 1219-1248.
Bertram, SM, VLM Rook & LP Fitzsimmons (2010) Strutting their
stuff: victory displays in the spring field cricket, Gryllus
veletis. Behaviour
147: 1249-1266.
Abstracts
Marquez, Rafael, J Bosch & X Eekhout (2010) Intensity of female
preference for call source level in midwife toads Alytes cisternasii
and A. obstetricans. Behaviour 147: 1185-1199.
We address the question of whether female preference exerts
selection on male calling energy (souce level). We investigate
whether female midwife toads express a preference between
advertisement calls that have different source levels but that reach
them with similar intensities (due to differences in distance).
Females were presented with pairs of recordings of identical
synthetic calls, recorded at the same location in the field site,
and reaching the microphone at similar sound levels (69 dB peak
SPL). Stimulus 'Hi source level' was recorded two meters away from
the sound source but emitted with higher sound intensity, and
stimulus 'Low source level' was recorded one meter away from the
source but emitted with lower source level. We use a protocol of
'playback setpoints' for tests with no a priori expectations. We did
not find evidence of female preference for source level in either
species. Alytes obstetricans females reversed their choice
when differences in intensity were lower, suggesting lower
selectivity during the approach phase. We conclude that any
selection on male call intensity is unlikely to occur, possibly
being severely limited by calling location (male-female distance)
and by transmission conditions.
Digweed, SM & D Rendall (2010) Are the alarm calls of North
American red squirrels (Tamiasciurus hudsonicus) functionally
referential?
Behaviour
147: 1201-1218.
North American red squirrels are a small-bodied and solitary-living
species that faces a diversity of predators and produces two
different variants of alarm calls in response to them. Recent
studies have yielded conflicting interpretations of the
predator-specific and functionally referential nature of these alarm
call variants. We undertook a systematic set of playback experiments
to quantify the responses of red squirrels to alarm calls produced
by other squirrels during encounters with different predators. The
experiment was designed to test a core requirement of functionally
referential alarm calls, namely that different alarm call types
induce distinct and functionally appropriate escape responses in
listeners. Results indicated that squirrels registered and responded
to alarm calls produced by others; however, their responses were not
differentiated according to the type of alarm call they heard and,
thus, did not provide evidence that the different alarm call
variants hold any predator-specific, referential value. These
outcomes are discussed in light of complementary work on alarm call
production in red squirrels and broader aspects of this species'
life history in an effort to better understand the necessary and
sufficient pressures promoting the evolution of referential call
systems in animals.
Foote, JR, LP Fitzsimmons, DJ Mennill & LM Ratcliffe (2010)
Black-capped chickadee dawn choruses are interactive communication
networks. Behaviour
147: 1219-1248.
The dawn chorus of songbirds provides an ideal opportunity to study
communication networks because multiple singers are within
signalling range of each other, permitting eavesdropping by both
males and females. Using an Acoustic Location System, we examined
the dawn chorus singing behaviour of male black-capped chickadees (Poecile
atricapillus) in 15 neighbourhoods to determine whether
singing behaviour is consistent with the communication network
model. We calculated levels of frequency matching for 19 focal males
and all of their neighbours. The observed level of frequency
matching was greater than expected by chance. All males were
involved in multi-way matching at dawn and often matched two or
three neighbours simultaneously. The identity of individuals
involved in three-way matches was related to both previous
winter-flock membership and the relative dominance rank of the
interacting males. We show that male black-capped chickadee dawn
choruses are interactive communication networks where males are
involved in high levels of matching with neighbours, and they match
multiple individuals both simultaneously and sequentially.
Additionally, the existence of multi-way matching and the identities
of individuals involved suggest that individual males may eavesdrop
at dawn. This is the first study to quantify network communication
during the dawn chorus in multiple neighbourhoods.
Bertram, SM, VLM Rook & LP Fitzsimmons (2010) Strutting their
stuff: victory displays in the spring field cricket, Gryllus
veletis. Behaviour
147: 1249-1266.
Contest winners may perform victory displays at the conclusion of
agonistic contests. Victory displays are hypothesized to function in
browbeating or advertisement. To date, victory displays have
received little attention. Following agonistic contests, several
field cricket species produce aggressive songs and shake their body
forwards and backwards (body jerks). We examined 20 agonistic
contests between field-captured adult male spring field crickets, Gryllus
veletis. We characterized the aggressive songs and body jerks
that occurred both during and immediately following conflicts to
evaluate whether these behaviours should be classified as victory
displays. Aggressive songs and body jerks were observed throughout
the contests, not just immediately following the conclusion of the
fight. Winner aggressive song and body jerk rates were higher during
the post-conflict period than during the fight period. Further,
while both winners and losers performed aggressive songs and body
jerks, winners performed them at five times the rate of the losers
during the post-conflict period. We conclude that aggressive songs
and body jerks should be considered victory displays, and that these
victory displays may function as both browbeating and advertisement.
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