@article {57888, title = {Vocal divergence is concordant with genomic evidence for strong reproductive isolation in grasshopper mice ( Onychomys )}, year = {2019}, abstract = {

Behavioral barriers to gene flow often evolve faster than intrinsic incompatibilities and can eliminate the opportunity for hybridization between interfertile species. While acoustic signal divergence is a common driver of premating isolation in birds and in- sects, its contribution to speciation in mammals is less studied. Here we characterize the incidence of, and potential barriers to, hybridization among three closely related species of grasshopper mice (genus Onychomys). All three species use long-distance acoustic signals to attract and localize mates; Onychomys arenicola and Onychomys torridus are acoustically similar and morphologically cryptic whereas Onychomys leu- cogaster is larger and acoustically distinct. We used genotyping-by-sequencing (GBS) to test for evidence of introgression in 227 mice from allopatric and sympatric lo- calities in the western United States and northern Mexico. We conducted laboratory mating trials for all species pairs to assess reproductive compatibility, and recorded vocalizations from O. arenicola and O. torridus in sympatry and allopatry to test for evidence of acoustic character displacement. Hybridization was rare in nature and, contrary to prior evidence for O. torridus/O. arenicola hybrids, only involved O. leu- cogaster and O. arenicola. In contrast, laboratory crosses between O. torridus and O. arenicola produced litters whereas O. leucogaster and O. arenicola crosses did not. Call fundamental frequency in O. torridus and O. arenicola was indistinguishable in allopatry but significantly differentiated in sympatry, a pattern consistent with repro- ductive character displacement. These results suggest that assortative mating based on a long-distance signal is an important isolating mechanism between O. torridus and O. arenicola and highlight the importance of behavioral barriers in determining the permeability of species boundaries.

}, keywords = {acoustic communication, behavioral isolation, contact zone, hybridization, reproductive character displacement, speciation}, doi = {10.1002/ece3.5770}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ece3.5770https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.5770https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.5770https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ece3.5770}, author = {Campbell, Polly and Ar{\'e}valo, Lena and Martin, Heather and Chen, Charles and Sun, Shuzhen and Rowe, Ashlee H. and Webster, Michael S. and Searle, Jeremy B. and Pasch, Bret} } @article {53375, title = {Presence of a potential competitor and its individual identity modulate ultrasonic vocalizations in male hamsters}, journal = {Animal Behaviour}, volume = {145}, year = {2018}, month = {Jan-11-2018}, pages = {11 - 27}, abstract = {

Animal communication takes place in a complex environment that is constantly modulated by particular social conditions. The majority of examples of signalling behaviours modulated by social context involve the presence of an individual of a particular sex or one that simply represents general competition. However, the identity of the individuals and the social relationships among individuals could also significantly modulate acoustic behaviour. In this study, I examined whether the presence of another male competitor modulates the post-interaction vocal response of a male subject to an oestrous female stimulus in golden hamsters, Mesocricetus auratus. I found that the presence of a potential competitor during an interaction with a female across a wire-mesh barrier significantly decreased the duration, tempo and energy of \‘post-female calls\’ over time (experiment 1). Moreover, the call duration and energy of one-note simple calls changed over time depending on the identity of the stimulus male. Males that experienced social conflict and lost a fight maintained call duration and increased the energy of their calls over time, but only if the social interaction with the female was in the presence of another familiar neutral male and not in the presence of a familiar winner male (experiment 2). When the winner male stimulus was present, the duration and energy of the calls produced by the loser decreased with time. Individual recognition between familiar conspecifics with different shared experiences likely modulated the motivational state of the male subject and his vocal response after a social interaction with the female. This study provides new evidence that social complexity (competition and individual recognition) can induce dynamic changes of spectrotemporal features of hamster sexual ultrasonic vocalizations.

}, keywords = {familiarity, golden hamster, individual recognition, sexual ultrasonic vocalization, social defeat, Syrian hamster, USV duration, USV energy}, issn = {00033472}, doi = {10.1016/j.anbehav.2018.08.014}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0003347218302689https://api.elsevier.com/content/article/PII:S0003347218302689?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003347218302689?httpAccept=text/plain}, author = {Fern{\'a}ndez-Vargas, Marcela} } @article {53326, title = {Vocal Signals of Sexual Motivation in Male and Female Rodents}, journal = {Current Sexual Health Reports}, year = {2018}, month = {Jan-10-2020}, abstract = {

Purpose of the Review

Rodents produce ultrasonic vocalizations (USV) under different social contexts, including courtship and reproduction. The present review aims to summarize the behavioral, bioacoustical, and physiological evidence that USV are reliable signals of sexual motivation in both male and female rodents.

Recent Findings

USV are actively produced by both sexes during sexual interactions, contrary to earlier assumptions. Male-typical and female-typical vocal behaviors can be identified. Calling rates and acoustic parameters, such as call duration, frequency, and energy, can be modulated rapidly over time by motivational state and sexual context. USV produced in response to sexual context could be regulated by the brain on a moment-to-moment basis through non-classical mechanisms of steroid action. Finally, I provide some practical considerations for the acoustic and statistical analyses of these vocal signals.

Summary

USV can be used as signals of sexual motivation in both sexes to study brain and hormonal mechanisms underlying sexual behavior or sexual differentiation.

}, keywords = {bioacoustics, communication, Golden hamsters, House mouse, Nongenomic steroid action, Rats, Rodents, Sex steroids, Sexual behavior, Sexual motivation, Syrian hamsters, Ultrasonic vocalizations}, issn = {1548-3584}, doi = {10.1007/s11930-018-0179-9}, url = {http://link.springer.com/10.1007/s11930-018-0179-9}, author = {Fern{\'a}ndez-Vargas, Marcela} } @article {53256, title = {Testosterone pulses at the nest site modify ultrasonic vocalization types in a monogamous and territorial mouse}, journal = {Ethology}, volume = {124}, year = {2018}, pages = {804{\textendash}815}, abstract = {

Modulation of baseline testosterone (T) via long-lasting T implants alters territorial, sexual, and social behavior of animals in the field. Transient T increases occur in numerous species after social interactions, but these transient increases in T have not been manipulated in the field. In the laboratory, these T increases can influence future behavior for days, causing changes in social behavior and inducing preferences for specific locations. We manipulated transient increases in T in the field at the nests of the monogamous and territorial California mouse (Peromyscus californicus) to examine long-term (\>24 hr) changes in ultrasonic vocalizations (USVs). Males of bonded male\–female dyads (=pair) were administered a T injection (vs. saline) three times over seven days and USVs of the male\–female dyad were measured for three days after the last injection. At T nests, the male\–female dyad produced significantly more 1SV (one call SV: an SV is a sustained vocalization that is long in duration and low in modulation) and 4SV (four call SV) type USVs than controls, but no significant changes in aggressive barks. Overall, male\–female dyad mice at T nests produced a greater diversity in call types such that 1SV, 4SV, 5SV, and a complex sweep were produced at T nests but not control nests. There were significantly more USVs produced at T nests on night 2 after the final injection. There were no differences in spectral characteristics of SV calls or aggressive barks between T and control nests. The function of the changes that occurred is unknown, but is consistent with increased long-term changes in behavioral interactions with nest mates and may reflect T-induced conditioned place preferences to the nest site. Significantly, transient increases in T influence future acoustic communication under field conditions with competing biotic and abiotic stimuli.

}, keywords = {androgens, conditioned place preference, field, male-female dyad, pair bond, Peromyscus californicus, social behavior, vocal communication}, doi = {10.1111/eth.12812}, author = {Timonin, Mary E and Kalcounis-Rueppell, Matina C and Marler, Catherine A} } @mastersthesis {53116, title = {Using Bioacoustics to Examine the Effects of Industrial Disturbance on Owls and their Prey}, year = {2018}, school = {University of Alberta}, type = {PhD}, abstract = {

Anthropogenic disturbance is known to have negative population consequences and alter animal behaviour, and a growing body of research on the effects of anthropogenic noise is finding similar negative impacts on wildlife. Noise in natural environments can mask important acoustic signals used for animal communication. Owls use vocal communication to attract mates and defend territories, and rely on acoustic cues to locate their prey. Industrial noise has been shown to negatively affect owl hunting success and reduce foraging efficiency by affecting their ability to detect prey, but whether this results in reduced habitat suitability for owls in areas near industrial noise sources is largely unknown. It is also not known if the abundance of small mammals, the primary prey of owls, is affected by industrial noise. Communication between small mammals is unlikely to be directly affected by noise because they primarily communicate using olfactory rather than vocal signals, but small mammals could be indirectly affected through altered predation dynamics. I sought to determine if owls avoid the areas surrounding chronic industrial noise sources, if prey availability is affected by chronic industrial noise, and the relative importance of noise compared to other types of disturbance resulting from industrial development on owl habitat use. I used autonomous recording units and automated recognizers to survey for owls and scan recordings for owl vocalizations, to assess the impacts of disturbance from industrial development on owls in northeastern Alberta, a region that has seen increased development in the oil and gas industries in recent years. I found that barred owls (Strix varia), great horned owls (Bubo virginianus), and boreal owls (Aegolius funereus) were equally likely to occupy noisy sites compared to sites with no noise, indicating that site-level occupancy (representing a home range scale) was unaffected by the presence of noise sources on the landscape. I found no difference in abundance or activity of red-backed voles (Myodes gapperi)\ and deer mice (Peromyscus maniculatus), indicating that these important prey species are not strongly affected by noise. Finally, I found each owl species responded differently to the different disturbance types. Barred owls were less likely to be present in areas with greater proportions of human footprint and roads, whereas great horned owls were more tolerant to disturbance and were more likely to be present in areas with greater proportions of soft linear features (e.g. seismic lines, pipelines), though they did avoid areas with large industrial facilities. Boreal owl presence was more strongly affected by forest composition than disturbance; they prefer more coniferous forests, and it was less clear if they were sensitive or relatively tolerant to disturbance. Assessing the relative impacts of multiple types of disturbance and how the accumulation of disturbances can impact wildlife is important in understanding species declines and can help focus conservation efforts. My thesis contributes to research on the impacts of anthropogenic disturbance and suggests the effect of noise on barred owls, great horned owls, and boreal owls is minimal at the spatial scales I looked at. Similarly, the effect of noise on abundance and activity of red-backed voles and deer mice was weak, suggesting similar prey availability for owls. For the owl species I studied, forest composition and other types of disturbance on the landscape are more likely to influence their habitat use.

}, author = {Julia Shonfield} } @mastersthesis {52857, title = {The Auditory Sensitivity and Active Space of the Northern Grasshopper Mouse (Onychomys leucogaster) in Relation to Woody Plant Encroachment}, volume = {MSc}, year = {2018}, school = {Northern Arizona University}, abstract = {

Vocal communication is a critical component of mate choice and territoriality in many animals. The efficacy of communication depends on signal transmission through an often- cluttered environment. Anthropogenic-induced changes in vegetation structure may impact sound propagation and thus habitat quality, but few studies have explored this hypothesis. In the American Southwest, fire suppression and cattle grazing have facilitated displacement of grasslands by pinyon-juniper woodlands. Northern grasshopper mice (Onychomys
leucogaster) produce long-distance vocalizations to advertise their presence to rivals and potential mates and inhabit regions impacted by juniper encroachment. Here, we coupled acoustic recordings and physiological measurements of hearing sensitivity in the laboratory with sound transmission experiments in the field to estimate the active space of grasshopper mouse calls. We found that receivers are sensitive to loud (ca. 85 dB re: 20 \μPa at 1 m) 11.6 kHz calls at 30 dB and that calls travel 30 m (range: 20 \– 60 m). However, we found no effect of shrub encroachment on call propagation as juniper and grass density were inversely associated and\ both present barriers to a 9 cm mouse advertising at ground level. Our findings suggest that juniper encroachment does not affect sound propagation but may influence habitat quality through alternative mechanisms.

}, url = {https://search.proquest.com/openview/e347237ef0544cf639c2d95e4d50a22b}, author = {Dana M. Green} }