共查询到20条相似文献,搜索用时 567 毫秒
1.
Many mammals warn conspecifics with alarm calls about detected predators. These alarm calls are either functionally referential,
urgency based, or they can have multiple functions, including predator deterrence. The taxonomic distribution of these alarm
call systems is uneven, with primates providing the best-known examples for a functionally referential system and rodents
most examples of an urgency-based system. Reports of different alarm call systems in lemurid primates prompted us to examine
the anti-predator behavior of two additional lemur species. In an experimental field study we exposed adult redfronted lemurs
(Eulemur fulvus rufus) and white sifakas (Propithecus verreauxi verreauxi) to playbacks of vocalizations of their main aerial and terrestrial predators, as well as to their own alarm calls given
in response to the presentation of these predators. We scored the subjects' immediate behavioral responses, including alarm
calls, from video recordings made during the first minute following a playback. We found that both species gave specific alarm
calls only in response to raptor playbacks and the corresponding alarm calls, whereas calls given in response to carnivores
and the corresponding alarm calls were also observed in other situations characterized by high arousal. Other behavioral responses,
such as gaze and escape directions, corresponded to the hunting strategies of the two predator classes, suggesting that the
corresponding vocalizations were categorized correctly. These two lemur species, which represent different families, have
therefore independently evolved a mixed alarm call system, characterized by functionally referential calls for diurnal raptors,
but not for carnivores. Electronic supplementary material to this paper can be obtained by using the Springer LINK server
located at http://dx.doi.org/10.1007/s00265-001-0436-0
Electronic Publication 相似文献
2.
Kate Arnold Yvonne Pohlner Klaus Zuberbühler 《Behavioral ecology and sociobiology》2008,62(4):549-559
Some non-human primates produce acoustically distinct alarm calls to different predators, such as eagles or leopards. Recipients
respond to these calls as if they have seen the actual predator, which has led to the notion of functionally referential alarm
calls. However, in a previous study with free-ranging putty-nosed monkeys (Cercopithecus nictitans martini), we demonstrated that callers produced two acoustically distinct alarm calls to eagle shrieks and leopard growls, but both
alarm calls were given to both predators. We can think of two basic explanations for this surprising result, a methodological
and theoretical one. Firstly, acoustic predator models may not always be suitable to test alarm call behaviour in primates,
sometimes causing uncharacteristic behaviour. Secondly, referential alarm calling may not be a universal feature of primate
alarm call systems. Considering the methodological and theoretical importance of these possibilities, we conducted a follow-up
study using life-sized leopard, eagle, and human models on the same population and compared the resulting vocal responses
to those given to acoustic predator models. We compared the alarm call series given to each of these predator model types
and found a considerable degree of consistency suggesting that the mode of presentation did not affect anti-predator calling
strategies. However, evidence for audience effects on calling behaviour was inconclusive. While it appears that predator class
is reliably encoded by different call series types irrespective of the mode of presentation, observations of these same call
series given in non-predatory contexts indicate that predator class is unlikely to be the relevant organising principle underlying
the alarm-calling behaviour in this species. We conclude by offering an alternative, non-referential, account of the alarm-calling
system exhibited by this species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
Chick-a-dee calls function in social organization in Poecile (chickadee) species. Recent field and aviary studies have found that variation in chick-a-dee calls relates to the type or
proximity of avian predator, or level of threat. Earlier studies on calls in the context of predator stimuli have typically
used stationary and perched predator models. For chickadees and other small songbirds, more frequently detected and more dangerous
avian predatory stimuli are flying predators. In the present study, we tested whether simulated flying avian predator and
control models influenced chick-a-dee calling behavior of wild Carolina chickadees, Poecile carolinensis. At 20 independent field sites, chickadee subjects were presented with wooden models that were painted to resemble either
a predatory sharp-shinned hawk (Accipiter striatus) or a blue jay (Cyanocitta cristata) and that were made to “fly” down a zip line near a feeding station chickadees were using. The note composition of chick-a-dee
calls was affected by both the flight of stimuli and type of model. Call variation in this flying predator context suggests
interesting similarities and differences with experimental findings with congeners. Finally, increased production of certain
notes to the flying of both model types provides support for a “Better Safe than Sorry” strategy. When costs of alarm calling
are low but costs of discriminating potentially serious threats may be extremely high, individuals should err on the side
of caution, and alarm call to any potentially threatening stimulus. 相似文献
4.
Field observations and model-presentation experiments have shown that yellow warblers (Dendroica petechia) produce seet calls preferentially in response to brood-parasitic brown-headed cowbirds (Molothrus ater). In this study, we investigated whether seet calls are functionally referential alarm calls denoting cowbirds by determining whether female warblers responded appropriately to seet calls in the absence of a cowbird, whether alarm calling by warblers varied with response urgency, and how warblers in a population allopatric with cowbirds responded to cowbird and avian predator models and seet playbacks. As a control, we presented chip calls, which are elicited by nest predators as well as by non-threatening intruders, but are not strongly associated with cowbirds. Yellow warblers responded differently to playbacks of seet than chip calls. To seet playbacks, almost 60% of females gave seet calls and rushed to sit in their nests, responses typically elicited by cowbirds, whereas these responses were given infrequently in response to chip calls. Yellow warblers seet called equally in situations that simulated low, medium and high risk of parasitism, which suggests that these calls did not vary with response urgency. In a population allopatric with cowbirds, seet calls were rarely produced in response to cowbird or avian nest predator models and never to seet playbacks. These results suggest that seet calls are functionally referential signals denoting cowbirds and that cowbird parasitism was a strong selective pressure in the evolution of functional referentiality in the seet call of yellow warblers.Communicated by W.A. Searcy 相似文献
5.
Julia Bartmess-LeVasseur Carrie L. Branch Sheri A. Browning Jessica L. Owens Todd M. Freeberg 《Behavioral ecology and sociobiology》2010,64(7):1187-1198
Evidence from different chickadee species (Poecile genus) indicates that birds can modify the note composition of their “chick-a-dee” calls in the presence of predator stimuli.
Here, we tested the effects of predator models and the distance of those models on calls of three species foraging together
at feeding stations: Carolina chickadees (Poecile carolinensis) and tufted titmice (Baeolophus bicolor), both members of the Paridae family, and white-breasted nuthatches (Sitta carolinensis), a member of the Sittidae family. Model and distance affected seed-taking rates in all three species. “Chick-a-dee” calling
rates were higher in the predator context for both chickadees and titmice, but we detected no predator context effects on
“quank” call rates for nuthatches. Predator and distance contexts affected acoustic parameters of notes of the “chick-a-dee”
calls of chickadees and titmice; no such effects were detected for nuthatch “quank” calls. These results suggest species differences
in encoding of information in the primary social calls of these three species that commonly occur in multi-species flocks.
Chickadees and titmice are “nuclear” species and nuthatches are “satellite” species, and these different roles might be related
to the differences in vocal signaling that we detected. 相似文献
6.
Klaus Zuberbühler 《Behavioral ecology and sociobiology》2001,50(5):414-422
One of the most prominent behavioural features of many forest primates are the loud calls given by the adult males. Early observational studies repeatedly postulated that these calls function in intragroup spacing or intergroup avoidance. More recent field experiments with Diana monkeys (Cercopithecus diana) of Taï Forest, Ivory Coast, have clearly shown that loud male calls function as predator alarm calls because calls reliably (1) label different predator classes and (2) convey semantic information about the predator type present. Here, I test the alarm call hypothesis another primate, the Campbell's monkey (C. campbelli). Like Diana monkeys, male Campbell's monkeys produce conspicuous loud calls to crowned hawk eagles (Stephanoaetus coronatus) and leopards (Panthera pardus), two of their main predators. Playback experiments showed that monkeys responded to the predator category represented by the different playback stimuli, regardless of whether they consisted of (1) vocalisations of the actual predators (crowned hawk eagle shrieks or leopard growls), (2) alarm calls to crowned hawk eagles or leopards given by other male Campbell's monkeys or (3) alarm calls to crowned hawk eagles or leopards given by sympatric male Diana monkeys. These experiments provide further evidence that non-human primates have evolved the cognitive capacity to produce and respond to referential labels for external events. 相似文献
7.
Intensive study of arboreal forest-dwelling primates and their predators in Africa is increasingly revealing that crowned
eagles (Stephanoaetus coronatus) are major predators of primates. Gray-cheeked mangabeys (Lophocebus albigena) are overrepresented in the diets of crowned eagles in Kibale National Park, Uganda, and adult male mangabeys are represented
more than females. We focused on the behavior of adult male gray-cheeked mangabeys living in social groups in Kibale National
Park (1) to clarify the interactions between mangabeys and eagles that might put adult males at greater risk and (2) to better
understand individual variation in behavioral responses to predators. Adult male mangabeys in five groups responded to observer-confirmed
presence of crowned eagles 88 times over a 13-month period. While all males gave alarm calls, only the highest-ranking male
in each of four groups chased eagles. These males had elevated levels of fecal cortisol metabolites in the days immediately
after they engaged in active defense, suggesting that they perceived such behavior as risky. In the one group where male ranks
were unstable and there were no infants, no male was observed to chase eagles. We suggest that males pursue the dangerous
tactic of chasing eagles only when they are likely to have offspring in the group. Males in larger groups also spent less
time alarm calling to crowned eagles (from first to last call in a group), and our observations confirmed that the duration
of their alarm calls was related to eagle presence. Thus, eagles spent less time around larger mangabey groups. Alarm calling
by adult male mangabeys may signal to this ambush predator that it has been detected and should move on. 相似文献
8.
Linda I. Hollén Tim Clutton-Brock Marta B. Manser 《Behavioral ecology and sociobiology》2008,62(5):821-829
In many species, individuals suffer major mortality in their first year because of predation. Behaviours that facilitate successful
escape are therefore under strong selection, but anti-predator skills often emerge gradually during an individual’s early
development. Using long-term data and acoustic recordings of alarm calls collected during natural predator encounters, we
aimed to elucidate two largely unsolved issues in anti-predator ontogeny: (1) whether incorrect predator assignment is adaptively
age-appropriate, given that vulnerability often changes during development, or whether age-related differences reflect true
mistakes made by immature individuals; and (2) the extent to which the development of adult-like competence in alarm-call
production and usage is simply a function of maturational processes or dependent upon experience. We found that young meerkats
(Suricata suricatta) were less likely to give alarm calls than adults, but alarmed more in response to non-threatening species compared to adults.
However, stimuli that pose a greater threat to young than adults did not elicit more calling from young; this argues against
age-related changes in vulnerability as the sole explanation for developmental changes in calling. Young in small groups,
who were more likely to watch out for predators, alarmed more than less vigilant young in larger groups. Moreover, despite
similarities in acoustic structure between alarm call types, calls appeared in the repertoire at different rates, and those
that were associated with frequently encountered predators were produced relatively early on. These results indicate that
experience is a more plausible explanation for such developmental trajectories than maturation. 相似文献
9.
Diana monkeys produce acoustically distinct calls to a number of external events, including different types of predators. In a previous study, we found population-wide differences in male alarm call production in Taï Forest, Ivory Coast, and on Tiwai Island, Sierra Leone, mostly likely originating from differences in predator experience. In Taï Forest, leopards (Panthera pardus) are common but on Tiwai Island they have been absent for decades, while the predation pressure from crowned eagles (Stephanoaetus coronatus) has been similar. To further evaluate the impact of predator experience, we here analyse the vocal behaviour of female Diana monkeys in both habitats. Female Diana monkeys produce predator-specific alarm calls, alert calls and contact calls in response to predators, suggesting that their calls serve in a broader range of functions compared to males. Results showed that females produced the same call types at both sites, despite the differences in predator fauna. Regarding call usage, leopard alarm calls were extremely rare on Tiwai Island, but not in Taï Forest, whereas we found no differences in eagle alarm call production. When comparing response latencies, Tiwai females were slower to respond to both predators compared to Taï females. Finally, we found no habitat-specific acoustic differences in the alert and predator-specific alarm calls, but significant differences in frequency-based parameters of contact calls. Overall, our results suggest that ontogenetic experience can affect primate vocal behaviour in both usage and acoustic structure but that the way in which particular call types are affected may be closely linked to function. 相似文献
10.
Black-capped chickadees Poecile atricapillus alter the number of D notes of their chick-a-dee call to reflect urgency and threat. Here, I tested whether heterospecific
responses of an allopatric species to these mobbing calls occur. Heterospecific chickadee mobbing calls and songs from North
America were broadcast to European great tits (Parus major) and compared with conspecific mobbing calls. During conspecific mobbing playbacks, all great tits approached the speaker,
during the heterospecific “chick-a-dee” playbacks, 63.3% individuals approached the speaker, while during the song playback,
only 31.3% of the great tits approached the speaker. Minimum distances of great tits were lower during conspecific mobbing
calls compared to allopatric chick-a-dee calls and to allopatric chickadee song. Also, minimum distances were lower when comparing
allopatric chick-a-dee calls and chickadee song. Great tits approached the speaker on average down to (mean ± SE) 20.0 ± 1.8 m
during playbacks of 1–4 D elements, to 17.7 ± 2.0 m during playbacks of 5–7 D elements and down to 11.5 ± 2.0 m during playbacks
of 8–11 D elements. The number of D notes was inversely related to minimum distance. Thus, the urgency message encoded in
the D notes was perceived also by an allopatric but phylogenetically related European species, suggesting that the heterospecific
response is possibly phylogenetically conserved. 相似文献
11.
Facultative traits that have evolved under sexual selection, such as the acoustic ornaments present in the advertisement signals
of male túngara frogs (Physalaemus pustulosus), offer a unique opportunity to examine selection for trait exaggeration with a focus on individual differences amongst signalers.
By contrast, many studies of mate choice use experimental designs that obscure the inter-individual variation amongst signalers
available for selection to act on—through the use of “typical” or average signals from the population. Here, we use dichotomous
female phonotaxis choice tests to determine how the value of male call embellishment varies across 20 individual males frogs
recorded from the wild—a sample which captures the acoustic diversity present in the population. We tested 20 females for
each male call pair (i.e., 400 females). The results show widespread preference amongst females for ornamented calls (“whine–chucks”)
over simple calls (“whines”), yet also demonstrate substantial variation in the relative benefits for individual male frogs—some
males enjoy appreciable benefits by using ornaments while others (30% of males in this study) do not. We also show that the
relative amplitude of the chuck to the whine correlates positively with the value of call elaborations across these 20 males.
Finally, by manipulating the relative amplitude of whines and chucks using both natural and synthetic calls, we demonstrate
directly that this single call parameter is key to determining the relative value of call elaborations across males. 相似文献
12.
Summary The vocal behavior of Hyla versicolor was studied in the field by means of behavioral observations and playback experiments, and these data were coupled with measurements of oxygen consumption in calling frogs to estimate the effect of social interactions on calling energetics. Male gray treefrogs have intense calls (median peak SPL=109 dB, fast RMS SPL=100 dB at 50 cm). At an air temperature of 23° C, males produced an average of 1,200–1,300 calls/h for 2–4 h per night. Calling rates and call durations differed among individuals, but were relatively constant for each male during periods of sustained calling. Males in dense choruses gave calls about twice as long as isolated males, but produced calls at about half the rate. Consequently, total calling effort and estimated aerobic costs were largely independent of chorus density. Playbacks of recorded calls to males in the field elicited increases in call duration and decreases in calling rate, regardless of the rate or duration of the stimulus. Males gave longer calls in response to long calls or to stimuli presented at high rates, but they did not precisely match either stimulus rate or duration. Calling effort and estimated oxygen consumption changed only slightly during stimulus playbacks. These results indicate that male-male competition elicits pro-found changes in the vocal behavior of calling males, but these changes have little effect on energy expenditure. We estimated that most calling males had metabolic rates of about 1.7–1.8 ml O2/(g\h), or about 280 J/h for an average size (8.6 g) male at 20° C. Although changes in call duration and calling rate did not affect aerobic costs of calling, males producing long calls at slow rates called for fewer hours per night than males producing shorter calls at higher rates. This suggests that calling time may be limited by the rate at which muscle glycogen reserves are depleted. 相似文献
13.
Summary Auditory tuning curves of a small songbird, the great tit (Parus major), and of its principal avian predator, the European sparrowhawk (Accipiter nisus), were determined by an operant positive reinforcement conditioning procedure, using the method of constant stimuli. Thresholds were measured by the criterion of a 50% correct response and a d of 1.5 for intra- and interspecific comparison, respectively. The best frequency of both species was 2 kHz, the hawk being 6.5 dB SPL more sensitive than the tit. Although the high-frequency cutoff was very similar in both species, at 8 kHz the great tit was about 30 dB more sensitive than the sparrowhawk. The hearing abilities of the prey and its predator are discussed with reference to the acoustic alarm communication of great tits confronted with sparrowhawks. Two alarm calls lie in the frequency range of the best hearing of both the hawk and the tits: the mobbing call and a call given in response to a nearby hawk when fleeing from it. In contrast, the seeet call, an alarm call given mainly in response to distant flying sparrowhawks, can only be heard well by the tit. The implications of these results for hypotheses concerning the evolution of alarm calls in small songbirds are discussed. 相似文献
14.
Advertisement call duration indicates good genes for offspring feeding rate in gray tree frogs (Hyla versicolor) 总被引:2,自引:0,他引:2
Indicator or ”good genes” models of sexual selection predict that mating preferences allow females to choose mates that are
genetically superior. Female gray tree frogs (Hyla versicolor) prefer male advertisement calls of long call duration, which can be indicators of enhanced offspring growth performance.
We tested the effects of father’s call duration and the presence of a caged predator (dragonfly naiad) on tadpole activity
and growth in a factorial experiment, controlling for maternal and environmental effects. The effect of food availability
(a repeated measure) on tadpole activity was also examined. Tadpoles responded to predator presence and to high food availability
by decreasing activity and feeding. Tadpoles exposed to a caged predator were smaller after 14 days than those exposed to
an empty cage, suggesting that spending less time feeding carries the cost of reduced growth. Offspring of males with long
versus short calls responded similarly to the presence of a predator. Nonetheless, offspring of long-calling males spent more
time feeding than did offspring of short-calling males, except when a predator was present but no food was available. Increased
time spent feeding may contribute to enhanced offspring growth and, therefore, to the indirect benefit that a female may realize
by selecting a mate with long calls. However, because the behavioral differences depended on the environment, and because
the fitness consequences of such behavioral differences should also vary with the environment, the benefit of mating with
a long-calling male may depend on the conditions encountered by the offspring.
Received: 15 February 2000 / Revised: 24 September 2000 / Accepted: 16 October 2000 相似文献
15.
Michael S. Reichert 《Behavioral ecology and sociobiology》2010,64(4):529-539
Males in many chorusing anuran species use aggressive calls during defense of calling spaces from other males. The minimal
intensity of another male’s vocalizations that elicits an aggressive call response has been termed the aggressive threshold.
Previous studies of aggressive thresholds have shown that they are plastic: males habituated (increased their aggressive thresholds)
in response to repeated presentation of stimuli above initial threshold levels. Habituation likely contributes to the stable
chorus structure of these species, in which aggressive calling is rare compared to advertisement calls. I have observed high
levels of aggressive calling in the treefrog Dendropsophus ebraccatus, suggesting that males of this species do not habituate. In this study, I investigated the plasticity of aggressive thresholds
in D. ebraccatus. I measured the aggressive thresholds of males before and after suprathreshold stimulation by both advertisement and aggressive
calls. I found that the different call types had different effects: males habituated to advertisement calls but lowered their
aggressive thresholds in response to aggressive calls. I consider the latter response to be an example of sensitization, a
behavior that has been documented infrequently in vocalizing anurans. Sensitization is a plausible mechanism responsible for
the high levels of aggressive calling observed in this species. Given the high costs of aggressive calling, however, it is
unclear why a mechanism that increases aggressive call output would be maintained. 相似文献
16.
Pierrick Blanchard Rodolphe Sabatier Hervé Fritz 《Behavioral ecology and sociobiology》2008,62(12):1863-1868
Theory predicts that individuals at the periphery of a group should be at higher risk than their more central conspecifics
since they would be the first to be encountered by an approaching terrestrial predator. As a result, it is expected that peripheral
individuals display higher vigilance levels. However, the role of conspecifics in this “edge effect” may have been previously
overlooked, and taking into account the possible role of within-group competition is needed. Vigilance behavior in relation
to within-group spatial position was studied in impalas (Aepyceros melampus) feeding on standardized patches. We also controlled for food distribution in order to accurately define a “central” as opposed
to a “peripheral” position. Our data clearly supported an edge effect, with peripheral individuals spending more time vigilant
than their central conspecifics. Data on social interactions suggest that it was easier for a foraging individual to defend
its feeding patch with its head lowered, and that more interactions occurred at the center of the group. Together, these results
indicate that central foragers may reduce their vigilance rates in response to increased competition. Disentangling how the
effects of competition and predation risk contribute to the edge effect requires further investigations. 相似文献
17.
Summary The responses of individually marked pikas (Ochotona princeps) to terrestrial predators were investigated in 1980 and 1981 in the Rocky Mountains of Colorado. Pikas uttered short call vocalizations in a variety of contexts: preceding or following an individual's movement, and in response to conspecifics, other nonpredaceous mammals and predators. Adult pikas apparently discriminated contexts in which predators were present by short calling more frequently and for longer duration compared with calling in nonpredator contexts. Short calls uttered by juveniles were similar in all contexts.Adults responded differently to two types of terrestrial predators: weasels and pine martens. Pikas called less frequently in response to weasels than to martens and avoided weasels more often than martens. They delayed the initiation of calling following the first sighting of a weasel more often than to martens. Weasels were determined to be more effective predators of pikas than martens, and these asymmetries in behavior and alarm vocalizations may indicate that responses reduce an individual's risk of predaton by weasels.Both male and female pikas called in response to predators, and residents called more often than nonresidents. The possible function of predator-related vocalization in pikas is discussed. It is suggested that calls to predators may function to warn local residents, which in pikas are usually closely related. 相似文献
18.
Females across many taxa commonly use multiple or complex traits to choose mates. However, the functional significance of
multiple or complex signals remains controversial and largely unknown. Different elements of multiple or complex signals may
convey independent pieces of information about different aspects of a prospective mate (the “multiple messages” hypothesis).
Alternatively, multiple or complex signals could provide redundant information about the same aspect of a prospective mate
(the “redundant” or “back-up” signal hypothesis). We investigated these alternatives using spadefoot toads, Scaphiopus couchii. Spadefoot toads primarily use calls to attract their mates, but males also exhibit sexually dimorphic coloration. We investigated
whether male coloration is indicative of male size, condition, or infection status by a socially transmitted monogenean flatworm.
We found that male coloration and dorsal patterning predicts male size and condition but not infection status. Moreover, when
we presented females with a choice between a bright male model and a dark male model, we found that females preferred the
bright model. Because aspects of males’ calls are also associated with male size and condition, we conclude that coloration
is a potentially redundant indicator of male phenotype. We suggest that coloration could enhance mate choice in conjunction
with male calling behavior by providing females with a long distance cue that could enable them to identify prospective mates
in a noisy chorus environment where the discrimination of individual calls is often difficult. Generally, such redundant signals
may facilitate mate choice by enhancing the quality and accuracy of information females receive regarding prospective mates. 相似文献
19.
Daniel T. Blumstein Louise Cooley Jamie Winternitz Janice C. Daniel 《Behavioral ecology and sociobiology》2008,62(3):457-468
We conducted four experiments to determine whether yellow-bellied marmots, Marmota flaviventris, discriminate among predator vocalizations, and if so, whether the recognition mechanism is learned or experience-independent.
First, we broadcast to marmots the social sounds of coyotes, Canis latrans, wolves, Canis lupus, and golden eagles, Aquila chrysaetos, as well as conspecific alarm calls. Coyotes and eagles are extant predators at our study site, while wolves have been absent
since the mid-1930s. In three follow-up experiments, we reversed the eagle call and presented marmots with forward and reverse
calls to control for response to general properties of call structure rather than those specifically associated with eagles,
we tested for novelty by comparing responses to familiar and unfamiliar birds, and we tested for the duration of predator
sounds by comparing a wolf howl (that was much longer than the coyote in the first experiment) with a long coyote howl of
equal duration to the original wolf. Marmots suppressed foraging and increased looking most after presentation of the conspecific
alarm call and least after that of the coyote in the first experiment, with moderate responses to wolf and eagle calls. Marmots
responded more to the forward eagle call than the reverse call, a finding consistent with a recognition template. Marmots
did not differentiate vocalizations from the novel and familiar birds, suggesting that novelty itself did not explain our
results. Furthermore, marmots did not differentiate between a wolf howl and a coyote howl of equal duration, suggesting that
the duration of the vocalizations played a role in the marmots’ response. Our results show that marmots may respond to predators
based solely on acoustic stimuli. The response to currently novel wolf calls suggests that they have an experience-independent
ability to identify certain predators acoustically. Marmots’ response to predator vocalizations is not unexpected because
25 of 30 species in which acoustic predator discrimination has been studied have a demonstrated ability to respond selectively
to cues from their predators. 相似文献
20.
Size assessment in simulated territorial encounters between male green frogs (Rana clamitans) 总被引:2,自引:0,他引:2
Mark A. Bee Stephen A. Perrill Patrick C. Owen 《Behavioral ecology and sociobiology》1999,45(3-4):177-184
We examined the ability of male green frogs to assess the size of an opponent based on the dominant frequency of their advertisement
call, which is negatively correlated with size, using synthetic stimuli to simulate intruders of different sizes. In one field
playback experiment, we broadcast a pair of stimuli representing a small and a large male; in a second experiment, we broadcast
calls of a medium and a large male. In both experiments, males produced calls with significantly lower dominant frequencies
in response to each stimulus. Contrast analyses revealed that males lowered the dominant frequency of their calls more in
response to the large-male stimulus than in responses to the small- and medium-male stimuli. In the second experiment, males
also responded to the large-male stimulus by calling at higher rates. There were no differences in mean note duration or the
number of moves made toward or around the playback speaker in response to any stimulus. Thus, the frequency of an opponent's
calls elicits a differential modification of calling behavior, primarily in the form of differential dominant frequency alteration,
suggesting that males use dominant frequency to assess the size of opponents during aggressive encounters.
Received: 17 April 1998 / Accepted after revision: 7 October 1998 相似文献