Bioacoustic Papers in Behaviour 148: 9-10.
(Abstracts below)
Fitzsimmons, LP & SM Bertram (2011) The calling songs of male
spring field crickets (Gryllus veletis) change as males age.
Behaviour 148: 1045-1065.
Morrison, EB (2011) Vigilance behavior of a tropical bird in
response to indirect and direct cues of predation risk. Behaviour
148: 1067-1085.
Sandoval, L (2011) Malemale vocal interactions in a territorial
neotropical quail: which song characteristics predict a territorial
male's response? Behaviour 148: 1103-1120.
Abstracts
Fitzsimmons, LP & SM Bertram (2011) The calling songs of male
spring field crickets (Gryllus veletis) change as males age.
Behaviour 148: 1045-1065.
Sexual traits are typically thought to convey information about a
male's quality or condition. Female preference for older males has
been documented in many taxa, but the evidence that males signal
their age is inconclusive. We investigated lifetime patterns of
acoustic mate attraction signalling in a longitudinal study of the
spring field cricket, Gryllus veletis. We recorded males
continuously throughout their lives, such that every pulse of sound
produced by every male was analyzed. Our study answers two main
questions: (1) Do calls change as males age? Our results reveal that
the calls of male spring field crickets change with age; the calls
of older males were quieter, with more silent periods within and
between chirps, and produced less often than those of younger males.
As males aged most of the changes in call structure reflect
decreased calling effort. (2) What is the relationship between
calling effort and longevity? Lifetime calling effort was positively
related to longevity, such that males that called the most over
their life also lived longer than males that called less. Together,
our findings provide the most thorough exploration of lifetime
signalling patterns in crickets to date.
Morrison, EB (2011) Vigilance behavior of a tropical bird in
response to indirect and direct cues of predation risk. Behaviour
148: 1067-1085.
Animals use a variety of cues to evaluate their risk of predation
when foraging, including direct cues of predator presence such as
vocalizations or scent, and indirect cues, or environmental
correlates of predation risk, such as vegetation structure. Research
took place in a large-scale forest restoration experiment where
habitat patches of different sizes were planted. I examined the
effects of predator vocalizations (direct cues) on the vigilance
behavior of Cherrie's Tanagers (Ramphocelus costaricensis)
foraging in three different locations with varying amounts of
vegetation cover (indirect cues): small patches and the centers and
edges of large patches. Results show that the indirect cue of
predation risk mediated birds' response to the direct cue. The
increase in time birds spent alert in response to the predator call
was significantly greater in the presumably riskier small patches
and large patch edges compared to the relatively safe large patch
centers. The increase in frequency of head-turns also was
significantly greater in small patches compared to the large patch
centers in response to the predator call. Although birds recognized
the threat of the predator call and reacted by fleeing more quickly
than after the non-predator call, this response did not differ
between locations. Birds appeared to integrate information from both
types of cues to evaluate their predation risk and determine their
vigilance response. Individuals responded more strongly to the
direct cue of predation risk when foraging in the presumably riskier
smaller patches and large patch edges by increasing vigilance. These
results highlight the importance of investigating behavioral
responses to the characteristics of forest restoration sites, many
of which consist of small patches of habitat.
Sandoval, L (2011) Malemale vocal interactions in a territorial
neotropical quail: which song characteristics predict a territorial
male's response? Behaviour 148: 1103-1120.
Males singing within their territories can change their song
characteristics in order to interact with conspecifics; males may
respond to territorial intrusions by vocalizing, approaching the
intruder and/or displaying. I studied male-male interactions by
quantifying vocal and behavioural responses of male spot-bellied
bobwhites (Colinus leucopogon) toward playback of conspecific
male songs. Male responses toward playback song depended on the
quality of the territorial male's song relative to the playback
stimulus. In this species males who sang songs with higher peak and
low frequency, longer song duration, and lower song rate were less
responsive to simulated territorial intrusions. Spot-bellied
bobwhite males that sang in response to the playback increased the
low frequencies of their songs relative to pre-playback song, a
vocal behaviour related to dominance in males of other species.
Males that approached the speaker sang longer songs, a
characteristic associated with increased aggression or motivation to
fight in other bird species. The results of this playback experiment
suggest that male spot-bellied bobwhite song characteristics
according to playback characteristics predict response to
territorial intrusions and may, therefore, play an important role in
male-male interactions.
|
|