Age and body size of captive hawksbill turtles at the onset of follicular development

Kawazu, Isao; Kino, Masakatsu; Maeda, Konomi; Teruya, Hideshi

doi:10.1002/zoo.21190

Cited by 5 publications

(2 citation statements)

References 17 publications

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“…LAG compaction consistent with rapprochement has been identified in adult female and male loggerhead, Kemp's ridley, and leatherback Dermochelys coriacea sea turtles, allowing estimation of ASM and SSM as the ages and SCLs associated with rapprochement LAGs, as well as post-maturation longevity from LAG counts following rapprochement (Avens et al , 2017(Avens et al , 2020a. Encouragingly, Kawazu et al (2015) documented a significant reduction in somatic growth associated with maturation in captive hawksbills, which should manifest as a significant decrease in LAG spacing, given the interrelatedness of SCL and HSD (Avens et al 2012(Avens et al , 2017. Unfortunately, lack of samples from larger turtles in the current study did not allow for comprehensive analysis of rapprochement-related characteristics, and as a result, our estimates of initial ASM (15− 25 yr) may be skewed lower than the true range of total possible ASMs for the population as a whole.…”

Section: Oceanic Stage Duration and Age At Maturationmentioning

confidence: 93%

Hawksbill sea turtle life-stage durations, somatic growth patterns, and age at maturation

Avens

Ramirez

Goshe

et al. 2021

Endang. Species. Res.

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Sea turtles exhibit complex life histories, encompassing intermittent use of multiple spatially separated habitats throughout long lifespans. This broad scope presents challenges for collecting comprehensive biological and ecological data, yet absence of such information complicates evaluation of management strategies for populations at risk of extinction. Hawksbill sea turtles Eretmochelys imbricata are endangered worldwide, primarily due to long-term, directed harvest. However, available information regarding life stage durations, somatic growth patterns, and maturation attributes to enhance understanding of anthropogenic impacts and recovery potential remains constrained. To address these data gaps in the western North Atlantic, we conducted skeletochronological analysis for hawksbills stranded along US coastlines to generate straight-line carapace length (SCL)-at-age and somatic growth data. Generalized additive mixed models and bootstrapped von Bertalanffy growth curves were used to characterize age at maturation and covariate influence on somatic growth. For a subset of turtles, annual bone growth increment-specific stable isotope and trace element analyses were incorporated to evaluate habitat use relative to age. Integration of these data sources indicated that juveniles transitioned from oceanic to neritic habitat at 1-3 yr old and mean SCLs of 23-24 cm (range 15.7-35.0 cm). Initial ages at maturation for this population at minimum nesting female SCLs were estimated at 15-25 yr. Somatic growth varied significantly relative to size, age, and stranding location, while no association with sex or calendar year was observed. Our results demonstrate the utility of these complementary analytical approaches for generating baseline data fundamental to characterizing hawksbill sea turtle population attributes.

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Section: Oceanic Stage Duration and Age At Maturationmentioning

confidence: 93%

Hawksbill sea turtle life-stage durations, somatic growth patterns, and age at maturation

Avens

Ramirez

Goshe

et al. 2021

Endang. Species. Res.

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“…The water temperature of the tanks ranged from 20 to 30°C throughout the 12-month study period, i.e., it was maintained at a thermal range similar to that experienced by hawksbill turtles under natural conditions (sea surface temperature) around Okinawa Island (26°30 N, 127°00 E). The turtles were identified as females after this study based on observed follicular development (Kawazu et al, 2015). The turtles were fed once daily; their diet included fish, shrimp, and squid, at 0.5-2% of their body mass.…”

Section: Study Animalsmentioning

confidence: 99%

Rock Installation Reduces Aggressive Behavior in Captive Hawksbill Turtles

Kawazu

Suzuki

Maeda

2022

Current Herpetology

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Are we working towards global research priorities for management and conservation of sea turtles?

Rees¹,

Alfaro‐Shigueto²,

Barata³

et al. 2016

Endang. Species. Res.

248

161

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In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. To obtain a picture of how research is being focused towards these key questions, we undertook a systematic review of the peer-reviewed literature (2014 and 2015) attributing papers to the original 20 questions. In total, we reviewed 605 articles in full and from these 355 (59%) were judged to substantively address the 20 key questions, with others focusing on basic science and monitoring. Progress to answering the 20 questions was not uniform, and there were biases regarding focal turtle species, geographic scope and publication outlet. Whilst it offers some meaningful indications as to effort, quantifying peer-reviewed literature output is ob viously not the only, and possibly not the best, metric for understanding progress towards informing key conservation and management goals. Along with the literature review, an international group based on the original project consortium was assigned to critically summarise recent progress towards answering each of the 20 questions. We found that significant research is being expended towards global priorities for management and conservation of sea turtles. Although highly variable, there has been significant progress in all the key questions identified in 2010. Undertaking this critical review has highlighted that it may be timely to undertake one or more new prioritizing exercises. For this to have maximal benefit we make a range of recommendations for its execution. These include a far greater engagement with social sciences, widening the pool of contributors and focussing the questions, perhaps disaggregating ecology and conservation.

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Age and body size of captive hawksbill turtles at the onset of follicular development

Cited by 5 publications

References 17 publications

Hawksbill sea turtle life-stage durations, somatic growth patterns, and age at maturation

Hawksbill sea turtle life-stage durations, somatic growth patterns, and age at maturation

Rock Installation Reduces Aggressive Behavior in Captive Hawksbill Turtles

Are we working towards global research priorities for management and conservation of sea turtles?

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