Behavioral effects of environmental enrichment on harbor seals (Phoca vitulina concolor) and gray seals (Halichoerus grypus)

Zoos and aquariums have been incorporating environmental enrichment into their animal care programs for the past 30 years to increase mental stimulation and promote natural behaviors. However, most attempts to document the effects of enrichment on animal behavior have focused on terrestrial mammals. Staff at the National Aquarium in Baltimore conducted an investigation of the behavioral effects of enrichment on the seven harbor seals and two gray seals housed in the aquarium's outdoor seal exhibit. We expected that enrichment would change the amount of time the animals spent engaged in specific behaviors. The behaviors recorded were: resting in water, resting hauled out, maintenance, breeding display, breeding behavior, aggression, pattern swimming, random swimming, exploration, and out of sight. Activity levels (random swimming and exploration) were expected to increase, while stereotypic behaviors (pattern swimming) were expected to decrease. The frequency and duration of behaviors were documented for 90 hr in both the control phase (without enrichment) and the experimental phase (with enrichment). Statistically significant differences (P<0.05) in the time spent in pattern swimming, random swimming, exploration, and out of sight were observed between the two phases. With enrichment, pattern swimming and out of sight decreased, while random swimming and exploration behavior increased. These findings demonstrate that enrichment can promote behaviors (random swimming and exploration) that are likely to be normal for phocids in the wild, and that may contribute to the behavioral complexity of these seals in captivity. Zoo Biol 21:375–387, 2002. © 2002 Wiley‐Liss, Inc.     

A QUANTITATIVE STUDY OF THE DAILY ACTIVITY OF THE WARTHOG IN THE QUEEN ELIZABETH NATIONAL PARK, UGANDA

Warthog activity was recorded at 4-min intervals for continuous periods of 14 h on three consecutive days. The major activities were feeding or lying down and walking. The amount of time spent in feeding is related to the size of the animal and maximum-intensity feeding occurs in the early morning and in the late afternoon and evening. The animals drank usually only once each day. Adult females urinate much more often than males and this is thought to be a behavioural adaptation whereby the males can tell whether or not a female is in heat.     

Sex ratios in mule duck embryos at various stages of incubation

Mule duck hatcheries have long reported varying degrees of unbalance in the sex ratio, with a preponderance of male mules at hatching. The aim of the present study was to assess the distributions of sex ratios at various stages of development in embryos originating from intra- and intergeneric crosses between parental lineages (Muscovy male x Muscovy female, Pekin male x Pekin female, Muscovy male x Pekin female or Mule, and Pekin male x Muscovy female or Hinny). In Experiment I, embryo sexing was performed on Days 1 and 5 of incubation (by multiplex PCR) and at hatching (by vent observation). The sex ratio was not significantly modified during the early stages of embryo development whatever the genetic origin (P>0.05, Days 1 and Day 5) but our results in mule and hinny ducklings confirmed the preponderance of males among normally hatched ducklings originating from the intergeneric lineage (58.9 and 55.4% males in mules and hinnies, respectively; P<0.05 in both cases). Sex ratio (vent sexing) in second grade (cull) ducklings revealed that 68% of these ducklings were females (P<0.05). In Experiment II, the distribution of sex ratio was also performed in mule duck eggs from 6 batches (400,000 eggs/batch) first examined for fertility (candling) on Day 18 of incubation. These results indicate that the percentage of males present in the population of normally hatched ducklings increases when fertility decreases. In addition, this experiment also revealed that 83.7-90.5% of viable male mule embryos develop up to hatching, compared to only 43.0-51.0% of female mule embryos. Given that a deviation in sex ratio during the first stages of incubation is unlikely (Experiment I), it is concluded that the skewed sex ratio of mule ducks at hatching is primarily due to increased late mortality in female mule embryos occurring between egg transfer and hatching. This mortality originated, at least in part, from the intergeneric origin of female mules, and was marked to a greater or lesser extent depending on the initial success of fertilization in a given batch, a possible indication that the initial quality of gametes may selectively exert its influence at the later stages of embryo development.     

Behavior of Adult Anoplophora glabripennis on Different Tree Species Under Greenhouse Conditions

We observed behaviors and compiled activity budgets of adult Anoplophora glabripennis (Coleoptera: Cerambycidae) given a choice of different species of living trees as hosts in a greenhouse. Frequency of observation of beetles on different tree species provided a good overall indicator of host preference. Beetles were most often observed resting; they were least active early in the day and most active late in the day, but mating was observed with equal frequency during all 4-h time intervals between 0800 and 2400 h. Adults of both sexes were promiscuous, mating repeatedly and with different partners. Males engaged in mate guarding for periods of several hours or more to ensure paternity of the guarded female's progeny.     

半散放东北虎产仔行为的初步观察

1999年4月至2003年6月,采用随机取样法、扫描取样法和目标取样法对黑龙江东北虎林园半散放条件12只成年雌性东北虎的产仔行为进行观察。结果表明,半散放雌性东北虎的产仔行为可分为9种:站立、行走、躺卧、嗅闻、努责、梳理、生产、亲仔和舔食。雌性东北虎的躺卧和亲仔行为时间最长,分别为42.9% 和34.5% ;躺卧、努责和亲仔行为发生频率较高,分别为21.1%、16. 9% 和24.6%。单因素方差分析表明,不同雌性东北虎个体间躺卧、亲仔等行为有显著差异;不同年份雌性成年东北虎的站立、躺卧、梳理等产仔行为也具有显著差异。相关分析显示,躺卧行为与亲子行为(r_s= 0.602, P<0.05)、梳理行为(r_s=0.589,P<0.05)均呈负相关。     

Diel activity pattern and food search behaviour in cod, Gadus morhua

Food search behaviour in cod, Gadus morhua, was studied by means of a stationary positioning system. Six fish in a fjord in northern Norway were tagged in situ by allowing them to shallow bait-wrapped acoustic tags, and their swimming behaviour was continuously recorded. The fish exhibited a diel activity rhythm, with higher swimming speeds and a larger range during the day than at night. Chemically mediated food search was studied in periods of both high and low activity by setting a string of baits in the morning and at night. During the period of high activity, more fish localized the baits (70 versus 45% of the observations) and the time to localization was 50% shorter, indicating that high swimming activity increased the probability of encountering the odour plume and the odour source. No diel variations in the response threshold to olfactory stimuli were found, as the proportion of fish in the odour plume that responded rheotactically, and their response distances were similar in the two periods (240 and 227 m respectively). Cod performed area-restricted searches on encountering the string of baits during the day. The probability of cod detecting prey by taste receptors, encountering the odour plume of prey or localizing a stationary food source after olfactory stimulation should be relatively independent of light, and this could explain why cod were active throughout the 24 h cycle. On the other hand, the visual detection distance and the ability to capture active prey are influenced by the light level, resulting in higher activity during the day.     

Socio-sexual behavior of female northern muriquis (Brachyteles hypoxanthus)

Female northern muriquis (Brachyteles hypoxanthus) are known to engage in frequent copulations with multiple partners, a pattern that in other primates has been attributed to various functions such as confusing paternity, reducing male aggression, or ensuring fertilization. However, in some female primates, promiscuity is restricted to times when conceptions are unlikely. We investigated whether female northern muriquis might exhibit a similarly mixed strategy by examining their mating, social, and activity patterns during their conception cycles versus other times. Systematic behavioral data were collected during an 18-month period between August 2001 and February 2003 on 13 adult females in a well-studied group at the RPPN-Feliciano Miguel Abdala, Minas Gerais, Brazil. Females mated on an average of 12.5+/-7.9 days during the study period, and spent significantly less time resting and engaging in non-sexual social behaviors, and significantly more time in sexual behaviors on days that they copulated than on days they did not. Three of the eight females for which sufficient data were available copulated significantly more often with their spatially closest non-kin associates, and four of five females that could be analyzed copulated significantly more often with their most frequent non-kin embrace partners. Comparisons between conception and non-conception periods revealed no differences in female activity budgets or in either the number of copulations or the number of different mating partners per female. Our results suggest that some females mate preferentially with close associates and social partners, but there is no indication that females alter their behavior during the cycles in which they conceive.     

In situ swimming behaviors and oxygen consumption rates of juvenile lemon sharks (<Emphasis Type="Italic">Negaprion brevirostris</Emphasis>)

Knowing how often animals engage in different behaviors and their energetic costs may explain why animals behave the way they do in the wild. This study sought to investigate the relationship between the frequency of various swimming behaviors and their associated energetic costs (oxygen consumption rates) in situ for juvenile lemon sharks (Negaprion brevirostris). Behaviors were identified for captive animals and remotely observed for animals in the wild with accelerometers, and oxygen consumption rates of behaviors were estimated using acceleration-calibrated relationships. Lemon sharks rested infrequently (4.3% of deployment), and the occurrence of active swimming behaviors was inversely related to their respective oxygen consumption rates. Furthermore, time of day and tide state influenced when lemon sharks exhibited active swimming behaviors – but not resting – such that sharks were most active during the day on flooding tides. Oxygen consumption rates also differed across and within different behaviors with time of day and tide state, although mean oxygen consumption rates were highest on daytime flooding tides and uniformly reduced across all other diel and tide combinations. Despite variation in oxygen consumption rates, however, lemon shark activity occurred at 32.3–35.6% of their aerobic metabolic scope. These data do not provide a clear oxygen consumption basis for swimming behaviors observed in situ, which may have been masked by potentially stronger ecological drivers (e.g., predator-prey dynamics). However, these data are relevant to linking behavioral modifications to changes in energy use that shows much promise for addressing conservation issues in fishes.     

Pair bond characteristics and maintenance in free‐flying jackdaws Corvus monedula: effects of social context and season

Most birds rely on cooperation between pair partners for breeding. In long‐term monogamous species, pair bonds are considered the basic units of social organization, albeit these birds often form foraging, roosting or breeding groups in which they repeatedly interact with numerous conspecifics. Focusing on jackdaws Corvus monedula, we here investigated 1) the interplay between pair bond and group dynamics in several social contexts and 2) how pair partners differ in individual effort of pair bond maintenance. Based on long‐term data on free‐flying birds, we quantified social interactions between group members within three positive contexts (spatial proximity, feeding and sociopositive interactions) for different periods of the year (non‐breeding, pre‐breeding, parental care). On the group level, we found that the number of interaction partners was highest in the spatial proximity context while in the feeding and sociopositive contexts the number of interaction partners was low and moderately low, respectively. Interactions were reciprocated within almost all contexts and periods. Investigating subgrouping within the flock, results showed that interactions were preferentially directed towards the respective pair partner compared to unmated adults. When determining pair partner effort, both sexes similarly invested most into mutual proximity during late winter, thereby refreshing their bond before the onset of breeding. Paired males fed their mates over the entire year at similar rates while paired females hardly fed their mates at all but engaged in sociopositive behaviors instead. We conclude that jackdaws actively seek out positive social ties to flock members (close proximity, sociopositive behavior), at certain times of the year. Thus, the group functions as a dynamic social unit, nested within are highly cooperative pair bonds. Both sexes invested into the bond with different social behaviors and different levels of effort, yet these are likely male and female proximate mechanisms aimed at maintaining and perpetuating the pair bond.     

Energy intake, energy expenditure, and reproductive costs of female wild golden lion tamarins (Leontopithecus rosalia)

Callitrichid females are often described as energetically constrained. We examined the energy budgets of 10 female wild golden lion tamarins (GLTs, Leontopithecus rosalia) in an effort to understand how energy intake and expenditure might influence physical condition and therefore reproductive performance. We used focal animal sampling to record behavioral data and conducted energy analyses of foods consumed by GLTs to estimate intake and expenditure. We used two-tailed Wilcoxon signed-rank tests to compare intake in the reproductive vs. nonreproductive period and expenditure in the reproductive vs. nonreproductive period. Energy intake decreased during the reproductive period compared to the nonreproductive period. While total expenditure did not vary significantly across the two periods, females spent more time and therefore expended significantly more energy engaged in energetically inexpensive behaviors (i.e., sleeping or being stationary) during the reproductive period compared to the nonreproductive period. We suggest that reproductive female GLTs may adopt a reproductive strategy that includes high intake prior to pregnancy and lactation, and energy conservation during pregnancy and lactation.     

It's just ducky to be clean: the water repellency and water penetration resistance of swimming mallard Anas platyrhynchos ducklings

Ducklings reared by a hen swim with dry plumage a day or two after hatching, while incubator-hatched ducklings of the same age may sink and even drown when placed in water. The common interpretation is that wild-reared chicks receive preen oil from the parent, and this oil makes them more waterproof. Using mallard ducklings Anas platyrhynchos we tested the effect of preen and other oils, as well as hydrophilic or surfactant contaminants, on the water resistance of down. We found that the true cause for the difference between incubator and hen-reared ducklings is the presence of hydrophilic hatching fluid residues in the down of incubator-hatched ducklings. Once well rinsed and dried, incubator-hatched ducklings can swim for over an hour with essentially dry down. Other tests showed that clean down is quite water resistant, and that water resistance was not improved by preen or other oils. Small amounts of preen or other oils had no effect on water repellency or wetting during surface swimming. However, oil decreased the hydraulic pressure needed to penetrate down. Down lacks the stabilizing interlocking structure of adult contour feathers, and small amounts of oil apparently cause barbules to stick together and reduce the effective number of down fibers. Detergent decreases water repellency and increases water retention, and has a more severe effect on oiled down or when applied in combination with oil. The penetration pressure of a clean down coat, 866±154 Pa, could allow static immersion to ca. 8cm before water would saturate the down and increase thermal conductance. Thus, clean ducklings have a 2×–3× safety margin for surface swimming. Saturation increases the thermal conductance of the down coat from 14.3±1.38 W/m²-°C to 193±25 W/m²-°C. Thus, water pollution or down contamination causing wetting can significantly increase energy use and the frequency of hypothermia.     

Individual Effects of Seasonal Changes,Visitor Density,and Concurrent Bear Behavior on Stereotypical Behaviors in Captive Polar Bears (Ursus maritimus)

Stereotypical behaviors in captive polar bears (Ursus maritimus) can be detrimental to their welfare. These behaviors can be reduced through enrichment programs but are often not completely eliminated, so identifying potential triggers is important. The present study investigated the influences of seasonal changes, visitor density, and concurrent bear activity on stereotypical behaviors exhibited by 3 captive polar bears at the Toronto Zoo. All bears exhibited these behaviors; however, individual differences were found in duration and form. The male exhibited less stereotypical behavior during spring, and the females exhibited less stereotypical behavior during winter. An increase in visitor density was associated with more stereotypical behavior in 1 female but less stereotypical behavior in the other 2 bears. All bears engaged in more stereotypical behaviors when the other bears were inactive, and 1 female engaged in more stereotypical behaviors when the other bears were out of sight. Further, when conspecifics were active, all bears engaged in less stereotypical behaviors. Given the variability among individual bears, future enrichment programs must be tailored to the needs of individuals to maximize efficacy.     

Circadian rhythms in juvenile american shad, Alosa sapidissima

Swimming activity (in cm s⁻¹) of a school (55 individuals) of young-of-the-year ( total length=110 mm) American shad, Alosa sapidissima , was determined under a variety of photoperiod conditions. These included a normal (ambient), a shifted, and constant-light day. Swimming activity was measured over 4-day periods. During normal days swimming speeds followed periods of about 24 h, with fast speeds (up to 45 cm s⁻¹) and schooling occurring during the photoperiod. Under dark conditions speeds were slower (8 cm s⁻¹) with most fish swimming as individuals. During a shifted day swimming speeds and schooling corresponded to the imposed day. Under constant light (equivalent to bright moonlight) no schooling was evident, and a constant, but slow, swimming speed was observed in each 24-h period. These shad demonstrated an exogenous rhythm with respect to the imposed day length. It is hypothesized that an endogenous circadian rhythm would only be of use to a fish required to hunt or chase its prey. Shad, being plankton feeders, do not chase prey and therefore can exhibit an exogenous circadian rhythm with no detrimental feeding results.     

Genetic evidence for kin-based female social structure in common eiders (Somateria mollissima)

Kin-based social groups are commonly studied among cooperativelybreeding species but have been less studied in "nontraditional"group breeding systems. We investigated the presence of kin-basedsociality among females in the common eider (Somateria mollisima),a colonial nesting sea duck that exhibits high levels of natalphilopatry in females. Previous studies of female socialityin common eiders have been restricted to observations duringbrood rearing. However, aggregations of female common eidersare also observed during other periods of the life cycle suchas colony arrival and nesting. Here we apply a novel, empiricalframework using molecular markers and field sampling to geneticallycharacterize female social groups at several stages of the commoneider life cycle. When compared with mean estimates of interindividualrelatedness for the entire colony, significantly higher levelsof relatedness were found between females within groups arrivingto the colony in flight, between females and nearest neighborsat the time of nest site selection, and between groups of femalesdeparting the colony with ducklings. Both full-sibling and half-siblingequivalent relationships were also found within these groups.Therefore, throughout each of several stages including in-flightcolony arrival, nesting, and brood rearing, we provide the firstgenetically confirmed evidence of female kin-based social groupsin common eiders and anseriformes in general.     

Long-term effects of stress in critical periods of development on reactivity of adult female rats

Effects of stress during different periods of ontogeny, namely, the prenatal, prepubertal, or their combination (prenatal+prepubertal), on the indices of psychoemotional and tonic pain-related behaviors, as well as corticosterone reactivity after pain behavior were investigated in adult 90-day-old female Wistar rats. Our data show for the first time, the similarity of effects of prenatal (immobilization stress of a rat dam during the last week of pregnancy) and prepubertal (forced swimming, pain-related response in the formalin test) stresses on the indices under study, an increase in the time of immobility and in licking duration, but the difference between effects of combined stress on these indices. Pain-related response increased corticosterone in prepubertally stressed rats while in prenatally stressed rats, decreased it. In rats experienced combined stress, formalin-induced pain increased corticosterone as compared with that in prenatally, but not in prepubertally stressed rats. A positive correlation between pain-related reaction and stressed hormonal response was revealed in prepubertally stressed animals. So, long-term effects of stress during critical periods of ontogeny determine stress reactivity of behavioral and hormonal responses in adult female rats.     

中华秋沙鸭越冬行为时间分配及日活动节律

2007年12月-2008年1月和2008年11-12月,在江西省境内4条主要河流及其支流对中华秋沙鸭(Mergus squamatus)越冬期的各种行为活动节律及时间分配进行了实地调查研究。结果表明:中华秋沙鸭越冬期的主要行为有取食、游泳、理羽、静息、睡眠、游戏、飞行和观察。其中取食、游泳、理羽、静息呈明显的节律性变化,且取食与静息呈相反的节律变化;睡眠、飞行、游戏和观察没有明显的节律性变化。取食在7:00-8:00、10:00-11:00、12:00-13:00有明显的峰值,峰值平均间隔2.3h,其它时段具相近取食频次,且上午高于下午。睡眠和静息下午发生频次明显高于上午,并呈现节律性变化,对应3个取食高峰表现为低频次。行为时间分配如下:取食(46%),游泳(23%),理羽(9%)、静息和睡眠(各占8%)、飞行(4%)、游戏(2%)和观察(0.5%)。越冬期中华秋沙鸭大量时间用于取食,意图是为了积累能量。相关分析表明:取食与睡眠的发生呈显著负相关(R=-0.73,df=8,P0.05);取食与飞行的发生呈显著正相关(R=0.70,df=8,P0.05);理羽与静息的发生呈极显著正相关(R=0.88,df=8,P0.01);其他各种行为之间无显著相关性。     

The effect of egg size variability on thermoregulation of Mallard (Anas platyrhynchos) offspring and its implications for survival

Summary There is a range of egg size phenotypes in Mallards (Anas platyrhynchos) that has a large genetic component. It was hypothesized that egg size variation could play an important role in survival of newly hatched ducklings during their first few days out of the nest when they are most susceptible to thermal stress and starvation. Precocial young must be physiologically capable of maintaining homeothermy in order to spend adequate time foraging. Duckling size at hatching was highly correlated with egg mass, and those hatching from heavier eggs were able to maintain homeothermy at colder environmental temperatures than those from lighter eggs. Heavy ducklings had significantly lower mass-specific cooling rates, but lower critical temperature did not vary significantly among ducklings of different size. Although insulation and energy reserves were not proportionally greater in larger ducklings, those hatching from heavier eggs can survive starvation longer than those from lighter eggs. The relative cold tolerance of young from light and heavy eggs will affect the ratio of time spent foraging to time spent being brooded by the female parent. Although there is no direct evidence that selection is acting on egg size, variation in this trait within a population could be maintained by fluctuating environmental conditions at hatch.     

Distribution and at‐sea behavior of Bermudan White‐tailed Tropicbirds (Phaethon lepturus catesbyi) during the non‐breeding season

The movements and behavior of many taxa of seabirds during the non‐breeding season remain poorly known. For example, although studies conducted in the Pacific and Indian oceans suggest that White‐tailed Tropicbirds (Phaethon lepturus) seldom fly more than a few thousand kilometers from nest colonies after breeding, little is known about the post‐breeding movements and behavior of a subspecies of White‐tailed Tropicbirds (P. l. catesbyi) that breeds on islands in the North Atlantic Ocean. Our objective, therefore, was to use light‐based geolocators to identify the ranges and pelagic activities of White‐tailed Tropicbirds from Bermuda during the non‐breeding periods in 2014–2015 (N = 25) and 2015–2016 (N = 16). Locations were estimated based on changes in light intensity across time, and pelagic activities were determined based on whether geolocators attached to leg bands were wet (i.e., birds resting on the water's surface) or dry (i.e., birds in flight). In 2014, birds spent late summer (July–September) near Bermuda and the British Virgin Islands; by mid‐September, most (N = 17; 68%) birds took a direct easterly route to the Sargasso Sea. In 2015, most post‐breeders (N = 15; 94%) flew east from Bermuda and to the Sargasso before the end of late summer. For both years combined, fall and winter (October–February) ranges extended as far west as North Carolina and as far east as the mid‐Atlantic Ridge. In both years, all birds were located between Bermuda and the British Virgin Islands during the spring (April–May). All birds then flew north to Bermuda in both years, with variations in timing, during April and May. We also found extensive overlap in the ranges of males and females during the non‐breeding season in both years. During the non‐breeding season, White‐tailed Tropicbirds spent 5% of night periods and 41% of day periods in flight in 2014; in 2015, birds spent 8% and 42% of night and day periods, respectively, in flight. Tropicbirds spent more time flying during the day because they hunt by day, detecting prey on the wing by sight. Overall, our results suggest that White‐tailed Tropicbirds that breed in Bermuda are diurnal, nomadic wanderers that range over an extensive area of the Atlantic Ocean during the non‐breeding season.     

Heterosexual interactions in laboratory-housed stumptail macaques (Macaca arctoides): observations during the menstrual cycle and after ovariectomy.

Heterosexual interactions of pairs of stumptail macaques (Macaca arctoides) were studied in relation to the female menstrual cycle and after ovariectomy. Five intact male and 10 tubal-ligated female macaques were observed in laboratory pair tests of 20-mins duration, and data were obtained on various male and female behaviors. Each male was tested with the same two females during four 40-day observation periods. Males were tested daily and females were tested every other day. After two 40-day testing periods, one female partner of each male was ovariectomized and the other was sham-operated. Blood was collected regularly from the females during the course of observation and serum levels of estradiol and progesterone were determined by radioimmunoassay. The midcycle peak of estradiol was observed to occur approximately 18 days prior to menses. A distinct secondary peak in estradiol was observed to occur during the luteal phase of all cycles examined. Of 28 different male and female behaviors studied only female presentation to male sexual contact showed a significant midcycle peak related to the endogenous estradiol surge. After ovariectomy a significant decrease in the frequency of several male copulatory behaviors was observed, but most males continued to copulate regularly with their spayed partners throughout the period of this study. Thus, the pattern of copulatory behavior observed in stumptail macaques over the cycle of the female partner and subsequent to ovariectomy differs from that observed in other macaque species studied in the laboratory. It is concluded that cyclical fluctuations in the level of ovarian hormones are not significantly related to measures of sexual interactions in laboratory tests of this species, although the maintenance of copulation and associated behaviors at high levels depends to some degree upon the ovary.     

饥饿对扶桑绵粉蚧存活率和产卵量的影响

【背景】扶桑绵粉蚧是近年来入侵我国的重要害虫,食物是影响其生长发育及种群发展的重要因素。【方法】在室内条件下研究了饥饿对扶桑绵粉蚧不同龄期若虫和初羽化雌成虫存活率和雌成虫产卵量的影响。【结果】扶桑绵粉蚧不同虫态在饥饿条件下存活的时间存在显著差异,表现为雌成虫〉2龄若虫=3龄若虫〉1龄若虫。扶桑绵粉蚧各龄若虫和雌成虫随着饥饿时间的延长,存活率逐渐下降。其中,雌成虫存活率下降速度较慢,完全饥饿8d后存活率仍有50％左右;2、3龄若虫50％个体死亡需要饥饿的时间约为6d,1龄若虫约需5．5d。饥饿会显著降低1龄若虫存活率,但对2、3龄若虫没有显著影响。扶桑绵粉蚧雌成虫饥饿4d对其产卵前期、平均每头雌虫一生的产卵量没有显著影响,但寿命显著低于对照。【结论与意义】扶桑绵粉蚧耐饥力较强,这有助于它在野外建立种群。该结果为进一步评价扶桑绵粉蚧的入侵潜能提供了依据。