Browsing by Subject "Hyla chrysoscelis"

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    Acoustic communication in noisy environments:Signal recognition in fluctuating backgrounds.
    (2012-04) Meléndez, Alejandro Vélez
    Following one conversation in multi-talker environments is a difficult perceptual task that we encounter frequently. How the human auditory system solves this problem has been the focus of research for decades. While many nonhuman animals also communicate in noisy social aggregations, we know very little about how they solve analogous problems. Dip listening, an ability to catch `acoustic glimpses' of target signals when the level of fluctuating backgrounds momentarily drops, represents one way by which receivers may recognize signals in noise. It has even been suggested that animals may be adapted to exploit level fluctuations of the natural soundscape (i.e., the mixture of sounds in the environment) to recognize communication signals. This hypothesis, however, is not yet supported by empirical evidence because (i) we know little about the characteristics of level fluctuations in natural soundscapes, (ii) very few studies have investigated the ability of nonhuman animals to recognize communication signals in fluctuating backgrounds, and (iii) no study has investigated signal recognition in the presence of noises with level fluctuations of natural soundscapes. I addressed these gaps in knowledge using gray treefrogs (Hyla chrysoscelis) and green treefrogs (Hyla cinerea) as model systems. I found that level fluctuations of the noise generated in social aggregations vary across species. I also show that gray treefrogs, but not green treefrogs, have an ability to listen in the dips of fluctuating backgrounds when recognizing communication signals. This ability, however, is not specifically `tuned' to exploit level fluctuations of natural soundscapes. Together, my findings offer little support for the hypothesis that receivers are adapted to exploit level fluctuations of the natural soundscape to recognize communication signals.
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    Advertisement call length preferences of female Cope's gray treefrogs (Hyla chrysoscelis) in two-alternative choice tests
    (2020-07-23) LaBarbera, Katie; Nelson, Peggy B; Bee, Mark A; klabarbe@umn.edu; LaBarbera, Katie; University of Minnesota Animal Communication Lab
    Female Hyla chrysoscelis collected from the wild during the breeding season were tested in two-alternative choice tests for their preference between two synthetic calls, modeled closely after wild male calls, differing in their call length. This experiment was designed to examine whether females exhibit proportional processing (e.g., Weber's Law) of the acoustic signal. The data are being released along with the publication based upon them.
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    Data supporting "Vocal sacs do not act as visual cues in acoustically guided courtship in Cope’s gray treefrog (Hyla chrysoscelis)"
    (2020-06-22) Li, Hongyu; Schrode, Katrina M; Bee, Mark A; mbee@umn.edu; Bee, Mark A; University of Minnesota Animal Communication Lab
    Components in multiple sensory modalities are present in many animal signals, which provides opportunities for receivers to use them as complementary cues in communication, especially in noisy environments that impose difficulty on signal perception. In frogs, it has been suspected that females use the visual byproduct of call production - the inflation of vocal sacs - as a cue in finding individual calling males in loud choruses. This mate recognition and selection behavior was traditionally considered as acoustically guided but recently there has been rising discussion on whether it was a multimodal process. We investigated whether female Cope’s gray treefrog (Hyla chrysoscelis) use visual cues in the context of sexual communication to find and select males. We performed playback experiments in a field setting under natural light using robotic frog models as visual stimuli and examined females’ responses. Acoustic stimuli were played back in quiet, in noise, and with ambiguous acoustic features. Despite the various acoustic conditions tested in a realistic lighting environment, we did not find any evidence that females use visual cues in the context of sexual communication. We review previous reports on the use of vocal sacs as visual cues in nocturnal anurans and discuss potential reasons for the stark contrast between those reports and this research.
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    Vocal sacs do not act as visual cues in acoustically guided courtship in Cope’s gray treefrog (Hyla chrysoscelis)
    (2020-06) Li, Hongyu
    Components in multiple sensory modalities are present in many animal signals, which provides opportunities for receivers to use them as complementary cues in communication, especially in noisy environments that impose difficulty on signal perception. In frogs, it has been suspected that females use the visual byproduct of call production - the inflation of vocal sacs - as a cue in finding individual calling males in loud choruses. This mate recognition and selection behavior was traditionally considered as acoustically guided but recently there has been rising discussion on whether it was a multimodal process. We investigated whether female Cope’s gray treefrog (Hyla chrysoscelis) use visual cues in the context of sexual communication to find and select males. We performed playback experiments in a field setting under natural light using robotic frog models as visual stimuli and examined females’ responses. Acoustic stimuli were played back in quiet, in noise, and with ambiguous acoustic features. Despite the various acoustic conditions tested in a realistic lighting environment, we did not find any evidence that females use visual cues in the context of sexual communication. We review previous reports on the use of vocal sacs as visual cues in nocturnal anurans and discuss potential reasons for the stark contrast between those reports and this research.