螟长距茧蜂对植物挥发物质的行为反应

本文报道玉米螟Ostrinia furnacalis(Guenée)幼虫寄生蜂——螟长距茧蜂Macrocentrus Linearis(Ness)对植物挥发物质的行为反应.用嗅觉仪测定表明,雌蜂能被寄主植物(玉米、棉花)的挥发物质所吸引,但正常寄主植物的气味不能明显地引起雌蜂产卵管的刺探行为.然而,寄主幼虫损伤的寄主植物,即使不存在寄主幼虫,亦能明显地诱发雌蜂进行产卵管刺探.非寄主植物(黄豆、灰菜)的气味对雌蜂既无明显的吸引力,亦无特别的排斥作用.当把正常的和寄主幼虫损伤的寄主植物同时提供给雌蜂时,雌蜂明显地选择后者.在寄主植物和非寄主植物同时存在时,雌蜂明显地被寄主植物的气味所吸引.寄主植物的挥发物质能被乙醚抽提,抽提液滴加在滤纸上同样能诱发雌蜂触角搜索和敲打行为.     

四种鲤科鱼类对捕食胁迫行为响应的种间比较

为了比较早期捕食胁迫经历和当前环境中存在的捕食者对鱼类行为的影响,并考查这些影响是否存在种间差异,研究分别考查了测定环境(有、无捕食者存在)对有、无捕食胁迫经历的鳊(Parabramis pekinensis)、草鱼(Ctenopharyngodon idellus)、鲫(Carassius auratus)和中华倒刺鲃(Spinibarbus sinensis)等4种鲤科鱼类探索性、活跃性和勇敢性的影响。结果发现:早期捕食胁迫经历与当前环境条件对鱼类行为产生截然不同的影响,且存在较大的种间差异。无捕食胁迫经历的鳊、草鱼和中华倒刺鲃均会对陌生的捕食者乌鳢(Channa argus)做出行为响应,提示这3种鱼可能对陌生捕食者具有一定的识别能力,但这种识别与猎物鱼通过捕食胁迫经历获得的识别仍具有一定差距;具有捕食胁迫经历的鳊和中华倒刺鲃在空白环境中未表现出反捕食行为,可能是节约能量的一种策略。总体而言,草鱼对捕食胁迫经历和测定环境处理反应更为敏感,而中华倒刺鲃的反应则相对保守。但当周围环境中存在捕食者时, 4种鲤科鱼类均会通过维持较高运动状态的方式来应对捕食者。维持这种应激状态可能对猎物鱼...     

BEHAVIORAL RESPONSES OF EAST AUSTRALIAN HUMPBACK WHALES MEGAPTERA NOVAEANGLIAE TO BIOPSY SAMPLING

The response of migrating humpback whales to biopsy sampling was investigated off North Stradbroke Island, South East Queensland. Whales were allocated a behavioral category prior to biopsy sampling according to the general behavior of their pod. Behavioral reactions were recorded after each attempt. Sex was determined using a molecular genetic technique.
Detectable reactions occurred in 41.6% of successful biopsy attempts, a significantly lower response rate than that reported by two studies carried out on the feeding and breeding grounds of the North Atlantic. There was no difference in the response rate of whales on their northward or southward migration. Pod size was not an important factor in predicting the response of an individual. Females responded to biopsy sampling at a significantly higher rate than males.
Our results indicate that a substantial difference in response rate can occur between studies. Factors such as the type of boat used and the prior exposure of whales to human impact may be of importance. Our study suggests that female humpback whales may be particularly responsive to human disturbances. Overall, however, biopsy sampling has minimal impact on humpback whales.     

THE SHORT-TERM BEHAVIORAL REACTIONS OF BOTTLENOSE DOLPHINS TO INTERACTIONS WITH BOATS IN DOUBTFUL SOUND, NEW ZEALAND

Doubtful Sound is home to one of the southernmost resident populations of bottlenose dolphins ( Tursiops sp.). This population regularly interacts with scenic cruises. During these interactions, dolphins tend to horizontally and vertically avoid vessels, especially when the behavior of these vessels is intrusive. This study aimed at understanding the behavioral reactions of individuals to these interactions that lead to the disruption of the school's behavioral state. Observing the behavioral events performed by individuals during an interaction can help define the short-term reactions elicited by the boat presence. I recorded the behavioral events performed by all individuals of focal schools. The frequency of occurrence of all events was compared depending on the presence of vessels, their behavior, and the behavioral state of the focal school. Dolphins tended to perform more side flops while interacting with powerboats, a behavior which may be used as a non-vocal communication tool. Moreover, the movement of dolphins became more erratic during interactions with all types of vessels. These effects increased when the boats were more intrusive while interacting. This study shows that the impact of interaction with boats can be minimized if the vessels respect the guidelines in place.     

RESPONSES BY HECTOR'S DOLPHINS TO BOATS AND SWIMMERS IN PORPOISE BAY,NEW ZEALAND

Theodolite tracking (61 d; 251 h) was used to quantify dolphin reactions to boats and swimmers in the austral summers of 1995-1996 and 1996-1997. Dolphins were accompanied by swimmers (within 200 m) for 11.2% of the total observation time, whereas boats accounted for an additional 12.4%. Dolphins were not displaced by either of these activities. Swimmers caused only weak, non-significant effects, perhaps because dolphins could very easily avoid them. Reactions to the dolphin-watching boat were stronger. Analyses of relative orientation indicate that dolphins tended to approach the vessel in the initial stages of an encounter but became less interested as the encounter progressed. By 70 min into an encounter dolphins were either actively avoiding the boat or equivocal towards it, approaching significantly less often than would be expected by chance. Analyses of group dispersion indicate that dolphins were significantly more tightly bunched when a boat was in the bay.     

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.     

EXPERIMENTAL RETURN TO THE WILD OF TWO BOTTLENOSE DOLPHINS

In the first scientific experiment of its kind, two young male bottlenose dolphins ( Tursiops truncatus ) were captured in Tampa Bay, Florida, and then returned to the wild at the same locale in October 1990, after two years in captivity. The dolphins' age/sex class and the capture and release site were selected prior to their collection. The ranging and social association patterns of the host community were examined prior to, and, including the two animals, after release. The dolphins remained together for the first month, then began interacting more with other dolphins and less with each other. Within the first year, one dolphin returned to the waters near his capture site and has remained there at least through September 1993. The other dolphin has remained in his original home range at least through June 1996. Observations of each dolphin have shown them to be fully integrated into the local dolphin societies. They displayed typical behavioral, ranging, and social association patterns. Their body condition has been excellent at each observation. They have not been observed interacting with humans. The apparent success of this experiment cannot necessarily be generalized to all potential candidates for return to the wild, but the results can be used to guide future experiments.     

BEHAVIORAL ASPECTS OF SLEEP IN PACIFIC WHITE-SIDED DOLPHINS (LAGENORHYNCHUS OBLIQUIDENS,GILL 1865)1

Dolphin sleep is unlike typical mammalian sleep in that slow wave sleep occurs in one hemisphere at a time and rapid eye movement (REM) sleep is apparently reduced or absent (Mukhametov 1987). Lilly (1964) observed that bottlenose dolphins (Tursiops truncatus) sleep with one eye open and one eye closed and suggested that the open eye monitored the immediate area for predators. Mukhametov (1987) and Supin et al. (1978) found no physiological correlation between the active brain hemisphere and the open eye, and suggested that no sentinel function exists. I describe the behavioral and social aspects of sleep in a captive school of four Pacific white-sided dolphins (Lagenorhynchus obliquidens) at Long Marine Lab at the University of California at Santa Cruz for 32 nights. As the animals swam in formation, I recorded their positions and eye condition. Dolphins did not close their eyes or switch positions in the school randomly. While in formation, dolphins switched positions in bouts while concurrently changing eye condition. This resulted in a sleeping formation in which the dolphins likely had the eye open towards schoolmates, not toward the external environment. I suggest that this allows sleep to proceed while allowing dolphins to maintain visual contact with group members.     

PHYSIOLOGICAL AND BEHAVIORAL DEVELOPMENT IN DELPHINID CALVES: IMPLICATIONS FOR CALF SEPARATION AND MORTALITY DUE TO TUNA PURSE-SEINE SETS

Tuna purse-seiners in the eastern tropical Pacific (ETP) capture yellowfin tuna by chasing and encircling herds of associated dolphins. This fishery has caused mortality in 14 dolphin species (20 stocks) and has led to significant depletions of at least three stocks. Although observed dolphin mortality is currently low, set frequency remains high and dolphin stocks are not recovering at expected rates. Mortality of nursing calves permanently separated from their mothers during fishery operations may be an important factor in the lack of population recovery, based on the recent discovery that calves do not accompany 75%–95% of lactating females killed in the purse-seine nets. We assessed age-specific potential for mother–calf separations and subsequent mortality of calves by reviewing and synthesizing published data on physiological and behavioral development in delphinids from birth through 3 yr postpartum. Results indicate that evasive behavior of mothers, coupled with the developmental state of calves, provides a plausible mechanism for set-related mother–calf separations and subsequent mortality of calves. Potential for set-related separation and subsequent mortality is highest for 0–12-mo-old dolphins and becomes progressively lower with age as immature dolphins approach adult stamina and attain independence.     

PLASTINATION FOR DISPLAY: A NEW WAY TO DISPOSE OF THE DEAD

Plastination provides a new method, governed by medical technique rather than religious ritual, by which human remains may be transformed from unstable/wet to stable/dry. In the Körperwelten/Body Worlds exhibition, the public pay to view plastinated bodies, and are invited to donate their bodies for plastination after death. This article addresses the question of whether Body Worlds visitors accept plastination for display as a legitimate form of disposal. Three sources of data are drawn on: the ethnographer's account of his first visit to the exhibition in Brussels; the written comments of visitors to the London exhibition; and the stated motives of some donors. Plastination as final disposal is accepted by the vast majority of visitors; they perceive the dry, odourless body interiors within the clinical, scientific framework encouraged by the exhibition, and are often fascinated by what they see. This is complicated, however, by certain surface features and modes of display which enable the problematic reinsertion of personhood. So, plastination itself is accepted, but not all forms of display.     

SURFACE BEHAVIOR OF BOTTLENOSE DOLPHINS IS RELATED TO SPATIAL ARRANGEMENT OF PREY

We tested the hypothesis that spatial arrangement and movements of bottlenose dolphins ( Tursiops truncatus ) are related to the spatial arrangement of their prey. From 65 groups we: (1) classified feeding behavior of dolphins according to spatial arrangement and movements of individuals; (2) assessed spatial arrangement and location of prey from direct observations, numbers of associated seabirds, and echosounder recordings; and (3) related feeding behavior of dolphins to spatial arrangement and location of prey. Four feeding categories were defined from cluster and principal component analyses: (1) moving rapidly with no diving, (2) milling with no diving, (3) diving in several locations, and (4) diving in one location. These feeding categories were related to spatial arrangement and location of prey.     

A SERUM FACTOR INDUCING MONOCYTOSIS DURING AN ACUTE INFLAMMATORY REACTION CAUSED BY NEWBORN CALF SERUM

An intraperitoneal injection of newborn calf serum (NBCS) into CRF Swiss mice causes an inflammatory reaction characterized by an increase in the number of macrophages in the peritoneal cavity and a concomitant monocytosis. The serum of such mice contains a monocytosis-inducing factor, as demonstrated by the intravenous injection of serum collected 18 (CalS 18) and 24 hr (CalS24) after the intraperitoneal injection of NBCS. Serum from normal untreated mice, from mice given an intraperitoneal injection of sterile pyrogen-free saline, which does not cause an inflammatory reaction, or from mice 72 hr after an intraperitoneal injection of NBCS, when the inflammatory reaction has subsided, does not cause a monocytosis in test mice. Intravenous injection of CalS 18 causes not only a monocytosis but also an increase in the number of promonocytes and bone marrow monocytes, suggesting an increased production of monocytes. The effect of CalS 18, CalS24 and CalS 18 filtrate is specific for the mononuclear phagocytes, since only non-significant increases in the numbers of lymphocytes and granulocytes were observed. The active factor in CalS 18 was shown to be different from the monocytosis-inducing factor present in NBCS. The monocytosis-inducing factor in CalS 18 passes through an ultrafiltration membrane with an exclusion limit of 50,000 Daltons, so that the molecular weight must be below this value.