Factors affecting reproduction in zoo‐housed geoffroy's tamarins(Saguinus geoffroyi)

The captive population of Geoffroy's tamarins (Saguinus geoffroyi) has suffered a severe decline over the past 10 years. This population decline is attributed not to a failure to produce offspring, but rather to a failure to successfully rear offspring. To date, no studies have quantitatively examined the behaviors and hormones of this tamarin species in captivity. Therefore, this study was conducted to determine whether there were any discernable factors that could be correlated with failure to rear offspring in S. geoffroyi. Fifteen adult Geoffroy's tamarins (GTs) at the Cleveland Metroparks Zoo (CMZ) were observed by means of instantaneous sampling on a focal animal. In addition, all instances of social behaviors were recorded. A factorial arrangement of treatments was used, as animals were divided between a colony‐housing situation and a non‐colony situation with hand‐reared and mother‐reared animals in both treatments. Repeated‐measures analysis of variance (ANOVA) showed no interactions between the treatments, and no differences between rearing histories for the behaviors studied. However, animals housed in a colony setting exhibited higher levels of aggressive behaviors and lower activity levels compared to those in a non‐colony setting. There also was a trend for colony‐housed animals to huddle, scent‐mark, and exhibit sexual behaviors more often than non‐colony animals. First‐morning‐void urine samples were collected once per week, and assays for E₁C and PdG indicated that reproduction was not being suppressed. ANOVA conducted on samples assayed for excreted cortisol showed no differences in mean cortisol concentration by rearing histories or housing conditions. While these physiological indicators reveal no signs of stress, high levels of aggressive and territorial behaviors indicate social unrest in the colony‐housed condition, which may be contributing to the poor reproductive success of those individuals. Zoo Biol 22:545–559, 2003. © 2003 Wiley‐Liss, Inc.     

Fecal Glucocorticoid Measurements and Their Relation to Rearing,Behavior, and Environmental Factors in the Population of Pileated Gibbons (<Emphasis Type="Italic">Hylobates pileatus</Emphasis>) Held in European Zoos

Pileated gibbons (Hylobates pileatus) are rated as endangered according to the International Union of Conservation of Nature (IUCN) Red List. The captive population suffers from poor breeding success and is threatened to become overaged. Although several factors are likely to contribute to the poor breeding success, one in particular may be chronic stress associated with prolonged periods of high glucocorticoid (GC) output. We investigated fecal GC levels of pileated gibbons (Hylobates pileatus) and their relationship to specific life-history variables and environmental factors. After validation of an enzyme immunoassay for the measurement of 5-reduced 3α,11β-dihydroxy cortisol metabolites to assess GC output reliably in pileated gibbons, we collected fecal samples over several days from all 36 European adult pileated gibbons located in 11 institutions and compared GC levels to intrinsic individual parameters, husbandry, behavior, and breeding history. Age, sex, and origin (wild vs. captive born) had no effect on GC levels. However, unnaturally reared gibbons had higher GC levels and showed more behavioral abnormalities than parent-reared individuals. Further, nonreproducing gibbons living in a pair without infants had higher GC concentrations than gibbons living in a family, bachelor group, or as singletons. With respect to environmental factors, a large size of the inside enclosure and the existence of visual protection from visitors was associated with lower fecal GC output. The data indicate that rearing and housing conditions appear to correlate to GC levels in pileated gibbons housed under captive conditions. It is hoped this knowledge will support the future management of the species in captivity and thus lead to a more successful breeding of this endangered primate.     

Salivary concentration of progesterone and cortisol significantly differs across individuals after correcting for blood hormone values

Between‐individual variation of salivary progesterone (P4) and cortisol levels does not always closely reflect blood hormone concentrations. This may be partly a function of individual differences in salivary hormone excretion. We tested whether time of day at sampling and ethnicity contributed to individual variation in salivary hormones after adjusting for blood hormone levels. Forty‐three Caucasian and 15 Japanese women (18–34 years) collected four sets of matched dried blood spot (DBS) and saliva specimens across a menstrual cycle (N = 232 specimen sets). Linear fixed‐effects (LFE) models were used to estimate the effects of diurnal variation and ethnicity on salivary P4 and cortisol while adjusting for DBS levels. For each hormone, women with exclusively positive or negative residuals (unexplained variance) from the LFE models were categorized as high‐ or low‐saliva‐to‐DBS hormone ratio (SDR; high or low salivary secretors), respectively. We found that salivary P4 (P < 0.05) was significantly higher in early morning compared to the afternoon, after controlling for DBS levels, ethnicity, and BMI. After further adjusting for this diurnal effect, significant individual variation in salivary P4 and cortisol remained: sixteen and nine women, respectively were categorized as low or high salivary secretors for both hormones (P < 0.001), suggesting systematic individual‐specific variation of salivary hormonal concentration. We conclude that when saliva is used to quantify P4 or cortisol levels, time of day at sampling should be controlled. Even with this adjustment, salivary P4 and cortisol do not closely mirror between‐ individual variation of serum P4 and cortisol in a substantial proportion of individuals. Am J Phys Anthropol 149:231–241, 2012. © 2012 Wiley Periodicals, Inc.     

Effect of the enclosure on carriers' body weight loss in the cotton-top tamarin (Saguinus oedipus)

Infant carrying in cotton-top tamarins is a costly activity that results in weight loss by the fathers and helpers. However, to date, measures of carrying costs have been obtained in small indoor enclosures. We studied body weight changes in adult and subadult individuals from eight large groups (n > 5) for 9 weeks after the birth of infants. Four groups were housed in large indoor/outdoor enclosures (42 m(2) x 3.3 m high), and four were housed in small indoor enclosures (12 m(2) x 2.4 m high). All of the individuals were weighed regularly at least three times a week. Reproductive males lost more weight in the big indoor/outdoor enclosures (mean=6.51%) than in the small indoor ones, as did male adult helpers (mean=5.59%) and female adult helpers (mean=4.4%). Still-growing subadult individuals also lost weight in the big indoor/outdoor enclosures (mean=3.17%), although the differences did not reach significance (P=0.07). These results support the hypothesis that cotton-top tamarins living in more natural settings experience higher weight loss than those housed under less-natural conditions.     

Fecal Concentrations of Cortisol,Testosterone, and Progesterone in Cotton-Top Tamarins Housed in Different Zoological Parks: Relationships Among Physiological Data,Environmental Conditions,and Behavioral Patterns

The aim of this investigation was to study the welfare of 3 captive groups of cotton-top tamarins housed in different zoological parks. Ethological observations were conducted during 1 year. In addition, fecal samples were collected and the concentrations of glucocorticoids, androgens, and progestogens were measured. Within each group, no significant differences in fecal cortisol concentrations were found between subjects. The fecal concentrations of testosterone and progesterone significantly differed depending on the sexes and ages of the tamarins. A significant association was found among hormone concentrations, exhibit dimensions, and group composition. A highly significant correlation was found between all hormones considered and the space available for each subject. Significant differences in behavioral patterns were observed among groups, including social–individual, affiliative–aggressive, and anogenital–suprapubic scent marking. Correlations between hormone measurements and behaviors were detected. In conclusion, this study confirmed the associations between some behaviors exhibited by these nonhuman primates and both cortisol and testosterone; these data also highlight the role played by progesterone in these behaviors.     

The effect of the lunar cycle on fecal cortisol metabolite levels and foraging ecology of nocturnally and diurnally active spiny mice

We studied stress hormones and foraging of nocturnal Acomys cahirinus and diurnal A. russatus in field populations as well as in two field enclosures populated by both species and two field enclosures with individuals of A. russatus alone. When alone, A. russatus individuals become also nocturnally active. We asked whether nocturnally active A. russatus will respond to moon phase and whether this response will be obtained also in diurnally active individuals. We studied giving-up densities (GUDs) in artificial foraging patches and fecal cortisol metabolite levels. Both species exhibited elevated fecal cortisol metabolite levels and foraged to higher GUDs in full moon nights; thus A. russatus retains physiological response and behavioral patterns that correlate with full moon conditions, as can be expected in nocturnal rodents, in spite of its diurnal activity. The endocrinological and behavioral response of this diurnal species to moon phase reflects its evolutionary heritage.     

Noninvasive technique for the repeated sampling of salivary free cortisol in awake,unrestrained squirrel monkeys

The use of noninvasive measures of hypothalamic-pituitary-adrenal (HPA) axis function is of growing interest among preclinical and clinical investigators. This report describes a method for the repeated assessment of salivary free cortisol in awake, unrestrained squirrel monkeys (Saimiri sciureus) based on a saliva sampling technique previously developed for rhesus monkeys. Individually housed adult male squirrel monkeys were trained to chew on dental rope attached to a pole, from which saliva was extracted by centrifugation and analyzed for cortisol by radioimmunoassay (RIA). Eight of nine monkeys readily acquired the task, reliably providing adequate saliva samples for the assay. Salivary free cortisol levels were examined in these subjects under basal conditions and in response to two types of neuroendocrine challenge. Levels of salivary free cortisol showed relatively low intra- and interindividual variability, with mean individual morning levels ranging between 17.1 and 37.9 microg/dl. Squirrel monkeys demonstrated a consistent daily rhythm in salivary free cortisol ranging from a high of 27.4 +/- 5.2 microg/dl (mean +/- SEM) at 12 P.M. to a low of 7.5 +/- 1.6 microg/dl at 6 P.M. Intravenous (IV) challenges with 1 microg/kg ACTH, or 10 and 50 microg/kg CRF resulted in significant increases in salivary free cortisol. The described sampling technique provides a reliable and sensitive means for repeated measurement of HPA activity in unrestrained, awake squirrel monkeys. In addition, our findings illustrate several features of HPA system rhythmicity and reactivity using salivary cortisol instead of blood plasma or serum.     

Circadian Rhythm of Salivary Cortisol in Asian Elephants (Elephas maximus): A Factor to Consider During Welfare Assessment

Elevated glucocorticoid levels during an extended time period might be a stress indicator in nonhuman animals. Therefore, knowledge of the circadian pattern of cortisol secretion is very important to correctly interpret data obtained for welfare assessment of animals in captivity through salivary cortisol. In order to define the circadian rhythm of salivary cortisol secretion in the Asian elephant (Elephas maximus), morning and evening saliva samples of 3 Asian elephants were collected and analyzed by radioimmunoassay. Significantly higher salivary cortisol concentrations were found in the morning than in the evening in all individuals. These results show that salivary cortisol of Asian elephants follows a diurnal pattern of secretion, which could be taken into account when using this methodology to assess welfare in captive Asian elephants.     

Phenotypes optimized for early‐life reproduction exhibit faster somatic deterioration with age,revealing a latent cost of high condition

High condition enables individuals to express a phenotype with greater reproductive potential. However, life‐history theory predicts that reproduction will trade off with somatic maintenance and viability, and several studies have reported faster age‐related decline in performance in high‐condition individuals, suggesting that high condition in early life is associated with accelerated somatic deterioration. This trade‐off may be especially pronounced in males, which often express condition‐dependent secondary sexual traits that can impose viability costs during development and through damage‐inflicting adult sexual behaviours. To test this prediction, we reared larvae of the neriid fly Telostylinus angusticollis on diets of varying nutrient content and quantified somatic deterioration in solitary males, males housed in all‐male or mixed‐sex groups and immobilized males subjected to mechanical stress. We found that males reared on a nutrient‐rich larval diet (high‐condition males) suffered a higher rate of somatic deterioration with age, particularly when housed in groups. Perhaps as a result of accelerated somatic deterioration, high‐condition males did not outlive low‐condition males. In addition, high‐condition males housed in all‐male groups experienced a greater reduction in escape response with age than males housed in mixed‐sex groups, suggesting that male–male combat promotes somatic deterioration. However, even when immobilized, high‐condition males were still found to be more susceptible to somatic damage than low‐condition males. Our findings suggest that a high‐condition male phenotype is more prone to somatic damage, both as a result of associated behaviours such as combat, and because of the inherent fragility of the high‐condition body.     

Predator exposure alters stress physiology in guppies across timescales

In vertebrates, glucocorticoids mediate a wide-range of responses to stressors. For this reason, they are implicated in adaptation to changes in predation pressure. Trinidadian guppies (Poecilia reticulata) from high-predation environments have repeatedly and independently colonized and adapted to low-predation environments, resulting in parallel changes in life history, morphology, and behavior. We validated methods for non-invasive waterborne hormone sample collection in this species, and used this technique to examine genetic and environmental effects of predation on basal glucocorticoid (cortisol) levels. To examine genetic differences, we compared waterborne cortisol levels in high- and low-predation fish from two distinct population pairs. We found that fish from high-predation localities had lower cortisol levels than their low-predation counterparts. To isolate environmental influences, we compared waterborne cortisol levels in genetically similar fish reared with and without exposure to predator chemical cues. We found that fish reared with predator chemical cues had lower waterborne cortisol levels than those reared without. Comparisons of waterborne and whole-body cortisol levels demonstrated that populations differed in overall cortisol levels in the body, whereas rearing conditions altered the release of cortisol from the body into the water. Thus, evolutionary history with predators and lifetime exposure to predator cues were both associated with lower cortisol release, but depended on distinct physiological mechanisms.     

The impact of chronic environmental stressors on growing pigs, Sus scrofa (Part 1): stress physiology, production and play behaviour

Commercially farmed animals are frequently housed in conditions that impose a number of concurrent environmental stressors. For pigs housed indoors, elevated levels of mechanical noise, atmospheric ammonia and low light intensities are commonplace. This experiment examined the effects on growing pigs of chronic exposure to combinations of commercially relevant levels of these potential stressors. Four-week-old hybrid female pigs (n = 224) were housed under experimentally manipulated conditions of nominally either <5 or 20 ppm atmospheric concentration of ammonia (24 h), a light intensity of 40 lux or 200 lux (12 h) and mechanical noise at either ⩽60 or 80 dB(A) (24 h) for 15 weeks in a fully factorial arrangement (2³) of treatments. The response of pigs to these environmental factors was assessed using a suite of physiological, production and behavioural measures. These included indicators of hypothalamic–pituitary–adrenal (HPA) axis activation such as salivary cortisol and adrenal morphometry, as well as body weight, food conversion efficiency and general health scores. Play behaviour was recorded as it is thought to be inversely related to stress. Chronic exposure to ammonia produced the strongest effect, shown by lower concentrations of salivary cortisol and larger adrenal cortices in the pigs reared under 20 ppm ammonia, which may have been indicative of a period of HPA activation leading to a downregulation of cortisol production. The pigs in the ammoniated rooms also performed less play behaviour than pigs in non-ammoniated rooms. There was evidence for an interaction between high noise and ammonia on the health scores of pigs and for brighter light to ameliorate the effect of ammonia on salivary cortisol. However, there was no measurable impact of these potential stressors on the productivity of the pigs or any of the other physiological parameters measured. We conclude that there should be little concern in terms of performance about the physical stressors tested here, within current European Union legal limits. However, 20 ppm ammonia may have had an adverse influence on the well-being of growing pigs. In this study, all other aspects of the pigs’ husbandry were optimal; therefore, it is possible that under less favourable conditions, more pronounced effects of ammonia, noise and dim light would be observed.     

Preparental hormone levels and parenting experience in male cotton-top tamarins, Saguinus oedipus

Male cotton-top tamarins, Saguinus oedipus, display hormonal changes associated with parenting prior to the birth of their infants. Here we examined the hormonal changes that occurred in experienced and inexperienced fathers during the postconception period, prior to the birth of infants. Noninvasive techniques were used to collect urine from 10 male cotton-top tamarins (5 experienced and 5 inexperienced breeders) three times weekly during the 6-month gestation period. Samples were analyzed for prolactin, testosterone, dihydrotestosterone (DHT), and cortisol, averaged by gestational month. Experienced males showed elevated prolactin during the mate's 3rd gestational month, and the elevation correlated with the number of infants surviving from the previous birth (0, 1, and 2) but not with outcome of the current pregnancy. However, an experienced male with no infants present still showed elevated prolactin and some inexperienced males showed elevated prolactin just before parturition, suggesting noninfant cues are also important. While prolactin levels were influenced by the male's prior infant experience, testosterone levels did not differ between experienced and inexperienced males. Testosterone levels were significantly elevated for all males during the 3rd, 4th and 5th months but had no relationship with number of infants present or with outcome of current pregnancy. DHT decreased during the second half of pregnancy compared with testosterone but this finding was not consistent for every male. No significant changes occurred in cortisol levels. These results suggest that infant-rearing experience affected the hormonal responsitivty of the male to his mate's current pregnancy.     

季节和等级顺位对雄性黄山短尾猴粪样皮质醇水平的影响

在长期的进化选择压力下,灵长类动物大多数群居生活,群体中的动物个体也面临来自群内成员强度不一的社会压力,压力大小的重要生理指标通常用其体内的皮质醇水平的变化来衡量。季节性繁殖的黄山短尾猴（Macaca thibetana）,群体内的个体有严格的社会等级,是研究等级顺位与社会压力水平之间关系的理想研究对象。我们采集13只野生短尾猴雄性个体的新鲜粪便样品,并测定其皮质醇水平。本研究发现,雄性短尾猴的粪便皮质醇水平表现为交配季节显著高于非交配季节。在交配季节,中等顺位雄性个体的皮质醇水平显著高于高顺位个体和低顺位个体,而在非交配季节3种等级类型的雄性个体之间则无显著差异。本研究首次测定了野生短尾猴的粪便皮质醇含量,并分析了季节、等级顺位对粪便皮质醇含量的影响。     

Larval food composition affects courtship song and sperm expenditure in a lekking moth

1. Variation in larval food composition can have far‐reaching effects on the adult phenotype of insects. To maximise reproductive output, it is therefore beneficial if insects are able to plastically adapt to nutritional cues in their larval diet. 2. The expression of sexual traits implicated in pre‐ and postcopulatory sexual selection of the lesser wax moth, Achroia grisella Fabricius, across different rearing environments of varying diet composition was investigated. 3. Moths reared on diet with relatively low amounts of carbohydrate, but more protein and fats, had lower survival rates, decreased body mass, and longer development times. Males reared on this diet produced songs with higher pulse pair rates (which are attractive to females) and transferred more sperm per copulation than males reared on the alternative diets. 4. There was no evidence for a trade‐off between pre‐ and postcopulatory traits. Interestingly, individuals with both higher pulse pair rates and more transferred sperm came from the treatment group with higher mortality rates and generally poorer development. The present results suggest that both of these sexual characteristics are developmentally plastic, but that only moths reared on the protein‐rich diet were able to benefit from this plasticity.     

Effects of the Higashi-Nihon earthquake: posttraumatic stress, psychological changes, and cortisol levels of survivors

On March 11, 2011, the Pacific side of Japan's northeast was devastated by an earthquake and tsunami. For years, many researchers have been working on ways of examining the psychological effects of earthquakes on survivors in disaster areas who have experienced aftershocks, catastrophic fires, and other damage caused by the earthquake. The goal of this study is to examine scores on psychological measures and salivary cortisol level in these individuals both before and three months after the earthquake. The participants had been measured for these variables before the earthquake. After the earthquake, we carried out PTSD screening using CAPS for participants for another experiment, and then again conducted the aforementioned tests. We collected saliva samples from all survivors. Our results show that social relationship scores on the WHO-QOL26, negative mood scores of the WHO-SUBI, total GHQ score, POMS confusion scores, and CMI emotional status score after the earthquake showed scores indicating significantly decreased compared to before the earthquake. On the other hand, salivary cortisol levels after the earthquake was significantly increased compared to before the earthquake. Moreover, the result of a multiple regression analysis found that negative mood score on the WHO-SUBI and social relationship score on the WHO-QOL26 were significantly related to salivary cortisol levels. Our results thus demonstrate that several psychological stress induced by the earthquake was associated with an increase in salivary cortisol levels. These results show similar findings to previous study. We anticipate that this study will provide a better understanding of posttraumatic responses in the early stages of adaptation to the trauma and expand effective prevention strategies and countermeasures for PTSD.     

Behavioural Interactions and Hormones in Naturally and Hatchery‐Spawned Chinook Salmon

Artificial breeding programmes commonly lead to domestication, which is associated with many behavioural differences that can reduce the success of animals released into natural environments. To better understand the factors contributing to domestication, we used a captive population of Chinook salmon (Oncorhynchus tshawytscha) to partition hormonal and behavioural differences to effects of the breeding method and rearing environment. We compared 9‐mo‐old juveniles from three lines that shared a common genetic background: (1) the Channel line produced by natural spawning and reared in a low‐density environment with a natural substrate for approx. 6 mo before being transferred to the hatchery; (2) the Hatchery line produced by artificial spawning; and (3) the Transfer line produced by natural spawning but reared in the hatchery from the eyed‐egg stage. Plasma concentrations of 11‐ketotestosterone (11‐KT) and cortisol were measured in groups of 150 fish and again after 4 d of social interactions in groups of six fish. There was no difference in 11‐KT among lines in large groups, but in small groups, Transfer fish had lower 11‐KT concentrations and were significantly less aggressive than both Channel and Hatchery fish. Regardless of group size, concentrations of the stress hormone cortisol were nearly twofold higher in Channel fish than in Hatchery and Transfer fish. Furthermore, the elevated cortisol concentrations in Channel fish were associated with 35% lower feeding rates than in the other two lines. Our study details complex behavioural and hormonal responses to breeding method and rearing environment in juvenile salmon.     

Hypoxia and life‐history traits in a eurytopic African cichlid

This study quantified variation in key life‐history traits of the widespread African mouth‐brooding cichlid Pseudocrenilabrus multicolor victoriae. Egg size, number, batch reproductive effort, size at maturity and brooding efficiency were compared among field populations across a wide range of dissolved oxygen (DO) concentrations from extreme hypoxia to normoxia. In the laboratory, a similar suite of characters was quantified in F1 of low‐ and high‐DO origin reared under low or high DO. In general, females from low‐DO habitats and females reared under low DO were characterized by a smaller size at maturity and no difference in batch reproductive effort when compared with females from high‐DO habitats or females reared under normoxia. A trade‐off between egg size and number was evident in the field and in the laboratory‐rearing experiment, but the direction of the trade‐off differed. Egg size was negatively correlated with egg number across field populations; females collected from low‐DO sites generally had more, smaller eggs relative to females from high‐DO sites. In the laboratory‐rearing experiment, F1 females of high‐DO origin produced larger, fewer eggs than F1 females of low‐DO origin, lending support to the field results and suggesting a heritable component to these traits. There was also an element of developmental plasticity, F1 females raised under low DO produced larger, fewer eggs compared with F1 females raised under high DO (regardless of population) suggesting that DO may interact with other variables to determine egg size in the field.     

Effect of rearing density on thyroid and interrenal gland activity and plasma and hepatic metabolite levels in rainbow trout, Salmo gairdneri Richardson

There were significant inverse correlations between rearing density of rainbow trout, Salmo gairdneri Richardson, and final body weight, plasma L-thyroxine (T₄), trüodo-L-tryronine (T₃), cortisol and protein concentrations, plasma T₄/T₃ ratios and thyroid epithelial cell height. In addition, hepatosomatic indices and plasma free fatty acid concentrations were higher in fish reared at low (134 g 1⁻¹) density compared with groups reared at medium (210g1⁻¹) or high density (299g 1⁻¹), and the post-feeding (3.5-4h) elevation in plasma glucose and triglyceride levels evident in trout maintained at low rearing density was not found in those fish reared at higher densities. There were no significant effects of rearing density on hematocrit, carcass composition, hepatic glycogen and lipid levels and interregnal nucleus size.     

Saliva and serum cortisol dynamics following intravenous dexamethasone in normal volunteers

In order to further explore the utility of saliva cortisol as an accurate measure of adrenal steroid production, dexamethasone (DEX) and saline were administered intravenously at 0800h to eight normal male volunteers in a randomized design, and the effects on serum and saliva cortisol concentrations were measured at hourly intervals from 0800h-2300h. Saliva cortisol values were highly correlated to serum cortisol levels within-subjects under both conditions (r = 0.78, p less than 0.025), however correlations were reduced in the DEX day sample pairs. Across-subject correlations at each time point were considerably more variable, reflecting interindividual differences in the saliva to serum cortisol ratios. No consistent time lag of saliva cortisol values in response to serum cortisol fluctuations was observed. These data suggest that saliva cortisol is an excellent index of changes in adrenal production of cortisol over time within individuals; however, it also suggests that salivary cortisol measures have less usefulness in comparing values across groups of individuals.