Tannin-binding salivary proteins in three captive rhinoceros species

Tannin-binding salivary proteins (TBSP) are considered to be counter-defences acquired in the course of evolution by animals whose natural forage contains such tannins. As tannins mostly occur in browse material but not in grasses, it is assumed that grazers do not have a need for TBSP. Whereas it has been shown in several non-ungulate species that TBSP can be induced by dietary tannins, their presence or absence in ungulates has, so far, been shown to be a species-specific characteristic independent of dietary manipulations. We investigated saliva from three rhinoceros species from zoological gardens fed comparable, conventional zoo diets. As expected, saliva from white rhinoceroses (Ceratotherum simum, grazer) had lower tannin-binding capacities than that from black rhinoceroses (Diceros bicornis, browser). Surprisingly, however, Indian rhinoceroses (Rhinoceros unicornis), commonly regarded as grazers as well, displayed the highest tannin-binding capacities of the three species investigated. It is speculated that this discrepancy might be a result of an evolutionarily recent switch to a grass-dominated diet in Indian rhinoceroses, and that the black rhinoceros, which is closer related to the white rhinoceros than the Indian species, has evolved an inducible mechanism of TBSP production. In separate trials during which the tannin content of the diets of black rhinoceroses was increased by the addition of either tannic acid or quebracho, the tannin-binding capacity of black rhinoceros saliva was increased to levels within the same range as that of Indian rhinoceroses on the conventional diets. While induction trials in white and Indian rhinoceroses remain to be performed for a full understanding of salivary anti-tannin defence in rhinoceroses, these results are the first report of an induced salivary response to increased dietary tannin levels in an ungulate species.     

Reproductive biology of captive and free-ranging spider monkeys

Records from 42 zoos and from long-term studies of wild populations were analysed to describe the reproductive biology of spider monkeys (Ateles spp.). Both data sets suggested that spider monkey females typically have their first infant between 7 and 8 years of age with an interbirth interval of approximately 32–36 months. Infant sex ratio for zoo populations was approximately 1 male to 1 female; infant sex ratios from wild populations were variable. Zoo records provided adequate sample size to suggest that interbirth interval was not influenced by the sex of the infant produced, and that the sex ratio and the probability of infant survival did not change with the number of infants the mother had produced. The findings of this study have implications with respect to the conservation of New World primate species. Since spider monkeys take a long time to reach sexual maturity and their interbirth interval is longer than that expected based on their body size, their populations may be slow to recover following disturbances. Thus, particular care should be taken for the protection of these species.     

Heart rates in the captive, free-ranging beaver

1. Heart rates of beaver (Castor canadensis) under free-ranging captive conditions for active behaviors and resting in water (approximately 121 beats/min) were significantly (P less than 0.01) higher than for resting on land (100 beats/min). 2. Although no transient recovery tachycardia was evident in swimming heart rates following diving, average swimming heart rates were higher (127 beats/min) after diving than after other precursor behaviors (123 beats/min). 3. Beaver exhibited bradycardia when sleeping (75 beats/min), diving (61 beats/min), and when threatened on land (57 beats/min). 4. The respiratory sinus arrhythmia indicated a respiratory rate of 15 breaths/min. 5. Cold temperatures (approximately 0 degree C) elicited higher heart rates than did warmer temperatures (approximately 20 degrees C) in active, non-diving behaviors (P less than 0.05).     

Serosurvey for selected infectious disease agents in free-ranging black and white rhinoceros in Africa

Two hundred and eighty one serum samples collected from free-ranging black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros, in the Republic of South Africa (RSA), Namibia, and Kenya from 1987-97, were examined for antibody to 16 different infectious agents. Positive antibody titers were detected against Akabane (59.8%), bluetongue (55%), African horse sickness (27.9%), epizootic haemorrhagic disease of deer (19.4%), parainfluenza type 3 (25.3%), bovine herpes virus 1 (3.1%), equine herpes virus 1 (8.8%) and bovine viral diarrhea (1.2%) viruses, and four serovars of Leptospira interrogans, (ranging 1.2 to 8.8%). No antibody was detected against Rift Valley fever virus, encephalomyocarditis virus, Brucella abortus, and Trypanosoma equiperdum. Interspecies differences were detected for African horse sickness, epizootic haemorrhagic disease of deer and parainfluenza type 3 viruses. There appeared to be some geographic variation in the prevalence of antibody for African horse sickness, bluetongue, epizootic haemorrhagic disease of deer, parainfluenza type 3, equine herpes virus 1 and Leptospira interrogans serovar bratislava.     

Effects of sociosexual environment on serum testosterone in captive male African rhinoceros

The relationships between testosterone concentrations in male African rhinoceros and the presence of conspecific males and females were investigated. Serum testosterone concentrations were measured using enzyme-linked immunoassay (EIA) in 37 male black rhinoceros (Diceros bicornis) and 21 male white rhinoceros (Ceratotherium simum) housed at 37 institutions in the USA. Testosterone concentrations in both black (n = 37) and white (n = 21) rhinoceros males rose with increasing numbers of females present (P < 0.05). Average testosterone concentrations also rose with an increased number of conspecific males (n = 34) in black rhinoceros (P < 0.05). However, no specific pattern was found among male white rhinoceros housed with other males. We inferred that introduction of females to a male may play an important role in stimulating libido and spermatogenesis. The similar response of black rhinoceros and white rhinoceros to increased numbers of females suggested that, at least historically, herd structure for blacks may have been more similar to whites than previously realized, and should be investigated further.     

Viruses isolated from captive and free-ranging wild ruminants in Alberta.

Nasal secretions, leukocytes and preputial or vaginal swabs from a group of 15 captive wild ruminants, comprising six pronghorn antelope (Antilocapra americana), seven fallow deer (Dama dama) and two mule deer (Odocoileus hemionus), and from 50 free-ranging pronghorns in southern Alberta, were examined for viral agents. Captive animals were given injections of dexamethasone daily for 6 days in attempts to reactivate latent infections. Specimens were collected at 2-3 day intervals from days 0 to 18. Free-ranging pronghorns were sampled only once, at the time of capture. Fifteen viral isolates were obtained from the animals: six isolates of parainfluenza 3 (PI3) from nasal swabs from one fallow deer and one mule deer; five isolates of herpesvirus from leukocytes, vaginal, preputial and nasal swabs from three fallow deer; and four isolates of PI3 from nasal secretions of the 50 free-ranging pronghorns.     

Seasonal sex skin coloration and hormonal fluctuations in free-ranging and captive monkeys

Seasonal hormonal and sex skin coloration peaks were found to be synchronized in free-ranging, socially enclosed, and individually isolated rhesus monkeys of both sexes. These occurred during the October–January mating season on La Cueva island, Puerto Rico. Individually isolated females displayed a mid-cycle peak in sex skin coloration during the period of regular cycles (September–April). Females who became pregnant during the mating season did not show the significant sex skin coloration decrease seen in nonpregnant females during the months that follow the mating season. Environmental cues, perhaps acting on a seasonal biological clock rather than social factors, are thought to be mainly responsible for the synchronous seasonal fluctuations observed. The technique used for assessing changes in sex skin coloration is shown to be an effective and reliable method for recording seasonal and intramenstrual variations of sex hormones in free-tanging and captive rhesus monkeys. Furthermore, the procedure may prove useful in studies relating behavior with sex endocrines.     

Plasma cholesterol levels in free-ranging macaques compared with captive macaques and humans

Plasma total cholesterol in free-ranging Japanese macaques (Macaca fuscata) on Koshima islet and in free-ranging long-tailed macaques (Macaca fascicularis) at Pangandaran in Indonesia was found to occur at very low levels compared with captive macaques and humans. Although total cholesterol levels in captive macaques were lower than humans, differences in HDL cholesterol levels were only small. In both sexes of wild and captive Japanese macaques, total cholesterol levels decreased from birth through to young adulthood but then increased in adult females of the captive group. In contrast, the value for adult females of the wild troop remained at a low level. Low TCH levels in adult females of the wild Japanese macaque troop may be due to a low energy intake and may have caused a delay in the onset of sexual maturation. Plasma TCH levels increased with the addition of 0.1% dietary cholesterol over six weeks in captive long-tailed macaques. That the cholesterol value after six weeks was dependent on cholesterol levels prior to supplementation indicates that captive macaques are slightly saturated with cholesterol.     

Similarity in ejaculate-endocrine characteristics in captive versus free-ranging cheetahs of two subspecies

Ejaculate-endocrine characteristics were measured in 23 captive cheetahs (Acinonyx jubatus jubatus) in North American zoos and in 8 free-ranging cheetahs (A.j. raineyi) in eastern Africa (Tanzania). A standardized electroejaculation protocol was used, and numbers of motile spermatozoa were similar (p greater than 0.05) between groups. Of the spermatozoa collected by electroejaculation, 70.6 +/- 3.3% and 75.9 +/- 4.4% were morphologically abnormal in the captive "North American" and in the free-ranging, eastern African populations, respectively. Adrenal activity, as measured by an acute, temporal rise and fall in serum cortisol levels during and after electroejaculation, was no different (p greater than 0.05) between groups. Although serum luteinizing hormone (LH) levels were less (p less than 0.05) in the free-ranging than in the captive animals, serum testosterone concentrations were similar. The data indicate that the comparatively poor reproductive performance of cheetahs maintained in zoological parks is not attributable to a captivity-induced response afflicting the male. Furthermore, there is no evidence that ejaculate/endocrine characteristics differ between the two subspecies. Because adrenal/gonadal activity and the number of pleiomorphic spermatozoa are similar between the test groups, the results suggest that spermatozoal diversity originates as a result of the extreme genetic monomorphism observed universally in the species.     

Seroepidemiology of parapoxvirus infections in captive and free-ranging California sea lions Zalophus californianus

Cutaneous nodular lesions caused by parapoxvirus infections are commonly observed in stranded pinnipeds following their arrival at rehabilitation facilities. An indirect enzyme-linked immunosorbent assay (ELISA) was developed and validated to determine exposure to parapoxviruses in California sea lions Zalophus californianus in captivity and in the wild. The diagnostic performance of this assay was evaluated using receiver-operating characteristic analysis. At a selected cut-off value, the calculated sensitivity was 100% (95% CI = 86 to 100%) and the specificity was 100% (95% CI = 87 to 100%). Analysis of sera collected from 26 affected sea lions during various stages of the disease revealed anti-parapoxvirus antibodies in all affected sea lions prior to the development of cutaneous pox lesions. This indicated that previous exposure to a parapoxvirus does not confer protection against clinical disease. In at least 7 cases, exposure to the virus occurred during hospitalization. Analysis of paired sera from 74 unaffected sea lions indicated subclinical infections in at least 3 animals. Finally, the prevalence of anti-parapoxviral antibodies in 761 free-ranging California sea lions captured and tested was 91% (95% CI = 89 to 93%). This indicated that infection with a parapoxvirus is a common occurrence in the wild and that the release of captive sea lions infected with parapoxvirus into the wild should not increase the risk of a parapoxvirus outbreak in free-ranging sea lions.     

Seroprevalence of SV40-like polyomavirus infections in captive and free-ranging macaque species

BACKGROUND AND METHODS: To investigate the seroprevalence of polyomavirus infections in macaques, we analyzed 1579 sera from nine different species for antibodies cross-reactive with simian virus 40 (SV40) in an enzyme-linked immunosorbent assay. Most samples were collected from captive animals, but we also investigated a colony of free-ranging Barbary macaques (Macaca sylvanus). RESULTS: High seropositive rates were found in rhesus macaques (Macaca mulatta; 74.7%), cynomolgus macaques (Macaca fascicularis; 44.8%) and Tonkean macaques (Macaca tonkeana; 41.7%), especially in animals imported from China. Low rates were measured in cynomolgus macaques from Mauritius (8.8%), and in Barbary macaques (1.4%). Seropositivity was age-dependent increasing to >70% in animals of 5 years and older. CONCLUSIONS: High seroprevalence rates were found in different species of macaques, dependent on their origin. Very low infection rates found in Barbary macaques and cynomolgus macaques from Mauritius suggest that these animals in the wild are not commonly infected by SV40-like viruses.     

Ranavirus infection of free-ranging and captive box turtles and tortoises in the United States

Iridoviruses of the genus Ranavirus are well known for causing mass mortality events of fish and amphibians with sporadic reports of infection in reptiles. This article describes five instances of Ranavirus infection in chelonians between 2003 and 2005 in Georgia, Florida, New York, and Pennsylvania, USA. Affected species included captive Burmese star tortoises (Geochelone platynota), a free-ranging gopher tortoise (Gopherus polyphemus), free-ranging eastern box turtles (Terrapene carolina carolina), and a Florida box turtle (Terrepene carolina bauri). Evidence for Ranavirus infection was also found in archived material from previously unexplained mass mortality events of eastern box turtles from Georgia in 1991 and from Texas in 1998. Consistent lesions in affected animals included necrotizing stomatitis and/or esophagitis, fibrinous and necrotizing splenitis, and multicentric fibrinoid vasculitis. Intracytoplasmic inclusion bodies were rarely observed in affected tissues. A portion of the major capsid protein (MCP) gene was sequenced from each case in 2003-2005 and found to be identical to each other and to Frog virus 3 (FV3) across 420 base pairs. Ranavirus infections were also documented in sympatric species of amphibians at two locations with infected chelonians. The fragment profiles of HindIII-digested whole genomic DNA of Ranavirus, isolated from a dead Burmese star tortoise and a southern leopard frog (Rana utricularia) found nearby, were similar. The box turtle isolate had a low molecular weight fragment that was not seen in the digestion profiles for the other isolates. These results suggest that certain amphibians and chelonians are infected with a similar virus and that different viruses exist among different chelonians. Amphibians may serve as a reservoir host for susceptible chelonians. This report also demonstrated that significant disease associated with Ranavirus infections are likely more widespread in chelonians than previously suspected.     

Tooth wear in captive wild ruminant species differs from that of free-ranging conspecifics

The mesowear method evaluates the wear patterns of herbivore cheek teeth by visually evaluating the facet development of the occlusal surfaces. It thus allows classification of most herbivorous ungulates into browsers, grazers or intermediate feeders, due to the fact that in grazers, tooth wear is characterized by a comparatively high degree of abrasion, most probably due to the presence of silicacious phytoliths in grasses, a higher amount of dust and grit adhering to their forage, or both. It has been suggested that excessive tooth wear could be a particularly limiting factor in the husbandry of captive large browsing species, and major tooth wear was demonstrated in captive as compared to free-ranging giraffe. If this increased tooth wear in captivity was an effect of feeding type and diets fed, then it would be expected that other browsing species are affected in a similar manner. In order to test this hypothesis, we investigated the dental mesowear pattern in captive individuals of 19 ruminant species and compared the results to data on free-ranging animals. Compared to free-ranging populations, captive browsers show a significantly more abrasion-dominated tooth wear signal. The reverse applies to captive grazers, which tend to show a less abrasion-dominated wear in captivity. Captive ruminants were generally more homogenous in their wear signature than free-ranging ruminants. If grit contamination in the natural habitat is a major cause of dental wear in grazers, then diets in captivity, although similar in botanical composition, most likely contain less abrasives due to feeding hygiene. If dental wear is one of the major factors limiting longevity, then captive grazers should achieve longer lifespans than both captive browsers and free-ranging grazers. In particular with respect to browsers, the results suggest that captive feeding regimes could be improved.     

Molecular identification of a papilloma virus from cutaneous lesions of captive and free-ranging Florida manatees

Cutaneous papillomatous lesions were biopsied from three captive Florida manatees (Trichechus manatus latirostris) at Homosassa Springs State Wildlife Park (HSSWP), Homosassa, Florida, USA, and from six free-ranging Florida manatees from Crystal and Homosassa rivers, Florida. Total DNA extracted from these lesions was assayed for the presence of papilloma virus genomes using the polymerase chain reaction (PCR) with primers that target the L1 capsid protein gene. The amplification generated DNA fragments 458 base pairs in length that encompassed a highly conserved domain within the L1 capsid protein and translated into identical polypeptides of 152 amino acids, suggesting the involvement of a single papilloma virus genotype. Multiple amino acid sequence and phylogenetic analyses of the L1 fragment indicated that the Florida manatee papilloma virus is a unique and quite distinct papillomavirus from other known papilloma viruses. The emergence of this new pathogen raises concerns about its potential impact on the already endangered Florida manatee.