Seasonal variation in positional behavior of malagasy lemurs

I describe the positional behavior of four species of Malagasy lemur (Propithecus diadema, Eulemur fulvus rufus, Eulemur rubriventer,and Varecia variegata)at two times of year at Ranomafana National Park,Madagascar. There were significant seasonal differences in locomotor behavior in all species except P. diademaAmong the lemurids, leaping was more frequent and quadrupedism less frequent in the dry season. Only E. rubriventerexhibited seasonal differences in posture, and there were few seasonal differences in support use. The observed differences in positional behavior were not the result of differences in activity budget or in microhabitat use attributable to seasonal variation in resource use.     

Intercolonial differences in raiding activities in the Japanese slave-making antPolyergus samurai

Summary Intercolonial differences in raiding activity were investigated in the field on 9 colonies of the slavemaking antPolyergus samurai. Duration of raiding season, the mean start time of the first raiding trip in a day, the mean speed of outbound and inbound trips, and the mean distance to target nests varied significantly among colonies. The variance in start time of raiding was correlated with that in soil temperature and diurnal change pattern in soil temperature at the nest sites. The speed of trips and the first day with trips in the season also correlated with soil temperature at the nest site. Simple environmental factors well explained the observed variances in raiding activity among colonies. Therefore, raiding behaviour ofP. samurai seemed to be a stereotyped behaviour that is regulated through simple environmental factors.     

Ultrastructure of sensory receptors on the labium of the cassava mealybug,Phenacoccus manihoti Matile Ferrero

The ultrastructure of the sensory receptors located on the labium of the cassava mealybugPhenacoccus manihoti Matile-Ferrero (Homoptera, Pseudococcidae) was studied with scanning and transmission electron microscopes. Trichoid hairs of probable mechanoreceptive function are distributed over the labium. Uniporous chemosensilla which possess a mechanoreceptive dendrite, multiporous chemosensilla and mechanoreceptive pegs are present on the tip of the labium. The presence of contact and olfactory chemoreceptors on the labial tip ofP. manihoti suggests that tapping it on the cassava leaf provides the pest with information about the chemical nature of the leaf surface. ORSTOM     

Behavioral reproductive isolation among sympatric strains of Brachionus plicatilis Müller 1786: insights into the status of this taxonomic species

We present results on cross-mating experiments using Brachionus plicatilis strains collected in three ponds of a coastal marsh (Torreblanca Marsh, Castellón, Spain). These strains were known to differ widely both in morphology and allozyme patterns from a previous study, where they were grouped into three genetically different clonal groups. Although some of the strains co-occurred in the same pond and sexual periods overlapped, no gene flow was found among them. Our first objective was to determine whether behavioral reproductive isolation was responsible for the absence of interbreeding. A second objective was to explore the relationship between sexual isolation and genetic divergence. We performed two experiments. In Experiment 1, we tested five strains from different clonal groups; in Experiment 2, we added a strain from a congeneric species, and strains from different ponds. We recorded male mating behavior in all possible male-female strain pairings. Our data show that males of a strain tend to mate with females of the same strain or genetically similar strains, regardless of the pond they come from. We also found a high positive correlation between isolation distance and genetic distance. These results support the view that mating behavior acts as an important isolating barrier giving cohesion to clonal groups, and structuring populations of this rotifer, and that Brachionus plicatilis is a taxon composed of more than one biological species.     

Effectiveness of acoustic “prey”: Environmental enrichment for a captive African leopard (Panthera pardus)

In the course of developing active naturalistic exercise opportunities for zoo felines at moderate cost, a computer-controlled acoustic prey device was established. Changes in the behavior of a 16-year-old melanistic leopard (Sabrina) were studied as she learned to actively pursue bird sounds and obtained food treats as a function of the activity. By the twenty-ninth day she began to capture all 24 bird parts supplied on the feeder belt and continues to actively use the opportunity on a daily basis. General activity and apparent well-being have been enhanced, while stereotypic behaviors have decreased. © 1995 Wiley-Liss, Inc.     

Cartesian representation of stimulus direction: Parallel processing by two sets of giant interneurons in the cockroach

The cockroachPeriplaneta americana responds to wind puffs by turning away, both on the ground and when flying. While on the ground, the ventral giant interneurons (ventrals) encode the wind direction and specify turn direction, whereas while flying the dorsal giant interneurons (dorsals) appear to do so. We report here on responses of these cells to controlled wind stimuli of different directions. Using improved methods of wind stimulation and of positioning the animal revealed important principles of organization not previously observed.All six cells of largest axonal diameter on each side respond preferentially to ipsilateral winds. One of these cells, previously thought to respond non-directionally (giant interneuron 2), was found to have a restricted directional response (Fig. 3). The organization of directional coding among the ventral giant interneurons is nearly identical to that among the dorsals (Fig. 2). Each group contains, on each side, one cell that responds primarily to wind from the ipsilateral front, another primarily in the ipsilateral rear, and a third responding more broadly to ipsilateral front and rear.These results are discussed in terms of the mechanisms of directional localization by the assembly of giant interneurons.Abbreviations GI giant interneuron - vGI ventral giant interneuron - dGI dorsal giant interneuron - CF 5-carboxyfluorescein - A6 6th abdominal ganglion - TI thoracic interneuron - BED best excitatory direction     

SATELLITE-MONITORED MOVEMENTS AND DIVE BEHAVIOR OF A BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) IN TAMPA BAY, FLORIDA

An adult, female bottlenose dolphin ( Tursiops trucncatus ) was radio tagged and monitored via satellite-based Argos receivers for 25 d from 28 June to 23 July 1990, in Tampa Bay, Florida. A total of 794 transmissions were obtained during 106 satellite passes. A mean of 3.9 (SE = 0.24) locations/day were determined by Service Argos and showed the animal remained in the bay, usually close to the southeastern shore. The dolphin moved at least 581 km at a minimum mean speed of 1.2 (SE = 0.1) km/h. Data from 63, 922 dives were recorded. The animal spent an average of 87.1 (SE = 0.6)% of the time submerged, with a mean dive duration of 25.8 (SE = 0.5) sec. Mean dive duration differed significantly between four periods of the day, as did the mean percent of time spent submerged. During the early morning the animal spent more time at the surface, averaged shorter dives, and was submerged less than other times of day. This is the first study to demonstrate die1 dive cycles in a bottlenose dolphin. Four months after tag loss, the dolphin was photographed with no evidence of necrosis or disfigurement of the dorsal fin. Satellite telemetry was demonstrated as an effective means of documenting the movements and dive behavior of a small inshore cetacean.     

QUANTITATIVE BEHAVIORAL STUDY OF BOTTLENOSE DOLPHINS IN SWIM-WITH-DOLPHIN PROGRAMS IN THE UNITED STATES

The behavior of dolphins in four Swim-With-Dolphin programs was compared by type of Swim encounter, defined by the presence ("Controlled") or absence ("Not-Controlled") of explicit trainer regulation of interactions between dolphins and human swimmers. Dolphin-swimmer interactions involving aggressive, submissive, or sexual behavior were designated as "high-risk" in the Swim context; sexual behavior was included as high-risk based on analyses that demonstrated co-occurrence of sexual and agonistic behaviors. High-risk activity comprised a substantial proportion of dolphin-swimmer social activity during Not-Controlled Swims. In contrast, high-risk activity rarely occurred during Controlled Swims, even though agonistic and sexual behaviors were normal components of the same dolphins' free-time social repertoire. These results indicated that direct trainer control of dolphin-swimmer interactions virtually eliminated high-risk activity from the Swim context, and thereby diminished the potential for dolphin distress, swimmer injury, and rejection of dolphins from Swim programs due to swimmer injury. This study illustrates effective use of quantitative behavioral sampling techniques for evaluation of captive management concerns and promotes broader use of these techniques for a better understanding of cetacean behavior.     

Changes in the behavior of the female short-tailed cricket,Anurogryllus muticus (De Geer) (Orthoptera: Gryllidae) following mating

InAnurogryllus muticus females, mating stimulates burrow construction, burrow provisioning, feeding, egg production, and egg-laying. Since mating often occurs before the ovaries are fully developed, the time span between mating and oviposition is used for increased food intake and the accumulation of nutrient reserves in the fatbody. Oviposition triggers maternal care of eggs and emerging hatchlings, and blocks egg consumption. Hatchling behavior is investigated. When hatchlings eat eggs, they prefer newly laid over older, embryonic eggs.