灰胸薮鹛鸣声及繁殖行为的初步研究

2005年5～8月、2006年1～2月、2008年10月在四川省老君山自然保护区对灰胸薮鹛(Liodchla omeiensis)的鸣声及繁殖行为进行了初步研究.在繁殖期和非繁殖期都能记录到的灰胸薮鹛鸣声可分为召唤、应答、觅食、采食、休息、飞行联络、报警叫声14种,仅在繁殖期能记录到的有占区、驱逐、逃避、求偶叫声12种.通过声谱分析获得了各种叫声的语谱图及其频谱特征.本文还对灰胸薮鹛繁殖期占区、求偶、交配、营巢、产卵和孵卵前3 d的行为进行了描述.     

Ultrasonic communication in concave-eared torrent frogs (Amolops tormotus)

The concave-eared torrent frogs (Amolops tormotus) have highly unusual ear morphology--in males the eardrums are embedded deep inside ear cavities. In collaboration with our colleagues we investigated the functional significance of this morphological feature in hearing. Sound recordings in the field showed that males of A. tormotus produce diverse bird-like melodic calls with pronounced frequency modulations and non-linear phenomena (e.g., frequency jumps, different orders of subharmonics, and chaos) that often contain spectral energy in the ultrasonic range. The audible as well as the ultrasonic components of the species call could effectively evoke males' vocal responses, demonstrating that they can hear and respond to ultrasound. Electrophysiological recordings from the auditory midbrain confirmed the ultrasonic hearing capacity of these frogs. The recessed tympana and extremely thin tympanic membranes are adaptations for hearing ultrasound--this sensitivity may have evolved in response to the intense, predominately low-frequency ambient noise from local streams. Finally, results from the isolated laryngeal preparation in euthanized frogs revealed that the origin of call complexity and diversity lies with having a vocal system with nonlinear properties.     

Differentiation of vocalizations in bushbabies (Galaginae, Prosimiae, Primates) and the significance for assessing phylogenetic relationships

A comparative bioacustic analysis of vocalizations of the prosimian subfamily Galaginae revealed that morphologically similar sibling taxa within the main groups of the lesser galagos and the greater galagos can be reliably identified phenotypically on the basis of the acoustic structure of their loud call or advertisement call. Results confirm the separation of two distinct species of greater galagos, Galago crassicaudatus and Galago garnettii, and strongly suggest the discrimination of three distinct species from the senegalensis lesser bushbaby group, Galago senegalensis, Galago moholi and Galao zanzibaricus. An investigation of the ontogenetic development of the loud call indicated that it is derived from the infant's isolation call, displaying in all studied bushbaby taxa a fairly similar acoustic pattern. Shared acoustic characters of the loud call among the different taxa as well as the infant's isolation call were used to propose a hypothesis about the phylogenetic affinities in bushbabies. The results seem to be supported by recent fossil records.     

Researching little-known species: the African bat Otomops martiensseni (Chiroptera: Molossidae)

Listed as 'vulnerable' by the International Union for theConservation of Nature, the molossid bat Otomopsmartiensseni occurs widely in Africa and, according to someauthorities, in Madagascar. Apart from a few known cave roosts, there are fewrecords of O. martiensseni, although around Durban, SouthAfrica, the species is common and roosts in buildings. Originally described asthree species, populations of O. martiensseni differsignificantly in size (length of forearm) between East Africa and Durban orMadagascar, but not between Durban and Madagascar. Seventeen buildings used asroosts by O. martiensseni averaged 34.5 ± 15.8years old. In the Durban area, bats entered roosts by landing andcrawling. Roost populations ranged from 7 to 29 individuals, typicallyconsisting of one adult male, several adult females and young (bats withunossified epiphyses), suggesting a harem social structure. The ratio of adultfemales to young was virtually 1:1, and among young the ratio of males:femalesaveraged 2:1. Radio-tracking showed that individuals used several day and nightroosts, and foraged widely in a landscape dominated by sugarcane and urbandevelopment. The echolocation and many social calls of O.martiensseni are readily audible to human observers, allowing anon-contact, low technology method for monitoring the local distribution andactivity of these bats. Although listed as a species of special concern inKwaZulu Natal, there these bats appear to be candidates for inclusion on a'blue' list of species, ones showing stabilized or increasedabundance. We recommend that O. martiensseni be recognizedas a 'flagship' species in the Durban area, r epresenting theresilience of nature.     

Vocal communication in captive golden monkeys (Rhinopithecus roxellanae)

The Sichuan golden snub-nosed monkey,Rhinopithecus roxellanae, is an endangered Colobine endemic to China. The behavior and biology of this species are little known, and it has rarely been kept in captivity outside China. Results from 42 hr of observations of a male-female golden monkey pair provide preliminary information on the vocal behavior of this species in captivity. Vocalizations by the animals often occurred within antiphonal sequences, which were primarily initiated by the female. Sequences were brief (2–3 calls), showed little or no temporal overlap, and were emitted primarily when the animals were distal from one another, suggesting that sequences may function as contact calls in nature. Some vocalizations appeared to be cryptic, i.e. unaccompanied by mouth or body movement, and these were observed more often than noncryptic calls in both animals. Vocal communication appears to be complex in this species, and remains poorly understood.     

“Girney” vocalizations among Japanese macaque females: Context and function

One vocalization in the Japanese macaque (Macaca fuscata) system of communication is the “girney.” Previous studies indicated that the “girney” is used for short range communication and that it tends to occur when subordinate animals approach and groom dominant ones and when females without infants approach females who have infants. Data were collected on the social behavior of adult female Japanese monkeys of the Arashiyama-A troop in Texas in order to test those results. The study indicates that “girneys” are the most frequently occurring vocalizations of females during and following the birth season and that they occur primarily in two contexts. Those are the proximity of a female to another female with a new infant and the proximity of a lower ranking animal to a higher ranking one. The contexts are ones in which the risk of aggression is high, and the “girneys” appear to function as appeasement gestures to reduce the risk.     

Domestic chicks' runway responses to video images of conspecifics

Because chickens are highly social animals, live conspecifics are often used to provide an incentive or goal in studies of gait, sociality or fear that require the bird to traverse a runway. However, the variable behaviour of the stimulus birds can influence the approach/avoidance responses of the test birds and thereby confound the results. Because chickens modify their behaviour readily and appropriately to a variety of video images, including social stimuli, we asked if video playback might represent easily controllable and standardized alternatives to live birds. Female ISA Brown chicks were housed in groups of eight and then exposed to a blank illuminated television for 10 min per day from 2 to 7 days of age. At 8 or 9 days of age they were placed individually in the start box of a 1.6 m long runway and we recorded their responses to a monitor displaying selected video images that was situated in the goal box at the opposite end of the runway. In Experiment 1 chicks approached a monitor playing the video image and soundtrack of feeding chicks significantly sooner than one of a goal box with the food dish and background noise. In Experiment 2, chicks were exposed to the same video of feeding conspecifics with or without the associated sounds or to a video of the goal box with or without the chick soundtrack. Both the videos of other chicks elicited faster approach than did those of the goal box and the sound and silent versions were equally attractive. Adding the soundtrack of feeding chicks to the goal-box video failed to increase its attractiveness. The present results suggest that chicks are attracted towards televised images of other chicks. They also indicate that the visual and auditory components of the video stimuli did not exert additive effects and that approach reflected attraction to the visual image. Collectively, our findings suggest that video playback of selected social stimuli, such as feeding conspecifics, could be a valuable tool in tests requiring voluntary locomotion along a predetermined path.     

Ghrelin's quick inhibition of androgen-dependent behaviors of male house mice (Mus musculus)

Ghrelin is a peptide hormone released by the stomach that stimulates hunger. Ghrelin also suppresses reproductive physiology by inhibiting the HPG axis. However, to our knowledge, our results are the first to demonstrate ghrelin's quick suppression of sex-hormone-regulated behaviors. In experiment 1, 2 orexigenic i.p. ghrelin injections (0.165 mg/kg and 0.33 mg/kg) suppressed male courtship behavior (ultrasonic calling to a female) and intermale aggression (latency to attack a stimulus male) 20 min following administration. Experiment 2 (examining only the 0.33 mg/kg dose ) replicated ghrelin's suppression of ultrasonic calling and intermale aggression; however, a third behavior, preference for volatile female odors (20 min following administration), was not significantly inhibited. In experiment 2, ghrelin treatment did not affect general locomotor activity (distance traveled 20 min following injection) or seminal vesicle weight (measured 5 days after completing ghrelin injections). We hypothesize that ghrelin's quick suppression of male aggression and ultrasonic mating calls was mediated through its effects on the brain (rather than indirectly through inhibition of the HPG axis).     

Mobbing vocalizations as a coping response in the common marmoset

Using a non-invasive method of sampling saliva followed by assay for cortisol levels, we found that common marmosets (Callithrix jacchus) show a decrease in cortisol levels after seeing a snake-model stimulus that reliably elicits mobbing (tsik) calls. In fact, there was a significant positive correlation between the number of tsik vocalizations made and the magnitude of the decrease in the cortisol concentrations. Furthermore, marmosets with higher levels of cortisol prior to being exposed to the stimulus produce more tsik calls than those with lower levels of cortisol. Subsequent experiments showed that, in response to 15 min of isolation with no visual or auditory contact with conspecifics (a traditional stressor), cortisol levels increased significantly. However, playback of the mobbing calls of a familiar conspecific to individual isolated marmosets not only prevented the rise in cortisol, but also actually caused a decrease in the levels of this hormone. This suggests that the mobbing calls serve to calm the marmoset after experiencing a stressful situation. This finding results in a greater understanding as to the role of physiological responses during communication in this species and could have implications for the welfare of marmosets in captivity.