Advertisement calls are essential for communication among anuran amphibians,with their production influenced by a range of environmental factors and morphological traits.To understand the primary sources of variation ...Advertisement calls are essential for communication among anuran amphibians,with their production influenced by a range of environmental factors and morphological traits.To understand the primary sources of variation of advertisement calls in male Leptobrachium liui,we recorded their advertisement calls during the breeding season and analyzed two primary acoustic parameters: call duration(CD) and dominant frequency(DF),along with their within-individual coefficients of variation.Additionally,we collected nest-related environmental parameters and morphological traits to investigate how these factors influence the variation in advertisement calls.Our analyses revealed that both nest-related environmental parameters(particularly water temperature) and individual morphological traits(especially head morphology) significantly influenced advertisement call characteristics in male L.liui.Water temperature showed a negative relationship with CD,while head morphology was positively associated with both CD and DF.These findings enhance our understanding of the factors shaping acoustic communication in L.liui during the breeding season and highlight the importance of both environmental and morphological factors in anuran vocalization.展开更多
The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with th...The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with the nesting behaviour of the Olive Ridley turtles. In the present study, characteristics of the breeding beach and nesting pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of Andaman Islands were investigated, during the nesting periods 2016-2017. The study area hosts Olive Ridley, the dominant sea turtles with more than 300 individuals nesting each year. For this study, the number of sea turtles visited, nested, the sediment characters, salinity, and temperature were taken. The exposed sandy nesting beach characteristics are prone to varying degrees of morphological changes every day. The results depict that even though similar grain size (Coarse Sand to Fine Sand and Very well sorted to Poorly Sorted), with an ambient incubating temperature, pH and salinity with wide nesting area, the selective nesting in the particular location of the beach identified because of comfortable energy conditions in the waters (1.5 m/s) favours the female turtles to reach the beach at the preferable site of Ramnagar and nest.展开更多
The nest environment may limit the ability of nest-bound birds to hear sounds from the outside world.In vocal learning species,such as humans and songbirds,it is vital for young animals to hear the voices of conspecif...The nest environment may limit the ability of nest-bound birds to hear sounds from the outside world.In vocal learning species,such as humans and songbirds,it is vital for young animals to hear the voices of conspecific animals early in life.In songbirds,nest structure varies considerably across species,and the resulting impact on sound transmission may have consequences for vocal learning in nestlings.In this study,we tested the hypothesis that the nest environment attenuates song of Savannah Sparrows(Passerculus sandwichensis),grassland songbirds that build nests on the ground under cover of dense vegetation.We recorded live Savannah Sparrows singing at variable distances from 21 nests.We recorded songs using one microphone inside the nest(the typical position of a nestling)and another placed 1 m directly above the nest(a typical position of an adult).We found a substantial reduction in signal-to-noise ratio,where songs recorded inside the nest were an average of 11 dB lower than songs recorded directly above the nest.We estimate that the attenuation imposed by the nest reduced the maximum acoustic environment from 117.7 m(for recordings above the nest),to 78.6 m(for recordings within the nest),which is analogous to listening from a position 39.1 m farther away from the singer.Previous research estimated that song transmits up to 100 m in this species,so any adult male within 100 m of a young bird was previously considered a potential vocal tutor.By reducing the nestling acoustic environment from 100 m to 78.6 m,the number of male tutors available to nestlings is reduced by an average of 27%.Given the growing evidence that song learning begins very early in life,future research on vocal development should account for how the structural properties of the natal environment affect the songs that nestlings hear.展开更多
Low-oxygen conditions(hypoxia;<21%O_(2))are considered unfavorable for growth;yet,embryos of many vertebrate taxa develop successfully in hypoxic subterranean environments.Although enhanced tolerance to hypoxia has...Low-oxygen conditions(hypoxia;<21%O_(2))are considered unfavorable for growth;yet,embryos of many vertebrate taxa develop successfully in hypoxic subterranean environments.Although enhanced tolerance to hypoxia has been demonstrated in adult reptiles,such as in the painted turtle(Chrysemys picta),its effects on sensitive embryo life stages warrant attention.We tested the hypothesis that short-term hypoxia negatively affects growth during day 40 of development in C.picta,when O_(2) demands are highest in embryos.A brief,but severe,hypoxic event(5%O_(2) for 0.5 h)moderately affected embryo growth,causing a 13%reduction in mass(relative to a normoxic control).The same condition had no effect during day 27;instead,a nearly anoxic event(1%O_(2) for 72 h)caused a 5%mass reduction.All embryos survived the egg incubation period.Our study supports the assumption that reptilian embryos are resilient to intermittently low O_(2) in subterranean nests.Further work is needed to ascertain responses to suboptimal O_(2) levels while undergoing dynamic changes in developmental physiology.展开更多
基金supported by the County-School Cooperation Project in Suichang County (2024-HZ12)Ecological Discipline Construction Fund of Lishui University。
文摘Advertisement calls are essential for communication among anuran amphibians,with their production influenced by a range of environmental factors and morphological traits.To understand the primary sources of variation of advertisement calls in male Leptobrachium liui,we recorded their advertisement calls during the breeding season and analyzed two primary acoustic parameters: call duration(CD) and dominant frequency(DF),along with their within-individual coefficients of variation.Additionally,we collected nest-related environmental parameters and morphological traits to investigate how these factors influence the variation in advertisement calls.Our analyses revealed that both nest-related environmental parameters(particularly water temperature) and individual morphological traits(especially head morphology) significantly influenced advertisement call characteristics in male L.liui.Water temperature showed a negative relationship with CD,while head morphology was positively associated with both CD and DF.These findings enhance our understanding of the factors shaping acoustic communication in L.liui during the breeding season and highlight the importance of both environmental and morphological factors in anuran vocalization.
文摘The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with the nesting behaviour of the Olive Ridley turtles. In the present study, characteristics of the breeding beach and nesting pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of Andaman Islands were investigated, during the nesting periods 2016-2017. The study area hosts Olive Ridley, the dominant sea turtles with more than 300 individuals nesting each year. For this study, the number of sea turtles visited, nested, the sediment characters, salinity, and temperature were taken. The exposed sandy nesting beach characteristics are prone to varying degrees of morphological changes every day. The results depict that even though similar grain size (Coarse Sand to Fine Sand and Very well sorted to Poorly Sorted), with an ambient incubating temperature, pH and salinity with wide nesting area, the selective nesting in the particular location of the beach identified because of comfortable energy conditions in the waters (1.5 m/s) favours the female turtles to reach the beach at the preferable site of Ramnagar and nest.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)for financial support through grants to D.J.M., D.R.N.,and A.E.M.N.the Animal Behaviour Society+1 种基金the American Ornithological Societythe Society of Canadian Ornithologists for research grants to S.L.D.
文摘The nest environment may limit the ability of nest-bound birds to hear sounds from the outside world.In vocal learning species,such as humans and songbirds,it is vital for young animals to hear the voices of conspecific animals early in life.In songbirds,nest structure varies considerably across species,and the resulting impact on sound transmission may have consequences for vocal learning in nestlings.In this study,we tested the hypothesis that the nest environment attenuates song of Savannah Sparrows(Passerculus sandwichensis),grassland songbirds that build nests on the ground under cover of dense vegetation.We recorded live Savannah Sparrows singing at variable distances from 21 nests.We recorded songs using one microphone inside the nest(the typical position of a nestling)and another placed 1 m directly above the nest(a typical position of an adult).We found a substantial reduction in signal-to-noise ratio,where songs recorded inside the nest were an average of 11 dB lower than songs recorded directly above the nest.We estimate that the attenuation imposed by the nest reduced the maximum acoustic environment from 117.7 m(for recordings above the nest),to 78.6 m(for recordings within the nest),which is analogous to listening from a position 39.1 m farther away from the singer.Previous research estimated that song transmits up to 100 m in this species,so any adult male within 100 m of a young bird was previously considered a potential vocal tutor.By reducing the nestling acoustic environment from 100 m to 78.6 m,the number of male tutors available to nestlings is reduced by an average of 27%.Given the growing evidence that song learning begins very early in life,future research on vocal development should account for how the structural properties of the natal environment affect the songs that nestlings hear.
基金funded in part by graduate student research awards from the ISU-EEOB and NSF grant DEB-1242510(to F.Janzen)J.C.Svendsen was supported by grant SFRH/BPD/89473/2012 from the Foundation for Science and Technology in Portugal.
文摘Low-oxygen conditions(hypoxia;<21%O_(2))are considered unfavorable for growth;yet,embryos of many vertebrate taxa develop successfully in hypoxic subterranean environments.Although enhanced tolerance to hypoxia has been demonstrated in adult reptiles,such as in the painted turtle(Chrysemys picta),its effects on sensitive embryo life stages warrant attention.We tested the hypothesis that short-term hypoxia negatively affects growth during day 40 of development in C.picta,when O_(2) demands are highest in embryos.A brief,but severe,hypoxic event(5%O_(2) for 0.5 h)moderately affected embryo growth,causing a 13%reduction in mass(relative to a normoxic control).The same condition had no effect during day 27;instead,a nearly anoxic event(1%O_(2) for 72 h)caused a 5%mass reduction.All embryos survived the egg incubation period.Our study supports the assumption that reptilian embryos are resilient to intermittently low O_(2) in subterranean nests.Further work is needed to ascertain responses to suboptimal O_(2) levels while undergoing dynamic changes in developmental physiology.
