Wild Iguanas Research Articles

Hand grab or noose pole? Evaluating the least stressful practice for capture of endangered Turks and Caicos Rock Iguanas Cyclura carinata.

As the analysis of blood metabolites has become more readily accessible thanks to the use of point-of-care analyzers, it is now possible to evaluate stress level of wild animals directly in the field. Lactate is receiving much attention as a good stress level proxy in individuals subjected to capture, manual restraint, and data sampling in the wild, and appropriate protocols to maintain lactate values low should be preferred. In this study we compare how two different capture methodologies, hand grab vs. noose pole, affect the variation of blood lactate values in Cyclura carinata iguanas when captured for sampling. We used blood lactate concentration, measured immediately upon- and 15 min after-capture, as a proxy for stress level. While the primary goal of this work is to determine the least stressful capture methodology to be favored when sampling this and other wild iguanas, we also evaluated additional baseline physiological parameters relevant to the health and disease monitoring for this species. Our results show that while initial lactate values level-out in sampled individuals after 15 min in captivity, regardless of the capture methodology, rock iguanas captured by noose pole showed significantly higher lactate concentration and increased heartbeat rate immediately after capture. While the overall health evaluation determined that all analyzed individuals were in good health, based on our results we recommend that, when possible, hand capture should be preferred over noose pole when sampling wild individuals.

First report and molecular identification of a reptilian tick, Amblyomma helvolum (Acari: Ixodidae), infesting wild green iguanas, Iguana iguana (Reptilia: Iguanidae), in southern Taiwan.

The genetic identity of the reptilian tick, Amblyomma helvolum, infesting wild green iguanas (Iguana iguana) in Taiwan, was examined. Genetic identity was determined by analyzing the 16S mitochondrial DNA gene sequences obtained from 11 Taiwan A. helvolum compared with other Amblyomma species, with two Dermacentor species and two Rhipicephalus species serving as outgroups. Phylogenetic analysis revealed that all the Taiwan specimens were genetically affiliated with a monophyletic group of A. helvolum and can be discriminated from other Amblyomma species. Our results provide the first genetic identification of adult A. helvolum ticks infesting wild iguanas in Taiwan. Further studies focused on the seasonal prevalence and vectorial capacity of A. helvolum for various tick-borne pathogens will help to clarify the epidemiological significance of this species and its impact on animal and human health in Taiwan.

Ecotourism causing northern Bahamian rock iguana's sugar high

As the old English saying goes, ‘a little of what you fancy does you good’, but the current human type 2 diabetes epidemic suggests that you can have too much of a good thing. ‘A prolonged high sugar diet can “exhaust” the ability to regulate blood glucose’, says Susannah French from Utah State University, USA. In addition, the human obsession with feeding wildlife may be placing other species at risk from unbalanced diets: ‘Catalina Monzon-Arguello and colleagues discovered in 2018 that juvenile green sea turtles in the Canary Islands have high fat and cholesterol levels in their blood as a result of being fed by tourists’, says French. Northern Bahamian rock iguanas on the Exuma Islands are also familiar with sightseers. ‘Many visitors take day boat trips to visit and feed the iguanas’, says French, explaining that the tourists ply the iguanas with grapes. The question was how much of an impact the sugar-charged diet is having on the reptiles’ health? But first, Dale Denardo from Arizona State University, USA and French needed to know how captive iguanas would respond to a high sugar diet.‘We chose to study the more common green iguana in the lab, because rock iguanas are critically endangered’, says French, who supplemented the youngsters’ usual ‘Tortoise Diet’ and greens meals with either a high (5 g kg−1) or low (2.5 g kg−1) glucose drink. ‘The low dose provides glucose in an amount similar to that found in consumed grapes’, says Denardo. Then, after 17 days, he gave each iguana an intermediate strength glucose drink (3.75 g kg−1) and monitored the animals’ blood glucose over the following 2 days. The reptiles’ glucose levels peaked 3 h after consuming the sugar; however, the iguanas that had been fed the high glucose diet had the most difficulty regulating their blood sugar levels, reaching ∼520 mg dl−1, in contrast to iguanas that had been fed Tortoise Diet and greens alone, whose levels peaked at only ∼420 mg dl−1. A high glucose diet seemed to impact the captive iguanas’ ability to regulate their blood glucose levels after a meal. But what about the wild iguanas on the Exuma Islands?French, Denardo and colleagues from various institutions from the USA travelled to the remote islands. ‘When we pull up onto picturesque sandy beaches on the tourist islands, the sound of the boat motors draws the iguanas down, but landing on the islands where tourists do not travel requires carefully timing your jump from the boat’, French recalls. Gently capturing 48 rock iguanas, 24 from islands frequented by tourists and another 24 from islands that are too rugged for tourists to reach, the team fed each iguana a glucose drink and monitored their blood sugar responses for almost a day; the results were concerning. The iguanas from one island where they are fed frequently by tourists experienced the highest glucose peak ∼570 mg dl−1 after 5 h, remaining high 8 h later, although the grape-fed iguanas from another island had a less extreme response (∼505 mg dl−1 after 5 h). In contrast, the blood sugar of the iguanas from the islands that rarely see tourists was much lower (peaking at ∼450 mg dl−1), rose at a slower rate and returned to normal more quickly.Ecotourists feeding the wild iguanas on the Exuma Islands are definitely affecting the iguanas physically. Now, the question is whether they are also affecting the animals’ health. ‘If these were humans, we would be talking about diabetes; however, it is not yet clear what the health implications are here. That is something we are continuing to work on’, says French.

Gut microbial ecology of the Critically Endangered Fijian crested iguana (Brachylophus vitiensis): Effects of captivity status and host reintroduction on endogenous microbiomes.

Animals often exhibit distinct microbial communities when maintained in captivity as compared to when in the wild. Such differentiation may be significant in headstart and reintroduction programs where individuals spend some time in captivity before release into native habitats. Using 16S rRNA gene sequencing, we (i) assessed differences in gut microbial communities between captive and wild Fijian crested iguanas (Brachylophus vitiensis) and (ii) resampled gut microbiota in captive iguanas released onto a native island to monitor microbiome restructuring in the wild. We used both cloacal swabs and fecal samples to further increase our understanding of gut microbial ecology in this IUCN Critically Endangered species. We found significant differentiation in gut microbial community composition and structure between captive and wild iguanas in both sampling schemes. Approximately two months postrelease, microbial communities in cloacal samples from formerly captive iguanas closely resembled wild counterparts. Interestingly, microbial communities in fecal samples from these individuals remained significantly distinct from wild conspecifics. Our results indicate that captive upbringings can lead to differences in microbial assemblages in headstart iguanas as compared to wild individuals even after host reintroduction into native conditions. This investigation highlights the necessity of continuous monitoring of reintroduced animals in the wild to ensure successful acclimatization and release.

PARASITES OF THE BLUE IGUANA (CYCLURA LEWISI) FROM GRAND CAYMAN ISLAND.

Feces (n = 226; 2004-2015) from healthy captive and wild blue iguanas (Cyclura lewisi) from Grand Cayman, Cayman Islands, were examined for endoparasites. Parasites identified included Nyctotherus sp. and Entamoeba sp. cysts and trophozoites, trichomonad trophozoites, and oxyurid and trichostrongylid eggs. Endoparasites from postmortem examinations (n = 13) included adult and larval nematodes: Ozolaimus megatyphlon, Ozolaimus monhystera, Alaeuris travassosi, Atractis mega, and an unidentified species of Oswaldocruzia. Entamoeba spp. were more likely in captive juveniles of both sexes than captive or wild adults of either sex; Entamoeba spp. were more likely in captive adult females than captive adult males; trichomonad trophozoites were more likely in adult captive and wild iguanas of both sexes than in captive juveniles of either sex; and Nyctotherus spp. were more likely in juvenile captive males than captive adult males or females and more likely in adult wild males than captive juvenile males. Trichostrongylid eggs were more likely in adult wild females than adult captive females and more likely in captive and wild adults of both sexes than in captive juveniles of both sexes. Oxyurid eggs were more likely in adult captive and wild iguanas of both sexes than captive juveniles of either sex. Blue iguanas have a variety of endoparasites regardless of age, sex, or captive vs wild status, with no type found exclusively in either captive or wild populations. Ectoparasites from wild adults included adult ticks (Amblyomma torrei) and a single adult mite (Hirstiella trombidiformis). All are new host records for this species and Grand Cayman. Knowledge of parasite status of captive and wild populations is important to evaluate the relative risk of introduction of captive animals into wild populations.

PREVALENCE, INCIDENCE, AND IDENTIFICATION OF SALMONELLA ENTERICA FROM WILD AND CAPTIVE GRAND CAYMAN IGUANAS ( CYCLURA LEWISI).

From 2005 to 2017, a total of 334 fresh fecal samples was obtained from 236 captive and free-ranging Grand Cayman iguanas ( Cyclura lewisi) in a captive breeding and release program. One-hundred-sixteen samples were obtained from individual captive iguanas living in enclosures with natural substrate, 161 samples from captive iguanas living in elevated wire-bottom enclosures, and 57 samples from free-ranging wild iguanas. These samples were cultured to isolate subspecies of Salmonella enterica. as part of prerelease health evaluations, and to determine baseline health assessments of captive and wild populations of these iguanas. There was a 5.45% (95% confidence interval [CI]: 1.14-15.12) prevalence of S. enterica in iguanas housed on natural substrate ( n = 51), 3.85% (CI: 1.42-8.19) in iguanas housed in elevated wire-bottom enclosures ( n = 157), and 6.06% (CI: 0.74-20.23) in wild free-ranging iguanas ( n = 38). These results demonstrate no significant difference ( P = 0.73) in S. enterica prevalence among these housing conditions. The incidence of S. enterica from 2005 to 2017 in the population sampled was 4.19% (CI 3.10-5.29). Ten different serotypes of S. enterica were isolated from 14 iguanas. Salmonella enterica ser. Saintpaul was the most frequent isolate. Annual S. enterica prevalence was calculated for iguanas housed in different enclosure types, for free-roaming wild iguanas, and for all cultured iguanas. The highest yearly prevalence was 23.08% (CI: 5.04-53.81) in iguanas tested in 2007 ( n = 21). No Salmonella enterica were cultured in 2005, 2008, 2009, 2010, 2011, 2012, and 2015. These results suggest that the shedding of S. enterica was not significantly different between housing types or between captive versus wild iguanas and therefore that release of captive iguanas did not significantly affect the health of the wild population or their exposure to S. enterica.

The Madagascan spiny-tailed iguana alters the sequence of anti-predator responses depending on predator types

Some prey are able to avoid specific predators by altering defensive behaviours depending on predator type. In the Ampijoroa forest of Ankarafantsika National Park in Madagascar, Madagascan spiny-tailed iguanas (Oplurus cuvieri cuvieri) inhabit a species rich vertebrate community and are exposed to multiple potential predators, such as raptors and snakes. We examined the response of wild iguanas to visual stimuli of avian and serpent predators by presenting iguanas with either a hawk or snake model. In most cases, the iguanas fled following contact with the hawk model. Exposure to the snake model also mostly resulted in the iguanas fleeing, but this response was preceded by other behaviours (e.g. push-up and dewlapping) that were not exhibited in response to the hawk model. Our results suggest that the spiny-tailed iguana adaptively alters anti-predator responses depending on the hunting methods and risk level of the immediate predators.

Helmintos oxiuridae parasitos de Iguana iguana (Squamata, Lacertilia, Iguanidae) procedentes do Brasil

The results of a study on nematode fauna occurring in wild iguanas (Iguana iguana) from Brazilian Northeast (Alagoas and Maranhao) and Central-west (Goias and Mato Grosso) areas were presented. Six adult iguanas, three males and three females, were necropsied and the digestive system removed to examination. All the iguana specimens were heavily parasitized. The helminths diagnosed were: Ozolaimus cirratus in the cecum and colon of five iguanas; Ozolaimus megatyphlon in cecum, colon and rectum of three iguanas; and Alaeuris vogelsangi in the small intestine, cecum, colon and rectum of five animals. Two larvae of Ozolaimus sp. were recovered from the pyloric region of the stomach of one iguana. The three diagnosed species of nematodes were reported for the first time in the Brazilian Central-West region.

Using microsatellite diversity in wild Anegada iguanas (Cyclura pinguis) to establish relatedness in a captive breeding group of this critically endangered species

Awareness of the genealogical relationships between founder animals in captive breeding programs is essential for the selection of mating pairs that maintain genetic diversity. If captive founder relationships are unknown they can be inferred using genetic data from wild populations. Here, we report the results of such an analysis for six Cyclura pinguis (Sauria: Iguanidae) acquired as adults in 1999 by the San Diego Zoo Institute for Conservation Research to begin a captive breeding program for this critically endangered species. The six founder animals were reportedly hatched in captivity from eggs collected on Anegada in 1985. No records exist, however, as to where on Anegada the eggs were collected or from how many nests they originated. To assist determination of genealogical relationships, we genotyped the six captive founders, their first six offspring, and 33 wild adult iguanas from Anegada at 23 informative microsatellite loci. With these data, we estimated allele frequencies among the wild samples and then estimated the relatedness of the captive population. Using likelihood inference, we determined that three closely related pairs exist among the six captive founders and that each pair is not closely related to the other two. In addition, we were able to assign parentage for all six of the founders’ offspring tested, one of which had been previously misdiagnosed. Using the assigned parentage and inferred relatedness of the six founders, we calculated mean kinship for each of the six founders and their five living offspring. Finally, based on the allelic diversity of the wild iguanas sampled, we conclude that the C. pinguis population on Anegada is not excessively inbred; however, further investigation is warranted.

Evaluating headstarting as a management tool: Post-release success of green iguanas (Iguana iguana) in Costa Rica

Headstarting has become a popular tool employed by wildlife managers to help animal species, specifically those lacking or providing minimal parental care-offset extinction. However, many researchers challenge the conservation value of headstarting and urge proponents to monitor headstarted individuals following release into the wild to evaluate the success of headstart programs. As part of an experimental headstarting program managed by the Iguana Verde Foundation in Costa Rica, we conducted a 1.5-month radiotelemetry study of 11 headstarted 2 year old green iguanas (Iguana iguana) following their release into the wild at the Gandoca-Manzanillo Wildlife Refuge. Headstarted iguanas were compared to their wild counterparts (two radiotelemetered and 18 opportunistically-encountered) with respect to changes in growth, arboreal microhabitat use, social aggregation, activity ranges and movements. Male and female headstarted iguanas exhibited similar behaviours and headstarted iguanas were similar to wild iguanas for most variables measured. Thus, the headstarted green iguanas were clearly capable of short-term (1.5-month) survival in the wild and their apparently normal behaviours reflected the suitable conditions under which they were raised. The results provide insight into the ecology of green iguanas and will help guide headstarting and reintroduction programs for iguanas at this location and endangered iguanas elsewhere. Key words: Captive-breeding, conservation, headstarting, home range, lizard, radiotelemetry, reptilian, spatial use.

Do headstart programs work? Survival and body condition in headstarted Mona Island iguanas Cyclura cornuta stejnegeri

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 6:55-65 (2008) - DOI: https://doi.org/10.3354/esr00130 Do headstart programs work? Survival and body condition in headstarted Mona Island iguanas Cyclura cornuta stejnegeri Néstor Pérez-Buitrago1,2,3,*, Miguel A. García2,3, Alberto Sabat1, Johanna Delgado4, Alberto Álvarez3, Owen McMillan1,2, Stephan M. Funk1,2,5,* 1Center for Applied Tropical Ecology and Conservation, University of Puerto Rico – Río Piedras, San Juan, Puerto Rico 00931, USA 2Department of Biology, University of Puerto Rico – Río Piedras, San Juan, Puerto Rico 00931, USA 3Department of Natural and Environmental Resources, Wildlife Division, San Juan, Puerto Rico 00906, USA 4Texas A&M University – Kingsville, Caesar Kleberg Wildlife Research Institute, Kingsville, Texas 78363, USA 5Durrell Wildlife Conservation Trust, Les Augres Manor, Trinity, Jersey JE3 5BP, Channel Islands *Corresponding authors: Email: yani@yahoo.com, stephan.funk@durrell.org ABSTRACT: Headstarting refers to the raising of hatchlings in captivity and subsequently releasing them into the wild and it is a widely used tool to protect endangered species by increasing survivorship. Evaluating the success of headstart programs is necessary but challenging. We evaluated a headstart program for the endangered Mona Island iguana Cyclura cornuta stejnegeri by analyzing demographic and spatial data and by comparing growth rate, body condition, and external parasitic load of headstarted and wild iguanas. Hatchlings were released at about 3 yr age. Minimum survival rate was 40.3 %, at 7.6 to 48.3 mo after release. Most migrated from the release site back to the rearing facilities about 633 m away. Density around the rearing facility increased from 7.5 to 11.5 iguanas ha–1 (25 of 75 captures were headstarted iguanas). Released headstarted iguanas exhibited growth rates similar to the maxima observed in captive and wild mid-sized iguanas. Growth rates decreased immediately prior to release, indicating that husbandry practices ought to be reviewed. There was no evidence for an effect of captivity on susceptibility to external parasites. Increased local density indicates that the program was successful. However, the longer-term success remains unknown, as most headstarted iguanas returned to the headstart facility without establishing territories typical for adult wild Mona iguanas. KEY WORDS: Conservation management · Headstarting · Reintroduction · Rock iguana · Cyclura · Mona Island · Caribbean· Puerto Rico Full text in pdf format PreviousNextCite this article as: Pérez-Buitrago N, García MA, Sabat A, Delgado J, Álvarez A, Mcmillan O, Funk SM (2008) Do headstart programs work? Survival and body condition in headstarted Mona Island iguanas Cyclura cornuta stejnegeri. Endang Species Res 6:55-65. https://doi.org/10.3354/esr00130 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 6, No. 1. Online publication date: October 14, 2008 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2008 Inter-Research.

Do headstart programs work? Survival and body condition in headstarted Mona Island iguanas Cyclura cornuta stejnegeri

Headstarting refers to the raising of hatchlings in captivity and subsequently releasing them into the wild and it is a widely used tool to protect endangered species by increasing survivor- ship. Evaluating the success of headstart programs is necessary but challenging. We evaluated a headstart program for the endangered Mona Island iguana Cyclura cornuta stejnegeri by analyzing demographic and spatial data and by comparing growth rate, body condition, and external parasitic load of headstarted and wild iguanas. Hatchlings were released at about 3 yr age. Minimum survival rate was 40.3 %, at 7.6 to 48.3 mo after release. Most migrated from the release site back to the rear- ing facilities about 633 m away. Density around the rearing facility increased from 7.5 to 11.5 iguanas ha -1 (25 of 75 captures were headstarted iguanas). Released headstarted iguanas exhibited growth rates similar to the maxima observed in captive and wild mid-sized iguanas. Growth rates decreased immediately prior to release, indicating that husbandry practices ought to be reviewed. There was no evidence for an effect of captivity on susceptibility to external parasites. Increased local density indi- cates that the program was successful. However, the longer-term success remains unknown, as most headstarted iguanas returned to the headstart facility without establishing territories typical for adult wild Mona iguanas.

Spatial Ecology of the Endangered Iguana, Cyclura lewisi, in a Disturbed Setting on Grand Cayman

Abstract West Indian rock iguanas (genus Cyclura: Iguanidae) are among the most endangered lizards in the world, and many species will need to occupy human-modified and -occupied habitats to escape extinction. The Grand Cayman Blue Iguana, Cyclura lewisi, is critically endangered with fewer than 25 wild iguanas remaining. To aid the conservation of this and other iguanas, we investigated the spatial ecology of a captive-bred, released population of C. lewisi occupying a botanic park on Grand Cayman. Iguanas were monitored using transect walks and radio telemetry during the summer and fall of 2002. Males used larger areas and had greater movement distances than females during tracking periods in the summer but not in the fall. Overall home ranges for both seasons combined were larger in males than in females. Some home-range estimates were greater than any previously reported in Cyclura. Several iguanas, especially males during the breeding season, used areas outside the park where they are vulnerable to i...

Paramyxoviral and reoviral infections of iguanas on Honduran Islands.

Thirty-five free-ranging healthy spiny-tailed iguanas (31 Ctenosaura bakeri, 4 C. similis) and 14 green iguanas (Iguana iguana rhinolopha) were caught and held in captivity for 2 days. Blood was collected from all animals and their sera were evaluated for antibody titres against reptilian reoviruses, reptilian paramyxoviruses, and avian paramyxovirus-1 (PMV-1). Cloacal and pharyngeal swabs also were collected and examined for viral content by incubation on chicken embryo fibroblasts (CEF) and terrapene heart cells (TH-1). No virus was isolated from the pharyngeal and cloacal swabs on CEF and TH-1. Twenty-three (47%) of 49 sera samples tested positive for reptilian reoviruses by virus neutralization tests. Twenty (41%) of 49 samples had antibodies against one reptilian PMV isolate by virus neutralization tests and 3 (9%) of 34 by hemagglutination inhibition tests. No antibodies were detected against the other PMV isolate of reptilian origin nor against avian PMV-1. This is the first description of serum antibodies against reptilian reoviruses and PMV in wild iguanas.