Captive and wild orangutan (Pongo sp.) survivorship: a comparison and the influence of management

For managers of captive populations it is important to know whether their management provides a species with the physical and social environment that maximizes its survivorship. To determine this, survivorship comparisons with wild populations and long‐term evaluations of captive populations are important. Here we provide both for orangutans. We show that survivorship has increased during the past 60 years for captive orangutan populations in zoos. In addition, we show that survivorship of captive orangutans in the past used to be lower than for wild orangutans, but that for recently born (1986–2005) orangutans survivorship is not significantly different from the wild. This indicates that captive management in the past was suboptimal for orangutan survivorship, but that modern management of captive orangutans has increased their survivorship. We discuss the possible factors of modern management that could have influenced this. Am. J. Primatol. 71:680–686, 2009. © 2009 Wiley‐Liss, Inc.     

Environmental enrichment for zoo bears

The high incidence of stereotypic behaviors in zoo bears (van Keulen-Kromhout: International Zoo Yearbook 18:177–186, 1978) suggests that the environment of these animals lacks essential stimuli for guiding normal behavior. Three experiments investigated ways in which bear husbandry procedures can be altered to promote normal behavior. In experiments 1 and 2, honey-filled logs were given to a sloth (Melursus ursinus), American black (Ursus americanus), and brown bear (Ursus arctos) to determine 1) the role of food in stimulating investigatory behavior, 2) the rate of habituation to manipulable objects introduced into the exhibit, and 3) effects on locomotory behaviors. Results show specific and general habituation to the introduced objects that can be counteracted by refilling the logs with honey and by providing multiple logs in the exhibit. Investigatory activity directed toward honey-logs replaces pacing and walking in the sloth bear and is most effective in doing so when the log is novel. Experiment 3 examined the behavioral effects of feeding an American black bear in three different ways: 1) once daily in the den, 2) once daily with supplemental food from a mechanical feeder, and 3) once daily with food hidden in the exhibit in manipulatable objects. The latter method reduced stereotypic pacing from a median of 150 min/day to 20 min/day; the mechanical feeder method had no such effect. The results of a survey of 67 zoos concerning the diet and manner of feeding these three species of bears, as well as Asian black bears (Ursus thibetanus) are presented. Results are discussed with respect to the ways in which husbandry procedures can be improved to stimulate functional foraging and feeding behavior in confined bears.     

Variation in nature: its implications for zoo elephant management

Despite many advances in animal care and welfare over the past few decades, zoos have been criticized recently for the quality of their elephant management programs. More specifically, critics have argued that elephants live miserable lives in captivity and thus should not be kept in zoos. Poor health and reproductive success, they say, are the result of the combined impact of: a lack of exercise; exposure to cold temperatures and disease; and stress due to the use of “brutal” training techniques, chaining and inappropriate social environments. Everyone, including zoo professionals, seems to agree that improvements in zoo elephant management are necessary and appropriate. However, there is considerable disagreement on how to proceed and little information on which to base such decisions. One tactic that the critics have adopted in their efforts to promote change is their frequent reference to “nature” as a yardstick for gauging the adequacy of zoo animal management and care. An argument is made that direct zoo–wild comparisons are of questionable utility and may be invalid from a scientific perspective. Some critics talk about “nature” as if it represented a fixed set of rules by which captive managers must either abide by or risk diminishing the health and welfare of their charges. However, many aspects of elephant natural history vary greatly depending on prevailing environmental conditions and elephants may be much more flexible than many critics are giving them credit for. Thus, although zoo animal managers should look to nature for clues about how to best care for captive elephants, they should not feel constrained by them. This revelation is not intended as an excuse for poor elephant management or to support the status quo. On the contrary, a better approach is to develop realistic and biologically meaningful metrics that reflect the quality of elephant care and welfare and to use them to measure the success of evolving zoo elephant programs. Zoo Biol 25:161–171, 2006. © 2006 Wiley‐Liss, Inc.     

Increasing browse and social complexity can improve zoo elephant welfare

While recent work has assessed how environmental and managerial changes influence elephant welfare across multiple zoos, few studies have addressed the effects of management changes within a single institution. In this paper, we examine how management changes related to social structure and diet affect the behavior of a group of zoo elephants over a 23‐month period while also considering underlying factors, such as time of day, hormonal cycle, and individual differences. We recorded individual behaviors using 2‐min scan samples during 60‐min sessions. We analyzed behavioral changes across several study variables using generalized linear mixed models. We found that increasing browse can improve opportunities for foraging throughout the day but may not be sufficient to reduce repetitive behaviors. We observed that increasing group size and integration of bulls with cows can lead to increased social interaction in African elephants. Our results highlight the importance of using multiple management alterations to address elephant welfare, and considering environmental factors, when making management decisions.     

Survey of Saguinus mortality in a zoo colony.

Six years of necropsy records from a zoo colony of four tamarin species (Saguinus oedipus, S. geoffroyi, S. imperator, and S. mystax) were examined. Mean age at death was 4.0 years, average length in the colony at time of death was 3.4 years. Annual mortality rate varied between 9 and 30%. Gross necropsy findings, histopathologic, and bacteriological results indicate primary cause of death as follows: peritonitis (26%), septicemia (14%), nephritis (5%), hepatitis (5%), pneumonia (2%), and others.     

Forest elephant mitochondrial genomes reveal that elephantid diversification in Africa tracked climate transitions

Among elephants, the phylogeographic patterns of mitochondrial (mt) and nuclear markers are often incongruent. One hypothesis attributes this to sex differences in dispersal and in the variance of reproductive success. We tested this hypothesis by examining the coalescent dates of genetic markers within elephantid lineages, predicting that lower dispersal and lower variance in reproductive success among females would have increased mtDNA relative to nuclear coalescent dates. We sequenced the mitochondrial genomes of two forest elephants, aligning them to mitogenomes of African savanna and Asian elephants, and of woolly mammoths, including the most divergent mitogenomes within each lineage. Using fossil calibrations, the divergence between African elephant F and S clade mitochondrial genomes (originating in forest and savanna elephant lineages, respectively) was estimated as 5.5 Ma. We estimated that the (African) ancestor of the mammoth and Asian elephant lineages diverged 6.0 Ma, indicating that four elephantid lineages had differentiated in Africa by the Miocene–Pliocene transition, concurrent with drier climates. The coalescent date for forest elephant mtDNAs was c. 2.4 Ma, suggesting that the decrease in tropical forest cover during the Pleistocene isolated distinct African forest elephant lineages. For all elephantid lineages, the ratio of mtDNA to nuclear coalescent dates was much greater than 0.25. This is consistent with the expectation that sex differences in dispersal and in variance of reproductive success would have increased the effective population size of mtDNA relative to nuclear markers in elephantids, contributing to the persistence of incongruent mtDNA phylogeographic patterns.     

Note on optimizing environmental enrichment: a study of fennec fox and zoo guests

Environmental enrichment is widely used to stimulate animal time budgets that seem more natural and diverse than those of unenriched animals. Uncertainty of reward is a suggested means to maintain enrichment's efficacy. Foraging tasks are widely applied in zoo animal enrichment, yet few rely on the logic of optimal foraging theory to help maintain animal motivation. We applied a foraging strategy to zoo housed fennec foxes as enrichment. We varied only the probability of when and where food would occur in the animals' exhibit. Our methods increased behavioral diversity, animal activity, and stimulated guest interest in the exhibit.     

温、湿度对美洲斑潜蝇发育、存活及食量的影响

以花斑芸豆Phaseolus vulgaris为食料植物,在不同温、湿度组合下,观测了美洲斑潜蝇Liriomyza sativae的发育、存活及取食特征。结果表明,卵、幼虫和蛹期的发育速率与温度的关系均呈S型曲线。发育起点温度为：卵,8.9℃;幼虫, 10.1℃;蛹,9.6℃;整个未成熟期,9.5℃。有效积温为：卵,57.7日·度;幼虫,53.9日·度;蛹,151.9日·度;整个未成熟期,264.2日·度。湿度对发育速率的影响不明显。温度对存活的影响较大,当温度>34℃或<19℃时,各虫态的存活率都显著降低。湿度对存活率的影响主要发生在蛹期,当湿度低于50%时,蛹的羽化率显著降低。在高温、低湿的条件下,蛹不能羽化。在相对低温下的累计取食面积大于高温时的相应值,在25℃时达到1.6 cm²,而在28℃及以上温度时取食面积只有0.9 cm²左右。     

Host plant effects on the development and survivorship of the galling insect Neopelma baccharidis (Homoptera: Psyllidae)

In this study, the mortality factors acting upon the galling psyllid Neopelma baccharidis Burckhardt (Homoptera) caused by its host plant, Baccharis dracunculifolia De Candole (Asteraceae) were analysed. In March 1999, 982 galls of the same cohort were randomly marked on 109 individuals of B. dracunculifolia in the field. Galls were censused each month during their development, from April to August, and dead galls were collected and analysed for mortality factors. Gall dehiscence rates were calculated for each month. The major mortality source of N. baccharidis was gall dropping (13.2% of the original cohort), which is probably a normal outcome of previous mortality caused by the other factors observed in this study. Unknown factors killed 11.7% of this gall population and were ascribed to plant resistance during gall development. Empty galls represented 7.7% of the observed mortality and may be a consequence of egg retention or egg mortality/abortion related to variations in plant quality. Shoot mortality was high during the dry season and killed 7.5% of the galls, but this impact was minimized after the third month from gall formation due to the ability of nymphs to accelerate development and emerge from galls on dying shoots. However, the size of dehisced galls on dead shoots tended to be smaller, possibly affecting adult performance. Mortality of N. baccharidis attributed to B. dracunculifolia strongly controlled the galling insect population, killing 40.7% of the original cohort of galls. Plant‐mediated mortality was caused by often neglected factors acting predominantly during the first 3 months of development, which are critical to gall survivorship. These results reinforce the importance of bottom‐up forces in plant‐insect systems.     

Stereotypic behavior of a female Asiatic elephant (Elephas maximus) in a zoo

This study recorded daytime behavior of a female Asiatic elephant at the Municipal Zoo, Wroclaw, Poland, in both an indoor pen and an outdoor paddock as continuous scan sampling for 140 hr, over 35 days in 1 year. Stereotypic sequences involved bouts of highly repetitive stereotypic movements and much more variable interbout behavior. The study found both stereotypic movements, nodding and body (corpus) swaying, were asymmetric, accompanied by protraction of the right hind leg and to-and-fro swinging of the trunk. The elephant spent 52% of the daytime in stereotypic movements, 3.5 times the level reported for females in other zoos' groups. The share of time devoted to stereotypic behavior was lowest in the summer when the elephant was regularly released to the paddock and highest in the late fall after she had stayed in the pen after months of days outside. This suggests that changes in the management routine enhance stereotypies. Comparing the summer and winter stable management periods, stereotypies were much more frequent in the indoor pen than the outdoor paddock, suggesting that the confinement to a barren pen contributed to the observed levels of stereotypies.     

Fire refugia: The mechanism governing animal survivorship within a highly flammable plant

Identifying factors that influence the survival of individuals during disturbance is critical to understanding patterns of species reassembly within ecological communities. Although most studies of recovery of populations post‐burning acknowledge the potentially important contribution of animals surviving in situ, few have measured the effectiveness of refugia. This paper tests the hypothesis that some plants with tightly packed leaf‐bases provide a refuge for invertebrates during fire (even when the plants themselves burn) by using the highly flammable grass tree (Xanthorrhoeaceae: Xanthorrhoea). Invertebrates were sampled from four unburnt and five experimentally burnt grass trees (Xanthorrhoea preissii Endl.). Also collected were invertebrates fleeing during burning. The dataset comprises 949 specimens, representing 81 species from 18 orders, of which 749 individuals were from unburned plants. Slaters (Isopoda), silverfish (Thysanura), spiders (Araneae) and bugs (Hemiptera) dominated assemblages of the unburnt grass trees. Despite grass trees burning at temperatures of up to 515°C, some invertebrates survived in situ. Species‐specific microhabitat preferences within the plant appeared to influence survivorship. Species collected in the crown of unburned plants were found more often alive on burnt plants than species typically inhabiting the dead skirt of decaying leaves (thatch). We contend that the mechanism causing differential mortality is fire temperature. In the dead skirt, temperatures reached 225.33 ± 66.57°C. In contrast, a region of mild temperature (25.00 ± 3.54°C) persisted throughout burning near the apical meristem (within the crown). We conclude that grass trees are a potential reservoir from which invertebrates might re‐colonize recently burnt areas. However, owing to species‐specific microhabitat preferences and differential mortality across microhabitats, the invertebrate assemblage remaining in situ will be restricted taxonomically compared with the original grass tree fauna. Moreover, different fire regimes might mediate the effectiveness of grass trees as refugia. Finally, we argue that in situ survival of invertebrates within plants with tightly packed leaf‐bases is an unrecognized global phenomenon applicable to a wide array of plant taxa.     

Mesocyclops longisetus effects on survivorship of Aedes aegypti immature stages in car tyres

Abstract .The effect of the introduction of the entomophagous copepod Mesocyclops longisetus (Acuacultura F.C.B. strain) on the survival of Aedes aegypti immature stages in car tyres was evaluated under semi-natural conditions in the municipality of Merida, Yucatan, Mexico. Life tables were constructed for the immature stages of the mosquito in the presence and absence of M. longisetus , and the survival data were compared using log–linear models. The data set was adjusted using the GLIM statistical package and the quality of adjustment was evaluated with a chi-squared test . Survivorship curves were constructed for each treatment.
In the absence of M. longisetus , the survivorship of Ae. aegypti immature stages averaged 9%. The highest mortality rate was observed during the fourth larval instar (54%) and the resulting survival pattern corresponded to a type II survivorship curve. The mortality rate of Ae. aegypti first-instar larvae (fifty per tyre) increased more than 200-fold in the presence of M. longisetus (twenty per tyre) and the highest mortality was during the first two larval instars, where it reached 98.9%, with a resulting survivorship of 0.2%. Overall mortality was sixfold greater in the presence of the copepod than in its absence. The survival pattern of immature stages of Ae. aegypti in the presence of the copepod corresponded to a type III survivorship curve. As M. longisetus was so effective against Ae. aegypti immature stages in tyres under semi-natural conditions, its long-term effectiveness should be evaluated under socially and ecologically realistic field conditions in Mexico.     

昆虫拟态的历史发展

昆虫的拟态理论是由英国自然学家Bates于1862年提出的,Fisher称其为"达尔文后自然选择最重要的依据之一".大量的科学研究表明,昆虫的拟态行为最晚出现在石炭纪,自那时起昆虫与捕食者、昆虫与植物之间开始出现了共同的演变和进化.拟态的模仿方式一般包括颜色、花纹以及形态,但是也可以单指行为方面,且拟态大部分情况下可能模仿的是一个动物群体或者只是另外一种动物身上的一部分.拟态包括多种定义,不同的定义之间用小同的标准来区分拟态现象和非拟态现象,如贝茨氏拟态、缪勒氏拟态、侵略性拟态和瓦曼氏拟态等.本文从其中广义拟态的角度,对当前不同类群昆虫化石中拟态现象的研究进展进行了简要总结.     

Range-wide analysis of eastern massasauga survivorship

Decisions affecting wildlife management and conservation policy of imperiled species are often aided by population models. Reliable population models require accurate estimates of vital rates and an understanding of how vital rates vary geographically. The eastern massasauga (Sistrurus catenatus catenatus) is a rattlesnake species found in the Great Lakes region of North America. Populations of the eastern massasauga are fragmented and only a few areas harbor multiple, sizable populations. Eastern massasauga research has typically focused on single populations or local metapopulations but results suggest that demographic parameters vary geographically. We used 21 radiotelemetry datasets comprising 499 telemetered snakes from 16 distinct locations throughout the range of the eastern massasauga to characterize geographic patterns of adult survival using the known-fate model in Program MARK. Annual adult survival ranged from 0.35 to 0.95 (mean = 0.67) and increased along a southwest to northeast geographic axis. Further analysis of 6 datasets indicated no consistent difference in survival between males and females. Our results provide a better understanding of the relationship between survivorship and geography for the eastern massasauga and suggest that such variation should be incorporated into population models as well as local and regional management plans. © 2012 The Wildlife Society.