Zoo BiologyPub Date : 2025-01-01Epub Date: 2024-10-30DOI: 10.1002/zoo.21873
Louisa A Rispoli, Jessye Wojtusik, Terri L Roth
{"title":"Exploring Serum Ferritin's Connection to the Acute Phase Response in Zoo-Managed African Rhinoceroses.","authors":"Louisa A Rispoli, Jessye Wojtusik, Terri L Roth","doi":"10.1002/zoo.21873","DOIUrl":"10.1002/zoo.21873","url":null,"abstract":"<p><p>Despite serum ferritin's potential as an iron status indicator, its concentrations vary significantly throughout a black rhinoceros's (Diceros bicornis) life, sometimes irrespective of iron load. We explored acute phase response-related biomarkers, serum amyloid A (SAA) and ceruloplasmin (Cp), to better understand the mechanisms influencing serum ferritin changes in managed black rhinoceroses. The objective was to evaluate the relationships between circulating levels of ferritin, SAA, and Cp in black and white rhinoceroses (Ceratotherium simum). We analyzed banked serum samples collected serially from 11 black (n = 222) and 7 white (n = 134), rhinoceroses (rhinos) and classified samples based on SAA values: clinically healthy (< 1 mg/L), subclinical (1-7 mg/L), or clinically abnormal (> 7 mg/L). In black rhinos, serum ferritin was not different between health status categories (p = 0.5292), nor was it correlated with SAA (p = 0.4164). However, Cp activity was significantly lower in clinically healthy sera (p < 0.0001) and had a moderate positive association with SAA (r = 0.477, p < 0.0001). Among the white rhino samples, only five had SAA values greater than 1 mg/L, limiting the assessment of ferritin and Cp activity in the health context. Minor, yet significant, relationships were observed between serum ferritin and Cp activity, negative in black rhinos (r = -0.206; p = 0.0022) and positive in white rhinos (r = 0.289, p = 0.0008). Cp activity may aid in diagnosing illness in black and white rhinos, based on values observed in sera collected near the time of death. However, acute inflammatory processes do not appear to be one of the primary drivers of the high ferritin concentrations detected in some black rhinos.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"16-23"},"PeriodicalIF":1.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11802482/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142547962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2025-01-01Epub Date: 2024-11-08DOI: 10.1002/zoo.21877
Laura E Shipp, Nicole P Boisseau, Corinne P Kozlowski, Dustin W Shipp, Ashley D Franklin, Jilian M Fazio, Janine L Brown
{"title":"Positive Correlation Between Fecal Estrogen and Glucocorticoid Metabolites in a Female Clouded Leopard.","authors":"Laura E Shipp, Nicole P Boisseau, Corinne P Kozlowski, Dustin W Shipp, Ashley D Franklin, Jilian M Fazio, Janine L Brown","doi":"10.1002/zoo.21877","DOIUrl":"10.1002/zoo.21877","url":null,"abstract":"<p><p>Clouded leopards are notoriously difficult to manage under human care due to their tendency toward high stress, intersex aggression, and limited reproductive success. This case study investigated the endocrinological interplay between adrenal and ovarian steroids and describes a positive correlation between concentrations of fecal estrogen and glucocorticoid metabolites in a female clouded leopard. The female was monitored through two sampling periods approximately 16 months apart, and each data set yielded similar results using a simple linear regression model. The finding of a significant positive correlation between the two steroids represents a novel finding in felids and a hitherto unidentified potential interplay between adrenal and ovarian steroid activity. It also adds to our collective understanding of the effects of estrus on female clouded leopards, impacting conservation efforts as we encourage reproduction in this vulnerable species.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"98-101"},"PeriodicalIF":1.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11802478/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142606175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2025-01-01Epub Date: 2024-10-25DOI: 10.1002/zoo.21876
Justin Claude Rakotoarisoa, Andolalao Rakotoarison, Solonirina Rasoanantenaina, Eric Robsomanitrandrasana, Samina Sidonie Sam Edmonds, Jeanne Soamiarimampionona, Edupsie Tsimialomanana, Sebastian Wolf, Devin Edmonds
{"title":"Captive Breeding Reveals Insights Into the Ecology and Reproductive Biology of 11 Little-Known Malagasy Frog Species.","authors":"Justin Claude Rakotoarisoa, Andolalao Rakotoarison, Solonirina Rasoanantenaina, Eric Robsomanitrandrasana, Samina Sidonie Sam Edmonds, Jeanne Soamiarimampionona, Edupsie Tsimialomanana, Sebastian Wolf, Devin Edmonds","doi":"10.1002/zoo.21876","DOIUrl":"10.1002/zoo.21876","url":null,"abstract":"<p><p>Amphibians are facing an extinction crisis, with ex situ programs increasingly being used as a tool for their conservation. However, conservation efforts are often limited because we do not understand the ecological, behavioral, and life history traits of many amphibian species. Here, we report on the seasonal breeding patterns, egg-laying behavior, clutch size, and development of 11 frog species maintained at a conservation breeding facility in Andasibe, Madagascar. The frogs exhibited diverse breeding strategies aligned with life history theory. Counting the eggs in 1239 egg masses across these 11 species, we found endotrophic microhylids and terrestrial-breeding species had the smallest clutch size yet completed metamorphosis quickly, whereas species that laid eggs above or in water with exotrophic larvae had larger clutch sizes and took longer to develop. Most reproduction in captivity occurred during the warm, rainy season and followed seasonal patterns in temperature variation. Yet, Mantidactylus betsileanus bred throughout the year, and Heterixalus betsileo required additional environmental stimuli to trigger reproduction. Notably, we confirmed that Gephyromantis mitsinjo lays eggs on land with tadpoles developing terrestrially within jelly, a behavior previously theorized but which until now remained unobserved. Such observations show how captive breeding programs can be used to gain valuable data on the life history traits of species that are otherwise challenging to observe in nature. Our findings can be used to assess threats to closely related species, helping inform conservation efforts in a country harboring exceptional amphibian species richness and endemism.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"24-35"},"PeriodicalIF":1.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11802484/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2025-01-01Epub Date: 2024-11-26DOI: 10.1002/zoo.21869
D Cristina Macklem, Lauren Augustine, Mark D Wanner, Jeffery A Ettling, Trisha Crabill, Amanda S Pedigo, Chawna Schuette, Patty L Ihrig-Bueckendorf, Aja J Martin, Katie R Noble, Justin M Elden, Jeffrey T Briggler
{"title":"Egg Production, Egg Development, and Mortality of Zoo-Bred Ozark Hellbenders (Cryptobranchus alleganiensis bishopi).","authors":"D Cristina Macklem, Lauren Augustine, Mark D Wanner, Jeffery A Ettling, Trisha Crabill, Amanda S Pedigo, Chawna Schuette, Patty L Ihrig-Bueckendorf, Aja J Martin, Katie R Noble, Justin M Elden, Jeffrey T Briggler","doi":"10.1002/zoo.21869","DOIUrl":"10.1002/zoo.21869","url":null,"abstract":"<p><p>Populations of Ozark hellbenders (Cryptobranchus alleganiensis bishopi, Grobman 1943) in Missouri and Arkansas are federally listed as endangered. The Saint Louis Zoo WildCare Institute's Ron and Karen Goellner Center for Hellbender Conservation, in collaboration with the Missouri Department of Conservation and US Fish and Wildlife Service, has developed a sustainable conservation breeding and head-starting program, a priority for species recovery. Using 9 years of program data, we examined various egg production, egg development, and mortality responses of Zoo-bred Ozark hellbenders. Our results identified river of origin and breeding location as important predictors of egg production responses including average breeding female total lengths as well as brooding male clutch size, total egg count, and the estimated number of female clutches, respectively. We found that breeding group generation was a significant predictor of Zoo-bred hellbender egg development responses with hellbenders from the first breeding group generation ovipositing later and producing eggs that hatch later and develop longer than hellbenders from the second-generation breeding group. These responses are consistent with females from the first breeding group generation being larger at the time of reproduction. Breeding group generation was also a significant predictor of proportional egg and total mortality, while the proportion of hatchling mortality was best predicted by breeding location, and the proportion of larval mortality was best predicted by river of origin. Ultimately, our results provide baseline metrics for the program and identify areas for further inquiry to maximize the success of future conservation breeding and head-starting efforts at the Zoo.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"57-71"},"PeriodicalIF":1.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11802487/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142717153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2025-01-01Epub Date: 2024-10-22DOI: 10.1002/zoo.21874
Neil MacLachlan, Andrew Routh, Gordon Hunt, Alberto Barbon, Melissa Haworth, John Miller, Ann Pocknell, Eluned Price
{"title":"Diagnosis of Menopause in a Captive Sumatran Orangutan (Pongo abelii).","authors":"Neil MacLachlan, Andrew Routh, Gordon Hunt, Alberto Barbon, Melissa Haworth, John Miller, Ann Pocknell, Eluned Price","doi":"10.1002/zoo.21874","DOIUrl":"10.1002/zoo.21874","url":null,"abstract":"<p><p>Humans were long thought to be the only mammal to experience menopause, the permanent cessation of reproduction followed by a long post-reproductive lifespan. More recently, evidence has been found for the existence of menopause in other long-lived mammals, including chimpanzees and gorillas. However, orangutans, which have the longest interbirth interval of any primate, have rarely been studied in this period of their lives. In this paper, we describe clinical, ultrasound, endocrine, and histological evidence consistent with a natural menopause in a captive, previously fertile, Sumatran orangutan (Pongo abelii), aged approximately 50. Consecutive serum samples showed low levels of estradiol and high levels of follicle-stimulating hormone. Transvaginal ultrasound revealed an atrophic uterus with an antero-posterior diameter of 2.36 cm, an endometrial thickness of 2 mm, and inactive ovaries. Following this female's death from a subdural hematoma, histological examination of the ovaries showed a dense stroma with corpora albicantia, in comparison to the numerous primordial follicles seen in the ovaries of a stillborn infant female orangutan. These multiple lines of evidence suggest that Sumatran orangutans can now be added to the list of mammals which undergo a true menopause, which may ensure that females' final offspring can be reared to independence.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"87-91"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142476364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2024-11-01Epub Date: 2024-09-16DOI: 10.1002/zoo.21866
Tanya S Erzinçlioğlu, Georgina Groves, Samantha Ward
{"title":"An Analysis of Welfare Standards Within Tiger (Panthera tigris) Facilities in Thailand.","authors":"Tanya S Erzinçlioğlu, Georgina Groves, Samantha Ward","doi":"10.1002/zoo.21866","DOIUrl":"10.1002/zoo.21866","url":null,"abstract":"<p><p>In Thailand, tigers are more numerous in captivity than they are in the wild, with 51 facilities housing approximately 1962 tigers. As charismatic fauna, tigers are popular with tourists, and the majority of facilities offer a variety of entertainment activities with controversial reports towards the animals' welfare. The aim of this research was to investigate tiger welfare in Thai zoos to identify specific welfare issues. We assessed 34 tourism facilities holding tigers in Thailand in 2019 using a 25-point welfare assessment that utilizes the Five Domain model (incorporating all five domains: nutrition, physical environment, health, behavioural interactions and mental state). The mental domain score was derived from the scores of the other four domains. Additional data were collected from each facility, including the number of tigers, any colour variants, types of human interaction and admission cost. Welfare scores for each domain were calculated by totalling the scores per domain and dividing by the number of points allocated to that domain. A multiple regression was used to identify any significant predictors of mental domain score. The results revealed that the provision of a suitable physical environment scored the lowest, while nutrition scored the highest though this was still a low score overall. The multiple regression showed that 45.4% of the variance for the mental domain score was significantly affected by the number of colour variants housed and the types of human interaction available with facilities, with more of both these factors contributing to a more negative score. Our results demonstrate the need for urgent, comprehensive infrastructural, species-appropriate environment and design and animal management improvements to increase animal welfare. Informed institutional change toward the breeding and use of tigers for public interactions is also required. This is the first assessment completed of captive tiger welfare of tiger facilities in Thailand and shows that the welfare concerns encountered are within a high proportion (67%) of Thailand's facilities. This supports the need for the creation and enforcement of effective and clear captive wildlife operational standards to provide a sustained solution for captive tiger welfare and can provide a considered approach to ex-situ tiger management that, in conjunction with in-situ efforts, can improve much needed conservation efforts of this species.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"545-555"},"PeriodicalIF":1.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11624624/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142296986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2024-11-01Epub Date: 2024-09-25DOI: 10.1002/zoo.21864
Kristin Denryter, Kimberlee B Beckmen
{"title":"Suspected Case of Persistent Thiamin Deficiency in a Hand-Reared Caribou Calf.","authors":"Kristin Denryter, Kimberlee B Beckmen","doi":"10.1002/zoo.21864","DOIUrl":"10.1002/zoo.21864","url":null,"abstract":"<p><p>Hand-reared animals are invaluable and irreplaceable in studies of wildlife nutrition. Hand-rearing protocols provide insights into dietary and training programs, but less information is available on disease management. In young ruminants, thiamin (Vitamin B1) deficiency is a particularly important disease that is treatable early in the disease process, but otherwise can be fatal. In this husbandry report, we describe a case of suspected thiamin deficiency in a hand-reared calf (Rangifer tarandus granti) that resulted in clinical signs of polioencephalomalacia and persisted for > 3 months. We attempted treatment with thiamin injections; injections resolved clinical signs of disease, but clinical signs of disease returned once injections stopped. After > 2 months of thiamin injections, the caribou calf received a rumen transfaunation from a fistulated moose (Alces alces) housed at the same facility. Following rumen transfaunation, we did not observe signs of thiamin deficiency. The calf outgrew other females in the cohort initially and shows no long-term effects of thiamin deficiency or polioencephalomalacia. We recommend rumen transfaunation when thiamin deficiency is suspected and does not resolve with thiamin injections alone. We also recommend heterospecific donors if conspecific donors are not available.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"580-584"},"PeriodicalIF":1.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11624623/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2024-11-01Epub Date: 2024-09-20DOI: 10.1002/zoo.21862
Alison M Flanagan, Bryce Masuda, Jennifer Pribble, Kona Dancil, Tatum Kauka, Carina Tanaka, Hannah Bailey, Ronald R Swaisgood
{"title":"Starting From Scratch: Husbandry Techniques to Establish the First Population of 'Akikiki (Oreomystis bairdi) in Human Care Using Wild-Collected Eggs.","authors":"Alison M Flanagan, Bryce Masuda, Jennifer Pribble, Kona Dancil, Tatum Kauka, Carina Tanaka, Hannah Bailey, Ronald R Swaisgood","doi":"10.1002/zoo.21862","DOIUrl":"10.1002/zoo.21862","url":null,"abstract":"<p><p>Conservation breeding programs can save species from extinction by establishing assurance populations that provide individuals for achieving species recovery goals in the wild. However, keeping animals in human care can result in the selection of phenotypes that may be suboptimal for post-release survival and reproduction. It is therefore essential that conservation breeding programs provide animals with naturalistic conditions that facilitate the performance of species-typical behaviors, an endeavor that is also a vital aspect of animal welfare. Here, we describe how we established a conservation breeding program for the 'Akikiki (Oreomystis bairdi), a Hawaiian honeycreeper that is facing imminent extinction in the wild. We share how we utilized the species' native habitat as a template for developing husbandry practices with a primary focus on how we simulate wild environmental conditions in enclosures, mimic naturalistic foraging experiences, and facilitate pair bonding and parental breeding behaviors.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"585-589"},"PeriodicalIF":1.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11624620/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142296987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2024-11-01Epub Date: 2024-09-30DOI: 10.1002/zoo.21857
Leonie Fitskie, Jeroen Kappelhof, Filipe Cunha
{"title":"Effects of Random Feeding Schedule on Pacing in Asiatic Lions (Panthera leo persicus).","authors":"Leonie Fitskie, Jeroen Kappelhof, Filipe Cunha","doi":"10.1002/zoo.21857","DOIUrl":"10.1002/zoo.21857","url":null,"abstract":"<p><p>For large felids in the wild, intervals between feeding events are irregular since these depend on prey availability and individual hunting success. In contrast, many zoos feed their large felids on fixed schedules. Predictable feeding schedules could induce food anticipatory behavior, like pacing, and randomizing feeding schedules may reduce this anticipatory behavior. Furthermore, random feeding schedules create more variability in the animals environment, which may reduce frustration or boredom. This case study aimed to investigate the effects of a random feeding schedule on pacing behavior of captive Asiatic lions (Panthera leo persica) in the Rotterdam Zoo, The Netherlands. Study animals were observed directly under two treatments: \"fixed feeding\" (i.e., two fixed feeding days per week) and \"random feeding\" (i.e., two semi-randomly picked feeding days per week). Under the random feeding schedule, the mean pacing proportion of lions significantly decreased compared to the fixed feeding schedule. These findings suggest that a random feeding schedule could reduce pacing, either of anticipatory or stereotypic nature, in Asiatic lions. Random feeding schedules do pose a few logistic challenges, such as zookeeper schedules and transport or storage of feed. Nevertheless, random feeding could be a relatively inexpensive strategy to reduce pacing.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"590-594"},"PeriodicalIF":1.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11624625/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142355459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zoo BiologyPub Date : 2024-11-01Epub Date: 2024-09-06DOI: 10.1002/zoo.21865
Elisa Garand, Christiane Krauss, Dennis W H Müller, Leyla R Davis, Daryl Codron, Marcus Clauss, Flávia Miranda
{"title":"Larger Than Life? Body Mass Records of Zoo-Managed Giant Anteaters (Myrmecophaga tridactyla).","authors":"Elisa Garand, Christiane Krauss, Dennis W H Müller, Leyla R Davis, Daryl Codron, Marcus Clauss, Flávia Miranda","doi":"10.1002/zoo.21865","DOIUrl":"10.1002/zoo.21865","url":null,"abstract":"<p><p>It has been suggested repeatedly that zoo-kept giant anteaters (Myrmecophaga tridactyla) have higher body masses than their free-ranging conspecifics. Here, we assess this hypothesis by comparing body mass data of 184 female and 173 male individuals kept in zoos to published and unpublished data of free-ranging animals (n = 215). In zoos, the average adult body mass of all individuals was 45.9 ± 9.6 kg (range 19.2-72.6 kg), whereas body mass for free-ranging specimens was 33.0 ± 2.3 kg (21-45.5 kg). Among those zoo animals in which a sufficient number of subsequent intra-annual measures had been taken, we assessed visually whether regular, annual fluctuations in body mass were evident. We observed regular, likely seasonal, cycles in body mass, which (i) may be plausibly attributed to ambient temperature changes that affect the body temperature of anteaters, and (ii) would likely not have occurred if the animals were affected by obesity. Additionally, we explain our hypothesis that in the case of giant anteaters, the discrepancy in body mass between natural habitats and zoos most likely is not indicative of a generally obese population in zoos, as is typically concluded in the case of similar comparisons in primates, but represents an unleashing of the full growth potential of the species by conditions of optimal energy and nutrient provision. Future recording of not only body mass but also body dimensions is recommended to better compare the body condition of free-ranging and zoo-managed individuals.</p>","PeriodicalId":24035,"journal":{"name":"Zoo Biology","volume":" ","pages":"537-544"},"PeriodicalIF":1.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11624626/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142141175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}