scholarly journals Variation in alarm calls during different breeding stages of the common kestrel (Falco tinnunculus)

Biology Open ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. bio056648
Author(s):  
Xiaona Huo ◽  
Lei Zhou ◽  
Jiang Feng ◽  
Hui Wu
Keyword(s):  
Animal Communication ◽  
Second Harmonic ◽  
Acoustic Signals ◽  
Reproductive Period ◽  
Nest Defense ◽  
Alarm Calls ◽  
Impact Factors ◽  
Breeding Period ◽  
Falco Tinnunculus ◽  
Acoustic Parameters

ABSTRACTAcoustic signals play a key role in animal communication. Animals usually use alarm signals to warn mates or offspring of the presence of threats or to intimidate or distract predators. Birds commonly use acoustic signals as a means of communication. Alarm calls in passerines at different breeding stages can reflect their nest defense intensity. However, little is known about the characteristics, plasticity, and impact factors of alarm calls during the reproductive period in raptors. Here, from March to July in 2019, the alarm calls of eight pairs of common kestrels (Falco tinnunculus) during the breeding period were recorded using a portable recorder with a strongly directed microphone in the Zuojia Nature Reserve, Jilin province, China. The differences in acoustic parameters of parental alarm calls in different breeding stages were analyzed. The results showed that the alarm calls of common kestrels were composed of multi-harmonic arched frequency modulation with the maximum energy distribution in the second harmonic. The duration and rate of the alarm calls increased significantly as the breeding season progressed, showing that parents spent increasing amounts of time on nest defense. Additionally, the acoustic parameters of alarm calls in common kestrels were significantly different depending on offspring numbers, suggesting that offspring numbers influenced parental nest defense. These results showed that differences in alarm calls during different breeding stages may reflect a trade-off between defense costs and reproductive benefits.

scholarly journals Acoustic cues to individuality in wild male adult African savannah elephants (Loxodonta africana)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10736
Author(s):  
Kaja Wierucka ◽  
Michelle D. Henley ◽  
Hannah S. Mumby
Keyword(s):  
Communication Systems ◽  
Animal Communication ◽  
Current Knowledge ◽  
Individual Recognition ◽  
Social Bonds ◽  
Loxodonta Africana ◽  
Mature Male ◽  
Acoustic Cues ◽  
Acoustic Parameters ◽  
Male Adult

The ability to recognize conspecifics plays a pivotal role in animal communication systems. It is especially important for establishing and maintaining associations among individuals of social, long-lived species, such as elephants. While research on female elephant sociality and communication is prevalent, until recently male elephants have been considered far less social than females. This resulted in a dearth of information about their communication and recognition abilities. With new knowledge about the intricacies of the male elephant social structure come questions regarding the communication basis that allows for social bonds to be established and maintained. By analyzing the acoustic parameters of social rumbles recorded over 1.5 years from wild, mature, male African savanna elephants (Loxodonta africana) we expand current knowledge about the information encoded within these vocalizations and their potential to facilitate individual recognition. We showed that social rumbles are individually distinct and stable over time and therefore provide an acoustic basis for individual recognition. Furthermore, our results revealed that different frequency parameters contribute to individual differences of these vocalizations.

Sound-transparent anisotropic media for backscattering-immune wave manipulation

2022 ◽  
Author(s):  
Wei-Wei Kan ◽  
Qiu-Yu Li ◽  
Lei Pan
Keyword(s):  
Acoustic Signal ◽  
Acoustic Signals ◽  
Acoustic Medium ◽  
Subwavelength Structures ◽  
Beam Splitting ◽  
Acoustic Parameters ◽  
Straight Path ◽  
Specific Order ◽  
Anisotropic Layers ◽  
Transformation Acoustics

Abstract The scattering behavior of the anisotropic acoustic medium is analyzed to reveal the possibility of routing acoustic signals through the anisotropic layers with no backscattering loss. The sound-transparent effect of such medium is achieved by independently modulating the anisotropic effective acoustic parameters in a specific order, and experimentally observed in a bending waveguide by arranging the subwavelength structures in the bending part according to transformation acoustics. With the properly designed filling structures, the original distorted acoustic field in the bending waveguide is restored as if the wave travels along a straight path. The transmitted acoustic signal is maintained nearly the same as the incident modulated Gaussian pulse. The proposed schemes and the supporting results could be instructive for further acoustic manipulations such as wave steering, cloaking and beam splitting.

Fertility control of rodent pests

2008 ◽  
Vol 35 (6) ◽  
pp. 487 ◽  
Author(s):  
Jens Jacob ◽  
Grant R. Singleton ◽  
Lyn A. Hinds
Keyword(s):  
Reproductive Output ◽  
Simulation Models ◽  
Population Level ◽  
Fertility Control ◽  
Reproductive Period ◽  
Future Research ◽  
House Mice ◽  
Breeding Period ◽  
Pest Species ◽  
Small Rodents

Ricefield rats (Rattus argentiventer) in south-east Asian rice fields and house mice (Mus domesticus) in Australian grain fields are major pest species. They cause damage before and after harvest and carry zoonotic diseases. For both species, management techniques have been pursued using the approach of immunocontraceptive vaccination. We review results from a series of enclosure and field studies conducted with these species to assess the effects of fertility control in small rodents. In the experiments, fertility control was simulated by tubal ligation, ovariectomy or progesterone treatment. A once-off sterilisation of 50–75% of enclosed founder females considerably reduced reproductive output of ricefield rat populations until the end of the reproductive period. In house mice, similar success was achieved when a sterility level of 67% of female founders and offspring was maintained. Repeated antifertility treatments are required because of the much longer breeding period of house mice versus ricefield rats. Comparing the results of enclosure trials with the outcome of simulation models suggests that partial compensation of treatment effects can occur through enhanced reproduction of the remaining fertile females and improved survival of juveniles. However, such compensatory effects as well as behavioural consequences of sterility in field populations are not likely to prevent the management effect at the population level. The challenge for effective fertility control of small rodents in the field is the wide-scale delivery of an antifertility treatment to founders at the beginning of the breeding season and to fertile immigrants that are recruited into the population, which otherwise contribute to the reproductive output at the population level. Future research efforts should focus on species-specific techniques and on agents that can be effectively delivered via bait.

scholarly journals Construction grammar for monkeys?

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Michael Pleyer ◽  
Stefan Hartmann
Keyword(s):  
Communication Systems ◽  
Animal Communication ◽  
Language Evolution ◽  
Construction Grammar ◽  
Alarm Calls ◽  
Human Language ◽  
Communication Research ◽  
Evolution Of Language ◽  
Linguistic Communication ◽  
Key Issues

Abstract In recent years, multiple researchers working on the evolution of language have put forward the idea that the theoretical framework of usage-based approaches and Construction Grammar is highly suitable for modelling the emergence of human language from pre-linguistic or proto-linguistic communication systems. This also raises the question of whether usage-based and constructionist approaches can be integrated with the analysis of animal communication systems. In this paper, we review possible avenues where usage-based, constructionist approaches can make contact with animal communication research, which in turn also has implications for theories of language evolution. To this end, we first give an overview of key assumptions of usage-based and constructionist approaches before reviewing some key issues in animal communication research through the lens of usage-based, constructionist approaches. Specifically, we will discuss how research on alarm calls, gestural communication and symbol-trained animals can be brought into contact with usage-based, constructionist theorizing. We argue that a constructionist view of animal communication can yield new perspectives on its relation to human language, which in turn has important implications regarding the evolution of language. Importantly, this theoretical approach also generates hypotheses that have the potential of complementing and extending results from the more formalist approaches that often underlie current animal communication research.

scholarly journals Discrimination of Acoustic Stimuli and Maintenance of Graded Alarm Call Structure in Captive Meerkats

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3064
Author(s):  
Sebastian Schneider ◽  
Sarah Goettlich ◽  
Charlette Diercks ◽  
Paul Wilhelm Dierkes
Keyword(s):  
Clustering Algorithm ◽  
Escape Behavior ◽  
Cooperative Behavior ◽  
Alarm Call ◽  
Acoustic Signals ◽  
Alarm Calls ◽  
Call Structure ◽  
Graded Structure ◽  
Suricata Suricatta ◽  
In Captivity

Animals living in human care for several generations face the risk of losing natural behaviors, which can lead to reduced animal welfare. The goal of this study is to demonstrate that meerkats (Suricata suricatta) living in zoos can assess potential danger and respond naturally based on acoustic signals only. This includes that the graded information of urgency in alarm calls as well as a response to those alarm calls is retained in captivity. To test the response to acoustic signals with different threat potential, meerkats were played calls of various animals differing in size and threat (e.g., robin, raven, buzzard, jackal) while their behavior was observed. The emitted alarm calls were recorded and examined for their graded structure on the one hand and played back to them on the other hand by means of a playback experiment to see whether the animals react to their own alarm calls even in the absence of danger. A fuzzy clustering algorithm was used to analyze and classify the alarm calls. Subsequently, the features that best described the graded structure were isolated using the LASSO algorithm and compared to features already known from wild meerkats. The results show that the graded structure is maintained in captivity and can be described by features such as noise and duration. The animals respond to new threats and can distinguish animal calls that are dangerous to them from those that are not, indicating the preservation of natural cooperative behavior. In addition, the playback experiments show that the meerkats respond to their own alarm calls with vigilance and escape behavior. The findings can be used to draw conclusions about the intensity of alertness in captive meerkats and to adapt husbandry conditions to appropriate welfare.

scholarly journals Booming far: the long-range vocal strategy of a lekking bird

2017 ◽  
Vol 4 (8) ◽  
pp. 170594 ◽  
Author(s):  
C. Cornec ◽  
Y. Hingrat ◽  
T. Aubin ◽  
F. Rybak
Keyword(s):  
Long Range ◽  
Communication Networks ◽  
Second Harmonic ◽  
Natural Habitat ◽  
Low Frequency ◽  
Acoustic Signals ◽  
Long Distance ◽  
Sexual Competition ◽  
The North ◽  
Transmission Of Information

The pressures of selection acting on transmission of information by acoustic signals are particularly high in long-distance communication networks. Males of the North African houbara bustard ( Chlamydotis undulata undulata ) produce extremely low-frequency vocalizations called ‘booms’ as a component of their courtship displays. These displays are performed on sites separated by a distance of on average 550 m, constituting exploded leks. Here, we investigate the acoustic features of booms involved in species-specific identity. We first assessed the modifications of acoustic parameters during boom transmission at long range within the natural habitat of the species, finding that the frequency content of booms was reliably transmitted up to 600 m. Additionally, by testing males' behavioural responses to playbacks of modified signals, we found that the presence of the second harmonic and the frequency modulation are the key parameters for species identification, and also that a sequence of booms elicited stronger responses than a single boom. Thus, the coding–decoding process relies on redundant and propagation-resistant features, making the booms particularly well adapted for the long-range transmission of information between males. Moreover, by experimentally disentangling the presentation of visual and acoustic signals, we showed that during the booming phase of courtship, the two sensory modalities act in synergy. The acoustic component is dominant in the context of intra-sexual competition. While the visual component is not necessary to induce agonistic response, it acts as an amplifier and reduces the time of detection of the signaller. The utilization of these adaptive strategies allows houbara males to maximize the active space of vocalizations emitted in exploded leks.

scholarly journals Titi monkeys combine alarm calls to create probabilistic meaning

2019 ◽  
Vol 5 (5) ◽  
pp. eaav3991 ◽  
Author(s):  
Mélissa Berthet ◽  
Geoffrey Mesbahi ◽  
Aude Pajot ◽  
Cristiane Cäsar ◽  
Christof Neumann ◽  
...  
Keyword(s):  
Animal Communication ◽  
Language Evolution ◽  
Alarm Call ◽  
Alarm Calls ◽  
Playback Experiments ◽  
Multimodel Inference ◽  
Titi Monkeys ◽  
Callicebus Nigrifrons ◽  
Available Information ◽  
Free Ranging

Previous work suggested that titi monkeys Callicebus nigrifrons combine two alarm calls, the A- and B-calls, to communicate about predator type and location. To explore how listeners process these sequences, we recorded alarm call sequences of six free-ranging groups exposed to terrestrial and aerial predator models, placed on the ground or in the canopy, and used multimodel inference to assess the information encoded in the sequences. We then carried out playback experiments to identify the features used by listeners to react to the available information. Results indicated that information about predator type and location were encoded by the proportion of B-call pairs relative to all call pairs of the sequence (i.e., proportion of BB-grams). The results suggest that the meaning of the sequence is not conveyed in a categorical but probabilistic manner. We discuss the implications of these findings for current theories of animal communication and language evolution.

scholarly journals Description of the sound diversity of two species of tuco-tucos (Ctenomys torquatus and Ctenomys lami ) in natural environment

2021 ◽  
Author(s):  
Keila Cristina Zache ◽  
Lucas Machado Silveira ◽  
Gabriel Francescoli ◽  
Thales Renato Ochotorena de Freitas
Keyword(s):  
Natural Environment ◽  
Communication Channel ◽  
Low Frequency ◽  
Morphological Characteristics ◽  
Acoustic Signals ◽  
Subterranean Rodents ◽  
Acoustic Parameters ◽  
Different Types ◽  
First Time ◽  
Two Populations

Sound signals can travel through long distances, becoming an important communication channel between animals that need to establish contact beyond the visual form. They can then be considered a relevant form of communication between species living in the underground environment. Ctenomys torquatus and Ctenomys lami are solitary subterranean rodents, thus demanding an improvement of the communicative channels, especially in territorial defense actions and meeting potential reproductive partners. This work was aimed to describe the variability of acoustic signals emitted by C. torquatus and C. lami by analyzing the physical-morphological characteristics of the signals. The study was carried out in two populations, one of each species and was selected 14 individuals of C. torquatus and 15 C. lami.  The acoustic signals were recorded in a natural environment, obtaining the sounds straight from the animal tunnels. A total of 1,380 signals were captured and analyzed, 786 from C. torquatus and 594 from C. lami.  It was possible to characterize 5 different types of signals, emitted by both species. Most of the analyzed sequences presented low frequency, and many of these calls exhibited characteristics of long-range signals. It was verified a sharing of sound signals in both species, as regarding the acoustic parameters as the morphology of the analyzed spectrograms.  For the first time, it was possible to have access to sound data emitted by direct subterranean rodents from their tunnels in the natural environment.

scholarly journals Construction Grammar for Monkeys? Animal communication and its implications for language evolution in the light of usage-based linguistic theory

2020 ◽  
Author(s):  
Michael Pleyer ◽  
Stefan Hartmann
Keyword(s):  
Communication Systems ◽  
Animal Communication ◽  
Language Evolution ◽  
Construction Grammar ◽  
Alarm Calls ◽  
Human Language ◽  
Communication Research ◽  
Evolution Of Language ◽  
Linguistic Communication ◽  
Key Issues

In recent years, multiple researchers working on the evolution of language have put forward the idea that the theoretical framework of usage-based approaches and Construction Grammar is highly suitable for modelling the emergence of human language from pre-linguistic or proto-linguistic communication systems. This also raises the question of whether usage-based and constructionist approaches can be integrated with the analysis of animal communication systems. In this paper, we review possible avenues where usage-based, constructionist approaches can make contact with animal communication research, which in turn also has implications for theories of language evolution. To this end, we first give an overview of key assumptions of usage-based and constructionist approaches before reviewing some key issues in animal communication research through the lens of usage-based, constructionist approaches. Specifically, we will discuss how research on alarm calls, gestural communication and symbol-trained animals can be brought into contact with usage-based, constructionist theorizing. We argue that a constructionist view of animal communication can yield new perspectives on its relation to human language, which in turn has important implications regarding the evolution of language. Importantly, this theoretical approach also generates hypotheses that have the potential of complementing and extending results from the more formalist approaches that often underlie current animal communication research.

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