ORCID Profile
0000-0001-9214-8958
Current Organisations
University of Western Australia
,
Murdoch University
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Publisher: Wiley
Date: 03-2004
Publisher: Wiley
Date: 07-1998
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/MF12139
Abstract: Using 20 years of data (1986 to 2008), we examined relationships between oceanographic variables (Fremantle sea level (FSL) – a proxy for the strength of the Leeuwin Current – and sea surface temperature (SST)) and five measures of little penguin, Eudyptula minor, breeding performance near Perth, Western Australia: namely (1) the laying date, (2) the number of chicks produced per pair, (3) the proportion of eggs that hatched, (4) the overall breeding success, defined as the proportion of total eggs laid that resulted in successful fledglings and (5) chick mass at fledging. The next three years of data (2009 to 2011) were used to test the performance of our statistical predictive models. FSL provided more accurate predictions of timing of laying, whereas SST provided more accurate predictions of breeding success. A later end to laying was associated with a high FSL during the summer (December to February) before breeding. Higher SSTs in the pre-breeding period from April to May corresponded to reduced breeding success, with lower fledgling success, fewer chicks per pair and generally a lower mean mass of chicks at fledging. The models predict that future oceanographic warming is expected to reduce the breeding success of this colony of little penguins.
Publisher: Springer Science and Business Media LLC
Date: 06-01-2006
Publisher: American Association for the Advancement of Science (AAAS)
Date: 28-05-2021
Abstract: The vastness of the worlds' oceans makes them difficult to monitor. Seabirds that forage and breed across oceans globally have been recognized as sentinels of ocean health. Sydeman et al. looked across seabird species of both the Northern and Southern Hemispheres and found varying patterns. Northern Hemisphere species exhibited greater signs of stress and reduced breeding success, indicative of low fish resources. Southern Hemisphere species showed less impact on reproductive output, suggesting that the fish populations there have thus far been less disturbed. The differences across hemispheres indicate different strategies for conservation, with active recovery needed in the north and enhanced protection in the south. Science , abf1772, this issue p. 980
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.VETPAR.2013.04.025
Abstract: One hundred and thirty four Little Penguin (Eudyptula minor) carcases found since 2004 in south west Australia were necropsied. The livers and spleens from ten of the penguins exhibited varying degrees of multifocal, randomly scattered areas of necrosis and varying numbers of parasites were associated with these areas. Hepatomegaly and splenomegaly were noted in many of these ten cases. Necrosis and parasites were also observed in the cardiac muscle of four of the cases and in the lung tissue in one of the penguins. Using PCR, the parasites were positively identified in four of the cases as Haemoproteus spp. and morphologically identical tissue stage parasites associated with histopathological changes were observed in all ten dead penguins. This is the first study to demonstrate both the in situ presence of the Haemoproteus parasite in any member of the Sphensicidae family and mortality due to its presence. We postulate the involvement of anomalous environmental conditions in a potential increase in local vectors.
Publisher: Elsevier BV
Date: 2007
DOI: 10.1016/J.YHBEH.2006.08.002
Abstract: The effects of social stimuli on avian reproductive behaviors such as breeding schedules and courtship behaviors are well known due to numerous field studies. However, studies that have simultaneously examined the effects of social stimuli on reproductive behavior and the mediating endocrine mechanisms have been largely restricted to captive populations, which may not be representative of free-living populations. This study, conducted over two breeding seasons, aimed to simultaneously measure the effects of experimentally increasing auditory stimuli on the breeding schedule and endocrinology (levels of total androgen, estradiol, progesterone and prolactin) on free-living yellow-eyed penguins (Megadyptes antipodes). The yellow-eyed penguin is the least colonial of all penguins, nesting far apart from each other under dense vegetation, and, therefore, is presumed to experience much lower levels of social stimuli than other penguins. Egg laying was significantly more synchronous and tended to be earlier when birds were exposed to playbacks of the calls of conspecifics in 1 year of the study. We also found that levels of total androgen and estradiol of males in 1 year, and prolactin in another year, were proportionally higher among treated birds compared control birds that received no artificial auditory stimuli. These results show that even among supposedly solitary nesters, social stimuli could still play a role in influencing reproductive behavior and physiology. For the first time in free-living seabirds, we have demonstrated that behavioral responses to increased social stimuli are associated with hormonal changes.
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/WR11042
Abstract: Context Penguin Island supports the largest colony of little penguins in Western Australia. It is subjected to a suite of anthropogenic threats because of its proximity to an increasing urban population. For effective management of the colony, it is necessary to not only have knowledge of the size of the colony, but also the population trend of the colony. Aims To demonstrate a new cost-effective method of estimating the island-wide population of penguins on Penguin Island. Methods We estimated the island-wide population by combining mark–recapture s ling over 2 years on part of the island and beach counts of penguins arriving at night around the entire island. We estimated the abundance using closed population models, allowing for sex and time effects in capture probabilities. We had four capture occasions in 2008 only, and so considered heterogeneity of capture probabilities (Mh), using the Chao heterogeneity moment estimator. The proportion of all penguins counted that arrived at the four mark–recapture sites was then used to inflate the population estimate for the whole island. Key results In all, 62% of all penguins counted used the four mark–recapture sites. In 2007, there were an estimated 2369 ± 198 penguins, and 1543 ± 82 in 2008. When capture heterogeneity was allowed for in 2008, this estimate increased to 2069 ± 172. Conclusions Fewer eggs were laid and all measures of breeding performance were lower in 2008 than in 2007. Hence, the lower population estimate is most likely to represent fewer birds attempting to breed. However, further work on population estimates is required to determine whether capture heterogeneity occurs in both good and poor breeding years. Capture rates were affected by the presence of a full moon and high tides. Implications The estimate of the population can be used as part of the basis of a long-term monitoring program needed for effective management of the penguin colony. However, such studies must be coincident with the monitoring of a suite of reproductive and foraging parameters if short-term impacts of threats are to be recognised and well managed.
Publisher: Public Library of Science (PLoS)
Date: 06-10-2011
Publisher: Wiley
Date: 21-01-2020
DOI: 10.1002/AQC.3272
Publisher: Inter-Research Science Center
Date: 06-01-2022
DOI: 10.3354/MEPS13895
Abstract: The causes of intraspecific variation in diet and isotopic niche width can provide important insights into the local food resource requirements for a population. This information is particularly important for highly philopatric colonially nesting species, where local competition for food resources may be high. We investigated the relative influence of environmental, temporal and spatial attributes on intraspecific variation in the diet of colonially nesting brown boobies Sula leucogaster using both regurgitant s les and stable isotope analysis of blood and feathers. Diet analyses revealed that Indian anchovy Stolephorus indicus was the predominant prey species in brown booby diet. Despite the predominance of Indian anchovy, there was significant population-level intraspecific variation in diet. Our results supported the intersexual competition hypothesis, with female diet not only exhibiting greater species richness, but non-breeding females likely to feed in a different habitat. The isotopic niche also varied according to life-history stage, with in iduals utilising different food sources between the breeding and non-breeding seasons. Additionally, there were significant inter-annual differences in diet composition associated with warmer sea surface temperatures. Furthermore, we identified sub-colony differences in the non-breeding diet. The different patterns of food intake represent those typical of a central place forager: during the non-breeding season (when adults were not area-restricted due to breeding activity), the width of the isotopic niche of both sexes increased. This study has revealed multiple causes of intraspecific variation in diet and isotopic niche and highlights the need for comprehensive dietary analyses to manage seabird populations effectively within specific locations.
Publisher: Waterbird Society
Date: 2003
Publisher: Inter-Research Science Center
Date: 16-02-2006
DOI: 10.3354/MEPS308293
Publisher: Informa UK Limited
Date: 03-2016
DOI: 10.1071/MU15039
Publisher: Elsevier BV
Date: 11-2006
DOI: 10.1016/J.CBPA.2006.07.005
Abstract: Penguins show varying degrees of brood reduction behavior, from obligate brood reducers to brood maximizers, and we hypothesize that this is associated with differences in prolactin secretion. To address this hypothesis, we determined the breeding season prolactin profile of the yellow-eyed penguin (Megadyptes antipodes) for comparison with those of other penguin species found in the literature. We also measured sex steroid plasma concentrations to better characterize the reproductive cycle of the species. Plasma concentrations of prolactin increased from early in the season, reaching a peak during late incubation, and remained elevated up to the guard period. This general pattern was similar to that of other penguins for which we have corresponding data. However, we found that throughout the laying period, prolactin titers in yellow-eyed penguins remained elevated while they fell to basal levels after the laying of the first egg in macaroni penguins, which corresponds to differences in incubation behavior during this time. We conclude, therefore, that differences in the brood reduction behavior in penguins, may be reflected in the pattern of PRL concentrations around the time of egg laying.
Publisher: Routledge
Date: 14-01-2019
Publisher: Routledge
Date: 14-01-2019
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/WR15187
Abstract: Context Demographic parameters in wildlife populations are typically estimated by monitoring a limited number of in iduals in observable sites and assuming that these are representative of the whole population. If in iduals permanently disperse to unobservable breeding sites, recruitment and immature survival are expected to be negatively biased and breeding-site fidelity cannot be investigated. Aims To develop a method to obtain unbiased estimated of survival, recruitment and breeding dispersal when in iduals can move to, or recruit in, unobservable sites. Methods We used the flexibility of multi-event capture–recapture models to estimate dispersal and recruitment to unobservable sites, merging observations made at two sites within the same breeding locations. We illustrated the model with data on little penguin (Eudyptula minor) breeding in artificial as well as in natural nests. Natural nests are unknown or inaccessible and birds in these sites remain unobservable. Encounters at beaches surrounding the colony suggested that marked animals can permanently move to unobservable nests. We built the multi-event model considering two possible states of the in iduals (alive breeding in a nest box and alive in a natural nest) and three types of observations (encountered at a nest only, encountered at the beach only and encountered at both places). This model ensured that the breeding dispersal to unobservable places became estimable. Key results Results indicate that the estimated survival was 8% higher than when recaptures at artificial nests were analysed alone. Also, fidelity to artificial nests was 12% lower than to natural nests. This might reflect the greater availability of natural sites or, alternatively, a heterogeneity between these two types of nest. Conclusions We obtained an estimate of local survival of little penguins breeding at Penguin Island that incorporates the permanent migration to unobservable sites and found an asymmetric dispersion towards natural nests. Implication Our conclusions suggest a need for more careful treatment of data derived from artificial sites alone, as demographic parameters might be underestimated if animals prefer natural breeding sites or if they are in greater proportion compared with artificial ones. The analytical approach presented can be applied to many biological systems, when animals might move into inaccessible or unobservable breeding sites.
Publisher: Elsevier BV
Date: 04-2022
Publisher: Springer Science and Business Media LLC
Date: 10-08-2014
DOI: 10.1007/S00484-013-0711-6
Abstract: Seabirds are one of the most threatened groups of birds globally and, overall, their conservation status is deteriorating rapidly. Southern hemisphere countries are over-represented in the number of species of conservation concern yet long-term phenological data on seabirds in the southern hemisphere is limited. A better understanding of the implications of changes in the marine and terrestrial environments to seabird species is required in order to improve their management and conservation status. Here we conducted a meta-analysis of the phenological drivers and trends among southern hemisphere seabirds. Overall there was a general trend towards later phenological events over time (34 % of all data series, N = 47 67 % of all significant trends), though this varied by taxa and location. The strongest trends towards later events were for seabirds breeding in Australia, the Laridae (gulls, noddies, terns) and migratory southern polar seabirds. In contrast, earlier phenologies were more often observed for the Spheniscidae (penguins) and for other seabirds breeding in the Antarctic and subantarctic. Phenological changes were most often associated with changes in oceanographic conditions, with sea-ice playing an important role for more southerly species. For some species in some locations, such as the Little Penguin Eudyptula minor in south-eastern Australia, warmer oceans projected under various climate change scenarios are expected to correspond to increased seabird productivity, manifested through earlier breeding, heavier chicks, an increased chance of double brooding, at least in the short-term.
No related grants have been discovered for Belinda Cannell.