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1.
Jaguars are threatened with extinction throughout their range. A sustainable captive population can serve as a hedge against extinction, but only if they are healthy and reproduce. Understanding how jaguars respond to stressors may help improve the captive environment and enhance their wellbeing. Thus, our objectives were to: (1) conduct an adrenocorticotrophic hormone (ACTH) challenge to validate a cortisol radioimmunoassay (RIA) for noninvasive monitoring of adrenocortical function in jaguars; (2) investigate the relationship between fecal corticoid (FCM) and androgen metabolite (FAM) concentrations in males during the ACTH challenge; and (3) establish a range of physiological concentrations of FCMs for the proposed protocol. Seven jaguars (3 M, 4 F) received 500 IU/animal of ACTH. Pre‐ and post‐ACTH fecal samples were assayed for corticoid (M and F) and androgen metabolites (M) by RIA. Concentrations of FCMs increased (P80.01) after ACTH injection (pre‐ACTH: 0.90 ± 0.12 µg/g dry feces; post‐ACTH: 2.55 ± 0.25 µg/g). Considering pre‐ and post‐ACTH samples, FCM concentrations were higher (P80.01) in males (2.15 ± 0.20 µg/g) than in females (1.30 ± 0.20 µg/g), but the magnitude of the response to ACTH was comparable (P>0.05) between genders. After ACTH injection, FAMs increased in two (of 3) males; in one male, FCMs and FAMs were positively correlated (0.60; P80.01). Excretion of FCMs was assessed in 16 jaguars (7 M, 9 F) and found to be highly variable (range, 80.11–1.56 µg/g). In conclusion, this study presents a cortisol RIA for monitoring adrenocortical function in jaguars noninvasively. Zoo Biol 31:426–441, 2012. © 2011 Wiley Periodicals, Inc.  相似文献   

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There is a great need to develop efficient, noninvasive genetic sampling methods to study wild populations of multiple, co‐occurring, threatened felids. This is especially important for molecular scatology studies occurring in challenging tropical environments where DNA degrades quickly and the quality of faecal samples varies greatly. We optimized 14 polymorphic microsatellite loci for jaguars (Panthera onca), pumas (Puma concolor) and ocelots (Leopardus pardalis) and assessed their utility for cross‐species amplification. Additionally, we tested their reliability for species and individual identification using DNA from faeces of wild felids detected by a scat detector dog across Belize in Central America. All microsatellite loci were successfully amplified in the three target species, were polymorphic with average expected heterozygosities of HE = 0.60 ± 0.18 (SD) for jaguars, HE = 0.65 ± 0.21 (SD) for pumas and HE = 0.70 ± 0.13 (SD) for ocelots and had an overall PCR amplification success of 61%. We used this nuclear DNA primer set to successfully identify species and individuals from 49% of 1053 field‐collected scat samples. This set of optimized microsatellite multiplexes represents a powerful tool for future efforts to conduct noninvasive studies on multiple, wild Neotropical felids.  相似文献   

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Aim Jaguars and pumas, being similar in size and behaviour, are the largest felids of the Neotropics. However, pumas appear to be more resistant to human impacts. Our objective was to compare the response of both species with human impacts at a regional scale in a highly modified region where both species had continuous distribution in the past. Location The Upper Parana Atlantic Forest (UPAF). Methods Pumas and jaguars presence‐only data were used in an Ecological Niche Factor Analysis (ENFA). From the total number of records, we resampled 95 records of each species 10 times to characterize and compare their habitat requirements, built habitat‐suitability maps and examined interspecific differences in niche parameters related to present landscape characteristics. Results Both species showed high dependence on native forest and habitat protection, and low tolerance to anthropogenic environments. However, jaguars showed higher differences between their optimal habitat and the available landscape (mean ± SD; marginality M = 2.290 ± 0.072) and lower tolerance to deviations from their optimal habitat (tolerance T = 0.596 ± 0.013) than pumas (M = 1.358 ± 0.067, P < 0.001; T = 0.742 ± 0.022, P < 0.001). Although their niches highly overlapped (Pianka’s O = 0.746 ± 0.069), pumas’ higher tolerance resulted in a larger area covered by suitable patches of habitat with higher connectivity. All jaguar‐suitable areas were also suitable for pumas; however, 44 ± 8% of puma‐suitable areas were unsuitable or marginal for jaguars. Main conclusions Pumas showed more tolerance than jaguars to human impacts at a regional scale in the UPAF, a pattern also observed at local and continental scales. Although the proximate factors responsible for the differential response of pumas to human‐altered environments seem to be similar at all spatial scales (e.g. broader trophic niche than jaguars), the resultant spatial configuration of suitable habitat at a regional scale might be another important factor determining puma persistence and higher jaguar demands on conservation efforts.  相似文献   

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Aggression control is becoming an important component in the management of animals in captivity, but rigorous quantification of aggressive behavior has heretofore been lacking. This study was done to assess the ability of melengestrol acetate (MGA) given with feed (1.54 mg/kg) to control aggression in a bachelor group of fringe‐eared oryx (Oryx gazella callotis). Systematic behavioral observations were conducted and fecal androgen content was measured for 42 and 90 days, respectively, before treatment, and during the 42 days of treatment. There was a significant reduction in concentrations of fecal androgen from 153 ± 6.0 to 95 ± 4.5 ng/g (T66 = 7, P < 0.0001). This reduction in androgen excretion was apparent after the first week of treatment. There was measurable MGA excreted in the feces during treatment. Although treatment did not arrest all aggressive behaviors among animals, the decline in androgens and increase in MGA was accompanied by a significant reduction in several measures of agonistic behavior. Posturing, aggressive contact, pursuit, and submission occurred significantly less frequently after treatment, and there was also a reduction in fighting‐intention movements. Thus, both ritualized and nonritualized aspects of aggression were affected. Reductions in hormones and aggressive behaviors coincided temporally, suggestive of a potential causal relationship. Consistent with this hypothesis is a strong positive correlation between fecal androgen and total aggressive acts. This effect was not the result of a single behavioral element but occurred across several categories of agonistic behavior. Zoo Biol 20:375–388, 2001. © 2001 Wiley‐Liss, Inc.  相似文献   

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At the Calakmul Biosphere Reserve in Campeche, Mexico, the prey spectra of sympatric jaguars (Panthera onca) and pumas (Puma concolor) were studied by examination of their scats. 10 vertebrate species were identified for jaguars and 7 for pumas, mainly mammals and some birds. Based on these diet analyses, we conclude that jaguars and pumas coexist at Calakmul by means of different food habits.  相似文献   

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Cotton‐top tamarins have been housed in captivity in the United States for over five decades. These animals initially were managed in biomedical and research facilities, and more recently have been kept in zoos as well. Although the causes of mortality in captive cotton‐top tamarins have been a topic of investigation for biomedical colonies, they have not been addressed for the North American zoo population. In this retrospective study we review the causes of mortality in the AZA Cotton‐top Tamarin Species Survival Plan (SSP)© population during 1997–2001 to assess current husbandry practices and assist in further developing effective husbandry and management programs for this endangered species. Zoo Biol 23:127–137, 2004. © 2004 Wiley‐Liss, Inc.  相似文献   

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Habitat fragmentation may disrupt original patterns of gene flow and lead to drift-induced differentiation among local population units. Top predators such as the jaguar may be particularly susceptible to this effect, given their low population densities, leading to small effective sizes in local fragments. On the other hand, the jaguar's high dispersal capabilities and relatively long generation time might counteract this process, slowing the effect of drift on local populations over the time frame of decades or centuries. In this study, we have addressed this issue by investigating the genetic structure of jaguars in a recently fragmented Atlantic Forest region, aiming to test whether loss of diversity and differentiation among local populations are detectable, and whether they can be attributed to the recent effect of drift. We used 13 microsatellite loci to characterize the genetic diversity present in four remnant populations, and observed marked differentiation among them, with evidence of recent allelic loss in local areas. Although some migrant and admixed individuals were identified, our results indicate that recent large-scale habitat removal and fragmentation among these areas has been sufficiently strong to promote differentiation induced by drift and loss of alleles at each site. Low estimated effective sizes supported the inference that genetic drift could have caused this effect within a short time frame. These results indicate that jaguars' ability to effectively disperse across the human-dominated landscapes that separate the fragments is currently very limited, and that each fragment contains a small, isolated population that is already suffering from the effects of genetic drift.  相似文献   

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In the course of developing active naturalistic exercise opportunities for zoo felines at moderate cost, a computer-controlled acoustic prey device was established. Changes in the behavior of a 16-year-old melanistic leopard (Sabrina) were studied as she learned to actively pursue bird sounds and obtained food treats as a function of the activity. By the twenty-ninth day she began to capture all 24 bird parts supplied on the feeder belt and continues to actively use the opportunity on a daily basis. General activity and apparent well-being have been enhanced, while stereotypic behaviors have decreased. © 1995 Wiley-Liss, Inc.  相似文献   

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Aim We intend to characterize and understand the spatial and temporal patterns of vegetation phenology shifts in North America during the period 1982–2006. Location North America. Methods A piecewise logistic model is used to extract phenological metrics from a time‐series data set of the normalized difference vegetation index (NDVI). An extensive comparison between satellite‐derived phenological metrics and ground‐based phenology observations for 14,179 records of 73 plant species at 802 sites across North America is made to evaluate the information about phenology shifts obtained in this study. Results The spatial pattern of vegetation phenology shows a strong dependence on latitude but a substantial variation along the longitudinal gradient. A delayed dormancy onset date (0.551 days year?1, P= 0.013) and an extended growing season length (0.683 days year?1, P= 0.011) are found over the mid and high latitudes in North America during 1982–2006, while no significant trends in greenup onset are observed. The delayed dormancy onset date and extended growing season length are mainly found in the shrubland biome. An extensive validation indicates a strong robustness of the satellite‐derived phenology information. Main conclusions It is the delayed dormancy onset date, rather than an advanced greenup onset date, that has contributed to the prolonged length of the growing season over the mid and high latitudes in North America during recent decades. Shrublands contribute the most to the delayed dormancy onset date and the extended growing season length. This shift of vegetation phenology implies that vegetation activity in North America has been altered by climatic change, which may further affect ecosystem structure and function in the continent.  相似文献   

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This study focuses on a case of a red‐howler monkey (Alouatta guariba clamitans) which was found with a fetus in a transverse lie position with a prolapsed arm. The topic of this research is well justified as there are no data on this condition involving this type of non‐human primate in literature. In this study, a red‐howler monkey was observed by locals pulling at her pelvic region for 3 days near a farm. On the third day, the monkey was found lying on the ground at which point she offered no resistance when approached. The environmental police took the monkey to receive medical attention. During the physical examination, it was quickly observed that the monkey was pregnant; the right forelimb of the fetus was exposed from the vulva. An ultrasound revealed a non‐viable fetus, and due to the severe weakness of the mother, we opted for euthanasia. During the necropsy, not only was the fetus found macerated but it was also in a transverse lie position with a prolapsed arm and presented no external or internal injuries consistent with trauma.  相似文献   

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An analogue of the human granulocyte–macrophage colony‐stimulating factor (hGM‐CSF), hGM‐CSF(13–27)–Gly–(75–87) was synthesized by solid phase methodology. This analogue was designed to comprise helices A and C of the native growth factor, linked by a glycine bridge. Helices A and C form half of a four‐helix bundle motif in the crystal structure of the native factor and are involved in the interaction with α‐ and β‐chains of the heterodimeric receptor. A conformational analysis of the synthetic analogue by CD, two‐dimensional nmr spectroscopy, and molecular dynamics calculations is reported. The analogue is in a random structure in water and assumes a partially α‐helical conformation in a 1 : 1 trifluoroethanol/water mixture. The helix content in this medium is ∼ 70%. By 2D‐nmr spectroscopy, two helical segments were identified in the sequences corresponding to helices A and C. In addition to medium‐ and short‐range NOESY connectivities, a long‐range cross peak was found between the Cβ proton of Val16 and NH proton of His87 (using the numbering of the native protein). Experimentally derived interproton distances were used as restraints in molecular dynamics calculations, utilizing the x‐ray coordinates as the initial structure. The final structure is characterized by two helical segments in close spatial proximity, connected by a loop region. This structure is similar to that of the corresponding domain in the x‐ray structure of the native growth factor in which helices A and C are oriented in an antiparallel fashion. The N‐terminal residues Gly–Pro of helix C are involved in an irregular turn connecting the two helical segments. As a consequence, helix C is appreciably shifted and slightly rotated with respect to helix A compared to the x‐ray structure of the native growth factor. These small differences in the topology of the two helices could explain the lower biological activity of this analogue with respect to that of the native growth factor. © 1999 John Wiley & Sons, Inc. Biopoly 50: 545–554, 1999  相似文献   

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Linda Munson 《Zoo biology》1993,12(1):105-124
Knowledge of the diseases of cheetahs is essential to prevent and treat conditions that can modulate fertility and longevity. Toward this aim, a comprehensive pathology survey was conducted under a directive from the Cheetah Species Survival Plan. To date, 31 adult cheetahs and nine cubs from 16 zoological parks have been evaluated. Also, liver biopsies from 67 female cheetahs from 22 zoological parks were examined. Veno-occlusive disease (VOD) affected 82% of deceased cheetahs and 51% of live female cheetahs, and was the cause of death in nine cheetahs. Glomerulosclerosis and nephrosclerosis affected 84% and 39% of the population, respectively, and caused renal failure in eight cheetahs. The severity of VOD and glomerulosclerosis increased with age, and was not associated with infertility. Chronic gastritis was noted in 91% of the study population, and 95% of these cases also had spiral bacteria. Feline infectious peritonitis caused the death of two cheetahs. Male cheetahs had testicular degeneration, atrophy, and/or spermatogenic arrest, but these cheetahs also had severe systemic illness. Most females did not have reproductive tract lesions that would cause infertility, including those with parovarian cysts. Ovarian histology suggested that infertile cheetahs were not ovulating. Most cubs died from pneumonia or other systemic infections. The results of this study indicate that serious diseases are prevalent in the North American cheetahs, but these diseases do not appear to be the cause of infertility in the population. However, these diseases do limit the life span and well-being of cheetahs in captivity. Further research is needed to elucidate the causes of these diseases. © 1993 Wiley-Liss, Inc.  相似文献   

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The California condor (Gymnogyps californianus) recovery plan entails increasing the reproductive rate via replacement-clutch manipulation and artificial incubation of eggs. During the period from 1983 to 1990, 37 eggs have been artificially incubated; 32 of these were known to be fertile and 28 hatched (fertility: 86.5%; hatchability: 87.5%).  相似文献   

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Circular dichroism (CD) spectroscopy of proteins/peptides in thin films can provide valuable information on the structures in the aggregated states; however, it is difficult to estimate the secondary structure content quantitatively due to artifact signals arising from macroscopic anisotropies which is unique to the solid phase. Using a Universal Chiroptical Spectrophotometer (UCS‐1) together with the measurement and analytical procedures we have developed, we could obtain artifact‐free CD spectra of cast and Langmuir‐Blodgett (L‐B) films of synthetic peptides, Aβ (1–40) and (1–42) which are related to Alzheimer's disease. The work gave insights into the mechanisms for structural transformation and amyloid‐like aggregation. © 2010 Wiley Periodicals, Inc. Biopolymers 95: 127–134, 2011.  相似文献   

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