ORCID Profile
0000-0001-7541-9584
Current Organisations
University of Western Australia
,
Australian National University
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Publisher: Frontiers Media SA
Date: 2016
Publisher: Frontiers Media SA
Date: 11-2019
Publisher: Bulletin of Marine Science
Date: 2016
Publisher: Wiley
Date: 12-06-2023
DOI: 10.1111/JFB.15464
Abstract: Sharks are an important attraction for aquaria however, larger species can rarely be kept indefinitely. To date, there has been little work tracking shark movements post‐release to the wild. The authors used high‐resolution biologgers to monitor a sub‐adult tiger shark's pre‐ and post‐release fine‐scale movements following 2 years of captivity in an aquarium. They also compared its movement with that of a wild shark tagged nearby. Despite the differences in movement between the two sharks, with vertical oscillations notably absent and greater levels of turning seen from the released shark, the captive shark survived the release. These biologgers improve insight into post‐release movements of captive sharks.
Publisher: Wiley
Date: 14-09-2021
DOI: 10.1111/ECOG.05953
Abstract: Animals follow specific movement patterns and search strategies to maximize encounters with essential resources (e.g. prey, favourable habitat) while minimizing exposures to suboptimal conditions (e.g. competitors, predators). While describing spatiotemporal patterns in animal movement from tracking data is common, understanding the associated search strategies employed continues to be a key challenge in ecology. Moreover, studies in marine ecology commonly focus on singular aspects of species' movements, however using multiple analytical approaches can further enable researchers to identify ecological phenomena and resolve fundamental ecological questions relating to movement. Here, we used a set of statistical physics‐based methods to analyze satellite tracking data from three co‐occurring apex predators (tiger, great hammerhead and bull sharks) that predominantly inhabit productive coastal regions of the northwest Atlantic Ocean and Gulf of Mexico. We analyzed data from 96 sharks and calculated a range of metrics, including each species' displacements, turning angles, dispersion, space‐use and community‐wide movement patterns to characterize each species' movements and identify potential search strategies. Our comprehensive approach revealed high interspecific variability in shark movement patterns and search strategies. Tiger sharks displayed near‐random movements consistent with a Brownian strategy commonly associated with movements through resource‐rich habitats. Great hammerheads showed a mixed‐movement strategy including Brownian and resident‐type movements, suggesting adaptation to widespread and localized high resource availability. Bull sharks followed a resident movement strategy with restricted movements indicating localized high resource availability. We hypothesize that the species‐specific search strategies identified here may help foster the co‐existence of these sympatric apex predators. Following this comprehensive approach provided novel insights into spatial ecology and assisted with identifying unique movement and search strategies. Similar future studies of animal movement will help characterize movement patterns and also enable the identification of search strategies to help elucidate the ecological drivers of movement and to understand species' responses to environmental change.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Inter-Research Science Center
Date: 23-08-2018
DOI: 10.3354/MEPS12671
Publisher: Wiley
Date: 23-04-2015
DOI: 10.1111/JFB.12671
Abstract: The objective of this study was to determine the size and maturity status of the male blue sharks Prionace glauca attempting to mate with small, immature females in the north-west Atlantic Ocean. The relationship between male curved fork length (LFC ) and jaw gape was used in conjunction with the diameter of the mating scar to estimate the LFC and infer the maturity status of the male shark that produced the mating scar. The results indicate that mature males with a mean ± s.d. LFC of 218 cm ± 23 cm were attempting to mate with sexually immature females.
Publisher: Wiley
Date: 16-07-2019
DOI: 10.1002/EAP.1947
Abstract: Telemetry is a key, widely used tool to understand marine megafauna distribution, habitat use, behavior, and physiology however, a critical question remains: "How many animals should be tracked to acquire meaningful data sets?" This question has wide-ranging implications including considerations of statistical power, animal ethics, logistics, and cost. While power analyses can inform s le sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different s le sizes. We considered s le sizes from one to >100 in iduals and synthesized empirical findings, detailing the information that can be gathered with increasing s le sizes. We complement this review with simulations, using real data, to show the impact of s le size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance s le sizes and broaden the range, scale, and scope of questions that can be answered.
Publisher: American Society of Ichthyologists and Herpetologists (ASIH)
Date: 18-12-2012
DOI: 10.1643/CE-11-012
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.BBR.2015.03.003
Abstract: Androgen deprivation in males has detrimental effects on various tissues and bodily functions, some of which can be restored by estradiol (E2) administration. We investigated how the duration of androgen deprivation affects the autoregulation of estrogen receptors (ERs) levels in core brain areas associated with sexual behavior and cognition, as well as in pelvic floor muscles (PFM). We also measured c-Fos levels in brain areas associated with sexual behavior shortly after the rats mated. Prolonged castration increases ERα levels in the preoptic area (POA) and E2 treatment reverses these effects. In the POA, c-Fos levels after mating are not affected by the duration of androgen deprivation and/or E2 treatment. ERβ levels in the POA as well as c-Fos levels in the POA and the core area of nucleus accumbens correlate with the mounting frequency for E2-treated Short-Term castrates. Additionally, ERβ levels in the medial amygdala are positively correlated with the mounting frequency of Long-Term castrates that received E2 treatment. In the hippoc us, ERs are downregulated only when E2 is administered early after castration, whereas downregulation of ERα in the prefrontal cortex only occurs with delayed E2 treatment. Early, but not delayed, E2 treatment after castration increases ERβ levels in the bulbocavernosus and ERα levels in the levator ani of male rats. Our data suggest that the duration of androgen deprivation may influence the autoregulation of ERs by E2 treatment in select brain areas and pelvic floor muscles of male rats.
Publisher: Public Library of Science (PLoS)
Date: 22-08-2017
No related grants have been discovered for Hannah Calich.