Darden, Safi K., Torben Dabelsteen, and Simon Boel Pedersen. 2003. A Potential Tool for Swift Fox (Vulpes velox) Conservation: Individuality of Long-Range Barking Sequences. Journal of Mammalogy:84(4),1417-1427.
ABSTRACT: Vocal individuality has been found in a number canid species. This natural variation can have applications in several aspects of species conservation, from behavioral studies to estimating population density or abundance. The swift fox (Vulpes velox) is a North American canid listed as endangered in Canada and extirpated, endangered, or threatened in parts of the United States. The barking sequence is a long-range vocalization in the species' vocal repertoire. It consists of a series of barks and is most common during the mating season. We analyzed barking sequences recorded in a standardized context from 20 captive individuals (3 females and 17 males) housed in large, single-pair enclosures at a swift fox breeding facility. Using a discriminant function analysis with 7 temporal and spectral variables measured on barking sequences, we were able to correctly classify 99% of sequences to the correct individual. The most important discriminating variable was the mean spacing of barks in a barking sequence. Potential applications of such vocal individuality are discussed.
Keywords: animal communication, Canidae, conservation, individuality, swift fox, vocalization, Vulpes velox.
Macias, Silvio, and Emanuel C. Mora. 2003. Variation in Echolocation Calls of Pteronotus quadridens (Chiropters: Mormoopidae) in Cuba. Journal of Mammalogy:84(4),1428-1436.
ABSTRACT: Echolocation calls were recorded from Pteronotus quadridens flying in the field and in an enclosed space. In the field, search calls contained 1 or 2 harmonics. Patterns of call design show a segment of quasi-constant frequency (QCF--2nd-harmonic at 81-84 kHz), followed by a downward frequency-modulated (FM) component. The 2nd harmonic was always more intense than the 1st. Search, approach, and terminal phases of calls were described during hunting sequences of P. quadridens. The transition between call phases was characterized by monotonic variations in some acoustic parameters, including a decrease in call duration and an increase in repetition rate, bandwidth, and slope of the FM component. We also analyzed calls emitted by bats flying in confined spaces that consistently contained 3 harmonics, of which the 2nd harmonic contained the greatest energy. The values of call duration were shorter and bandwidth was higher than values characterizing calls emitted during the search phase in the field.
Keywords: bats, call variation, echolocation, Pteronotus quadridens.
NOTE: There was a special section on social biology of rodents in this issue. These articles are probably tangential to bioacoustics (the focus is primarily on chemical communication), but here is the info for articles that may mention vocal communication:
Lacey, Eileen A., and Solomon, Nancy G. 2003. Social Biology of Rodents: Trends, Challenges, and Future Directions. Journal of Mammalogy:84(4), 1135-1140.
ABSTRACT: Papers in this Special Feature were presented at a symposium on the social biology of rodents that was held in June 2001 at the 81st Annual Meeting of the American Society of Mammalogists. Our decision to host a symposium on this topic resulted from our realization that although rodents have played a vital role in research on social behavior, no recent summaries of the social biology of these animals were available. Given the number of biological disciplines, research strategies, and species that are relevant to this topic, a comprehensive review of rodent social biology was not possible. Instead, in structuring the symposium, we chose to focus on a subset of behavioral issues for which studies of rodents currently are providing exciting new insights. Topics selected for inclusion--communication, kin recognition, philopatry, and sociality--are timely and are of considerable interest to biologists studying a wide array of animal taxa. Thus, papers presented in the symposium reflect recent advances not only in our knowledge of rodent social biology but also in our conceptual understanding of animal social behavior.
Keywords: communication, kin recognition, philopatry, rodents, social biology, sociality.
Mateo, Jill M. 2003. Kin Recognition in Ground Squirrels and Other Rodents. Journal of Mammalogy:84(4), 1163-1181.
ABSTRACT: Significant advances have been made in understanding kin recognition as it pertains to nepotism (preferential treatment of kin) and mate choice (optimization of inbreeding and outbreeding). Yet complementary knowledge about how animals discriminate conspecifics on the basis of genetic relatedness remains unclear for most species. Because of the diversity of their scent sources and highly developed olfactory systems, rodents present a unique opportunity for examining chemical communication and kin recognition as a function of sociality. I review general processes of kin recognition and summarize mechanisms of recognition used by rodents. As a case study, I also examine recognition systems of ground squirrels, relating odor production and perception to differences in patterns of nepotism. Belding's ground squirrels (Spermophilus beldingi) produce >= 2 odors (from oral and dorsal glands) that correlate with relatedness (kin labels), and they are able to use these odors to make precise discriminations among their unfamiliar relatives. Thus, S. beldingi can recognize their distant female kin and male kin, even though these kin are not treated nepotistically (e.g., through cooperative territory defense or alarm call production). Furthermore, S. beldingi use these kin labels and recognition abilities to interact differentially with conspecifics as a function of relatedness. In ground squirrels and in other rodents, components of the kin recognition process (production of recognition cues, discrimination of these cues, and differential treatment of conspecifics) have evolved differentially among even closely related species. Kin recognition abilities in the absence of nepotism might reflect selection for inbreeding avoidance mechanisms, in addition to sex-biased natal dispersal. Together, data and the review demonstrate that recognition abilities cannot be predicted on the basis of sociality alone and suggest that comparative analyses, by multiple assays of discrimination, might be necessary to understand variation in the function of kin recognition within and across species.
Keywords: ground squirrels, kin discrimination, kin recognition, mate choice, nepotism, odors, olfactory behavior, rodents, Spermophilus.
Tang-Martinez, Zuleyma. 2003. Emerging Themes and Future Challenges: Forgotten Rodents, Neglected Questions. Journal of Mammalogy:84(4),1212-1227.
ABSTRACT: I identify 4 topics for future research. 1) Our knowledge of rodents from the developing world is limited, yet recent evidence suggests that many species are highly social. I concentrate on South American rodents to demonstrate the wealth of information available when we study these taxa and incorporate the findings into our current paradigms of social evolution. 2) Relatively little is known about proximate mechanisms that govern social systems. Research on the neuroendocrine basis of pair-bond formation and paternal care has provided valuable insights, but many questions remain. 3) Mounting evidence indicates that, in addition to genetics, social environment can play a major role in behavioral and physiological development. Studies on effects of early social environment would contribute to our understanding of ontogeny of individual differences in social species. 4) Recent evidence suggests a significant geographic variation in social characteristics of some rodent species. The extent and ecological correlates of such intraspecific variation merit further investigation.
Keywords: early environment, geographic variation, Latin America, neuroendocrinology, rodents, sociality.
-------------------------------------------------------------------- Brian R. Mitchell Ph.D. Candidate University of California, Berkeley Department of Environmental Science, Policy and Management [EMAIL PROTECTED] --------------------------------------------------------------------
