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Defense of territories in many animal species involves the advertisement of territory holder quality by acoustic signaling. In the sac-winged bat Saccopteryx bilineata, males engage in territorial countersinging when reoccupying their day-roost territories in the morning and in the evening before abandoning the roost for the night. Females roost mainly in male territories, and territory holders are reproductively more successful than nonterritorial males. In territorial songs of male S. bilineata, we distinguished 6 syllable types and parameterized their acoustic properties. The analysis of 11 microsatellite loci allowed assignments of juveniles to their parents. Males had a higher reproductive success both when they uttered more territorial songs per day and when their long buzz syllables had a lower end frequency of the fundamental harmonic. Long buzzes had a harsh quality due to a pulsation of the fundamental frequency at the syllable onset and also had the highest sound pressure level of all syllable types in most territorial songs. Territorial songs and especially long buzz syllables are thus likely to advertise territory holder quality and competitive ability. Copyright 2006.

Vocal group signatures facilitate group cohesion or the exclusion of nongroup members and thus greatly affect the social system of any given species. This is especially significant for highly mobile animals such as bats. The greater sac-winged bat, Saccopteryx bilineata, lives in a harem-based resource defence polygyny with patrilineal kin groups and female-biased natal dispersal. Pups of both sexes produce isolation calls to elicit maternal care. We analysed isolation calls from 25 pups born in seven different social groups in search of vocal signatures. In addition to a constant individual signature, isolation calls exhibited a group signature that became more prominent during ontogeny. Call convergence of fellow pups was independent of relatedness among pups and not driven by maturation effects, showing that the group signature was acquired through social modification, a form of vocal production learning. Behavioural observations of free-living bats indicated that isolation calls were used by adult males to appease more dominant males and to court unfamiliar females. The learned group signature in isolation calls may function as a ‘password’ that reliably associates individuals with their natal colony. This, in turn, could facilitate male harem acquisition and female inbreeding avoidance in the polygynous S. bilineata. The flexibility inherent in the vocal-learning process guarantees that crucial information can be promoted even under shifting social circumstances.

We recorded social vocalizations from two sympatric species of glossophagine bats, Glossophaga soricina and G. commissarisi, using habituated captive groups that were housed in separate flight cages. Whenever possible, the species-specific vocalization types were described in the light of the social context in which they were produced. Several vocalization types within each species’ repertoire had remarkable similarities to vocalization types in the other species’ repertoire. Out of these, four vocalization types with interspecific acoustic similarities (approach pulses, distress calls, aggressive trills, and alert calls) were used in similar behavioral contexts in both species. Approach pulses were produced whenever a bat was flying towards an already occupied roost. Distress calls were uttered whenever a bat was attacked by conspecifics or restrained by the observer, whereas aggressive trills were produced during aggressive encounters prior to physical contact. Alert calls were uttered when bats were disturbed or when several individuals were circling the same location. The interspecific similarity of both the social context and the acoustic structure of vocalization types suggest that the potential for interspecific communication is high in G. soricina and G. commissarisi.

In males of the grasshopper Chorthippus biguttulus the relationship between song and mating success was investigated in three isolated field populations of individually marked animals within their natural habitat. In a population with muted males (forewings removed), females mated on average 1.7 days later than in a population with intact males. But approximately 14 days after the imaginal moult, roughly corresponding with the time of the first oviposition, 100% of females in both populations had mated. In a further test population, females with a choice between singing and mute males mated almost exclusively (16 from 17 observed copulations) with the intact, singing males. The chance encounter frequency of a male and female was equally high for all populations (on average one encounter every 1.2 h). Different encounter probabilities cannot therefore have caused either mating delay in the population with muted males or preferential selection of intact partners.

Summary In mammals, adult behaviour patterns are often expressed by juveniles throughout ontogeny. In bats, many social behaviours develop before pups are weaned, but the ontogeny of social behaviours in juvenile bats is largely unexplored. We studied bat pups’ social behaviour, specifically the solicitations for maternal care in the greater sac-winged bat, Saccopteryx bilineata. Solicitation periods were prolonged (up to 25 min) and consisted of conspicuous behavioural interactions between pups and their mothers. Since solicitation periods could be initiated by pups or mothers, their duration is probably not caused by a conflict over nursing alone. Solicitation periods were the second most prevalent use of activity time in pups. Some pup behaviours resembled the courtship behaviours of adult males and these incipient courtship behaviours occurred most often within solicitation periods. Both length and complexity of solicitation periods increased significantly during ontogeny but there was no significant difference between male and female pups. Also, the activity outside of solicitation periods was not significantly different between pups of both sexes, even though their activity differs remarkably as adults. Prolonged solicitation periods of S. bilineata pups might be comparable to mammalian play and potentially function as practice for adult courtship behaviours.

Most bat species inhabit roosting sites in whichthey are well concealed during the day, such ascaves or tree holes, whereas others roost in exposedlocations on tree trunks or branches (Kunz and Lum -sden, 2003). For the latter, it is essential to appearcryptic in order to avoid predation or disturbance atthe day-roost. Several traits have evolved to enhancethe bats’ cryptic appearance, including cryptic col-oration (e.g., the greenish wings of the foliage-roost-ing bat

Like many other mammals, Saccopteryx bilineata exhibits a polygynous mating system, in which each male defends a group of females called a harem. Colonies consist of several harems, and nonharem males roost adjacent to harems. Unlike most other mammals, females disperse from their natal colony and most juvenile males remain in it. Thus, colonies consist of patrilines, which promotes intense local mate competition. Females are in estrus during a few weeks at the end of the rainy season. Mating is most likely initiated by females and preceded by intense courtship displays of males. Forty percent of colony males do not sire any offspring during their tenure in the colony, whereas a few males can sire up to 6 offspring in a single year. Males use olfactory, visual, and acoustic signals for courtship, and they demonstrate territory ownership by scent marks, lowfrequency calls, and visual displays. Harem males sire on average more offspring than do nonharem males but produce only 30% of the offspring within their own harem territory, with 70% being sired by other harem males or nonharem males. Reproductive success of males increases with decreasing size, fluctuating asymmetry, and fundamental frequency of territorial calls. In addition, females that are closely related to the harem holder are more likely to mate with other males than with the harem holder. Sexual selection in S. bilineata is most likely influenced by intense local mate competition caused by scarce roosts and the patrilineal organization of colonies.

In many animal species, individuals compete for resources but avoid escalated conflicts by threat displays, i.e. a mutual signalling behaviour that enables the opponents to predict the outcome of the conflict without the necessity of actual fighting. For example, territory holders may use acoustic signals to communicate not only their own identity and the borders of their territory but also their competitive quality, fighting ability and motivation. Here, we show that male sac-winged bats, Saccopteryx bilineata, adjust their vocal territorial displays according to the fundamental frequency of territorial songs of their opponents. In playback experiments with territorial males, low-frequency stimuli elicited a higher territorial song rate and length than high-frequency stimuli. Male S. bilineata that sing more often and with lower fundamental frequencies have been shown to sire more offspring than their competitors. Fundamental frequency of territorial songs, hence, may reveal male quality and, consequently, the resulting threat posed to competing males. We argue that this is reflected in the increased response of competitors to low-frequency territorial songs shown here. Such competitive signalling behaviour has been shown in a few mammal species like red deer and baboons but, thus far, not in bats.

We investigated the acoustical component of the recognition process leading to successful mother–pup reunions in the greater sac-winged bat, Saccopteryx bilineata , using both a statistical approach and playback experiments. Statistical evidence for individual distinctiveness was found in the isolation calls uttered by pups and, to a weaker degree, in the echolocation pulse trains emitted by mothers. In contrast to other bat species, isolation calls of S. bilineata pups were complex and multisyllabic, with most of the vocal signature information encoded in the composite syllables at the end of calls. Playback experiments with free-living bats revealed that mothers were able to discriminate between their own pup and an alien young on the basis of isolation calls alone, which confirms the results of the acoustical analysis on vocal signatures in isolation calls. Pups, on the other hand, indiscriminately vocalized in response to echolocation pulse trains from their own and alien mothers, rendering the mother–pup recognition process unidirectional. The one-sidedness of the vocal recognition process in S. bilineata as well as in other bat species might be explained by a lack of selection pressures that shape mutual vocal parent–offspring recognition in other species of mammals and birds. To our knowledge, this study is the first in which playbacks were used to elicit antiphonal calling behaviour between bat mothers and pups experimentally. We argue that vocal responses to playback stimuli are a more feasible and reliable response measure for conducting mother–pup recognition playbacks in bats than the phonotaxis behaviour used in the past.

Since its description in 2001 Alcathoe's myotis (Myotis alcathoe) was recorded from several locations across Europe. Here we describe the first records of this species from Germany, Poland, Albania, and from the European part of Turkey, including the northernmost locality in central Germany (51°23′N, 11°01′E). Compilation of all up-to-date records shows that M. alcathoe has a wide European distribution although it seems to be rare at most places. The habitats where the bat was recorded are natural, moist and deciduous forests with old trees and water streams as can be found, for example, in canyons or forests of alluvial origin. Such habitats suggest that the species probably has a more continuous and wider distribution than currently known and might be expected to occur even further to the North.

Neotropical nectar-feeding bats (Glossophaginae) are highly specialized in the exploitation of floral nectar and have one of the highest mass-specific metabolic rates among mammals. Nevertheless, they are distributed throughout the tropics and subtropics over a wide elevational range, and thus encounter many extreme and energetically challenging environmental conditions. Depressing their otherwise high metabolic rate, e.g., in situations of food restriction, might be an important adaptive physiological strategy in these dietary specialists. We investigated the thermoregulatory behavior of captive 10-g nectar feeding bats (Glossophaga soricina; Chiroptera, Phyllostomidae) under variable ambient temperatures (T a) and feeding regimes and predicted that bats would use torpor as an energy-conserving behavior under energetic constraints. All tested animals entered torpor in response to energetic restrictions and the depth of torpor was dependent on the body condition of the animals and hence on their degree of physiological constraints. Periods of torpor with body temperatures (T b) below 34°C were precisely adjusted to the photoperiod. The median length of diurnal torpor was 11.43 h. The lowest T b measured was 21°C at a T a of 19°C. Estimated energy savings due to torpor were considerable, with reductions in metabolic rate to as low as 5% of the metabolic rate of normothermic bats at the same T a. However, contrary to temperate zone bats that also employ diurnal torpor, G. soricina regulated their T b to the highest possible levels given the present energetic supplies. To summarize, G. soricina is a precise thermoregulator, which strategically employs thermoregulatory behavior in order to decrease its energy expenditure when under energetic restrictions. This adaptation may play a crucial role in the distribution and the assembly of communities of nectar-feeding bats and may point to a general capacity for torpor in tropical bats.

The songflight and the territorial behaviour of courting male pipistrelles (Pipistrellus pipistrellus) were observed in an urban habitat of this bat species, in the city of Bayreuth in Bavaria. (1) Within the city limits, from the middle of July to the end of October but most intensively in September, the male bats occupied courtship territories averaging about 200 m in diameter. At night they patrolled these territories along regular flight routes emitting characteristic advertisement calls. By day they sheltered in crevices in buildings. (2) The courtship territories were densely distributed in the center of the inner city and rarer at the outskirts. As all known larger winter roosts as well as the ‘invasion centers’ (typical late summer swarming sites of this species) also were in the inner city, territories were situated around winter quarters, but not in the vicinity of the nursery roosts, which were lying at the edge of the city and outside it. (3) The males evidently arrange their courtship territories in such a way that as many females as possible pass through them when they inspect the winter roosts. That is, they are not defending resources important to the females; instead, they position their courtship territories near the resources the females require. As male territories are densely packed, the males offer a possibility for mate choice to the females, so that the mating system also bears some likeness to a lek.

SUMMARYEcholocating bats emit ultrasonic calls through their mouth or their nostrils and receive echoes from objects with both their ears. Information conveyed in the echoes is the basis for their three-dimensional acoustic perception of the surroundings. The direction of an object is encoded in binaural echo differences, i.e. on the one hand in the different arrival times of its echo at the two ears, and on the other hand in spectral differences through direction-dependent frequency filtering of head and pinnae. Insufficient attention has been paid, however, to the fact that three-dimensional objects produce structured spatial echo fields, and that the position of the ear in this field determines the echo it receives. We were interested to determine whether the two ears, in addition to direction-specific echo differences, receive object-specific echo disparities that might be useful for the bat. Our measurements with an artificial bat head, which consisted of two microphones and a small ultrasound loudspeaker arranged to resemble a bat's ears and mouth, revealed that echoes at the two ears differed largely depending on the shape and orientation of the echo-giving object. Binaural echo disparities of a bat-pollinated flower did indeed carry information about the orientation and, to a lesser extent, the shape of the flower. During flower approach such object-specific binaural echo disparities even exceed the binaural differences encoding direction of echo incidence, because the echo from the flower in front undergoes the same directional filtering by the two symmetrical ears. Nectar-feeding bats could use these object-specific binaural echo disparities not only to determine the object's orientation relative to the approaching bat, facilitating flight planning, but also to improve object recognition through spatial reconstruction of details of the object creating the echo. Our results suggest that the evaluation of binaural echo disparity has a greater importance for these tasks than has previously been assumed.

SUMMARY Echolocating bats obtain three-dimensional images of their surroundings in complete darkness by emitting sonar signals and evaluating returning echoes. When flying close to objects, bats risk collision and therefore depend on the accuracy of images – particularly in the perceived distance of obstacles, which is coded by the time delay between call and echo. Yet, during flight, such accuracy is perturbed first because bats call and receive echoes at different positions and second because echoes are modified by Doppler shifts. Certain call designs avoid both sources of ranging error, but only for a limited range of distances [the `distance of focus' (DOF)]. Here, we show that whiskered bats (Myotis mystacinus) using broadband echolocation calls adjust call design in a range-dependent manner so that nearby obstacles are localised accurately. Such behaviour is adaptive because it reduces collision risk. The bats also reduced call duration to some extent as they approached obstacles so that most returning echoes arrived after they finished calling. This reduction in call duration during the approach to obstacles was neither the only nor the main factor that influenced DOF. Indeed, both duration and bandwidth of calls influenced DOF independently, with lower bandwidths and longer durations giving greater DOF. Our findings give a new perspective on the adaptive significance of echolocation call design in nature and have implications for sonar engineering.

Chorthippus lacustris is an endemic grasshopper (Orthoptera) species in Epirus, Greece. Its population status, habitat characteristics, and relation to historical and current human land use are investigated. The species has a restricted and fragmented distribution pattern. Five locations, four within Pamvotida Lake basin and one in Lake Paramythia, cover a total of 0.12 km2. It is strongly dependent on wet grasslands, flooded on a seasonal basis. The greatest population density is recorded in the site with the greatest diversity of dominant plant species. Ch. lacustris is estimated to have lost 85–99% of its habitat during the last 50 years due to wetland drainage. The main threat to the species survival is further habitat loss by urbanisation around Pamvotida Lake and by land conversion to agriculture in Paramythia Lake, even though both sites belong to the Natura 2000 network. The species status is Critically Endangered and it should be listed in Annex II of the Habitat Directive (92/43/EEC) as a priority species for conservation. Restoring wet grasslands, protecting them from further urbanisation and drainage, and monitoring species population are the main measures proposed for its conservation.

We studied the echolocation calls emitted by Phyllops falcatus (Chiroptera: Phyllostomidae) during foraging, in the field and in the lab. Calls emitted in free flight, in a more or less uncluttered situation, were about 4.5 ms (up to 5.3 ms) long and characterized by a sweep of the first harmonic (= fundamental) from ca. 73 kHz down to about 23 kHz, which is unusually large for phyllostomid bats. A less intense second harmonic was always present. The intervals between pulses varied between 55 and 170 ms with a mean of about 110 ms. During approach to bushes or trees (or during flight in confined space between bushes), or in the flight room, calls became shorter (ca. 2 ms) and more energy was allocated to the second harmonic, sometimes also a third harmonic appeared. During approach to a fruit calls were further shortened (about 1 ms or less), and call frequency increased to about 5 calls/100 ms, calls often being grouped. The large bandwidth of the first harmonic separates Phyllops from all other Cuban bat species and allows identification in the field.

In the duetting grasshopper Chorthippus biguttulus, a female's decision to reply to a conspecific male is based on the evaluation of a number of features of the male's song, which consists of uninterrupted syllables separated by pauses. Female responses are tuned to a restricted range of pause durations. However, males produce songs with noisy rather than silent pauses, which should make the measurement of pause durations more difficult for the female. We examined the adaptive value of these noisy pauses by testing female responses to (1) pairs of natural phrases, which differed only with respect to clear or noisy syllable pauses, and (2) synthetic phrases, in which the syllable onset accentuations and noise levels in the pauses were systematically varied. There was considerable variation between females, both in their preference for clear or noisy pauses in natural phrases, and in the optimal combinations of syllable onset accentuations and noise levels in pauses that they preferred in synthetic phrases. The response profiles of individual females were consistent. The experiments with synthetic phrases showed that, on average, females preferred more extreme values of syllable onset accentuations than were present in male songs. Noisy pauses increased the range of syllable pause durations accepted by females. The results suggest that noisy pauses could buffer signallers against the negative consequences of both signal degradation during transmission and extreme receiver choosiness.

Vocalisations of many songbirds, anurans, and insects are shaped by sexual selection. Males acoustically compete for territories, and females choose their mates by means of male courtship songs. In courtship, richness and complexity of elements are often favoured characters. Only a few examples of complex songs are known in mammals. Males of the harem-polygynous sac-winged bat (Saccopteryx bilineata, Emballonuridae) have an uncommonly complex vocal repertoire, and different song types of males are used in the context of territorial defence and in courting females. We classified the daytime vocalisations of 16 male S. bilineata from a colony in Costa Rica, both on the basis of their acoustical properties and the social context in which they occurred. Seven vocalisation types were differentiated: echolocation pulses, barks, chatter, whistles, screeches, territorial songs and courtship songs. Territorial songs were short, rather stereotyped and not obviously directed towards a certain conspecific. They appear to be of importance in male competition for harem territories, in which females roost during the day. Courtship songs were exclusively observed when males displayed towards a female; they were long and complex, and consisted of highly variable elements (“calls”). We classified the calls in courtship songs of six males into call types, based on acoustical properties, mainly spectral purity and duration. Four call types are described in detail: trills, noise-bursts, “short tonal” calls, and “quasi constant frequency” calls. Twelve parameter values were extracted from the most common call type, the trill. Discriminant function analysis of trills showed that different males had different repertoires. This could allow females to use trill parameters for recognition of individual males and thus for mate choice.

Glossophagine bats (Phyllostomidae, Glossophaginae) are specialized visitors to the flowers of several hundred species of neotropical plants. They are able to exploit flowers in hovering flight by imbibing nectar with a highly protrusile brush-tip tongue. As tongue extension is achieved by muscular and vasohydraulic mechanisms, its operational length can be inferred only from actively feeding animals. For this study, we measured maximum tongue extensions during nectar feeding in 9 species of glossophagine bats. We trained bats to feed from vertically oriented glass test tubes (9- and 15-mm inside diameter). The maximum depth of nectar drainage by a bat was recorded as maximum operational tongue length. Measured operational tongue lengths were in the range of the total body length of bats. The record length was 77 mm (in tubes with 15-mm inside diameter) in the 17-g flower specialist Choeronycteris mexicana. This compares with only 11–24 mm in the nonglossophagine frugivorous bat Carollia perspici...

SUMMARY Nectar-feeding glossophagine bats searching for flowers are guided by their echolocation system as well as olfactory cues in detecting and recognizing nectar sources. Therefore, chiropterophilous plants, which depend on these bats as pollinators, may be expected to have evolved acoustically conspicuous flowers that facilitate detection. As it is poorly understood how bats manage to find and recognize flowers acoustically, we investigated the echoes of some of the flowers pollinated by bats. Echoes of bell-shaped bat-pollinated flowers have characteristic features with respect to the echoes they reflect to a calling bat and differ from the echoes of leaves or other objects in their surroundings: the echoes are comparatively long and of complex spectral composition. Owing to the specific shape of the flowers, characteristic `spectral directional patterns' result when the spectra of the echoes are plotted against the angle of sound incidence. We suggest that bats are able to recognize such flowers — and probably other objects as well — not only by a characteristic spectral composition of the echo but also by comparing sequential echoes, at the same time taking into account their exact calling position relative to the object.

Alternative tactics in reproductive behavior enable individuals to maximize their fitness in relation to competitors in the same population. In many taxa, territoriality is a common tactic of males to increase their reproductive success. In the bat Saccopteryx bilineata, territorial males defend roosting areas for females against other males and court females throughout the year. Peripheral males in the same colonies do not defend territories but compete with territorial males for reproduction with females. In this study, we monitored the behavior of the males in a natural colony over three reproductive seasons. We compared morphological and age data and measured the reproductive output of males adopting the territorial or peripheral tactic. No differences in body size or weight were detected between male types, but the probability of adopting a tactic seemed to be age dependent. Peripherals were often young males and replaced territorials in several cases, whereas the opposite case was not observed. Peripherals were not excluded from reproduction, but territorials were more likely to reproduce. Variation in reproductive success was high within both male tactics, and the reproductive success of some peripherals was comparable to territorials, but, on average, the reproductive success of territorials was more than twice as high. Therefore, behavioral tactics do not seem to be equally profitable in general but may represent different phases in the reproductive life of many S. bilineata males. Copyright 2002.

Saccopteryx bilineata has a polygynous mating system in which males defend females in a harem territory. Harem defense and courtship include energetically costly flight maneuvers and hovering displays. We tested if (1) harem males have a greater field metabolic rate than non-harem males or females and if (2) the field metabolic rate of harem males is correlated with the number of females in a harem territory. We measured the energy budget in 32 S. bilineata with the doubly labeled water method and compared these estimates with behavioral observations in the daytime roost. Among adult bats, field metabolic rate varied with body mass by an exponent of approximately two. We found no significant difference in field metabolic rate or mass-specific field metabolic rate between harem and non-harem males. The mass-specific field metabolic rate of harem-males increased with harem size. The latter finding supports the hypothesis that the energy costs of courtship display and territorial defense influence the energy budget of harem males. Overall, field metabolic rates of S. bilineata were lower than those of similarly sized bats of the temperate zone and only 2.3 times above the basal metabolic rate recorded for this species. We suggest that male S. bilineata did not take advantage of their metabolic capacity because a prudent allocation of energy to activities of harem maintenance is an adaptive strategy for males in this mating system.

We studied the paternity in a colony of the harem-polygynous white-lined bat Saccopteryx bilineata by microsatellite typing and compared the data with group composition and stability. Although we recorded a high stability for harem groups, neither spatial proximity of males to harem females nor harem ownership allowed us to predict the paternity of the next year's harem offspring. Eight out of 28 juveniles were fathered by holders of the harem in which they were born, while the other 20 represent Extra-Harem-Young (EHY). 50% of EHY were fathered by males from outside the colony and 50% by other harem holders or peripheral males of the colony. On average, reproductive success of harem holders (1.2 offspring/year) was higher compared with peripheral males (0.4 offspring/year). Harem size seemed not to influence reproductive success of harem holders. Although maintaining of a territory seems to be costly for a harem male, his ability to control the females of his harem may be restricted; instead female Saccopteryx bilineata appear to have a high potential for female choice.

Many gomphocerine grasshoppers communicate acoustically: a male's calling song is answered by a female which is approached phonotactically by the male. Signals and recognition mechanisms were investigated in Chorthippus biguttulus with regard to the cues which allow sex discrimination. (1) The stridulatory files on the hindfemur of both sexes are homologous in that they are derived from the same row of bristles, but convergent with respect to the “pegs”. In males the pegs are derived from the bristles, and in females from the wall of the bristle's cup. (2) Male and female songs are generated by similar, probably homologous motor programs, but differ in the duration, intensity, “gappyness” of syllables, risetime of pulses, and the frequency spectra. The hindleg co-ordination during stridulation and the resulting temporal song patterns are less variable in males than in females. (3) For both sexes, recognition of a mate's signal depends on species-specific syllable structure. For males it is essential that the female syllables consist of distinct short pulses, whereas females reject “gappy” syllables. Males strongly prefer “ramped” pulses, females respond to syllables irrespective of steeply or slowly rising ramps. Males react only to the low-frequency component, whereas females prefer spectra containing both, low and high frequency components.

The Chorthippus biguttulus group distributed in the west Palaearctic, while intensively examined in Europe, is poorly known in the glacial refugia such as Anatolia. This produces constraints in making accurate statements about evolution and the biogeography of the group. The C. brunneus subgroup of this lineage is examined using large amounts of morphological and song data from Anatolia (Asian Turkey) and representatives from Europe. Song and morphology in combination suggested three species to be found in Anatolia. The first is C. bornhalmi Harz which is also known from south-east Europe. The other two are new species: Chorthippus antecessor sp. n. and Chorthippus relicticus sp. n.. Morphologically, C. antecessor sp. n. is the most aberrant species of the C. brunneus subgroup, but is similar to C. bornhalmi in song. The specific song and morphology (the aberrant number of stridulatory pegs) define C. relicticus as a new species and both also indicate that it is closely related to C. brunneus and C. jacobsi. A song and morphology based phyloylogenetic assumption for C. brunneus subgroup suggests C. antecessor, C. bornhalmi and C. miramae to constitute one clade and C. brunneus, C. jacobsi and C. relicticus another. The scenario suggested for their evolution assume the following steps: (i) divergence of C. bornhalmi from a C. antecessor like ancestor, (ii) derivation of an ancestral population (which later give rise to C. brunneus + C. jacobsi + C. relicticus) from a C. bornhalmi like ancestor, and (iii) later fragmentation of this ancestral population to result in the present three species (C. brunneus + C. jacobsi + C. relicticus). All of these events seem to be correlated with the climatic cycles during Pleistocene. The conclusion is that the two new species are range-restricted, vulnerable species as is the case for many other taxa present in the Mediterranean Taurus biodiversity hotspot.

Mating in the bushcricket Metaplastes ornatus Ramme 1931 entails a number of peculiar genital couplings that precede the transfer of the large spermatophore. During these “phase-I couplings,” the male introduces his specially structured subgenital plate into the female's genital chamber, performs back-and-forth movements, and turns her genital chamber inside out when he withdraws, whereupon the female carefully cleans her everted genital chamber with her mouthparts. During the last coupling (phase II) the male's subgenital plate is not introduced but the large spermatophore, which averages 22% of a male's body weight, is transferred. Counts of sperm in the spermathecae of females suggested that the phase-I couplings, which occur prior to spermatophore transfer, function to remove, or at least to reduce, the sperm of a female's previous mates. The form of the keel of the male's subgenital plate, its position within the female's genital tract during phase-I couplings, and the back-and-forth movements suggest that the male may stimulate release of sperm from the female's spermatheca by a mechanism similar to fertilization as eggs pass through the genital chamber during oviposition.

Auditory interneurones originating in the metathoracic ganglion of females of the grasshopper Chorthippus biguttulus were investigated with respect to their processing of models of the male’s song. In these models two temporal configurations were varied: (i) the song pattern, consisting of ‘syllables’ and ‘pauses’, and (ii) the duration of short gaps within syllables. A precise encoding of the song pattern is found only among receptors and ‘thoracic’ neurones (SN1, TNI), but not among ascending neurones. The only ascending neurone that reacts tonically at all intensities (AN6) encodes the song pattern much less precisely than do receptors. Other ascending neurones (AN3, AN11) encode the gross pattern of model songs, but only at low intensities. One spontaneously active ‘local’ neurone (SN6) is tonically inhibited and encodes the pauses of a model song. A similar response, however, is not found in three ascending neurones (AN13, AN14, AN15), which are merely inhibited. Among ascending neurones, AN12 is the most reliably influenced by the syllable-pause structure of the songs. Its phasic burst marks the onset of every syllable in a behaviourally attractive song. Its activity could account for the rising part of the corresponding behavioural response curve. However, no ascending neurone shows activity corresponding to the falling part of the behavioural response. Among local neurones, the phasic BSN1 neurones are most clearly influenced by varying syllable-pause combinations. Gaps within the song syllables cause a complete inhibition of the activity of AN4. The response of AN4 to syllables with and without gaps is strikingly similar to the behavioural response and is maintained over the whole intensity range tested. Several local neurones, especially SN6, are strongly influenced by gaps within model songs - though only in certain intensity ranges. In accordance with behavioural results, the pathways for information on song pattern and sound direction appear to be separated among ascending neurones. Among local interneurones, however, this separation does not appear to take place, since the most directional local neurone, BSN1, might also be suited for pattern-filtering tasks.

SUMMARY Nectar feeding bats use echolocation to find their flowers in the dense growth of tropical rainforests, and such flowers have evolved acoustic features that make their echo more conspicuous to their pollinators. To shed light on the sensory and cognitive basis of echoacoustic object recognition we conducted a size discrimination experiment with the nectarivorous bat Glossophaga soricina and compared the bats' behavioural performance with the echoic features of the training objects. We chose a simple geometric form, the hollow hemisphere, as the training object because of its resemblance to the bell-shaped concave form of many bat flowers, as well as its special acoustic qualities. The hemispheres showed a characteristic echo pattern, which was constant over a wide range of angles of sound incidence. We found systematic size-dependent changes in the echo's temporal and spectral pattern as well as in amplitude. Bats were simultaneously confronted with seven different sizes of hollow hemispheres presented from their concave sides. Visits to one particular size were rewarded with sugar water, while we recorded the frequency of visits to the unrewarded hemispheres. We found that: (1) bats learned to discriminate between hemispheres of different size with ease; (2) the minimum size difference for discrimination was a constant percentage of the hemisphere's size (Weber fraction: approximately 16% of the radius); (3) the comparison of behavioural data and impulse response measurements of the objects' echoes yielded discrimination thresholds for mean intensity differences (1.3 dB), the temporal pattern (3-22 μs) and the change of spectral notch frequency(approximately 16%). We discuss the advantages of discrimination in the frequency and/or time domain.

The male song of the duetting grasshopper Chorthippus biguttulus consists of syllables alternating with noisy pauses. The syllable-pause structure is important for song recognition by the female. Using playback experiments we investigated the mechanism by which intensity modulations within the song pattern are used to detect syllable onsets and offsets. We varied the relative onset level (level of the syllable beginning relative to the noisy pause) and the relative offset level (level of the noisy pause relative to the syllable end) independently in different experiments. For all females, an increase in intensity defining the syllable onset was necessary to evoke responses. Syllable offset cues were not always necessary: some females responded to continuous noise stimuli wherein only syllable onsets were marked by short pulses of high intensity. Those females that did not require syllable offset cues did not, however, lack a functional pause detection mechanism, since their responses to model songs containing silent pauses were restricted to a given range of pause durations. We propose that syllable-pause detection involves two independent processes: (1) syllable onset detection by a phasic neuronal unit that can be re-activated only after a short pause, and (2) the rejection of unacceptably long pauses by a second unit.

The habitat preferences and activity of greater mouse-eared bats were investigated by means of radio-telemetry in two regions in Upper Franconia (Bavaria, Germany) that are characterized by a mosaic of deciduous forests, coniferous forests and woodless areas. In one case bats roosted in a maternity colony from which they visited foraging habitats up to 10.8 km away; in the second, the bats started in a cave which served as a night roost. These bats foraged around the cave up to 2.5 km away. Mean size of foraging areas was 13.1 ± 4.6 ha. Most of the bats used several foraging areas per night (mean 5.1, range 1–10). Hunting time per foraging site ranged from 5 to 224 (median 25) minutes. Foraging habitats in some individuals remained constant over two consecutive years. The bats hunted almost exclusively in woodland (98% of the hunting time) with a significant preference for deciduous forests as opposed to coniferous forests. The preference for deciduous forests as foraging habitats is likely to be caused b...

Male grasshoppers of the acridid speciesChorthippus biguttulus respond to conspecific female song by turning abruptly toward the sound source and then singing themselves. The orienting response requires that (i) the male recognizes the female song and (ii) determines the location of its source. By observing the effects of various forms of surgical interference (cutting connectives, splitting ganglia, destruction of a tympanal organ) on the subsequent behavior, we were able to narrow down the paths of information flow necessary for these abilities and to make an estimate of the contributions of individual ganglia to the evaluation of sound direction. 1. The information from a single tympanal organ is sufficient for therecognition of the conspecific song. From the metathoracic ganglion (TG3) sufficient information for song recognition ascends both in the ipsilateral and in the contralateral connective chain. Thus, information for song recognition is transmitted to the opposite side within the metathoracic ganglion. 2. For a singing response to be elicited by hearing a female chirp, it is necessary and sufficient that the connectives linking TG3 and the supraesophageal ganglion (brain) of the male be intact on at least one side (as has been shown forGomphocerippus rufus by Loher and Huber 1966, and Elsner and Huber 1969). Neither the three thoracic ganglia alone nor the thoracic-ganglion complex plus the subesophageal ganglion suffice to elicit either the turning or the singing response. The most probable explanation of our results is that the information paths for both responses make a loop via the brain. 3. A crucial step in sound direction processing takes place within TG3 itself. The results after connective cutting indicate a reciprocally inhibitory interaction within this ganglion by which the difference between right and left tympanal input is enhanced. 4. The information about sound direction carried in either connective alone is incomplete. Therefore, an additional ‘comparator element’ must exist, which receives the ‘directional signals’ from both connectives and converts them into an unambiguous turning command. This step in direction processing must occur either in the brain or along the pathways descending from the brain to the anterior two thoracic ganglia. 5. The anterior two thoracic ganglia, as well as the subesophageal ganglion, make either no contribution or a negligibly small contribution to the determination of sound direction.

(i) The singing movements of acridid grasshoppers are recorded opto-electronically: a small retroflective “Scotchlite” sheeting (O2mm) is attached to the tip of the stridulating femur and illuminated via a semi-transmissive mirror mounted at 45° to the optical axis in front of a photographic object lens. The light retroflected through this mirror is focused by the lens on the surface of a position-sensing photo-detector from which the co-ordinates of the light spot are tapped off instantaneously. Using this principle and having one recording device on each side the stridulatory movements of both hindlegs are monitored simultaneously. (ii) The grasshoppersChorthippus biguttulus (L.) andChorthippus mollis (Charp.) and their hybrids are studied by this method. Each of the two hindlegs performs a different Stridulatory pattern, the movements being considerably phase-shifted. The legs change their patterns from time to time. In the pure species the two patterns are very tightly coupled. Although in the hybrids in principle the same close relationships exist between the two lateral sub-systems, the couplings of the two patterns can be temporarily loosened. In the extreme, one hindleg may stridulate aCh. mollis song-pattern, whereas the other produces aCh. biguttulus pattern.

In the two acridid speciesChorthippus parallelus andCh. montanus, the sound template by which females recognize male song varies with temperature, as does the song itself. At relatively high temperatures the females respond best to simulated songs with high syllable frequencies, and at lower temperatures songs with lower syllable frequencies are preferred. The temperature around the supraesophageal and metathoracic ganglia of female grasshoppers was monitored by implanted thermocouples, and either the head or the thorax was warmed selectively while the animal was free to move (within the imits of the wires). Then simulations of the conspecific song varying in syllable frequency corresponding to different song temperatures were presented, and the stridulatory responses of the animals were observed. The results were as follows. 1. Song recognition (in particular, the position of the peak of the response curve) depended on the temperature of the head. 2. The rate of stridulatory hindleg movement was determined by the temperature of the thoracic ganglia. This result provides strong evidence against the genetic coupling hypothesis.

1. Das Experiment, mit dessen Hilfe Karl v. Frisch die Polarisations-Wahrnehmung der Biene entdeckte, wurde so abgewandelt, das ein Wirkungsspektrum fur die spektrale Empfindlichkeit des Polarisationsempfangers im Bienenauge aufgenommen werden konnte. Auf horizontaler Wabe wurden die Tanze von Bienen beobachtet, die einen mehrere hundert Meter entfernten Futterplatz besuchten. Wahrend der Tanze hatten die Bienen keinen Ausblick auf die Sonne oder den naturlichen Himmel; stattdessen wurde ihnen im Zenit unter einem Sehwinkel von 17° ein Feld monochromatischen, polarisierten Lichtes geboten, dessen Wellenlange, Intensitat und Polarisationsrichtung variierbar waren. Die Bienen verhielten sich unter diesen Versuchsbedingungen bei ihren Tanzen so, als ob sie Ausblick auf ein entsprechend groses Feld blauen Himmels im Zenit hatten. 2. Die Orientiertheit der Tanze konnte uber die Streuung der Tanzwinkel (Richtungen der einzelnen Schwanzellaufe) quantitativ erfast werden. Nur im kurzwelligen Wellenlangen-Bereich bis etwa 430 nm konnten sich die Bienen nach der Polarisationsrichtung orientieren (Abb. 5). Je hoher die Intensitat des polarisierten Lichtes bei einer festgehaltenen Wellenlange dieses Bereichs war, umso besser waren die Tanze ausgerichtet (Abb. 6, 7). Daraus lies sich das Wirkungsspektrum der Polarisations-Wahrnehmung entnehmen (Abb. 8). 3. Ein Vergleich des Wirkungsspektrums mit einer Rhodopsin-Absorptions-Normkurve zeigt, das die Polarisations-Wahrnehmung ein Empfindlichkeitsmaximum bei etwa 345 nm besitzt. Der Polarisationsempfanger im Bienenauge ist also ein Ultraviolett-Rezeptor. Die Ergebnisse unserer Experimente sind mit beiden Deutungen vereinbar; die erstaunlich hohe Empfindlichkeit spricht moglicherweise nicht zugunsten der ersten Hypothese.

1. Die im Dressurexperiment gemessene spektrale Empfindlichkeitskurve der Honigbiene ist dreigipfelig, was die Ergebnisse von Thomas und Autrum (1965) bestatigt. Die Maxima liegen etwa bei den Wellenlangen 345 nm (Ultraviolett), 440 nm (Blau) und 550 nm (Gelbgrun), vgl. Abb. 11. 2. Die Kurve der spektralen Unterschiedsempfindlichkeit der Biene weist zwei Optima auf, die etwa bei den Wellenlangen 400 nm (Violett) und 500 nm (Blaugrun) liegen (Abb. 18, 19). Im empfindlichsten Bereich des Unterscheidungsvermogens, im Blaugrun, wurden unter den gegebenen Versuchsbedingungen von der Biene noch Wellenlangen-Differenzen von 4,5 nm mit einer Anflughaufigkeit von 70% unterschieden. Der spektrale Verlauf der Parbton-Unterscheidung last sich am besten unter der Annahme eines trichromatischen Farbsystems verstehen, insbesondere zeigen die Ergebnisse, das das farbauswertende System der Biene die Daten nur eines Blaurezeptor-Typs verwendet.