Nutritional effects on male calling behaviour in the variable field cricket

In the variable field cricket, Gryllus lineaticeps, females prefer higher chirp rates and longer chirp durations in male calling song. Higher chirp rates are energetically more expensive to produce, but the energetic cost of calling does not vary with chirp duration. We tested the hypothesis that nutrition affects male chirp rate and chirp duration. Full-sibling brothers of similar age were placed on high- and low-nutrition feeding regimes. There was no effect of feeding regime on male weight; neither group showed a significant change in weight, and the two groups did not differ from each other in weight change. However, males on the high-nutrition feeding regime both called more frequently and called at higher chirp rates when they did call. The two groups did not differ in chirp duration, the duration of pulses within chirps or chirp dominant frequency. These results suggest that females select mates based on one nutrition-dependent call character (chirp rate) and one nutrition-independent call character (chirp duration). In addition, because males in the two groups did not show significant differences in weight change, and because males on the high-nutrition feeding regime engaged in energetically more expensive calling, these results suggest that males invest any excess energy above their basic maintenance requirements in the production of call types that increase their attractiveness to females. The absence of a relationship between body condition and calling song structure for males in the field may be a consequence of this pattern of energy allocation. Copyright 1999 The Association for the Study of Animal Behaviour.     

Call Characteristics of Two Sympatric and Morphologically Similar Tree Frogs Species,Polypedates megacephalus and Polypedates mutus(Anura: Rhacophoridae), from Hainan,China

Anuran calls are usually species-specific and therefore valued as a tool for species identification. Call characteristics are a potential honest signal in sexual selection because they often reflect male body size. Polypedates megacephalus and P. mutus are two sympatric and morphologically similar tree frogs, but it remains unknown whether their calls are associated with body size. In this study, we compared call characteristics of these two species and investigated any potential relationships with body size. We found that P. megacephalus, males produced six call types which consisting of three distinct notes, while P. mutus males produced five types consisting of two types of notes. Dominant frequency, note duration, pulse duration, and call duration exhibited significant interspecific differences. In P. megacephalus, one note exhibited a dominant frequency that was negatively correlated with body mass, snout-vent length, head length, and head width. In P. mutus, the duration of one note type was positively correlated with body mass and head width. These differences in call characteristics may play an important role in interspecific recognition. Additionally, because interspecific acoustic variation reflects body size, calls may be relevant for sexual selection. Taken together, our results confirmed that calls are a valid tool for distinguishing between the two tree-frog species in the field.     

Sound Production in the Salientia: Mechanism and Evolution of the Emitter

Frog sounds involve expulsion of air through the larynx. Inmating, release, rain, and territorial calls, the air vibratesvocal cords and/or arytenoid cartilages. Sound is amplifiedand radiated by the distended buccal cavity and vocal sacs.Distress calls are emitted with open mouth, with minimum laryngealmodulation. The trunk is filled by inflation cycles, but airis driven out by synchronized contractions of the body wallmusculature. The pressure levels are more than five times thoseduring ventilation. In the release call of Bufo valliceps the dilatators and constrictorsof the larynx fire simultaneously keeping the larynx closed.As the pulmonary pressure reaches a peak they cease firing.The arytenoids then separate and vibrate, as do the vocal cords.The dilatators terminate the sound pulse by pulling vibratorsout of the air stream, hence the very sharp termination. Prolongedrelease call sequences include interpulse Teinflations thatreturn air from buccal cavity to lung. Frogs apparently evolved from amphibians too small to use aspirationbreathing. Vocalization represented a critical factor in theirsocial organization and its importance locked these animalsinto reliance upon pulse-pumping rather than the more efficientaspiration breathing.     

Oxygen uptake capacity of the amphibious fish - Amphipnous cuchia (Ham) (Symbranchiformes, Amphipnoidae)

The O2 uptake capacity of Amphipnous cuchia has been determined in relation to standard temperature of 25 degrees C. The measurement of O2 uptake indicates nearly 75% of the oxygen demand to be met through the air breathing organs and 25% by the skin and vestigeal gill through water in a normal habitat. The total VO2 during aerial-aquatic gas exchange is 60.5 ml/kg/hr. The prevention of surfacing resulted in a lower O2 uptake rate (38.29 ml/kg/hr). During submergence, the utilisation of air sacs for extracting O2 by regular pumping of water in and out is peculiar to the fish. Under normal respiratory conditions (air + water), the slope for O2 uptake through air is 0.72, 0.23 for water and 0.57 for both air + water. The average ratio borne by the fish for aquatic/air breathing (ml/kg/min) is higher in fishes below 60 g body weight, and aquatic respiration predominates in fishes weighing less than 6.0 g.     

Relationships among rodent taxa as indicated by reproductive biology1

Demonstrated that in rodents the duration of ontogenetic development (from conception to the age of eye openin) is allometrically related to the maternal body weight. The differences between actual developmental time and the expected time (counted for animals of that systematic position and that body weight) can be used as a tool to test phylogenetic relationships. As far as the relationships between sister-taxa are concerned, the results of the present analysis corroborate the conclusions of modern classifications. A long developmental time (which means by implication also a long pregnancy and precocity) is couled with hystricognathy and hystricomorhy. These traits must be considered plesiomorphic and their occurrence suggests conservatism of articular taxa. Parallell (coupled) with adopting sciurognathy and, particularly, protrogomorpiy, sciuromorphy, and eventually, myomorphy, rodents were able to shorten their developmental times. In this way they could increase the reproductive rate and made their reproduction more efficient. Consequently the respective taxa radiated more rapidly and successfully.     

Respiratory surface areas of an air-breathing siluroid fish Saccobranchus (Heteropneustes) fossilis in relation to body size

The surface area of the gills, air sacs and skin have been measured in specimens of different body size and their relationship to body weight fits the equation: area= aW^b . The slopes ( b ) of the double logarithmic plots are 0.746 (gills), 0.662 (air sacs) and 0.684 (skin). The gills are poorly developed and their average weight specific area is less than figures obtained for sluggish marine fishes. The skin has an area about 70% of the total respiratory surfaces (gills+air sac+skin). Nevertheless the greater thickness of the skin leads to a smaller diffusing capacity of the tissue barrier ( D_t ) as compared with the gills and air sac. The air sac area for each ml of air that it contains is about 10.5 cm² which is much lower than figures obtained for lungs of other air-breathing fish and for tetrapods.     

Interrelationship of static mechanical factors and anatomical structure in lung evolution

Summary The inflation curves in 8 reptilian and in 2 avian lungs are sigmoid in comparison with the complex curve in the rat. Compliance is greatest in the lungs of those reptiles possessing well developed, membranous lung regions, and is similar to the extremely high compliance of avian air sacs. The body-weight standardized compliance of mammalian lungs is 1 to 2 orders of magnitude lower than that in reptilian lungs or in avian air sacs. Comparison of breathing pattern, elastic work of breathing and ventilatory rate indicates that a low-work strategy predominates in reptiles and in birds, which are obligatory rib breathers. Mammals can sustain a work rate per unit ventilation rate some 10 times greater than that of other groups because of efficient diaphragm breathing. The evolutionary implications of static mechanics for lung structure are discussed.Supported by grants Du 50/3 and 50/4 from the Deutsche Forschungsgemeinschaft     

白眉长臂猿鸣叫的时间特征

滇西白眉长臂猿(Hylobateshoolock)鸣叫主要发生在上午,最早开始于黎明时分,最晚则在下午16:30以后。平均开始时间为09:05,SD=1095min(N=70,范围07:12～16:30),持续时间为197min,SD=934min(N=55,R=4～50)。多数鸣叫发生在07:00～10:00之间(80%)。不同季节鸣叫发生时间有显著差异,可能与黎明时间(光亮度)不同有关,但持续时间无差异。同一季节异地间鸣叫持续时间差异显著。气候、猿群密度、栖息地状态对鸣叫有一定影响,但未见明显相关性。与黑长臂猿的种间比较表明,白眉长臂猿的鸣叫声在时间分布上有较大的散开度,持续时间也较长,二者有显著差异。     

Effects of covert subject actions on percent body fat by air-displacement plethsymography

Air-displacement plethysmography (ADP) is used for estimation of body composition, however, some individuals, such as athletes in weight classification sports, may use covert methods during ADP testing to alter their apparent percent body fat. The purpose of this study was to examine the effect of covert subject actions on percent body fat measured by ADP. Subjects underwent body composition analysis in the Bod Pod following the standard procedure using the manufacturer's guidelines. The subjects then underwent 8 more measurements while performing the following intentional manipulations: 4 breathing patterns altering lung volume, foot movement to disrupt air, hand cupping to trap air, and heat and cold exposure before entering the chamber. Increasing and decreasing lung volume during thoracic volume measurement and during body density measurement altered the percent body fat assessment (p < 0.001). High lung volume during thoracic gas measures overestimated fat by 3.7 ± 2.1 percentage points. Lowered lung volume during body volume measures overestimated body fat by an additional 2.2 ± 2.1 percentage points. The heat and cold exposure, tapping, and cupping treatments provided similar estimates of percent body fat when compared with the standard condition. These results demonstrate the subjects were able to covertly change their estimated ADP body composition value by altering breathing when compared with the standard condition. We recommend that sports conditioning coaches, athletic trainers, and technicians administering ADP should be aware of the potential effects of these covert actions. The individual responsible for administering ADP should remain vigilant during testing to detect deliberate altered breathing patterns by athletes in an effort to gain a competitive advantage by manipulating their body composition assessment.     

Calling by Domestic Piglets during Simulated Crushing and Isolation: A Signal of Need?

This study examined whether piglet distress vocalizations vary with age, body weight and health status, according to the predictions of the honest signalling of need evolutionary model. Vocalizations were recorded during manual squeezing (a simulation of being crushed by mother sow) and during isolation on Days 1 and 7 after birth in piglets from 15 litters. We predicted that during squeezing, younger, lighter and sick piglets would call more intensely because they are in higher risk of dying during crushing and therefore they benefit more from the sow’s reaction to intensive vocalization. For isolation, we predicted that lighter and younger piglets would call more because they are more vulnerable to adverse effects of the separation. Calls were analyzed in their time and frequency domain. The rate of calling, call duration, proportion of high-pitched calls and eight acoustic parameters characterizing frequency distribution and tonality were used as indicators of acoustic signalling intensity. Piglets that experienced “squeezing” on Day 1 produced more intense acoustic distress signalling than on Day 7. Lighter piglets called more during squeezing than heavier piglets. Health status did not significantly affect any of the indicators of intensity of vocalization during squeezing. In isolation, none of the parameters of vocalization intensity were affected either by the age or by the weight of the piglets. In summary, the model of honest signalling of need was confirmed in the squeezed situation, but not in the isolation situation.     

Muscular control of the vocal tract during release signaling in the toad Bufo valliceps

The release vibration and release call of Bufo valliceps have been studied by electromyography of the muscles involved, coupled with pressure and sound recording. The sequences are powered by contraction of the muscles of the body envelope and with the energy transmitted via the compressed pulmonary contents. Each pulse of a call starts as the laryngeal muscles relax and pulmonary pressure forces the arytenoid cartilages apart. Sound emission ceases when the laryngeal dilators pull the arytenoids out of the airstream. Reverse flow of air from buccal cavity to lungs may occur within prolonged release sequences. Inflation of the vocal sac results in marked increase in amplitude of the radiated sound without equivalent increase in amplitude of the myograns. The call is intimately associated with the pulsepumping method of breathing used by frogs.     

Effects of increase in body temperature on the breathing pattern in premature infants

This study was designed to determine the effects of a mild increase in body temperature within the physiological range (0.8 degrees C) in healthy premature infants. Seven unsedated premature infants (38.4 wk +/- 1.5 postconceptional age) were monitored polygraphically during "morning naps" in an incubator under two different environmental temperatures: (1) normothermia with the incubator temperature set at 25 degrees C and the rectal temperature equal to 36.9 degrees C +/- 0.1; (2) hyperthermia with the incubator temperature set at 35 degrees C and the rectal temperature equal to 37.7 degrees C +/- 0.15. Respiratory frequency and heart rate, respiratory events, i.e., central and obstructive apnea, and periodic breathing with and without apneic oscillations were tabulated. Results for respiratory events were expressed as (1) indices of the total number of respiratory events, and of specific respiratory events per hour of total, quiet and active sleep times; (2) duration of total and specific respiratory events expressed as a percentage of total sleep, quiet and active sleep times. Respiratory frequency and heart rate were significantly increased by hyperthermia (P less than 0.05). Hyperthermia did not significantly modify the indices or the duration of central and obstructive apnea. But the indices and the duration of periodic breathing with and without apneic oscillations were significantly increased by hyperthermia during active sleep (P less than 0.05) but not during quiet sleep. The present study shows that a mild increase in body temperature within the physiological range in premature infants enhances the instability of the breathing pattern during active sleep.     

云南高黎贡山大塘东部白眉长臂猿鸣叫行为

通过2009年10月至2010年7月监测高黎贡山大塘的3群东部白眉长臂猿的鸣叫行为,收集了10个月(200d)的数据,发现东部白眉长臂猿的鸣叫行为主要发生在黎明后4h内;平均每次鸣叫持续14min59s,不同群体间鸣叫持续时间不同。天气情况影响东部白眉长臂猿的鸣叫开始时间(相对黎明)和持续时间,在雨天鸣叫相对黎明开始时间较晚,持续时间也较长。东部白眉长臂猿鸣叫频率在10月和11月明显高于其他月份,可能与食物(果实)的丰富度有关。根据研究结果,建议对东部白眉长臂猿的调查最好集中在10月或11月;每天监测时间至少持续至黎明后4h,以覆盖长臂猿90%以上的鸣叫;如果出现下雨天气,应适当延长调查时间。     

Effect of air breathing on acid-base and ion regulation after exhaustive exercise and during low pH exposure in the bowfin, Amia calva.

To explore a potential conflict between air breathing and acid-base regulation in the bowfin (Amia calva), we examined how individuals with access to air differed from fish without air access in their response to acidosis. After exhaustive exercise, bowfin with access to air recovered significantly more slowly from the acidosis than fish without air access. While arterial blood pH (pH(a)) of fish without air access recovered to resting levels by 8 h, pH(a) was still significantly depressed in fish having access to air. In addition, Pco(2) was slightly more elevated in fish having air access than those without it. Fish with access to air still had a significant metabolic acid load after 8-h recovery, while those without air access completely cleared the load within 4 h. These results suggest that bowfin with access to air were breathing air and, consequently, were less able to excrete CO(2) and H(+) and experienced a delayed recovery. In contrast, during exposure to low pH, air breathing seemed to have a protective effect on acid-base status in bowfin. During exposure to low pH water, bowfin with access to air developed a much milder acidosis than bowfin without air access. The more severe acidosis in fish without air access was caused by an increased rate of lactic acid production. It appears that enhanced O(2) delivery allowed air-breathing bowfin to avoid acidosis-induced anaerobic metabolism and lactic acid production. In addition, during low pH exposure, plasma Na(+) and Cl(-) concentrations of fish without air access fell slightly more rapidly than those in fish with air access, indicating that the branchial ventilatory changes associated with air breathing limited, to some degree, ion losses associated with low pH exposure.     

Evidence for High Variability in Temporal Features of the Male Coda in Müller’s Bornean Gibbons (<Emphasis Type="Italic">Hylobates muelleri</Emphasis>)

Most pair-living primate species engage in duets, wherein males and females produce coordinated vocalizations. Previous analyses of male gibbon contributions to the duet have shown that calls are individually distinct. Here we investigate variation in the temporal and spectral parameters in the male contribution to the duet, also known as the coda, of wild, nonhabituated male Müller’s Bornean gibbons (Hylobates muelleri), recorded both opportunistically and as a response to playbacks at the Stability of Altered Forest Ecosystems site in Sabah, Malaysia. We used linear discriminant function analysis to estimate the intra- and interindividual variation in 13 spectral and temporal parameters of the vocalizations (N?=?337) of 31 male gibbons. To further understand how call features vary within and between individuals we used a multivariate, variance components model to investigate how variance in features was partitioned at these two levels. We could identify males with a 66% accuracy using leave-one-out cross-validation, a relatively low score compared to female Müller’s Bornean gibbons and males of other species. We found that for some features (such as maximum frequency of the notes) most of the variance occurred between males, but for others (specifically total duration of the call and duration of rest in between notes) most of the variance occurred within a single male. Overall, male Müller’s Bornean gibbon coda vocalizations showed greater variability relative to their female counterparts, raising questions about potential differences in the function of the male and female contributions to the duet in Müller’s Bornean gibbons and the gibbon taxon as a whole.     

Plasma insulin-like growth factor-I,testosterone and morphological changes in the growth of captive agile gibbons ( Hylobates agilis) from birth to adolescence

We examined growth changes in concentrations of plasma insulin-like growth factor-1 (IGF-1) and testosterone, and somatometric parameters in two captive male agile gibbons from birth to about 4 years of age, to examine the evolution of growth patterns in primates. Plasma IGF-1 concentrations in agile gibbons generally increased with age with values ranging from 200 to 1,100 ng/ml. The growth profiles in plasma IGF-1 in the gibbons were similar to those reported for chimpanzees. The highest concentrations of plasma testosterone (230 and 296 ng/dl) were observed within the first 0.3 years from birth, then the concentrations rapidly decreased and fluctuated below 100 ng/dl. Continuously higher IGF-1 concentrations were observed after 2.6 and 3.5 years of age. The profiles of plasma testosterone in these gibbons also resembled those of other primates including humans. However, their plasma testosterone levels in both neonate and adult stages (60 ng/dl) were lower than those reported for macaques and chimpanzees of respective stages. The obtained growth profiles of plasma IGF-1 and testosterone suggest that the adolescent phase starts around 2.6 or 3.5 years of age in male agile gibbons. The growth trend in many morphological parameters including body weight showed a linear increase without a significant growth spurt at approximately the onset of puberty. Head length and first digit length had reached a plateau during the study period. Brachial index, which indicates the relative length of forearm to upper arm, significantly increased gradually through the growth period. This result indicates that forearm becomes relatively longer than the upper arm with growth, which may be an evolutionary adaptation for brachiation.     

Tracheal system and biology of the Early Cretaceous <Emphasis Type="Italic">Saurophthirus longipes</Emphasis> Ponomarenko, 1976 (Insecta, ?Aphaniptera,Saurophthiroidea stat. nov.)

The tracheal system of Saurophthiridae is described based on female fossils of Saurophthirus longipes Ponomarenko, 1976. Three very wide tracheal trunks are found running dorsolaterally along each side of the body. The tracheal system is amphipneustic, with the large mesothoracic and very large 8th abdominal spiracles. The 9th and following segments are able to turn back to open posterior spiracles for breathing. Taken together, these features are characteristic of air breathing aquatic insects. This urges us to modify the former hypothesis about parasitism of Saurophthirus on pterosaur wing membrane. We suppose that Saurophthirus females had gonotrophic cycles: they imbibed blood enough for maturation of a large egg batch, then retreated to a water body as a safe place for digesting and egg maturation, and after oviposition climbed onto emergent plants and waited for pterosaurs patrolling over the water and looking for fish, to start a new cycle. The families Saurophthiridae, Pseudopulicidae, and Tarwiniidae are united in the superfamily Saurophthiroidea Ponomarenko, 1986, stat. nov.     

No need to shout: Effect of signal loudness on sibling communication in barn owls Tyto alba

In animal communication, signal loudness is often ignored and seldom measured. We used a playback experiment to examine the role of vocal loudness (i.e., sound pressure level) in sibling to sibling communication of nestling barn owls Tyto alba. In this species, siblings vocally negotiate among each other for priority access to parental food resources. Call rate and call duration play key roles in this vocal communication system, with the most vocal nestlings deterring their siblings from competing for access to the food item next delivered by parents. Here, we broadcast calls at different loudness levels and call rate to live nestlings. The loudness of playback calls did not affect owlets' investment in call rate, call duration or call loudness. The rate at which playback calls were broadcast affected owlets' call rate but did not influence their response in terms of loudness. This suggests that selection for producing loud signals may be weak in this species, as loud calls may attract predators. Moreover, given that owlets do not overlap their calls and that they communicate to nearby siblings in the silence of the night, loud signals may not be necessary to convey reliable information about food need.     

Heart rates and gas exchange in the Amazonian Manatee (Trichechus inunguis) in relation to diving

Unrestrained Amazonian manatees (Trichechus inunguis) maintained a constant heart rate during diving and exhibited a slight tachycardia during breathing. 'Forcing' the manatees to dive caused a marked bradycardia. They exhibited a more pronounced tachycardia during breathing after 'forced' dives and hyperventilated during recovery dives. Manatees are capable of dives exceeding 10 min duration without having to resport to anaerobic metabolism, and even after 10 min dives recover within 3-4 short dives. The ability of manatees to make long dives, in spite of relatively poor O2 stores, is due to their low metabolic rate, while the rapid recovery is aided by their high CO2 stores which minimizes CO2 storage in the body. In manatees the changes in alveolar O2 and CO2 pressure (PAO2 and PACO2) in relation to dive time are slower and more variable than in other marine mammals. The lower rate of change is probably due to the manatees' reduced metabolic rate, while the greater variability is due to their breathing pattern, in which both ventilation and body gas stores influence alveolar gases.     

Echolocation behaviour of <Emphasis Type="Italic">Megaderma lyra</Emphasis> during typical orientation situations and while hunting aerial prey: a field study

Bats modify the structure and emission pattern of their calls to cope with the functional constraints of a given echolocation situation. As a consequence, the flexibility in sonar call use affects the potential niche use of a species. The present paper addresses call use in Megaderma lyra, a species with a short, broadband multiharmonic basic call, in typical orientation situations, when emerging from and re-entering a day roost, in cruising flight and when passing through vegetation, and during the pursuit of tethered, flying insects. While call duration and emission rate were adapted to the four orientation situations, call spectral composition was similar in these situations, except that bats emitted calls containing more harmonics when re-entering the roost. These moderate call modifications may be accounted for by the observation that M. lyra stayed close to landscape elements even in open habitats. Although M. lyra is a typical gleaner, all tested bats approached flying insects, guided by sonar calls of significantly decreasing duration and pulse interval, and of increasing sweep rate. Before capture, peak frequency was lowered from call to call. The spontaneous approaches towards flying insects with systematic changes in call pattern suggest regular aerial hunting in this species.