Temperature affects male and female potential reproductive rates differently in the sex-role reversed pipefish, Syngnathus typhle

The differences in potential reproductive rate between the sexescan be used to predict the operational sex ratio and the patternsand intensity of mating competition and hence sexual selectionin a population. This article describes how one environmentalcomponent, temperature, affects potential reproductive ratesof the two sexes in the paternally brooding, sex-role reversedpipefish (Syngnathus typhle). Males brooded embryos much longer(on average 58 days) in cold water (about 10°C) than inwarmer water (35 days at about 15°C). As a consequence,the potential reproductive rate (number of eggs brooded perday) of males was significantly higher in warm water. In females,however, potential reproductive rate, i.e., number of eggs producedper day given an unlimited access to mates, was not significantlydifferent between temperatures. In both sexes, potential reproductiverate was positively related to body size. At both temperatures,females had the potential to reproduce faster than males. Asa result, the operational sex ratio will become female biasedand sex-roles reversed, as is the case in this species. Sincetemperature differently influenced the potential reproductiverates of males and females, with the sexual difference largerat lower temperatures, more intense female-female competitionis predicted at low temperatures.     

Parental effort of kestrels (Falco tinnunculus) in nest defense: effects of laying time, brood size, and varying survival prospects of offspring

We studied the nest defense behavior of Eurasian kestrels (Falcotinnunculus) towards a stuffed pine marten (Martes martes) througha 3-year vole cycle (1990–92) in western Finland. Survivalprobability of offspring decreases with a later start of breeding,and, therefore, early breeders should protect their offspringmore than late ones. We found this true for males during theincubation period, but not for females. In addition, we expectedthe nest defense intensity to increase with offspring number.During the incubation period, this was true for females, butnot for males. During the nestling phase, parents did not adjusttheir defense effort to natural or manipulated (by one to twoyoung) brood size. Survival prospects of kestrel offspring werehighest in the increasing vole year 1991 and lowest in the decreasingvole year 1992, and, therefore, we expected the defense activityof kestrels to follow the same trend. However, the oppositeresult appeared true for females with a similar tendency formales. Most hypotheses predicting avian nest defense behaviorwere not supported by our data. Temporally heterogeneous environmentand low degree of nest-site tenacity of migratory kestrels maymake them unfamiliar with environmental variation and survivalprospects of their offspring. Therefore, fitness benefits ofparental care are not predictable, and kestrels may thus adjusttheir parental effort to their own future reproductive potential(i.e., number of future breeding attempts), rather than to somecurrent investment indicator, like offspring age and number.     

Rhesus monkey behavior during exposure to high-peak-power 5.62-GHz microwave pulses

Limits on the exposure to high-peak-power, short-duration microwave pulses have only recently been adopted. Additional data, however, are needed to understand the effects that may be produced by exposure to high-peak-power pulsed microwaves. Four male rhesus monkeys (Macaca mulatta) were trained on an operant task for food pellet reward to investigate the behavioral effects of very high-peak-power 5.62 GHz microwaves. The operant task required monkeys to pull one plastic lever on a variable interval schedule (VI-25 s) and then respond to color signals and pull a second lever to obtain food. The monkeys were conditioned to perform a color discrimination task using one of three colors displayed by a fiber-optic cable. A red signal was the discriminative stimulus for responding on the first lever. A response on the second lever when a green signal was presented (1 s duration) delivered a food pellet. If a response on the second lever was made in the presence of a white signal, a 30-s timeout occurred. While performing the behavioral task, the monkeys were exposed to microwave pulses produced by either a military radar (FPS-26A) operating at 5.62 GHz or the same radar coupled to a Stanford linear energy doubler (SLED) pulse-forming device (ITT-2972) that enhanced peak power by a factor of nine by adding a high power pulse to the radar pulse. The effects of both types of pulses were compared to sham exposure. Peak field power densities tested were 518, 1270, and 2520 W/cm² for SLED pulses and 56, 128, and 277 W/cm² for the radar pulses. The microwave pulses (radar or SLED) were delivered at 100 pps (2.8 μs radar pulse duration, ≈ 50 ns SLED pulse duration) for 20 min and produced averaged whole-body SARs of 2,4, or 6 W/kg. Compared to sham exposures, significant alterations of lever responding, reaction time, and earned food pellets occurred during microwave exposure at 4 and 6 W/kg but not 2 W/kg. There were no differences between radar or SLED pulses in producing behavioral effects. ©1994 Wiley-Liss, Inc.

1 This is a US Government work and, as such, is in the public domain in the United States of America.

     

Behavioral responses of Colorado potato beetle larvae to combinations of temperature and insolation, under field conditions

In short-term field trials at combinations of ambient temperature (°C) and insolation (W·m⁻²), larval Colorado potato beetles (Leptinotarsa decemlineata [Say] [Coleoptera: Chrysomelidae]) were observed after their release on the adaxial surface of leaflets on potato plants (Solanum tuberosum L. Solanaceae). The larvae either began feeding or moved under the leaflet; mean interval from release to expression of these behaviors (2.9±0.05 min [n =358]) was independent of air temperature and insolation. Proportion of larvae moving under the leaflet increased logistically with both air temperature and insolation. A 1 W·m⁻² change in insolation (P) evoked the same effect on this proportion as a 0.0838 °C change in air temperature (T _a ), so the two quantities were combined as T^*=T _a +P·0.0838 °C/(W·m⁻²), which has units of °C. The proportion of larvae moving under the leaflet increased logistically with T^*. In 1-day field trials we monitored air temperature, insolation and proportion of larvae under the leaflet, and compared the latter to predictions from the logistic regression derived from the short-term trials. Consistently more larvae occurred under leaflets than predicted from the logistic regression; this bias diminished as T^* increased until at T^*≥40 °C, observed and predicted proportions were equal. This pattern of deviation from the predictions of the logistic regression is consistent with a thermoregulatory strategy in which larvae move away from hostile conditions, rather than seek optimal conditions.     

A brief report on the social behavior of the crested mangabey (Cercocebus galeritus galeritus) with a comparison to the sooty mangabey (C. torquatus atys)

A group of 38 free ranging crested mangabeys in the Tana River Primate Reserve was studied over a 6-week period for a total of 209.5 hr and behavioral comparisons made to a captive group of sooty mangabeys. Although quantitative comparisons between these two mangabey species are not possible, the present data suggest that these geographically separated mangabeys share several behavioral similarities. Copulatory behavior in both species involved a pattern of female darting and female vocalizing following the mount by the male. Several similarities in agonistic behavior also existed: 1) The victim often returned or stayed within 1 m of the aggressor following an agonistic episode; 2) retaliation in which the victim first fled or avoided the aggressor, then subsequently, chased or lunged at the aggressor, typically while screaming; and 3) frequent redirection of aggression by the victim following an agonistic episode. A dominance rank reversal occurred between the two adult male crested mangabeys with no severe wounding. The rank reversal seemed to be related to two subsequent behaviors which included infant carriage by the deposed alpha in the presence of the new alpha male and female demonstrations of extreme protectiveness of their infants in the presence of the new alpha male. Both of these behaviors have been reported in the sooty mangabey group.     

The behavior of postreproductive females in a wild population of toque macaques (Macaca sinica) in Sri Lanka

I compared the behavior of three old postreproductive females in a wild population of toque macaques (Macaca sinica)in Polonnaruwa with those of reproductive females via focal-animal sampling techniques. Postreproductives foraged less, slept more, and were less active overall than reproductive females were. They also had significantly lower rates of agonistic behavior, were more peripheral, and had lower frequencies of overall affiliative contact. Although postreproductives initiated contact with others as frequently as reproductives did, group members initiated contact with them significantly less than they did with reproductive females. Postreproductives associated more with adult females than reproductives did and less with adult and subadult males than high-ranking reproductives did. Juvenile and infant females associated more frequently with reproductive females of high or low rank than with postreproductives. Postreproductives resembled low-ranking reproductive females in giving less grooming to others than they received. This contrasts with high-ranking females, which gave more grooming to others than they received. The results suggest that old age and cessation of reproduction are evident through the manifestation of distinct behavioral characteristics in toque macaque females.     

Postconflict social interactions among barbary macaques (Macaca sylvanus)

We investigated the occurrence of postconflict social interactions in a group of Barbary macaques (Macaca sylvanus)that live in a large enclosure. We collected data during the mating and the nonmating seasons and analyzed them via two methods. Separate analyses for the two seasons yielded very similar results. Reconciliation and redirection occurred. But we found no evidence for consolation and postconflict kin-oriented affiliation. The consistency of these findings with those on other species of Macacaindicates that reconciliation and redirection are typical postconflict social interactions of macaque victims.     

人工饲养蒙新河狸的发情交配行为

人工饲养的蒙新河猪其动情周期可划分为４个阶段：动情前期、动情期（发情交配期）、动情后期和停滞期（动情间隔期）。动情期间雌雄河狸均表现出活跃好动,浮躁不安,食量减小;发情交配期雌雄河狸均发出低沉嘶哑的叫声,雄性叫声频率比性略高,爬跨交配是动情期发情的高峰,动情周期各阶段的行为特征,在雌性与阴道涂片细胞学及外生殖器形态、色泽、阴道分泌物周期性变化特征相吻合,在雄性则与睾丸及阴茎形态特征吻合,在人工饲养     

The benefit to some minnows of spawning in the nests of other species

Synopsis Fishes that act as nest associates spawn simultaneously with nest-building hosts and then abandon their eggs. The proposed benefit for this behavior is increased brood survivorship, arising from the physical environment provided by the nest or the parental care provided by the host. Field and enclosure experiments indicated that associates benefit from the parental care provided by the host, and not from the physical environment provided by the nests of hosts. This information, along with the effect of nest association on host reproductive success, is necessary before the nature of this nesting symbiosis can be characterized.     

Mother-cub relationships in giant pandas in the Qinling Mountains,China, with comment on rescuing abandoned cubs

Six cases of mother-cub relationships in wild giant pandas (Ailuropoda melanoleuca) were observed in the Qinling Mountains, China. It was found that panda cubs are normally left alone in the den for 4–8 h while mothers forage. The mother's absence during bouts of foraging should be considered when rescuing abandoned cubs in order to avoid adding to the decline of the wild population. © 1994 Wiley-Liss, Inc.