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Male Calls (male + call)
Selected AbstractsDouble stimulation of the inner ear organs of an anuran species (Alytes cisternasii) with simple tonal advertisement callsJOURNAL OF ZOOLOGY, Issue 4 2003J. Bosch Midwife toads present one of the simplest calls in anurans, with the whole energy concentrated in a single band without frequency modulation. The tuning curves of the Iberian midwife toads Alytes cisternasii show the typical bimodal pattern in anurans, with two best excitatory frequencies at 0.412 kHz (corresponding to the amphibian papilla) and at 1.358 kHz (corresponding to the basilar papilla and matching the male call frequency). In this study, the hypothesis that complex calls arose in anurans because they were inherently more attractive to females, since they provided greater acoustic stimulation, was tested. However, our results indicate that splitting the call energy to stimulate both inner ear organs simultaneously, the male call is not more attractive to female midwife toads, but sometimes renders it unattractive. The biological role of the amphibian papilla is discussed in ecological and evolutionary terms. [source] Insect duets: underlying mechanisms and their evolutionPHYSIOLOGICAL ENTOMOLOGY, Issue 3 2003Winston J. Bailey Abstract., Duetting between the sexes in insects involves the use of airborne acoustic signals, substrate vibration and bioluminescence. Unlike avian duets, in which females may initiate the interaction, among insects the duet starts with the male, and the female usually provides a brief reply. Insect duets are characterized by low variance in the reply latency of the female (the time between a key element in the male call and the onset of the female's response). Duetting is reviewed principally in Orthoptera but also in Plecoptera, Hemiptera, Neuroptera and bioluminescence in the Coleoptera. The mechanisms of the duet are examined first, followed by evolution and the associated change in searching strategies of each sex. As defined, the duet has distinct temporal characteristics and these are compared with acoustic interactions among males in those species that exhibit male,male synchrony and alternation. For insects, the key element of a duet for species' recognition is low variance in the reply latency of females. In cases in which the male's initiating signal is extremely short, reply latencies become indicators of species' recognition. However, in those species in which the initiating male call is under selection through female choice, the male call is predictably longer and occasionally more complex. Under these circumstances, reply latencies often increase, creating an opportunity for alternative male tactics. When alternative tactics exist in nature, males may decrease the intensity of their call, insert a trigger pulse that signals to the female the end of its complex call, or males may even add a masking signal that obscures the competing signal. [source] Variation and Repeatability of Female Choice in a Chorusing Katydid, Ephippiger ephippiger: an Experimental Exploration of the Precedence EffectETHOLOGY, Issue 4 2004Michael D. Greenfield Female choice in various species of acoustic insects and anurans entails a psychoacoustic preference for male calls that lead their neighbors by a brief time interval. This discrimination, which can be termed a precedence effect, may select for various mechanisms with which males adjust call rhythm and thus reduce their incidence of ineffective following calls. At a collective level, alternating and synchronous choruses may emerge from these call timing mechanisms. Using playback experiments, we characterized the precedence effect in females of the katydid Ephippiger ephippiger, an alternating choruser in which males use a rhythm adjustment mechanism that prevents calling during brief intervals following their neighbors' calls. E. ephippiger females oriented toward leading male calls in >75% of trials when relatively young (<40 d old) and when playbacks were timed so that following calls began within 100,250 ms of the leading ones. However, this preference declined to below 60% as females aged and the interval separating leading and following call onsets increased. The strength of this precedence effect varied greatly between females, but within broad age classes the effect in a given female was statistically repeatable. Such repeatability indicates the possibility that additive genetic variance could be a significant component of variation in the precedence effect. We discuss the implications of our findings and inference on genetic variance for evolution of the precedence effect and for chorusing. [source] ADVERTISEMENT-CALL PREFERENCES IN DIPLOID-TETRAPLOID TREEFROGS (HYLA CHRYSOSCELIS AND HYLA VERSICOLOR): IMPLICATIONS FOR MATE CHOICE AND THE EVOLUTION OF COMMUNICATION SYSTEMSEVOLUTION, Issue 2 2005H. Carl Gerhardt Abstract Signals used for mate choice and receiver preferences are often assumed to coevolve in a lock-step fashion. However, sender-receiver coevolution can also be nonparallel: even if species differences in signals are mainly quantitative, females of some closely related species have qualitatively different preferences and underlying mechanisms. T o-alternative playback experiments using synthetic calls that differed in fine-scale temporal properties identified the receiver criteria in females of the treefrog Hyla chrysoscelis for comparison with female criteria in a cryptic tetraploid species (H. versicolor); detailed preference functions were also generated for both species based on natural patterns of variation in temporal properties. The species were similar in three respects: (1) pulses of constant frequency were as attractive as the frequency-modulated pulses typical of conspecific calls; (2) changes in preferences with temperature paralleled temperature-dependent changes in male calls; and (3) preference functions were unimodal, with weakly defined peaks estimated at values slightly higher than the estimated means in conspecific calls. There were also species differences: (1) preference function slopes were steeper in H. chrysoscelis than in H. versicolor; (2) preferences were more intensity independent in H. chrysoscelis than in H. versicolor; (3) a synergistic effect of differences in pulse rate and shape on preference strength occurred in H. versicolor but not in H. chrysoscelis; and (4) a preference for the pulse shape typical of conspecific calls was expressed at the species-typical pulse duration in H. versicolor but not in H. chrysoscelis. However, females of H. chrysoscelis did express a preference based on pulse shape when tested with longer-than-average pulses, suggesting a hypothesis that could account for some examples of nonparallel coevolution. Namely, preferences can be hidden or revealed depending on the direction of quantitative change in a signal property relative to the threshold for resolving differences in that property. The results of the experiments reported here also predict patterns of mate choice within and between contemporary populations. First, intraspecific mate choice in both species is expected to be strongly influenced by variation in temperature among calling males. Second, simultaneous differences in pulse rate and pulse shape are required for effective species discrimination by females of H. versicolor but not by females of H. chrysoscelis. Third, there is greater potential for sexual selection within populations and for discrimination against calls produced by males in other geographically remote populations in H. chrysoscelis than in H. versicolor. [source] Intraguild interactions promote assortative mating and affect sexual attractiveness in a phytophagous flyBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009TOM READER Changes in acoustic and substrate-borne sexual signals in phytophagous insects associated with host plant shifts are known to have the potential to promote assortative mating, reproductive isolation and speciation. In this article, we ask whether the switch between pure herbivory and intraguild predation (IGP), which is common amongst phytophagous insects, has similar potential. Male flies in the genus Lipara (Diptera: Chloropidae) search for females by vibrating reed stems and waiting for a reply. By kleptoparasitizing other phytophagous species in the genus (a form of IGP), Lipara rufitarsis can increase its nonsexual fitness considerably. We looked at the impact of IGP on the timing of hatching, body size and attractiveness of male calls in L. rufitarsis. L. rufitarsis males that had engaged in IGP hatched significantly earlier than purely phytophagous flies and were significantly larger, but their calls were less likely to elicit responses from females during playback experiments. We conclude that, although behavioural observations of females provided no evidence of ,like preferring like', changes in phenology associated with IGP are likely to promote assortative mating in this system. The general preference of females for the calls of smaller males is a phenomenon worthy of further study: it may have no adaptive significance, or it may indicate that mating with large males is associated with a fitness cost. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 171,180. [source] The highly specialized vocal tract of the male Mongolian gazelle (Procapra gutturosa Pallas, 1777 , Mammalia, Bovidae)JOURNAL OF ANATOMY, Issue 5 2003R. Frey Abstract The entire head and neck of a wild adult male Mongolian gazelle (Procapra gutturosa) was dissected with special reference to its enlarged larynx. Two additional adult male specimens taken from the wild were analysed by computer tomography. The sternomandibularis, omohyoideus, thyrohyoideus and hyoepiglotticus muscles are particularly enlarged and improve laryngeal suspension and stabilization. The epiglottis is exceptionally large. A permanent laryngeal descent is associated with the evolution of an unpaired palatinal pharyngeal pouch. A certain momentary descent seems to occur during vocalization. The high lateral walls of the thyroid cartilage are ventrally connected by a broad keel. The large thyroarytenoid muscle is divided into two portions: a rostral ventricularis and a caudal vocalis muscle. A paired lateral laryngeal ventricle projects between these two muscles. The massive vocal fold is large and lacks any rostrally directed flexible structures. It is supported by a large cymbal-like fibroelastic pad. Vocal tract length was measured in the course of dissection and in computer tomographic images. Two representative spectrograms, one of an adult male and one of a juvenile, recorded in the natural habitat of the Mongolian gazelle are presented. In the spectrograms, the centre frequency of the lowest band is about 500 Hz in the adult male and about 790 Hz in the juvenile. The low pitch of the adult male's call is ascribed to the evolutionary mass increase and elongation of the vocal folds. In the habitat of P. gutturosa a call with a low pitch and, thus, with an almost homogeneous directivity around the head of the vocalizing animal may be optimally suited for multidirectional advertisement calls during the rut. The signal range of an adult male's call in its natural habitat can therefore be expected to be larger than the high-pitched call of a juvenile. [source] Long-distance signals influence assessment of close range mating displays in the field cricket, Gryllus integerBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2010ANNE S. LEONARD Male sexual displays often include components detected across long distances, and those perceived only at close range. Understanding what information females gain from each component of a complex display and how they use these signals to make decisions are questions of major interest in sexual selection research. We evaluated content-based hypotheses (,redundant signals' and ,multiple messages') for the courtship displays of field crickets (Gryllus integer) by measuring female responses to males' long-distance calling song (calls) and close-range chemical cues. Females' responses to a male's calls and chemical cues were uncorrelated, supporting the ,multiple messages' hypothesis. We also tested the ,inter-signal interaction' hypothesis by investigating how long-distance calls influence evaluation of close-range courtship. The relationship between long- and close-range signals was complex and conditional: females accepted close-range courtship more quickly after exposure to attractive calling song than they did after exposure to either unattractive calling song or silence, and unattractive calls were no more or less effective than silence. This inter-signal interaction could affect our understanding of mate choice in species with multiple mating signals because it implies that females may save time and energy by not assessing the close-range signals of attractive long-distance signalers. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 856,865. [source] | ||||||||||