Kentwood Wells | University of Connecticut (original) (raw)

Papers by Kentwood Wells

The Magic Lantern Gazette Research Supplement no. 4, 2024

The Reproductive Biology of Amphibians

Frogs were once thought to have relatively uninteresting social behavior, but recent studies on t... more Frogs were once thought to have relatively uninteresting social behavior, but recent studies on tropical and temperate zone species have revealed a surprising diversity of social systems. There is a growing literature on anuran mating systems, aggression, spacing behavior, and territoriality (Wells 1977b). Unfortunately, many aspects of courtship have been neglected. I use the term “courtship” to refer to interactions between males and females leading to pair formation and mating, and I include the use of both long-range and short-range signals by courting males. The purpose of this paper is to bring together the largely anecdotal literature on anuran courtship and to outline a number of problems that require more detailed investigation.

Courtship and parental behavior of Dendrobates auratus were studied in the field and in captivity... more Courtship and parental behavior of Dendrobates auratus were studied in the field and in captivity. Males are nonterritorial, but occasionally engage in aggressive competition. Males call to attract 9 9 and lead them to oviposition sites in leaf litter. Court- ship includes elaborate tactile interactions between partners, with the 9 taking the more active role. Parental care is performed by the 8 and includes tending of eggs and transport of tadpoles to water. Males can care for >1 clutch simultaneously. High 8 parental investment may lead to a shortage of 8 8, limiting 9 reproductive success. This may result in interfemale competition and a partial reversal of the usual sex roles in courtship.

Journal of Herpetology

Abstract American Bullfrogs (Rana catesbeiana) and Green Frogs (Rana clamitans) share ranges and ... more Abstract American Bullfrogs (Rana catesbeiana) and Green Frogs (Rana clamitans) share ranges and breeding seasons, are ecologically similar, and often occupy the same breeding ponds throughout the summer. Males of both species use vocalizations to defend territories and attract females; however, Bullfrogs have longer calls and call much more frequently than Green Frogs. The calls of the two species overlap in frequency; thus, Bullfrog calls are a likely source of acoustic interference for Green Frogs that could affect their ability to attract females. Nevertheless, in natural settings where these species co-occur, Green Frogs reproduce successfully. This suggests that Green Frogs respond to the calling patterns of Bullfrogs in ways that maximize Green Frog signal-to-noise ratio. We used long-term pond environment recordings and bioacoustics analyzing software to explore the influence of Bullfrog calling patterns on the vocal activity of syntopic Green Frogs. We found both species call most actively within the same seasonal and diel periods. Our results show that Green Frogs avoid overlapping their calls with Bullfrogs more often than expected by chance. Therefore, to avoid Bullfrog call overlap, Green Frogs use the fine-scale behavioral response of placing their calls in silent gaps between the calls of Bullfrogs. This pattern was even more pronounced in interactions between nearest neighbors in which there was no overlap observed between Bullfrogs and their nearest neighbor Green Frog.

Ethology

Parents have evolved a variety of strategies to minimize risks to their offspring, including comp... more Parents have evolved a variety of strategies to minimize risks to their offspring, including complex choices regarding suitable rearing sites, based on abiotic and biotic factors, which differentially affect offspring survival. Because availability and quality of these sites are variable, parents may have to choose between immediately availa-How to cite this article: Goyes Vallejos J, Grafe TU, Wells KD. Factors influencing tadpole deposition site choice in a frog with male parental care: An experimental field study. Ethology.

Behavioral Ecology and Sociobiology

In many species that use acoustic signals for mate attraction, males are usually the most vocal s... more In many species that use acoustic signals for mate attraction, males are usually the most vocal sex. In frogs, females typically remain silent, while males produce advertisement calls to attract mates. In some species, females vocalize, but usually as a response to an initial male advertisement call. The smooth guardian frog (Limnonectes palavanensis), found on Borneo, has exclusive paternal care while the females mate and desert after laying the clutch. Males provide care to the eggs until hatching and then they transport the tadpoles to small bodies of water. The vocal repertoire of this species has never been described. Males have a distinctive advertisement call to attract females, but produce the call very infrequently. We found that females of L. palavanensis not only respond to male advertisement calls but also vocalize spontaneously, forming lek-like aggregations around a single male. Males may or may not respond to a particular female with a short courtship call, which is elicited only by the female call and not the male advertisement call. The calling rate of females is consistently higher throughout the night compared with the calling rate of males. These observations suggest that this species exhibits a reversal in calling behavior and possibly a sex-role-reversed mating system. Significance statement Exceptional cases of species with a sex-role reversed mating system have been observed in fishes and birds, but not in frogs. For sex-role reversal to occur, there must be intense parental care by the males and a surplus of females. Additionally, females should exhibit characteristics that are usually observed in males in species with conventional sex roles. We found that in L. palavanensis, females are highly vocal, exhibiting higher calling rates compared with the calling rates of the males. This behavior, where females out-signal males has not been observed in anurans. This female calling behavior coupled with observations of several females approaching a male provides evidence of a female-biased operational sex ratio, a characteristic of a sex-role-reversed mating system. Thus, this study provides quantitative evidence that L. palavanensis exhibits various aspects consistent with a sexrole reversed mating system.

Choice Reviews Online

... the book, especially be-cause this would result in the use of many genus and family ... the p... more ... the book, especially be-cause this would result in the use of many genus and family ... the proposed changes before the new scheme is widely adopted, and using the new names here ... traits discussed in this book, such as the evolution of feeding modes, reproductive modes, life ...

Journal of the History of Biology, 1973

Page 1. The Historical Context of Natural Selection: The Case of Patrick Matthew KENTWOOD D. WELL... more Page 1. The Historical Context of Natural Selection: The Case of Patrick Matthew KENTWOOD D. WELLS Section of Ecology and Systematlcs Cornell University Ithaca, New York INTRODUCTION In the history of science, every ...

Journal of Herpetology, 1988

Page 1. NOTES Journal of Herpetology, Vol. 22, No. 3, pp. 361-364, 1988 Copyright 1988 Society fo... more Page 1. NOTES Journal of Herpetology, Vol. 22, No. 3, pp. 361-364, 1988 Copyright 1988 Society for the Study of Amphibians and Reptiles Parental Behavior of an Aquatic-breeding Tropical Frog, Leptodactylus bolivianus KENTWOOD . ...

Journal of Herpetology, 1980

Page 1. 428 NOTES This work was supported by a Mellon-Rachelwood Wildlife Research Grant which al... more Page 1. 428 NOTES This work was supported by a Mellon-Rachelwood Wildlife Research Grant which also provided research and housing facilities in the field. My thanks to Michael Mares, David Tazik and two anonymous reviewers ...

Journal of Comparative Physiology B, 1985

Hyla versicolor were determined by measuring oxygen consumption and whole body lactate content of... more Hyla versicolor were determined by measuring oxygen consumption and whole body lactate content of calling animals. A stepwise multiple regression analysis identified both calling rate (calls/h) and call duration (s/call) as significant determinants of oxygen consumption during calling. These two variables accounted for 84 % of the total variation in oxygen consumption observed in calling frogs. Aerobic metabolism (ITo2call) increased linearly with calling rate and call duration, reaching a peak value of 1.7 ml O2/(g'h) at the highest vocalization effort. For comparison, metabolic rates of the same individuals were also measured during short bouts of vigorous locomotor exercise (Vo2eX) induced by mechanical stimulation. The mean value of lZo2eX was only 62% of the peak l/o2call , and 5 of 13 frogs had rates of oxygen consumption during calling that exceeded their Vo2eX. Whole body lactate levels were measured in two samples of calling frogs, one collected early in the evening (2100-2115h) and the other 1.5h later (2230-2245 h). The frogs in the second sample had significantly lower lactate levels (0.10 mg/g) than the frogs collected early in the evening (0.22 mg/g). Hence, vocalization does not entail the use of anaerobic metabolism, although lactate levels may be slightly elevated at the onset of an evening of calling. Calling rates of unrestrained frogs in a large chorus were measured at regular intervals during an evening. During the first half hour of calling, rates increased gradually from an initial mean value of 600 calls/h at 2030 h to nearly 1400 calls/h at 2100 h. These data indicate that acoustic advertise-Abbreviations: l)oTest resting rate of oxygen consumption; TZo,rnax maximum rate of oxygen consumption; ~2ex rate of oxygen consumption during forced exercise; Vo2call rate of oxygen consumption during calling merit by Hyla versicolor is among the most energetically expensive activities regularly undertaken by any anuran, and indeed, is the most demanding yet measured in an ectothermic vertebrate.

Copeia, 1981

Page 1. Copeia, 1981(3), pp. 615-624 Vocal Responses to Conspecific Calls in a Neotropical Hylid ... more Page 1. Copeia, 1981(3), pp. 615-624 Vocal Responses to Conspecific Calls in a Neotropical Hylid Frog, Hyla ebraccata KENTWOOD D. WELLS AND BEVERLY J. GREER We investigated the vocal behavior of Hyla ebraccata in Central Panama. ...

Copeia, 1981

Page 1. 726 COPEIA, 1981, NO. 3 chironomid larvae clung to the eggs as a sub-stitute. In so doing... more Page 1. 726 COPEIA, 1981, NO. 3 chironomid larvae clung to the eggs as a sub-stitute. In so doing, they mechanically disrupt-ed naked and encapsuled eggs. The actual mechanisms by which the mem-branes deter predation is not known. ...

Copeia, 1985

Page 1. Copeia, 1985(1), pp. 27-38 Intra-and Interspecific Vocal Behavior of the Neotropical Tree... more Page 1. Copeia, 1985(1), pp. 27-38 Intra-and Interspecific Vocal Behavior of the Neotropical Treefrog Hyla microcephala JOSHUA J. SCHWARTZ AND KENTWOOD D. WELLS The vocal communication of Hyla microcephala was studied in central Panama. ...

Biotropica, 1979

Page 1. Reproductive Behavior and Male Mating Success in a Neotropical Toad, Bufo typhonius Kentw... more Page 1. Reproductive Behavior and Male Mating Success in a Neotropical Toad, Bufo typhonius Kentwood D. Wells Biological Sciences Group, University of Connecticut, Storrs, Connecticut 06268, USA ABSTRACT Bufo typhonius ...

Behavioral Ecology and Sociobiology, 1986

Summary. The vocal behavior of Hyla versicolor was studied in the field by means of behavioral ob... more 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 ...

Behavioral Ecology and Sociobiology, 1984

The three species have calls exhibiting broad frequency overlap and call during the same season a... more The three species have calls exhibiting broad frequency overlap and call during the same season and time of day from similar microhabitats, frequently in close proximity. The vocal repertoires of the three species are structurally and functionally similar. All employ multi-part advertisement and aggressive calls which consist of a primary note followed by a variable number of clicks. H. ebraccata males often responded to heterospecific calls with multi-note synchronized responses, and calls with primary notes greater than 150-200 ms were most effective in eliciting synchrony. Playback experiments with synthetic 1-note advertisement calls of different durations and both synthetic 1-note advertisement calls and 200 ms tones of different frequencies demonstrated that H. ebraccata males will synchronize with stimuli which are similar in frequency and duration to conspecific calls. Data from a two-choice experiment with female H. ebraccata demonstrate that calls of individual H. microeephala can reduce the attractiveness of a H. ebraccata male's calls if primary notes overlap. By synchronizing response calls to those of H. microcephala, a H. ebraccata may reduce the chances that his calls are rendered less attractive to potential mates. Aggressive calls of these species are graded and are characterized by higher pulse repetition rates and often longer durations than advertisement calls. H. ebraccata males respond to aggressive calls of H. microcephala and H. phlebodes as they do to their own calls. Heterospecific aggressive interactions probably occur because the species interfere acoustically. Our results demonstrate that H. ebraccata males behave in ways which enhance their ability to communicate in a noisy assemblage of conspecific and heterospecific males.

Behavioral Ecology and Sociobiology, 1980

Page 1. Behav. Ecol. Sociobiol. 6, 199-209 (1980) Behavioral Ecology and Sociobiology 9 by Spring... more Page 1. Behav. Ecol. Sociobiol. 6, 199-209 (1980) Behavioral Ecology and Sociobiology 9 by Springer-Verlag 1980 Behavioral Ecology and Social Organization of a Dendrobatid Frog (Colostethus inguinalis) Kentwood D. Wells ...

Behavioral Ecology, 1994

We investigated individual, nightly, and seasonal variation in calling behavior of a population o... more We investigated individual, nightly, and seasonal variation in calling behavior of a population of gray tree frogs (Hyla versicolor) from Connecticut, USA. Repeated recordings of individual males on seven nights revealed significant differences among males in calling rate on all ...

Animal Behaviour, 1983

Hyla ebraccata and H. microcephala commonly occur together in Panama. There is considerable overl... more Hyla ebraccata and H. microcephala commonly occur together in Panama. There is considerable overlap in calling sites and spectral properties of calls in these species. H. ebraccata frequently call amidst dense choruses of H. microcephala. Choruses of the latter species are cyclical, producing fluctuating background noise levels. We recorded natural vocal interactions between these species and performed playback experiments using both recordings of H. microcephala choruses and artificially synthesized noise. Our data demonstrate that background noise generated by H. microcephala choruses causes a shift in the timing and type of calls given by nearby H. ebraccata. Males reduce their calling rates and the proportion of multi-note and aggressive calls at high chorus levels, Playbacks of filtered noise produced a similar change in calling behaviour. These changes may enhance the ability of male H. ebraccata to broadcast signals to conspecifics. Our results and those of other researchers indicate that vocal interactions in mixed species anuran choruses may have important effects on the calling behaviour of individual males.

The Magic Lantern Gazette Research Supplement no. 4, 2024

The Reproductive Biology of Amphibians

Frogs were once thought to have relatively uninteresting social behavior, but recent studies on t... more Frogs were once thought to have relatively uninteresting social behavior, but recent studies on tropical and temperate zone species have revealed a surprising diversity of social systems. There is a growing literature on anuran mating systems, aggression, spacing behavior, and territoriality (Wells 1977b). Unfortunately, many aspects of courtship have been neglected. I use the term “courtship” to refer to interactions between males and females leading to pair formation and mating, and I include the use of both long-range and short-range signals by courting males. The purpose of this paper is to bring together the largely anecdotal literature on anuran courtship and to outline a number of problems that require more detailed investigation.

Courtship and parental behavior of Dendrobates auratus were studied in the field and in captivity... more Courtship and parental behavior of Dendrobates auratus were studied in the field and in captivity. Males are nonterritorial, but occasionally engage in aggressive competition. Males call to attract 9 9 and lead them to oviposition sites in leaf litter. Court- ship includes elaborate tactile interactions between partners, with the 9 taking the more active role. Parental care is performed by the 8 and includes tending of eggs and transport of tadpoles to water. Males can care for >1 clutch simultaneously. High 8 parental investment may lead to a shortage of 8 8, limiting 9 reproductive success. This may result in interfemale competition and a partial reversal of the usual sex roles in courtship.

Journal of Herpetology

Abstract American Bullfrogs (Rana catesbeiana) and Green Frogs (Rana clamitans) share ranges and ... more Abstract American Bullfrogs (Rana catesbeiana) and Green Frogs (Rana clamitans) share ranges and breeding seasons, are ecologically similar, and often occupy the same breeding ponds throughout the summer. Males of both species use vocalizations to defend territories and attract females; however, Bullfrogs have longer calls and call much more frequently than Green Frogs. The calls of the two species overlap in frequency; thus, Bullfrog calls are a likely source of acoustic interference for Green Frogs that could affect their ability to attract females. Nevertheless, in natural settings where these species co-occur, Green Frogs reproduce successfully. This suggests that Green Frogs respond to the calling patterns of Bullfrogs in ways that maximize Green Frog signal-to-noise ratio. We used long-term pond environment recordings and bioacoustics analyzing software to explore the influence of Bullfrog calling patterns on the vocal activity of syntopic Green Frogs. We found both species call most actively within the same seasonal and diel periods. Our results show that Green Frogs avoid overlapping their calls with Bullfrogs more often than expected by chance. Therefore, to avoid Bullfrog call overlap, Green Frogs use the fine-scale behavioral response of placing their calls in silent gaps between the calls of Bullfrogs. This pattern was even more pronounced in interactions between nearest neighbors in which there was no overlap observed between Bullfrogs and their nearest neighbor Green Frog.

Ethology

Parents have evolved a variety of strategies to minimize risks to their offspring, including comp... more Parents have evolved a variety of strategies to minimize risks to their offspring, including complex choices regarding suitable rearing sites, based on abiotic and biotic factors, which differentially affect offspring survival. Because availability and quality of these sites are variable, parents may have to choose between immediately availa-How to cite this article: Goyes Vallejos J, Grafe TU, Wells KD. Factors influencing tadpole deposition site choice in a frog with male parental care: An experimental field study. Ethology.

Behavioral Ecology and Sociobiology

In many species that use acoustic signals for mate attraction, males are usually the most vocal s... more In many species that use acoustic signals for mate attraction, males are usually the most vocal sex. In frogs, females typically remain silent, while males produce advertisement calls to attract mates. In some species, females vocalize, but usually as a response to an initial male advertisement call. The smooth guardian frog (Limnonectes palavanensis), found on Borneo, has exclusive paternal care while the females mate and desert after laying the clutch. Males provide care to the eggs until hatching and then they transport the tadpoles to small bodies of water. The vocal repertoire of this species has never been described. Males have a distinctive advertisement call to attract females, but produce the call very infrequently. We found that females of L. palavanensis not only respond to male advertisement calls but also vocalize spontaneously, forming lek-like aggregations around a single male. Males may or may not respond to a particular female with a short courtship call, which is elicited only by the female call and not the male advertisement call. The calling rate of females is consistently higher throughout the night compared with the calling rate of males. These observations suggest that this species exhibits a reversal in calling behavior and possibly a sex-role-reversed mating system. Significance statement Exceptional cases of species with a sex-role reversed mating system have been observed in fishes and birds, but not in frogs. For sex-role reversal to occur, there must be intense parental care by the males and a surplus of females. Additionally, females should exhibit characteristics that are usually observed in males in species with conventional sex roles. We found that in L. palavanensis, females are highly vocal, exhibiting higher calling rates compared with the calling rates of the males. This behavior, where females out-signal males has not been observed in anurans. This female calling behavior coupled with observations of several females approaching a male provides evidence of a female-biased operational sex ratio, a characteristic of a sex-role-reversed mating system. Thus, this study provides quantitative evidence that L. palavanensis exhibits various aspects consistent with a sexrole reversed mating system.

Choice Reviews Online

... the book, especially be-cause this would result in the use of many genus and family ... the p... more ... the book, especially be-cause this would result in the use of many genus and family ... the proposed changes before the new scheme is widely adopted, and using the new names here ... traits discussed in this book, such as the evolution of feeding modes, reproductive modes, life ...

Journal of the History of Biology, 1973

Page 1. The Historical Context of Natural Selection: The Case of Patrick Matthew KENTWOOD D. WELL... more Page 1. The Historical Context of Natural Selection: The Case of Patrick Matthew KENTWOOD D. WELLS Section of Ecology and Systematlcs Cornell University Ithaca, New York INTRODUCTION In the history of science, every ...

Journal of Herpetology, 1988

Page 1. NOTES Journal of Herpetology, Vol. 22, No. 3, pp. 361-364, 1988 Copyright 1988 Society fo... more Page 1. NOTES Journal of Herpetology, Vol. 22, No. 3, pp. 361-364, 1988 Copyright 1988 Society for the Study of Amphibians and Reptiles Parental Behavior of an Aquatic-breeding Tropical Frog, Leptodactylus bolivianus KENTWOOD . ...

Journal of Herpetology, 1980

Page 1. 428 NOTES This work was supported by a Mellon-Rachelwood Wildlife Research Grant which al... more Page 1. 428 NOTES This work was supported by a Mellon-Rachelwood Wildlife Research Grant which also provided research and housing facilities in the field. My thanks to Michael Mares, David Tazik and two anonymous reviewers ...

Journal of Comparative Physiology B, 1985

Hyla versicolor were determined by measuring oxygen consumption and whole body lactate content of... more Hyla versicolor were determined by measuring oxygen consumption and whole body lactate content of calling animals. A stepwise multiple regression analysis identified both calling rate (calls/h) and call duration (s/call) as significant determinants of oxygen consumption during calling. These two variables accounted for 84 % of the total variation in oxygen consumption observed in calling frogs. Aerobic metabolism (ITo2call) increased linearly with calling rate and call duration, reaching a peak value of 1.7 ml O2/(g'h) at the highest vocalization effort. For comparison, metabolic rates of the same individuals were also measured during short bouts of vigorous locomotor exercise (Vo2eX) induced by mechanical stimulation. The mean value of lZo2eX was only 62% of the peak l/o2call , and 5 of 13 frogs had rates of oxygen consumption during calling that exceeded their Vo2eX. Whole body lactate levels were measured in two samples of calling frogs, one collected early in the evening (2100-2115h) and the other 1.5h later (2230-2245 h). The frogs in the second sample had significantly lower lactate levels (0.10 mg/g) than the frogs collected early in the evening (0.22 mg/g). Hence, vocalization does not entail the use of anaerobic metabolism, although lactate levels may be slightly elevated at the onset of an evening of calling. Calling rates of unrestrained frogs in a large chorus were measured at regular intervals during an evening. During the first half hour of calling, rates increased gradually from an initial mean value of 600 calls/h at 2030 h to nearly 1400 calls/h at 2100 h. These data indicate that acoustic advertise-Abbreviations: l)oTest resting rate of oxygen consumption; TZo,rnax maximum rate of oxygen consumption; ~2ex rate of oxygen consumption during forced exercise; Vo2call rate of oxygen consumption during calling merit by Hyla versicolor is among the most energetically expensive activities regularly undertaken by any anuran, and indeed, is the most demanding yet measured in an ectothermic vertebrate.

Copeia, 1981

Page 1. Copeia, 1981(3), pp. 615-624 Vocal Responses to Conspecific Calls in a Neotropical Hylid ... more Page 1. Copeia, 1981(3), pp. 615-624 Vocal Responses to Conspecific Calls in a Neotropical Hylid Frog, Hyla ebraccata KENTWOOD D. WELLS AND BEVERLY J. GREER We investigated the vocal behavior of Hyla ebraccata in Central Panama. ...

Copeia, 1981

Page 1. 726 COPEIA, 1981, NO. 3 chironomid larvae clung to the eggs as a sub-stitute. In so doing... more Page 1. 726 COPEIA, 1981, NO. 3 chironomid larvae clung to the eggs as a sub-stitute. In so doing, they mechanically disrupt-ed naked and encapsuled eggs. The actual mechanisms by which the mem-branes deter predation is not known. ...

Copeia, 1985

Page 1. Copeia, 1985(1), pp. 27-38 Intra-and Interspecific Vocal Behavior of the Neotropical Tree... more Page 1. Copeia, 1985(1), pp. 27-38 Intra-and Interspecific Vocal Behavior of the Neotropical Treefrog Hyla microcephala JOSHUA J. SCHWARTZ AND KENTWOOD D. WELLS The vocal communication of Hyla microcephala was studied in central Panama. ...

Biotropica, 1979

Page 1. Reproductive Behavior and Male Mating Success in a Neotropical Toad, Bufo typhonius Kentw... more Page 1. Reproductive Behavior and Male Mating Success in a Neotropical Toad, Bufo typhonius Kentwood D. Wells Biological Sciences Group, University of Connecticut, Storrs, Connecticut 06268, USA ABSTRACT Bufo typhonius ...

Behavioral Ecology and Sociobiology, 1986

Summary. The vocal behavior of Hyla versicolor was studied in the field by means of behavioral ob... more 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 ...

Behavioral Ecology and Sociobiology, 1984

The three species have calls exhibiting broad frequency overlap and call during the same season a... more The three species have calls exhibiting broad frequency overlap and call during the same season and time of day from similar microhabitats, frequently in close proximity. The vocal repertoires of the three species are structurally and functionally similar. All employ multi-part advertisement and aggressive calls which consist of a primary note followed by a variable number of clicks. H. ebraccata males often responded to heterospecific calls with multi-note synchronized responses, and calls with primary notes greater than 150-200 ms were most effective in eliciting synchrony. Playback experiments with synthetic 1-note advertisement calls of different durations and both synthetic 1-note advertisement calls and 200 ms tones of different frequencies demonstrated that H. ebraccata males will synchronize with stimuli which are similar in frequency and duration to conspecific calls. Data from a two-choice experiment with female H. ebraccata demonstrate that calls of individual H. microeephala can reduce the attractiveness of a H. ebraccata male's calls if primary notes overlap. By synchronizing response calls to those of H. microcephala, a H. ebraccata may reduce the chances that his calls are rendered less attractive to potential mates. Aggressive calls of these species are graded and are characterized by higher pulse repetition rates and often longer durations than advertisement calls. H. ebraccata males respond to aggressive calls of H. microcephala and H. phlebodes as they do to their own calls. Heterospecific aggressive interactions probably occur because the species interfere acoustically. Our results demonstrate that H. ebraccata males behave in ways which enhance their ability to communicate in a noisy assemblage of conspecific and heterospecific males.

Behavioral Ecology and Sociobiology, 1980

Page 1. Behav. Ecol. Sociobiol. 6, 199-209 (1980) Behavioral Ecology and Sociobiology 9 by Spring... more Page 1. Behav. Ecol. Sociobiol. 6, 199-209 (1980) Behavioral Ecology and Sociobiology 9 by Springer-Verlag 1980 Behavioral Ecology and Social Organization of a Dendrobatid Frog (Colostethus inguinalis) Kentwood D. Wells ...

Behavioral Ecology, 1994

We investigated individual, nightly, and seasonal variation in calling behavior of a population o... more We investigated individual, nightly, and seasonal variation in calling behavior of a population of gray tree frogs (Hyla versicolor) from Connecticut, USA. Repeated recordings of individual males on seven nights revealed significant differences among males in calling rate on all ...

Animal Behaviour, 1983

Hyla ebraccata and H. microcephala commonly occur together in Panama. There is considerable overl... more Hyla ebraccata and H. microcephala commonly occur together in Panama. There is considerable overlap in calling sites and spectral properties of calls in these species. H. ebraccata frequently call amidst dense choruses of H. microcephala. Choruses of the latter species are cyclical, producing fluctuating background noise levels. We recorded natural vocal interactions between these species and performed playback experiments using both recordings of H. microcephala choruses and artificially synthesized noise. Our data demonstrate that background noise generated by H. microcephala choruses causes a shift in the timing and type of calls given by nearby H. ebraccata. Males reduce their calling rates and the proportion of multi-note and aggressive calls at high chorus levels, Playbacks of filtered noise produced a similar change in calling behaviour. These changes may enhance the ability of male H. ebraccata to broadcast signals to conspecifics. Our results and those of other researchers indicate that vocal interactions in mixed species anuran choruses may have important effects on the calling behaviour of individual males.