Serial ultrasound examination of four mature female sevengill sharks (Notorynchus cepedianus) was carried out over 18 months. Monitoring the reproductive cycle and development of follicles and fetuses in sharks in a noninvasive manner using this technique has not been reported previously. Sharks were caught out of the "Oceanarium" tank by divers using a specially made catch-out bag, and brought to a holding area for examination. A behavior scoring system was used to monitor the impact of regular handling on the well-being of the animals. Ultrasound showed the growth and regression of follicles in sevengill ovaries, and allowed an approximation of the reproductive stage of these sharks. Monitoring behavior at five time points during the procedure showed that regular handling of sharks for clinical studies could be done with minimal impact on animal welfare. The ability to follow reproductive events in elasmobranches using ultrasonography is an important step in the application of assisted reproductive technology in these species. Assisted reproductive technology, such as monitoring female reproductive cycles and artificial insemination, could potentially be used to maintain genetic diversity and compliment aquaria-based breeding programs for endangered species such as the gray nurse shark (Carcharias taurus). Zoo Biol 26:383-395, 2007. (c) 2007 Wiley-Liss, Inc.
There are only a few documented cases of the use of either tools or substrates (anvils) as pseudotools in fishes. Described here is an anvil behavior of a labrid fish, Thalassoma hardwicke, observed under aquarium conditions. This fish was fed with pellets that are too large to swallow and too hard to break up into manageable bits using jaws only. The observed individual carried a pellet to an anvil to break it up into pieces small enough to be swallowed. This feeding behavior was frequently repeated (observed in detail about 15 times), nearly always successful, and remarkably consistent, suggesting that the rock selected for an anvil is remembered and its functional qualities or other factors may play a part in its choice. These observations agree with evidence for other advanced cognitive abilities in members of the genus Thalassoma and suggest that, for welfare demand, rocks with rough surfaces should be provided to these fish, especially when they receive hard food for variety.
Mitchell's water monitors (Varanus mitchelli) have been maintained on display at Perth Zoo since 1997. They are generally a timid species but have been maintained and bred in a mixed species water feature exhibit. In this article we describe their captive management and behavior with an insight into their reproductive biology. Between 2002 and 2005, 11 clutches were laid ranging from 13 to 27 (X = 20) eggs from one female. Egg size ranged between 3.00 and 6.08 g (X = 4.77 g) in weight, 22.8 and 31.9 mm (X = 28.3 mm) in length, and 11.1 and 19.3 mm (X = 17.1 mm) in width. Oviposition included double and triple clutches ranging between 41 and 60 days apart (X = 48 days), events n = 6. Four clutches were incubated at three different temperatures and hatchlings emerged after 157-289 days. The weight of the hatchlings ranged between 2.60 and 4.52 g (X = 4.34 g). Total length ranged between 140.1 and 178.0 mm (X = 165.9 mm) and snout-vent length ranged from 53.8 to 70.0 (X = 64.4 mm). Juvenile growth and development information is presented from hatching through to approximately 3 years of age.
Zoos may play an important role in conservation when they maintain and breed large numbers of animals that are threatened with extinction. Bird conservation is in a privileged situation owing to the extensive biological information available about this class. Annual inventories produced by the "Sociedade de Zoológicos do Brasil" in the years 1981, 1990, 2000, and 2005 were analyzed. Variables, such as the number of zoos per geographic region; number of birds held; number of bird species in each IUCN threat category; number of exotic and native bird species; number of potentially breeding bird species; number of bird species in each order; and number of threatened bird species breeding, were analyzed. Brazilian zoos kept more than 350 bird species. The number of bird species and specimens held by the Brazilian Zoos increased from 1981 to 2000, but decreased in 2005. The same pattern was observed for the number of species in each IUCN threat category. Results showed that the potential of the Brazilian zoos in bird conservation needs to be enhanced because they maintain threatened species but do not implement systematic genetic, reproductive, or behavioral management protocols for most species.
Eleven species of Amazon parrots (genus Amazona) are known to occur in Brazil, and nest poaching and illegal traffic pose serious conservation threats to these species. When the illegal owners realize these animals are incompatible with their expectations and lifestyle, or when the police arrests traders and owners, these trafficked animals are often considered unfit for release and sent to local zoos and captive breeders. A retrospective survey of animal and necropsy records from 1986 to 2007 was used to evaluate the impacts of animal traffic on the population composition and mortality patterns of Amazon parrots at the Quinzinho de Barros Municipal Zoological Park, Sorocaba, Brazil. Data were obtained for 374 Amazon parrots of ten Brazilian species, and there was evidence that the studied population could be split into two major groups: a majority belonging to the Amazona aestiva species and a minority belonging to the remaining species. In comparison, the animals of the first group were more frequently admitted from traffic-related origins (98 vs. 75%), had a shorter lifespan (median 301 days vs. 848 days) and a higher mortality within the first year postadmission (54 vs. 37%), were less likely to receive expensive treatments, and were more frequently housed off-exhibit. On an average, parrots were found to have a short postadmission lifespan (median 356 days), with 92.5% of the birds dying within their first five years in captivity. The paper discusses the difficult dilemmas these incoming traffic-related animals pose to zoo management and official anti-traffic policies.
Excessive absorption and subsequent storage of dietary iron has been found in a variety of captively held birds and mammals, including fruit bats. It is thought that feeding a diet that is low in iron can prevent the onset of this disease; however, manufacturing a diet with commonly available foodstuffs that contains a sufficiently low iron concentration is difficult. An alternative is to feed captive animals that may be susceptible to this disease potential iron chelators such as tannins that may bind to iron and block its absorption. Using stable isotope methods established in humans, we measured iron bioavailability in straw-colored fruit bats (Eidolon helvum) and tested whether tannic acid significantly reduced the extent of iron absorption. Regardless of dose, tannic acid significantly reduced iron absorption (by 40%) and in the absence of tannic acid, iron absorption was extensive in this species (up to 30%), more so than in humans. Species susceptible to iron storage disease may efficiently absorb iron in the gut regardless of iron status, and supplementing these species with tannic acid in captivity may provide an alternative or additional means of preventing the development of this disease.
Zoos focus on welfare, conservation, education, and research related to animals they keep. Academic institutions emphasize description, experimentation, modeling, and teaching of general and specific animal biology and behavior through work in both laboratory and field. The considerable overlap in concerns and methods has increased interest in collaborative projects, but there is ample room for closer and more extensive interactions. The purpose of this article is to increase awareness of potential research collaborations in three areas: (1) control and analysis of behavior, (2) conservation and propagation of species, and (3) education of students and the general public. In each area, we outline (a) research in zoos, (b) research in academics, and (c) potential collaborative efforts. Zoo Biol 27:470-487, 2008. (c) 2008 Wiley-Liss, Inc.
Noninvasive hormone assays provide a way to determine an animal's health or reproductive status without the need for physical or chemical restraint, both of which create unnecessary stress for the animal, and can potentially alter the hormones being measured. Because hormone metabolism is highly species-specific, each assay must be validated for use in the species of interest. Validation of noninvasive steroid hormone assays has traditionally required the administration of relatively high doses of radiolabelled compounds (100 µCi or more of (14)C labeled hormone) to permit subsequent detection of the excreted metabolites in the urine and feces. Accelerator mass spectrometry (AMS) is sensitive to extremely low levels of rare isotopes such as (14)C, and provides a way to validate hormone assays using much lower levels of radioactivity than those traditionally employed. A captive Asian bull elephant was given 1 µCi of (14)C-testosterone intravenously, and an opportunistic urine sample was collected 2 hr after the injection. The sample was separated by HPLC and the (14)C in the fractions was detected by AMS to characterize the metabolites present in the urine. A previously established HPLC protocol was used, which permitted the identification of fractions into which testosterone sulfate, testosterone glucuronide, and the parent compound testosterone elute. Results from this study indicate that the majority of testosterone excreted in the urine of the Asian bull elephant is in the form of testosterone sulfate. A small amount of testosterone glucuronide is also excreted, but there is no parent compound present in the urine at all. These results underscore the need for enzymatic hydrolysis to prepare urine samples for hormone assay measurement. Furthermore, they highlight the importance of proper hormone assay validation in order to ensure accurate measurement of the desired hormone. Although this study demonstrated the utility of AMS for safer validation of noninvasive hormone assays in nondomestic species, this methodology could also be applied to studies of nutrient metabolism and drug pharmakokinetics, both areas in great need of further study in wildlife species.
Induced ovulators, such as the koala, do not always have overt signs of estrus, which makes pairing these animals for breeding purposes difficult to achieve in a zoo setting. This study examined the possibility of using alternative methods to behavioral sampling and weight fluctuations for monitoring estrus in a female koala of reproductive age. We attempt to gain an improved understanding of koala estrus and enhance our ability to detect it by combining a noninvasive technique for hormone analysis with a newer method for recording activity level. The findings suggest that activity levels were accurately measured using an accelerometer and increased activity was associated with one estrus behavior, bellowing. Weekly weight declines occur with increases in activity registered from the accelerometer. We also validated an assay to detect progesterone and estradiol in female koala urine in an attempt to detect an estrus spike. However, neither urinary concentrations of estradiol nor progesterone was associated with behavioral cues of estrus in our subject. We suggest that increased female activity, bellowing, and weight loss all indicate a pro-estrus state that requires proper male stimulation in order to achieve a full estrus display.
Two central concerns for elephant husbandry and management are whether zoological enclosures are appropriately sized and the degree to which naturalistic exercise and activity are observed in such enclosures. In order to address these issues, accurate data on the daily walking distance of elephants both in situ and ex situ are necessary. We used an accelerometer, a pedometer that measures step count and activity level, to estimate walking distance in African elephants (Loxodonta africana) at the San Diego Zoo's Wild Animal Park. The accelerometer was worn simultaneously with a GPS unit that recorded actual walking distance. Estimates of walking distance were extrapolated from the accelerometer and compared with actual distances determined by GPS data. The accelerometer was found to overestimate step count, and subsequently walking distance, by including false counts of steps. Extrapolating walking distance based upon stride length measurements did not match actual GPS walking distance. However, activity level output from the accelerometer significantly correlated with actual GPS walking distance. In addition, we report that the rate of movement is comparable to that reported in other zoological settings. We provide a linear regression equation that can be utilized by other institutions to estimate daily walking distance of elephants in their collection who are outfitted with accelerometers.
Little is known about how socially housed captive carnivores respond to temporary reductions in available space. We documented rates of aggression and affiliation in our group of six female tigers, under their normal housing conditions and during a period of exhibit renovations which resulted in a 50% reduction in time spent in an outdoor enclosure. During the period of reduced availability of space, significant declines in aggression and affiliation were observed indicating that these tigers responded in a manner consistent with a strategy of conflict avoidance. These reductions in rates of social behavior remained in place during the year following the return to their original housing conditions. Thus, even temporary alterations to housing practices have the potential to have lasting impacts on the social behavior of this species.
There are a limited number of feeder-invertebrates available to feed captive insectivores, and many are deficient in certain nutrients. Gut-loading is used to increase the diversity of nutrients present in the captive insectivore diet; however, little is known about delivery of carotenoids via gut-loading. Carotenoids may influence health and reproduction due to their roles in immune and antioxidant systems. We assessed interspecific variation in carotenoid accumulation and retention in three feeder-cricket species (Gryllus bimaculatus, Gryllodes sigillatus and Acheta domesticus) fed one of three diets (wheat-bran, fish-food based formulated diet, and fresh fruit and vegetables). Out of the three species of feeder-cricket in the fish-food-based dietary treatment group, G. bimaculatus had the greatest total carotenoid concentration. All cricket species fed the wheat-bran diet had very low carotenoid concentrations. Species on the fish-food-based diet had intermediate carotenoid concentrations, and those on the fruit and vegetable diet had the highest concentrations. Carotenoid retention was poor across all species. Overall, this study shows that, by providing captive insectivores with G. bimaculatus crickets recently fed a carotenoid-rich diet, the quantity of carotenoids in the diet can be increased.
Contraception is a critical component of population management for lemurs, but concerns about potential deleterious effects of continuous, long-term treatment with synthetic progestins such as the widely used melengestrol acetate implant led us to evaluate seasonal contraception with injections of depot medroxyprogesterone acetate (Depo-Provera, Upjohn Pharmacia, Kalamazoo, MI) to limit the duration of exposure. We compared two dosage regimens in female black lemurs using vaginal cytology as an indirect measure of ovarian suppression. Our results indicate that both 10 mg/kg body weight at 90-day intervals or 2.5 mg/kg at approximately 30-day intervals can be effective in most females, although one female on the 10-mg dose showed signs of estrus at 53 days. Darkening of pelage during treatment was the primary side effect noted. A more important observation was that contraception can extend the breeding season to as much as 9 months, considerably longer than reported previously, which necessitates extending the period of contraceptive treatment. Zoo Biol 26:289-298, 2007. (c) 2007 Wiley-Liss, Inc.
Melengestrol acetate (MGA) implants were used for contraception in three addax and three Arabian oryx females housed at the Saint Louis Zoo. Serum estradiol and progesterone or fecal estrogen and progestin analysis and ultrasonography of reproductive tracts were used for monitoring changes before, during, and after MGA treatment. Follicular development and irregular uterine fluid accumulation were detected in all females during MGA treatment. Although housed with an intact male for all or most of the contraceptive period, no pregnancies occurred.
One female addax may have ovulated, based on sustained elevated progesterone levels, and another showed continued follicle development, as seen by fluctuating estradiol concentrations. Reversibility was documented in two of the three addax that resumed reproductive cycles post-MGA-implant removal, whereas the third, a peripubertal female, did not cycle before, during, or after treatment. Addax females were lost to further follow-up after transfer to another institution, so the possibility of subsequent pregnancies is not known.
All three Arabian oryx ovulated during the initial MGA treatment, but two of the three females had implants past the typical 2-year efficacy period. They had regular ovulatory cycles after implant removal, with mean cycle length of 27.5±1.5 days and mean luteal phase duration of 15.2±0.7 days. Reversibility was further shown in all three oryx by pregnancies after placement with a male approximately 2 years after MGA implant removal. Two produced healthy calves, but the third died owing to an unrelated terminal illness in the mother. Zoo Biol 26:299–310, 2007.
Analysis of fecal progestogen profiles during Depo-Provera injection (1,200 mg; DEPO, Pfizer Inc., New York, NY), melengestrol acetate (MGA) in feed (2 or 3 mg/head/day), and a combination treatment (DEPO+MGA) are presented for nine captive female Nile hippos housed at Disney's Animal Kingdom in Florida. All tested treatments reduced fecal progestogen elevations successfully to durations consistent with prevention of ovulation for a portion of the treatment period. Percentage of treatment months with suppression of luteal phases indicative of ovulation was maximal for high-dose MGA (91.7+/-13.9%) and DEPO+MGA (91.7+/-20.4%), followed by DEPO injection alone (69.2+/-13.9%) and low-dose MGA (57.6+/-33.2%). Both 1,200 mg DEPO and low-dose MGA (2.0 mg/day) treatments were insufficient to prevent an apparent seasonal breakthrough of ovarian activity from June-August 2002. Although luteal phases were observed, no females conceived during those months. Overall, in 133.5 treatment months with females housed with an adult male, one female conceived during the transition period between treatments. After cessation of contraceptive treatment, average latency to first normal ovarian cycle was 80.6+/-19.5 days (range = 22-179 days). Up to 12 months post-treatment, however, successive cycles were often irregular with evidence of short periods of anovulation and shortened luteal phases in all females monitored. In conclusion, high dose and combination treatments were most successful in preventing progestogen increases indicative of ovulation in hippos. Zoo Biol 26:259-274, 2007. (c) 2007 Wiley-Liss, Inc.
This pilot project began establishing a nutritional profile for free-ranging giraffe. The results will be used as a tool to begin assessing the nutritional status of captive giraffe. In October 2004 serum samples were collected opportunistically from seven adult and 17 sub-adult giraffe being anesthetized for different studies. Seventeen animals were from Double Drift Game Reserve and seven animals were from Kariega Private Game Reserve. The serum samples were analyzed for circulating concentrations of amino acids, fatty acids, lipoproteins, vitamins, and minerals. Information from 15 serum samples collected from anesthetized giraffe in Kruger National Park during April and August 2003 was included in the calcium and phosphorus concentration data. No significant differences were identified between genders. Significant differences between locations were identified for concentrations of certain amino acids, fatty acids, and lipoproteins. Differences between locations are likely due to different nutrient concentrations of foods and possibly the result of different animal densities forcing different food choices among locations. This pilot project may expand to include changes in circulating nutrient concentrations for free-ranging giraffe as is influenced by other locations, seasonal food availability, and different giraffe subspecies. Zoo Biol 0:1-13, 2007. (c) 2006 Wiley-Liss, Inc.
In response to new recommendations for feeding giraffe in zoos, giraffe (n = 6) were transitioned from a typical hoofstock diet to diets containing reduced starch, protein, Ca and P and added n3 fatty acids. This diet was fed as a 50:50 mix with alfalfa and grass hay. Over the next 4 years, serum Ca, P, and fatty acids were measured every 6 months (summer and winter). Serum Ca was not affected by season (P = 0.67) or by diet (P = 0.12). Serum P was not affected season (P = 0.14), but was reduced by diet (P<0.01), and serum Ca:P was also increased by diet (P<0.01). The ratio of serum Ca:P tended to be affected by season (P = 0.07), in which animals tended to have greater Ca:P during the summer vs. the winter. The diet transition resulted in reduced serum saturated fatty acids (including lauric, myristic, palmitic, arachidic, and behenic acids), and increases in n6 fatty acids (including linolenic and arachidonic acids) and n3 fatty acids (docosahexaenoic acid) (P<0.05 for each). Overall, this diet transition resulted in blood nutrient profiles that more closely match that of values found in free-ranging giraffe.
We examined 1,092 skulls of captive and free-living individuals, representing 33 felid species, to determine the prevalence of focal palatine erosion (FPE). FPE was detected in 3.2% of cats evaluated, including cheetah (Acinonyx jubatus) and 14 other felid species. The prevalence of FPE between cheetah (9.4%; n = 64) and non-cheetah species (2.8%; n = 1,028) (χ(2) test; P = 0.004) and between captive (5.7%; n = 246) and free-living (2.4%; n = 824) individuals (χ(2) test; P = 0.010) were significantly different, with prevalence between captive (19%; n = 21) and free-living (2.9%; n = 34) cheetahs approaching significance (Fisher's exact test; P = 0.064). FPE was diagnosed with equal prevalence in skulls from individuals in which the lower molars did not meet the palatine bone (60.6%) and individuals in which it did (39.4%; n = 33) (χ(2) test; P = 0.139). In cheetahs with FPE, one was a captive animal in Germany, one a free-living cheetah from Mali, one captive cheetah from Kenya, and three captive cheetahs of unknown origin. Additionally, we evaluated the medical records of 49 captive cheetahs in Namibia. Of these cheetahs, 48 (98.0%) had clinical signs consistent with FPE, although only 16 of these 48 (39.6%) had perforation of the palatine bone. Based on physical examinations, FPE was diagnosed in two caracals (Caracal caracal) and one fishing cat (Prionailurus viverrinus) from a North American Zoo. Results from this study confirm FPE in cheetahs outside of Namibia, in a minimum of 15 felid species, and a higher FPE prevalence in captive individuals than free-living ones. Clinical implications of these findings and recommendations for future studies are provided.
Commercially prepared milk replacers are frequently used to provide the sole source of nutrition for hand-reared cheetah cubs (Acinonyx jubatus). The nutrient composition of two commonly used milk replacers was determined. Using titanium dioxide as an indigestible marker, nutrient digestibility was calculated from the analyses of fecal samples collected from each cub (n = 4 on formula 1, and n = 2 on formula 2). Mean apparent total tract digestibility for both formulas was >90% for all nutrients analyzed (crude protein, amino acids, crude fat (CF), and dry matter). However, the total CF content and the concentration of the essential fatty acids, such as α-linolenic, linolenic, and arachidonic acid, of both formulas was lower than reported for maternal cheetah milk. Additionally, one formula contained a comparatively high amount of carbohydrate, at the expense of protein. Although data were lacking for cheetah maternal milk, comparison with domestic cat milk revealed high concentrations of a number of minerals (K, Fe, Zn, and Cu), while vitamin D(3) was not detected in one formula. Both formulas were low in the majority of essential amino acids compared with domestic cat maternal milk. Despite their apparently high digestibility, neither formula was complete or balanced in terms of nutrient concentrations and ratios when maternal cheetah milk and/or the requirements established for growth in domestic cats were used as estimates of ideal. On this basis, although all cubs in this study were healthy and maintained good body conditions for the duration of the trial, the results of dietary analyses indicate that these milk replacers may not provide optimal nutrition for growth in cheetah cubs when used for extended periods.
Four hand-reared cheetah cubs (Acinonyx jubatus) exhibited progressively severe bilateral valgus deformity of the carpi (CV) during the weaning period. Radiographs of the thoracic limbs suggested normal bone ossification, and serum chemistry was unremarkable. All affected cubs developed CV shortly after the onset of gastroenteritis, which was treated medically, and included use of a prescription diet. A sudden decrease in growth rate was associated with gastrointestinal disease. Before gastroenteritis and CV, affected cubs had higher growth rates than unaffected cubs, despite similar mean daily energy intake. Return to normal thoracic limb conformation was consequent to dietary manipulation (including a reduction in energy intake and vitamin and mineral supplementation), as well as decreased growth rates and recovery from gastroenteritis. The cause of the CV is likely to have been multi-factorial with potentially complex physiological interactions involved.
The Greater Rhea (Rhea americana) is a characteristic bird of the Argentine Pampas. Despite the increasing farming interest of this ratite, their natural populations are progressively decreasing in size and range. The object of this study was to evaluate the status of captive populations as potential genetic reservoirs. Using Inter-Simple Sequence Repeats as molecular markers, levels of genetic variability of F1 individuals from two captive populations were estimated and compared with those of wild populations in the same region. The captive populations were polymorphic for 12.22 and 13.33% of the loci, with a genetic diversity of 0.050. Differences with wild populations were not significant (z=1.79; P>0.05). Therefore, captive populations of rheas in Argentina should not be overlooked as genetic reservoir and source of individuals for reinforcement of natural populations, through reintroduction and translocation.
We studied over 1 year the spatial organization and the spatial distribution of activities in a captive springbok (Antidorcas marsupialis) population living in an 18-ha enclosure located in southern France. Throughout the study period, the two adult males occupied fairly exclusive home ranges, in the overlapping part of which the three subadult males were restricted. The spatial and temporal distribution of aggressive, marking, and avoidance behavior of males showed that the two adults were territorial, except during summer. They accounted for 71% of all marking behaviors recorded, for 77% of the aggressive behavior, and for 91% of the sexual interactions, whereas subadult males accounted for 94% of the avoidance behavior observed. The adult females used the whole enclosure, moving through the males' home ranges. They fed everywhere, but they all had the same preferred resting area, located in the center of the territory of one of the two adult males. They gave birth, accounted for maternal behavior and were engaged in sexual interactions in sectors differing from one individual to the other, but mainly outside the sector where all males' home ranges overlapped. Our results are compared to those reported in natural conditions and lead us to discuss both the functional interpretations of marking behavior, and the signification of a home range for an ungulate. Zoo Biol 27:19-35, 2008. (c) 2007 Wiley-Liss, Inc.
The behavior of free-ranging and captive Eastern grey kangaroos Macropus giganteus, was observed by the same observers, with similar methods and under similar vegetational/climatic conditions in a 4.2-ha enclosure at Neuwied Zoo, Germany and at Grampians National Park, Victoria, Australia. Data were collected from a zoo group of 56 animals and a free-ranging mob of 50 to 60 animals. Males were individually identified and observed: 3 large males, 9 medium males, and 10 small males in the zoo, and 8 large, 9 medium, and approximately 10 small males in the National Park were present. Activities in both situations were very similarly distributed: Feed took up less time in the zoo, resting was almost similar in both situations, alert behavior was significantly different for small and medium males, locomotor activities were similar in large males and females, autogrooming occurred significantly more in the zoo only for females. Frequencies of social interactions were slightly greater for large males and females in the zoo. Agonistic behavior in males was more frequent in the zoo situation, except for ritualized fights. Sequences of agonistic behavior were more predictable in the zoo. No differences in escalation tendencies toward potentially injurious fighting could be found. Zoo Biol 19:529-539, 2000. Copyright 2000 Wiley-Liss, Inc.
There are only a few published examinations of elephant visual acuity. All involved Asian elephants (Elephas maximus) and found visual acuity to be between 8' and 11' of arc for a stimulus near the tip of the trunk, equivalent to a 0.50 cm gap, at a distance of about 2 m from the eyes. We predicted that African elephants (Loxodonta africana) would have similarly high visual acuity, necessary to facilitate eye-trunk coordination for feeding, drinking and social interactions. When tested on a discrimination task using Landolt-C stimuli, one African elephant cow demonstrated a visual acuity of 48' of arc. This represents the ability to discriminate a gap as small as 2.75 cm in a stimulus 196 cm from the eye. This single-subject study provides a preliminary estimate of the visual acuity of African elephants.
Nearly one-third of reproductive age African elephants in North America that are hormonally monitored fail to exhibit estrous cycle activity, which exacerbates the nonsustainability of the captive population. Three surveys were distributed to facilities housing female African elephants to determine how social and environmental variables contribute to cyclicity problems. Forty-six facilities returned all three surveys providing information on 90% of the SSP population and 106 elephants (64 cycling, 27 noncycling and 15 undetermined). Logistic analyses found that some physiological and social history variables were related to ovarian acyclicity. Females more likely to be acyclic had a larger body mass index and had resided longer at a facility with the same herdmates. Results suggest that controlling the weight of an elephant might be a first step to helping mitigate estrous cycle problems. Data further show that transferring females among facilities has no major impact on ovarian activity. Last, social status appears to impact cyclicity status; at 19 of 21 facilities that housed both cycling and noncycling elephants, the dominant female was acyclic. Further studies on how social and environmental dynamics affect hormone levels in free-living, cycling elephants are needed to determine whether acyclicity is strictly a captivity-related phenomenon.
We studied the behavioral development of seven lesser adjutant stork (Leptoptilos javanicus) chicks from hatching to fledging over three breeding seasons at the Bronx Zoo. We developed an ethogram and compared the rate at which behaviors appeared in relation to brood size, sex, and the conditions in which the chicks were raised by their parents. Although sample sizes were small, there seem to be sex-related differences in the rate at which behaviors develop, with females developing more rapidly than males. Larger clutch size may be associated with slower growth rate because the single male developed faster than the two males in 2004. The slowest growth rate, observed in a single male chick in 1999, was most likely owing to nutritional deficiencies and other health complications. More research is needed, but these results can be used to help evaluate the age and health of lesser adjutant stork chicks in captivity and in the wild. Zoo Biol 26:533-538, 2007. (c) 2007 Wiley-Liss, Inc.
Adolescence, the period lasting from the onset of puberty to the emergence of physical and sexual maturity, is a period of social change for many species including chimpanzees. Several reports have implicitly linked the physiological changes that occur during male chimpanzee adolescence to significant disruption in the social group, which in turn may result in serious agonism and wounding. To assess the association between adolescent males and wounding rates, 38 institutions housing 399 chimpanzees among 59 social groups, recorded all wounds incurred by chimpanzees over a 6-month period. The rate of wounding did not differ between groups with or without adolescent males. Adolescent males received the most wounds, but were no more likely to cause wounds than group members of any other sex-age class. Social groups with multiple adult males experienced lower wounding rates than those with a single adult male. Results indicate that (1) adolescent male chimpanzees may receive, but not inflict, more wounds than chimpanzees in other sex-age classes; and (2) management strategies that support natural social groupings may control and limit group agonism.
Monitoring adrenal activity through noninvasive fecal hormone sampling is rapidly gaining popularity as a tool to assess zoo animal welfare. However, few studies have sought to investigate the interrelationships between behavior, adrenal activity, and environment, and ask whether both behavioral and adrenal monitoring strategies are required to assess welfare sufficiently. We present the findings of a 9-month study of a small group (one male, two females) of Western lowland gorillas, Gorilla gorilla gorilla. First, we examined the effect of environmental variables on gorilla behavior. Second, we examined the effect of environmental variables on the concentration of fecal glucocorticoid metabolites (FGC) and the relationship between behavior and FGC. Environmental variables had similar effects on all three gorillas. Negative vigilance of visitors (NVV; staring, posturing, and charging at visitors) significantly increased in all subjects as environmental noise levels increased, and food-related behavior significantly decreased in all subjects as crowd size increased. Exhibit modifications had a number of positive effects on behavior. Notably, when privacy screens were used, NVV significantly decreased in two subjects. We found no significant effects of environmental variables on FGC. However, we did find significant relationships between behavior and FGC in one female. Specifically, her NVV was significantly higher one day before, and on the same day as, raised FGC. Also, hair plucking significantly increased in the two days following raised FGC. Overall, this study demonstrates how concurrent noninvasive fecal and behavioral monitoring can be used for gorilla welfare assessment.
The North American African (Loxodonta africana) elephant population is not self-sustaining, in part because of a high rate of abnormal ovarian activity. About 12% of adult females exhibit irregular cycles and 31% do not cycle at all. Our earlier work revealed a relationship between dominance status and ovarian acyclicity, with dominant females being more likely to not cycle normally. One theory is that dominant females may be expending more energy to maintaining peace within the captive herd than for supporting reproduction. The goal of this study was to determine if there was a relationship among dominance status, serum cortisol concentrations, and ovarian acyclicity. We hypothesized that adrenal glucocorticoid activity would be increased in dominant, noncycling elephants as compared with subdominant individuals. Blood samples were collected weekly over a 2-year period in 81 females of known dominance and cyclicity status, and analyzed for cortisol. Based on a path analysis model (Reticular Action Model Or Near Approximation [RAMONA]), noncycling, dominant African elephant females did not have higher mean serum cortisol concentrations, or exhibit more variability (i.e., coefficient of variation, standard deviation) in cortisol secretion. This study suggests that alterations in adrenal activity are not related to dominance status nor contribute directly to acyclicity in captive African elephants.
The study objectives were to determine the predominant manatee glucocorticoid; validate assays to measure this glucocorticoid and adrenocorticotropic hormone (ACTH); determine diagnostic thresholds to distinguish physiological vs. pathological concentrations; identify differences associated with sex, age class, female reproductive status, capture time, and lactate; and determine the best methods for manatee biologists and clinicians to diagnose stress. Cortisol is the predominant manatee glucocorticoid. IMMULITE 1000 assays for cortisol and ACTH were validated. Precision yielded intra- and inter-assay coefficients of variation for serum cortisol: ≤23.5 and ≤16.7%; and ACTH: ≤6.9 and ≤8.5%. Accuracy resulted in a mean adjusted R(2)≥0.87 for serum cortisol and ≥0.96 for ACTH. Assay analytical sensitivities for cortisol (0.1 µg/dl) and ACTH (10.0 pg/ml) were verified. Methods were highly correlated with another IMMULITE 1000 for serum cortisol (r=0.97) and ACTH (r=0.98). There was no significant variation in cortisol or ACTH with sex or age class and no correlation with female progesterone concentrations. Cortisol concentrations were highest in unhealthy manatees, chronically stressed by disease or injury. ACTH was greatest in healthy free-ranging or short-term rehabilitating individuals, peracutely stressed by capture and handling. Cortisol concentrations ≥1.0 µg/dl were diagnostic of chronic stress; ACTH concentrations ≥87.5 pg/ml were diagnostic of peracute stress. In healthy long-term captive manatees, cortisol (0.4±0.2 µg/dl) and ACTH (47.7±15.9 pg/ml) concentrations were lower than healthy free-ranging, short-term rehabilitated or unhealthy manatees. Capture time was not significantly correlated with cortisol; ACTH correlation was borderline significant. Cortisol and ACTH were positively correlated with lactate.
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.