A Case Study: Fecal Corticosteroid and Behavior as Indicators of Welfare During Relocation of an Asian Elephant

This study was a preliminary investigation of an enzyme immunoassay for measuring fecal glucocorticoid metabolites in a male Asian elephant (Elephas maximus) by investigating changes in behavior and cortisol metabolite excretion associated with a putative stressful event. The study collected fecal samples for 10 days prior to, and 10 days after, 24-hr transport and relocation of the elephant to a new herd. The study measured cortisol metabolites using 2 enzyme immunoassays indicating a 389% and 340% increase in cortisol metabolite excretion following relocation. Maximal cortisol metabolite excretion occurred 2 days after relocation and remained elevated during establishment of the new herd. Stereotypic behavior increased approximately 400% after relocation. The relocation disturbed sleep patterns, the elephant spent less time sleeping during the night, and the elephant slept standing up. These results provide preliminary evidence that noninvasive monitoring of fecal cortisol metabolites can be used to investigate adrenal activity in Asian elephants and may be a safe, practical, and accurate welfare indicator.     

Noninvasive monitoring of fecal cortisol metabolites in the eastern chipmunk (Tamias striatus): validation and comparison of two enzyme immunoassays

Monitoring fecal glucocorticoid metabolites in wild animals, using enzyme immunoassays, enables the study of endocrinological patterns relevant to ecology and evolution. While some researchers use antibodies against the parent hormone (which is typically absent from fecal samples), others advocate the use of antibodies designed to detect glucocorticoid metabolites. We validated two assays to monitor fecal cortisol metabolites in the eastern chipmunk (Tamias striatus). We compared an antibody produced against cortisol and one produced against 5α-pregnane-3β, 11β, 21-triol-20-one using a radiometabolism study and an injection with adrenocorticotropic hormone (ACTH). Most cortisol metabolites were excreted in the urine (～83%). Peak excretion in the feces occurred 8 h after injection. Both assays detected an increase in fecal cortisol metabolite levels after injection of ACTH. Males, but not females, exhibited a circadian variation in metabolite levels. The sexes did not exhibit any difference over the time course and route of excretion or the relative increase in fecal cortisol metabolite levels after ACTH injection. The cortisol assay displayed higher reactivity to ACTH injection relative to baseline than did the metabolite assay. While both antibodies gave comparable results, the cortisol antibody was more sensitive to changes in plasma cortisol levels in eastern chipmunks.     

A non-invasive technique for analyzing fecal cortisol metabolites in snowshoe hares (<Emphasis Type="Italic">Lepus americanus</Emphasis>)

To develop non-invasive techniques for monitoring steroid stress hormones in the feces of free-living animals, extensive knowledge of their metabolism and excretion is essential. Here, we conducted four studies to validate the use of an enzyme immunoassay for monitoring fecal cortisol metabolites in snowshoe hares (Lepus americanus). First, we injected 11 hares with radioactive cortisol and collected all voided urine and feces for 4 days. Radioactive metabolites were recovered predominantly in the urine (59%), with only 8% recovered in the feces. Peak radioactivity was detected an average of 3.5 and 5.7 h after injection in the urine and feces, respectively. Second, we investigated diurnal rhythms in fecal cortisol metabolites by measuring recovered radioactivity 2 days after the radioactive cortisol injection. The total amount of radioactivity recovered showed a strong diurnal rhythm, but the amount of radioactivity excreted per gram of feces did not, remaining constant. Third, we injected hares with dexamethasone to suppress fecal cortisol metabolites and 2 days later with adrenocorticotropic hormone to increase fecal cortisol metabolites. Dexamethasone decreased fecal cortisol metabolites concentrations by 61% and adrenocorticotropic hormone increased them by 1,000%, 8–12 h after injection. Fourth, we exposed hares to a simulated predator (dog). This increased the fecal cortisol metabolites concentrations by 175% compared with baseline concentrations 8–12 h after exposure. Thus, this enzyme immunoassay provides a robust foundation for non-invasive field studies of stress in hares.     

Characterization of reproductive cycles and adrenal activity in the black‐footed ferret (Mustela nigripes) by fecal hormone analysis

The reproductive cycle of the black‐footed ferret (Mustela nigripes) was characterized by enzyme immunoassay (EIA) analysis of ovarian fecal steroids (estradiol, progestins) in 29 females over two consecutive breeding seasons. Estrous status was determined by measuring the vulva size and examining the percentage of superficial cells in vaginal lavages. Mean fecal estradiol concentrations were correlated with vulval area (r = 0.370, P < 0.0001) and the percentage of superficial cells (r = 0.380, P < 0.0001). Ovulation resulted in a rise in fecal progestin concentrations 5 days after breeding that differed (P < 0.05) between pregnant (n = 14) and pseudopregnant (n = 12) females during the late luteal phase (days 12–40), with concentrations remaining higher in pregnant animals. Gestation length was 41.3 ± 0.7 days with 3.6 ± 0.4 kits produced per female. Litter size correlated significantly (P < 0.05) with fecal estradiol, but not progestins during the 12 to 40 days after breeding. Females failing to breed (n = 3) remained in estrus for 31 ± 6.2 days before ovulation induction with human chorionic gonadotropin. Adrenal activity in male (n = 4) and female (n = 6) black‐footed ferrets was monitored by quantifying fecal corticoid metabolites after a series of manipulations (physical restraint, intramuscular saline, intramuscular gel adrenocorticotropic hormone (ACTH), intramuscular liquid ACTH). A significant (P < 0.0001) increase in fecal corticoids above the pre‐treatment baseline occurred 20 to 44 hours after restraint (five of 10 animals), saline (six of nine), gel ACTH (seven of 10), and liquid ACTH (nine of 10) treatments. Immunoreactivity of high‐performance liquid chromatography–separated fecal elutes was compared using antibodies against cortisol and corticosterone. The cortisol EIA demonstrated immunoreactivity that co‐eluted with ³H‐cortisol, whereas a corticosterone radioimmunoassay detected a metabolite peak that co‐eluted with ³H‐corticosterone in addition to a slightly less polar and one considerably more polar peak. Despite recognizing different metabolites, both assays produced similar temporal profiles of corticoid excretion after manipulation. This study provides new information on the black‐footed ferret regarding differences in fecal steroid excretion patterns between pregnancy and pseudopregnancy and the potential application of fecal corticoid metabolite monitoring for evaluating responses to stressors associated with practices used in breeding management. Zoo Biol 20:517–536, 2001. © 2002 Wiley‐Liss, Inc.     

Endocrine Correlates of Musth in Free-Ranging Asian Elephants (Elephas maximus) Determined by Non-Invasive Faecal Steroid Hormone Metabolite Measurements

The occurrence of musth, a period of elevated levels of androgens and heightened sexual activity, has been well documented for the male Asian elephant (Elephas maximus). However, the relationship between androgen-dependent musth and adrenocortical function in this species is unclear. The current study is the first assessment of testicular and adrenocortical function in free-ranging male Asian elephants by measuring levels of testosterone (androgen) and cortisol (glucocorticoid – a physiological indicator of stress) metabolites in faeces. During musth, males expectedly showed significant elevation in faecal testosterone metabolite levels. Interestingly, glucocorticoid metabolite concentrations remained unchanged between musth and non-musth periods. This observation is contrary to that observed with wild and captive African elephant bulls and captive Asian bull elephants. Our results show that musth may not necessarily represent a stressful condition in free-ranging male Asian elephants.     

Determination of Fecal Glucocorticoid Metabolites to Evaluate Stress Response in <Emphasis Type="Italic">Alouatta pigra</Emphasis>

Measuring fecal glucocorticoid metabolites is now a common practice to assess the stress response in primates. Nevertheless, it is important to validate the utilized immunoassay for each primate species before the technique is applied to populations in the wild. We determined the stress response of black howlers (Alouatta pigra) via 2 different group-specific enzyme immunoassays (EIAs). 11-oxoetiocholanolone EIAs are suited to assess the stress response of black howlers via fecal glucocorticoid metabolites. Levels of fecal glucocorticoid metabolites increased after we applied a stressor, i.e. anesthesia, reaching peak concentrations 24–96 h poststressor. Both basal and stress-induced fecal glucocorticoid metabolite levels showed individual variations. The increase of fecal glucocorticoid metabolites after the stressor (paralleling increases in serum) indicates that one can effectively measure adrenocortical activity in Alouatta pigra via these 2 enzyme immunoassays. However, it is important to consider individual variations in the excretion of fecal glucocorticoid metabolites when planning field endocrinological research on Alouatta pigra. Fecal glucocorticoid metabolite excretion takes 1–3 d poststressor depending on the individual. Further, there is an important individual variability in the concentrations of glucocorticoid metabolites, which might reflect differences in stress reactivity or fecal glucocorticoid metabolite metabolism and excretion.     

Comparative and functional analyses of fecal microbiome in Asian elephants

Asian elephant is large herbivorous animal with elongated hindgut. To explore fecal microbial community composition with various ages, sex and diets, and their role in plant biomass degrading and nutrition conversation. We generated 119 Gb by metagenome sequencing from 10 different individual feces and identified 5.3 million non-redundant genes. The comprehensive analysis established that the Bacteroidetes, Firmicutes and Proteobacteria constituted the most dominant phyla in overall fecal samples. In different individuals, the alpha diversity of the fecal microbiota in female was lower than male, and the alpha diversity of the fecal microbiota in older was higher than younger, and the fecal microbial diversity was the most complex in wild elephant. But the predominant population compositions were similar to each other. Moreover, the newborn infant elephant feces assembled and maintained a diverse but host-specific fecal microbial population. The discovery speculated that Asian elephant maybe have start to building microbial populations before birth. Meanwhile, these results illustrated that host phylogeny, diets, ages and sex are significant factors for fecal microbial community composition. Therefore, we put forward the process of Asian elephant fecal microbial community composition that the dominant populations were built first under the guidance of phylogeny, and then shaped gradually a unique and flexible gut microbial community structure under the influences of diet, age and sex. This study found also that the Bacteroidetes were presumably the main drivers of plant fiber-degradation. A large of secondary metabolite biosynthetic gene clusters, and genes related to enediyne biosynthesis were found and showed that the Asian elephant fecal microbiome harbored a diverse and abundant genetic resource. A picture of antibiotic resistance genes (ARGs) reservoirs of fecal microbiota in Asian elephants was provided. Surprisingly, there was such wide range of ARGs in newborn infant elephant. Further strengthening our speculation that the fetus of Asian elephant has colonized prototypical fecal microbiota before birth. However, it is necessary to point out that the data give a first inside into the gut microbiota of Asian elephants but too few individuals were studied to draw general conclusions for differences among wild and captured elephants, female and male or different ages. Further studies are required. Additionally, the cultured actinomycetes from Asian elephant feces also were investigated, which the feces of Asian elephants could be an important source of actinomycetes.

     

Relocation stress induces short-term fecal cortisol increase in Tonkean macaques (<Emphasis Type="Italic">Macaca tonkeana</Emphasis>)

The level of glucocorticoids, especially if obtained from noninvasive sampling, can be used as an index of animal well-being, allowing evaluation of the animal’s response to environmental modifications. Despite evidence that these hormones play a relevant role in energy metabolism regulation in perceived or real stress events, little is known regarding the factors that could modify the capability of animals to cope with relocation events. The aim of this research was to assess fecal cortisol metabolite concentrations before, during and after acute stress (transfer and relocation event) in two well-established social groups of Tonkean macaques (Macaca tonkeana). The results showed that the fecal levels of cortisol increased in individuals of both groups in response to the stress event, with a similar trend in males and females. Hormone levels were back to baseline values in both groups a few days after transfer and relocation. The presence of known social partners could be one of the factors that possibly facilitated the adaptation process.     

Salivary cortisol assessment for stress detection in the Asian elephant (Elephas maximus): A pilot study

Effects of introducing an unfamiliar female into an Asian elephant herd at Tierpark Berlin were monitored by means of salivary cortisol assessment. Saliva samples were obtained from a second female for comparative purposes. The period of familiarization was characterized by an enhanced cortisol level in both animals, with a maximum on the second day after joining. Cortisol returned to normal on the following day. Manipulations of the keepers caused a transitory increase on two other days. Possibilities for the use of this noninvasive method of stress monitoring in various management situations are indicated. © 1992 Wiley-Liss Inc.     

Urinary cortisol analysis for monitoring adrenal activity in elephants

Cortisol was measured in dichloromethane-extracted elephant urine using an ¹²⁵I solid-phase radioimmunoassay (RIA). The cortisol RIA was validated by demonstrating 1) parallelism between dilutions of pooled urinary extracts and the standard curve, 2) significant recovery of exogenous cortisol added to elephant urine, and 3) a relationship between changes in peripheral and urinary cortisol after an adrenocorticotropin hormone (ACTH) challenge. One African (Loxodonta africana) and one Asian (Elephas maximus) elephant were given three injections of ACTH (1.25 mg) at 2 h intervals. Serum cortisol increased four- to eightfold within 30 min after the first injection and peaked (nine- to twelvefold increase) after the second injection. Serum concentrations began to decline 2–3 h after the last injection but were still approximately fourfold higher than baseline at the end of the collection period (hour 8). In the urine, cortisol concentrations were increased in the first sample postinjection (1.5–4 h) and peaked twenty- to fortyfold by ～6 h. Urinary cortisol remained elevated at 8 h, but returned to baseline the following morning. Analysis of high performance liquid chromatography fractions of extracted urine revealed that immunoactivity was associated with free cortisol (～90% of total immunoactivity) and a more polar, unidentified metabolite. A method for preserving urine was developed to allow storing unfrozen samples. One pool of urine from each of one African and two Asian elephants was divided into aliquots, placed in tubes containing absolute ethanol (10%), sodium azide (0.1%) or distilled water (control), and frozen after 0, 1, 2, 3, 4, 6, 8, 10, 12, and 24 weeks of storage at ～25°C. In unpreserved samples, cortisol concentrations were reduced 46% by 2 weeks and 95% by 24 weeks. In contrast, ethanol- and sodium azide-preserved samples retained 100 and 95% of cortisol immunoactivity through 8 weeks and 93 and 85% of activity through 12 weeks, respectively. We infer from these data that changes in urinary cortisol excretion in the elephant reflect fluctuations in adrenal activity and may be a useful indicator of stress. Additionally, urine samples can be collected and stored unfrozen for at least 2 months before any appreciable loss in cortisol immunoactivity occurs, a finding potentially useful to field application of this technique. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America

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17-Hydroxylase/C17,20-lyase (CYP17) is not the enzyme responsible for side-chain cleavage of cortisol and its metabolites

The question addressed in this study was the nature of the enzyme required to remove the side-chain of 17-hydroxycorticosteroids, leading in the case of cortisol to the excretion of 11β-hydroxyandrosterone, 11-oxo-androsterone and the corresponding etiocholanolones. We questioned whether it could be CYP17, the 17-hydroxylase/17,20-lyase utilized in androgen synthesis. The conversion of exogenous cortisol to C₁₉ steroids in patients with complete 17-hydroxylase deficiency (17HD) was studied rationalizing that if CYP17 was involved no C₁₉ steroids would be formed. The urinary excretion of the four 11-oxy-C₁₉ steroids as well as many of the major C₂₁ cortisol metabolites were measured by GC/MS. Our results showed that the conversion of cortisol to C₁₉ steroids was normal in 17HD indicating that a currently unidentified enzyme must be responsible for this transformation.

A secondary goal was to determine to what extent 11-oxy-C₁₉ steroids were metabolites of cortisol or adrenal synthesized 11β-hydroxyandrostenedione. Since cortisol-treated 17HD patients cannot produce androstenedione, all C₁₉ 11-oxy-metabolites excreted must be derived from exogenous cortisol. The extent to which 17HD patients have lower relative excretion of C₁₉ steroids should reflect the absence of 11β-hydroxyandrostenedione metabolites. Our results showed almost all of 11-oxo-etiocholanolone and 11β-hydroxyetiocholanolone were cortisol metabolites, but in contrast the excretion of 11β-hydroxyandrosterone was less than 10% that of normal individuals, indicating that in excess of 90% must be a metabolite of 11β-hydroxyandrostenedione.     

Methodological Considerations in the Analysis of Fecal Glucocorticoid Metabolites in Tufted Capuchins (Cebus apella)

Analysis of fecal glucocorticoid (GC) metabolites has recently become the standard method to monitor adrenocortical activity in primates noninvasively. However, given variation in the production, metabolism, and excretion of GCs across species and even between sexes, there are no standard methods that are universally applicable. In particular, it is important to validate assays intended to measure GC production, test extraction and storage procedures, and consider the time course of GC metabolite excretion relative to the production and circulation of the native hormones. This study examines these four methodological aspects of fecal GC metabolite analysis in tufted capuchins (Cebus apella). Specifically, we conducted an adrenocorticotrophic hormone (ACTH) challenge on one male and one female capuchin to test the validity of four GC enzyme immunoassays (EIAs) and document the time course characterizing GC metabolite excretion in this species. In addition, we compare a common field-friendly technique for extracting fecal GC metabolites to an established laboratory extraction methodology and test for effects of storing “field extracts” for up to 1 yr. Results suggest that a corticosterone EIA is most sensitive to changes in GC production, provides reliable measures when extracted according to the field method, and measures GC metabolites which remain highly stable after even 12 mo of storage. Further, the time course of GC metabolite excretion is shorter than that described yet for any primate taxa. These results provide guidelines for studies of GCs in tufted capuchins, and underscore the importance of validating methods for fecal hormone analysis for each species of interest.     

Lipolysis and glycerol gluconeogenesis in simultaneously fasting and lactating northern elephant seals

Adult female elephant seals (Mirounga angustirostris) combine long-term fasting with lactation and molting. Glycerol gluconeogenesis has been hypothesized as potentially meeting all of the glucose requirements of the seals during these fasts. To test this hypothesis, a primed constant infusion of [2-(14)C]glycerol was administered to 10 ten adult female elephant seals at 5 and 21-22 days postpartum and to 10 additional adult females immediately after the molt. Glycerol kinetics, rates of lipolysis, and the contribution of glycerol to glucose production were determined for each period. Plasma metabolite levels as well as insulin, glucagon, and cortisol were also measured. Glycerol rate of appearance was not significantly correlated with mass (P = 0.14, r2 = 0.33) but was significantly related to the percentage of glucose derived from glycerol (P < 0.01, r2 = 0.81) during late lactation. The contribution of glycerol to glucose production was <3% during each fasting period, suggesting a lower contribution to gluconeogenesis than is observed in other long-term fasting mammals. Because of a high rate of endogenous glucose production in fasting elephant seals, it is likely that glycerol gluconeogenesis still makes a substantial contribution to the substrate needs of glucose-dependent tissues. The lack of a relationship between glucoregulatory hormones and glycerol kinetics, glycerol gluconeogenesis, and metabolites supports the proposition that fasting elephant seals do not conform to the traditional insulin-glucagon model of substrate metabolism.     

Serum and urinary hormones during pregnancy and the peri- and postpartum period in an Asian elephant (Elephas,maximus)

Blood and urine samples were collected weekly from an Asian elephant (Elephas maximus) for 10 months before conception, throughout pregnancy, and for 10 months after parturition. Additional daily samples were collected for 41 days before through 10 days after parturition to define endocrine events during the peripartum period. During gestation, serum progesterone concentrations increased gradually and, after ～13 weeks, were higher (P < 0.05) than those observed during the nonpregnant luteal phase. Concentrations peaked at ～12 months of gestation, gradually declined during the last month, and then decreased sharply to nondetectable levels 2 days before parturition. A 12 week lactational anestrus was observed before cyclicity resumed. The urinary profile of progestagen excretion paralleled that of circulating progesterone (r = 0.79; P < 0.05); however, radioimmunoassay of HPLC-separated fractions of urinary eluates indicated that this immunoactivity was not associated with native progesterone. After remaining basal through the first 16 weeks of gestation, serum prolactin concentrations increased to 100-fold about midterm and remained elevated until after parturition. Neither serum nor urinary cortisol concentrations were altered during pregnancy, but both increased markedly the day after parturition and remained elevated above prepartum levels for several weeks thereafter. These data indicate that analysis of serum prolactin can confirm pregnancy in the Asian elephant after ～4 months of gestation and that daily monitoring of serum or urinary progestagens is useful for predicting parturition. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Assessment of urine and fecal testosterone metabolite excretion in Chinchilla lanigera males

Endemic chinchilla (Chinchilla spp.) populations are nearly extinct in the wild (South America). In captive animals (Chinchilla lanigera and C. brevicaudata), reproduction is characterized by poor fertility and limited by seasonal breeding patterns. Techniques applied for studying male reproductive physiology in these species are often invasive and stressful (i.e. repeated blood sampling for sexual steroids analysis). To evaluate endocrine testicular function, the present experiments were designed to (a) determine the main route of testosterone excretion (14C-testosterone infusion in four males); (b) validate urine and fecal testosterone metabolite measurements (HPLC was used to separate metabolites and immunoreactivity was assessed in all metabolites using a commercial testosterone radioimmunoassay, and parallelism, accuracy and precision tests were conducted to validate the immunoassay); and (c) investigate the biological relevance of the techniques applied (quantification of testosterone metabolite excretion into urine and feces from five males injected with hCG and comparison between 10 males and 10 females). Radiolabelled metabolites of 14C-testosterone were excreted, 84.7+/-4.2 % in urine and 15.2+/-3.9 % in feces. A total of 82.7+/-4.2% of urinary and 45.7+/-13.6% of fecal radioactivity was excreted over the first 24 h period post-infusion (metabolite concentration peaked at 8.2+/-2.5 h and 22.0+/-7.0 h, respectively). Several urinary and fecal androgen metabolites were separated by HPLC but only fecal metabolites were associated with native testosterone; however, there was immunoreactivity in more than one metabolite derived from 14C-testosterone. After hCG administration, an increase in androgen metabolite excretion was observed (p<0.05). Males excreted greater amounts daily of urinary androgen metabolites as compared with females (p<0.05); this difference was not evident in feces. Results of the present study indicate that the procedure used is a reliable and non-invasive method to repeatedly monitor variations in testicular endocrine activity in this species. It can be a useful tool that would help ensure the survival of the wild populations as well as to provide the basis for a more efficient use by the fur industry.     

Relationship between androgens, environmental factors and reproductive behavior in male white rhinoceros (Ceratotherium simum simum)

We conducted a longitudinal study of the endocrine activity of free-range male white rhinos. An enzyme immunoassay to measure androgens in the feces was developed and validated to show that it can be used to study testicular activity. We identified two fecal metabolites similar to testosterone and dihydrotestosterone. Several lines of evidence suggest that these metabolites clearly reflect testicular activity. Firstly, the stimulation of testicular activity with synthetic GnRH caused a 156% increase in androgen metabolite concentrations in the feces 1 day after treatment. Secondly, androgen metabolite concentrations increased with sexual maturity in rhinos, and finally there was a correlation between testosterone concentrations in plasma and androgen metabolite concentrations in feces. Using the method that we developed, it was possible to establish whether a relationship exists between androgen metabolite concentrations, the behavior and environmental factors. Adult territorial males (n = 5) had elevated androgen metabolite concentrations during months of high rainfall (September-February) compared to months of little or no rainfall (March-August). The increase in concentrations coincided with the beginning of the rainy season, suggesting a seasonal trend in reproduction. This trend was confirmed by behavior observations showing both a higher frequency of conceptions within the first 4 months of increased androgen metabolite concentrations, and a higher number of inter-sexual conflicts, reflecting the initial aggression between the sexes during the consort period. It was also evident that males accompanying a receptive female had higher fecal androgen metabolite concentrations compared to being alone. The elevated levels were likely induced by female presence.     

Familiarity may buffer the adverse effects of relocation on marmosets (Callithrix kuhlii): Preliminary evidence

The relocation of exotic species is increasingly crucial for the proper management of captive populations. We investigated the effects of relocation on urinary cortisol levels and proximity behavior in four Wied's marmosets (Callithrix kuhlii). Two of the relocated marmosets constituted a well‐established pair, whereas two (the newly established pair) were introduced when they arrived at the new facility. Four adult females served as control animals in which we assessed cortisol response to pair formation in the absence of relocation. Urinary cortisol in the relocated subjects was monitored for 4 weeks before and 12 weeks after the relocation event. Urinary cortisol in the control subjects was monitored for 4 weeks before and 8 weeks after the pairs were formed. Proximity was monitored in the relocated subjects for 12 weeks following the move. After the animals were relocated, the newly established pair had significantly elevated levels of urinary cortisol compared to the well‐established pair and control females, which lasted at least 8 weeks. For both pairs, cortisol levels decreased over time across the 12 weeks following the relocation event. The members of the well‐established pair were in contact with each other for 65% of the intervals sampled in the 2 weeks immediately following relocation, compared to only 12% in the newly established pair. These preliminary findings suggest that relocation is associated with significant adverse physiological and behavioral changes that may be ameliorated by the presence of a highly familiar social partner. The study highlights the importance of future research in this field. Zoo Biol 24:93–100, 2005. © 2005 Wiley‐Liss, Inc.     

元江-李仙江流域亚洲象生境适宜性评价——基于荟萃分析和遥感大数据分析

生境适宜性评价是物种保护和生境管理与规划的基础。近几十年来,云南境内野生亚洲象数量剧增,外扩迁移事件频发,而新迁入区域生境适宜状况因物种出现点数据缺乏而难以评价,掣肘迁移亚洲象保护与风险防范应急。以亚洲象新近迁入的元江-李仙江流域为案例区,采用荟萃分析统计亚洲象生境评价因子,结合相关性分析和方差膨胀因子独立性检验,筛选出生境评价因子;基于开源遥感数据产品量化生境因子,综合主成分分析和层次分析计算生境评价因子权重,采用生境适宜性指数(Habitat Suitability Index, HSI)模型评价元江-李仙江流域亚洲象生境适宜性,并分析其景观格局。结果表明：(1)元江-李仙江流域亚洲象生境适宜性空间格局主要表现为由下游至上游呈递减趋势,最适生境主要分布于流域下游段,而流域上游段适宜生境少;(2)元江流域生境适宜性低于李仙江流域,且其生境斑块连接度更低、破碎化更严重;(3)2021年“北移象群”北迁沿程生境适宜性由西南向东北呈下降趋势。基于亚洲象生境适宜性评价结果,科学引导野生亚洲象迁入适宜生境区,以规避人象冲突,保障外迁亚洲象群及其活动区居民生命财产安全,服务于区域生物多样性保护与...     

Excretion and metabolic fate of radiolabeled estradiol and testosterone in the cockatiel (Nymphicus hollandicus)

The metabolism and time courses for clearance of radiolabeled estradiol and testosterone were studied in the female cockatiel (Nymphicus hollandicus) using a simple technique of solubilizing dried fecal/urine matter in an aqueous solution. Carbon ¹⁴ radiolabeled estradiol and testosterone were injected intramuscularly and the urine and fecal matter collected for the pursuant 168 hr. The predominant radiolabel peak was found associated with the aqueous residue of the ether extracted aliquot for both hormones. High-performance liquid chromatographic (HPLC) separation of solubilized fecal/urine material collected during the first sampling interval (0–4 hr after injection) demonstrated that the majority of the excreted radiolabel was in the form of conjugated steroid metabolites in both the estradiol and testosterone injected birds. Subsequent hydrolysis of the aqueous residue of the ether extracted aliquots and HPLC characterized the estrogen and testosterone metabolites as being estrone/estradiol and a variety of androgen based moieties, respectively. By 24 hr postinjection, 79.4 and 79.1% of the original radiolabel was recovered in birds injected with estradiol and testosterone, respectively. These findings demonstrate that steroid hormone excretion in the cockatiel is a rapid and efficient process that is 79% complete by 24 hr and that the primary excretion products are conjugated metabolites. This study also supports the concept that fecal/urine collection is a practical and efficient method of monitoring sex steroid excretion and provides additional evidence that simple solubilization of fecal matter is a sufficient and efficient method for processing feces for subsequent metabolite measurements. Zoo Biol 16:505–518, 1997. © 1997 Wiley-Liss, Inc.     

In vivo formation of omega-oxidized metabolites of leukotriene C4 in the rat

[3H8]Leukotriene C4 was administered to germfree rats and to conventional rats having a bile duct cannula. Several radioactive metabolites were isolated. Two polar biliary metabolites from conventional rats were identified as N-acetyl-omega-carboxy-leukotriene E4 and N-acetyl-omega-hydroxy-leukotriene E4. A polar fecal metabolite from germfree rats was found to be N-acetyl-omega-carboxy-leukotriene E4. Chemical identities were established using UV spectroscopy and cochromatographies with authentic compounds in several HPLC systems. The fecal metabolite was further characterized by reductive desulfurization followed by gas-liquid-radiochromatography. The yield of the two biliary metabolites was 5% of the administered tritium after three hours and the yield of fecal N-acetyl-omega-carboxy-leukotriene E4 was 3.5% after three days.