Penguin Island Research Articles

Modelling survival and breeding dispersal to unobservable nest sites

Context Demographic parameters in wildlife populations are typically estimated by monitoring a limited number of individuals in observable sites and assuming that these are representative of the whole population. If individuals 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 individuals 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 individuals (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.

A necrophilic copulation by a Bridled Tern Onychoprion anaethetus

A Bridled Tern Onychoprion anaethetus was observed copulating with a deceased conspecific on an offshore island, Penguin Island, in south-western Australia. The copulation lasted for c. 30 seconds, in contrast with the usually 3-10 seconds observed in this species. This unusual copulation may simply be the result of a strong breeding drive present in colonially nesting Bridled Terns.

Central place foraging and feather regrowth rate in bridled terns (Onychoprion anaethetus): an insight from stable isotopes

In this study, the stable isotope ratios of δ13C and δ15N of bridled terns’ (Onychoprion anaethetus) tail feathers were used to investigate changes in the food sources assimilated by the birds on Penguin Island, Western Australia, during different phases of the breeding season. Samples were taken immediately after they arrived on the island returning from migration (BM), before egg-laying (BEL), after egg-laying (AEL), after hatching (AH) and from fledglings (F). A one-way MANOVA (excluding the BM phase) and two one-way ANOVAs (including all phases), showed that the δ13C and δ15N values differed significantly between the stages of the breeding season, with the greatest differences between the BM and BEL stages. The mean δ13C values were higher and those for δ15N were lower for BM birds than all other stages, indicating that the food source assimilated by the birds, and their foraging locations, changed during the breeding season. These results support the hypothesis of the Central Place Foraging Theory, i.e. that adult breeding birds adjust their foraging strategies when they are bound to a central place to care for their young. Induced feathers were regenerated over ~70 days and their regrowth rates were similar before and after egg-laying.

Lichenometric ages of the little ice age moraines on king george island and of the last volcanic activity on penguin island (west antarctica)

The recently observed recession of glaciers on King George Island is associated with decades of climate warming in the Antarctic Peninsula region. However, with only 60 years of glaciological observations in the study area ages of the oldest moraines are still uncertain. The goal of the study was to estimate ages of lichen colonization on the oldest moraines of the Ecology and White Eagle Glaciers on King George Island and on the Principal Cone of Penguin Island volcano. The first lichenometric studies on these islands from the late 1970s used rates that had about four to five times slower Rhizocarpon growth rates. We re‐examined the sites and measured 996 thalli diameters to establish the surface ages. To estimate the age we used (1) long‐term Rhizocarpon lichen group growth rates established by authors using data from a previous lichenometric study on King George Island, and (2) previous data of lichen growth rates from other sub‐Antarctic islands. Our results suggest growth rates between 0.5 and 0.8 mmyr–1. According to these rates the ages of the oldest moraine ridges are of the Little Ice Age and were colonized at the beginning of the twentieth century. The mid‐twentieth century age of lichen colonization on the historically active Penguin Island volcano might support the date of the last eruption reported by whalers in the end of the nineteenth and the beginning of the twentieth century.

Genetic structure of declining chinstrap penguin (Pygoscelis antarcticus) populations from South Shetland Islands (Antarctica)

Seabirds and their response to climate perturbations are important bioindicators of changes in Antarctic ecosystems. During 30 years of observations of two chinstrap penguin (Pygoscelis antarcticus) colonies, one on King George Island and the other on Penguin Island (South Shetland Islands, Antarctica), the size of the breeding populations decreased by 84 and 41 %, respectively. We applied analyses of amplified fragment length polymorphisms to study the genetic structure of the two populations and to evaluate the influence of the sudden population decrease. Our data indicate that there were only weak genetic differences between the populations, which were not strong enough to support the hypothesis of population differentiation. Weak genetic differences observed between the two populations seem not to be determined by selection processes. We hypothesize that the very low level of between-population genetic structure can be explained by some extent of genetic drift, which is largely compensated by gene flow. Moreover, the two populations seem to remain in a stationary state. Our results support the hypothesis of limited natal philopatry in chinstrap penguins. The observed decrease in population size is probably caused by emigration or a rise in juvenile mortality due to the increasing krill limitation of the marine food web. However, detailed research is required to address this issue.

Blending a heritage of recreation and tourism with conservation of natural heritage: an example from Penguin Island, Western Australia

This paper discusses the recreational and natural heritage of Penguin Island in its journey from use as a recreation reserve to its current management within a Class A biodiversity conservation reserve. Protected natural areas were historically managed for tourism and recreation, resulting in a significant heritage of use. They are now mainly managed for biodiversity protection, but continue to be a focus for tourism and recreation. Visitors to natural areas are considered a prime audience to raise awareness about biodiversity protection, but Australia has a poor record of integrating cultural and natural heritage management. The long heritage of recreational use on Penguin Island was superimposed with a biodiversity protection mandate. Effective design based on minimal site hardening and selective restriction of recreational use, rather than education, has successfully restored the island's natural heritage. However, the island's cultural heritage has been obscured. This implies that the biodiversity protection and education mandate has been at the cost of preserving awareness of Penguin Island's recreation and tourism heritage.

Trace metals in sediment cores from Deception and Penguin Islands (South Shetland Islands, Antarctica)

This paper presents information on the levels of trace elements in sediments collected at Deception and Penguin Islands and tracks the sources of natural and anthropogenic inputs of metals into this sub-Antarctic region. The results suggest that natural processes, such as volcanic activity, hydrothermal processes and sediment transport, are more important than anthropogenic inputs in accounting for the metal concentrations measured in sediments at Deception Island. The higher levels of trace metals recorded in sediments at Penguin Island seem to reflect the composition of the source rocks of the island, which are dominated by the olivine-basalt group. Our findings show that human activities in the study areas may contribute to negligible levels of trace metals associated with anthropogenic inputs (e.g., Cr and Zn) in sediments, and these results can be used in the future as background levels related to low anthropogenic impacts.

Chick starvation in yellow‐eyed penguins: Evidence for poor diet quality and selective provisioning of chicks from conventional diet analysis and stable isotopes

AbstractThe link between poor reproductive success and diet was investigated in yellow‐eyed penguins Megadyptes antipodes, by assessing diet at two localities separated by about 30 km: the north coast of Stewart Island where breeding success is low (0.38–0.67 chicks per pair in recent years), and Codfish Island where breeding success is higher (0.96–1.51 chicks per pair), and relating this to published data from South Island localities, where average breeding success was 1.1 chicks per pair. Diet composition, meal sizes and energetic content of meals and prey were determined from stomach contents, and stable isotope analyses of chick down, fledgling feathers and adult blood provided information on diet throughout the fledging period. The high proportion of stomachs that were empty or lacked diagnostic remains reduced sample size considerably, and variability between samples reduced the power to detect significant differences in meal size, proportions of empty stomachs and prey diversity of meals. Energetic content of Stewart Island meals was less than Codfish Island meals, and there was a non‐significant trend for smaller meal sizes and reduced prey diversity among Stewart Island samples. Both localities had lower prey diversity and smaller meals than South Island penguins. Blue cod Parapercis colias accounted for 99% of prey biomass in Stewart Island and 70% in Codfish Island stomach samples, where 27% of prey biomass was opalfish Hemerocoetes monopterygius. Isotopic mixing models carried out on larger sample sizes indicated that opalfish comprised a large proportion of the diet at both locations, with adults selectively provisioning chicks with opalfish while feeding mainly on blue cod themselves. We suggest the large blue cod consumed by Codfish Island and Stewart Island penguins, larger than those consumed by South Island penguins, is difficult to transfer to chicks by regurgitation. Oyster dredging around Stewart Island may have reduced the availability and abundance of alternative prey to Stewart Island penguins.

Augmenting mark–recapture with beach counts to estimate the abundance of little penguins on Penguin Island, Western Australia

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 sampling 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.

Lines in the Sand: An Anthropological Discourse on Wildlife Tourism

Goal and objectives of the dissertationGoalThe management of wildlife tourism has been dominated by ideologies informed by western colonialism and its values of nature. These ideologies, made transparent through communicative and interpretative discourses, influence the way management policies and practices are devised and enacted. The inherent scientific and utilitarian views are supported by a doctrine of separation. This is apparent in the dualism posed, and enacted, between nature and culture that sees humans as being the sole carriers of culture that separates them from the uncultured and uncivilised world of nature into which all other animals, and certainly untamed wildlife, belong. It justifies the use of non-humans for human purposes and continues to allow us to treat non-human animals and other forms of nature in often abominable ways.This thesis explores one of the central dilemmas facing wildlife tourism: what are the implications of the separation constructed between wildlife and people in wildlife tourism settings? This exploration is an interdisciplinary journey drawing on understandings, methods and theories from anthropology, tourism and environmental science. It promotes an engagement between anthropology and the scholarly discourses of tourism and environmental science, and a broad approach to defining and understanding the wildlife tourism community.ObjectivesApproaches to wildlife tourism management are needed which will optimise stakeholder satisfaction with wildlife tourism, within the constraints of ensuring sustainability of the wildlife product. This thesis is designed around a series of objectives aimed at understanding these constraints and finding new approaches. Guiding the research that informs this thesis are questions that ask why management of the human-wildlife interface occurs in the way it does, and what values underpin the constructions of wildlife that, in turn, enable and legitimise the management.MethodologyThis thesis investigates two situations in which wildlife tourism occurs in Australia. Fraser Island and Penguin Island are two wildlife tourism destinations on opposite sides of the continent with very different wildlife but some very similar issues. From these two contexts data was collected through interviews, focus groups, participant observation, and from literary and documentary sources. Understanding the empirical data collected from these case studies is facilitated through a social constructionist view of discourse analysis that allows an unpacking of the messages and a stance from which to challenge the dominant ideologies that frame management and interaction.ResultsThe case studies and theories explored in this thesis highlight the way wildlife tourism is managed. The dominant constructions underlying management policies and practices are exposed, and challenged, and alternatives posed.I demonstrate throughout that anthropology, in its incarnation as environmental anthropology and as a team player in a necessarily interdisciplinary approach to understanding and resolving environmental issues, has much to offer. This engagement has the potential to enhance not only the sustainable future of nature-based activities like wildlife tourism but also the relevance of anthropology in the postcolonial contemporary world. Thus the thesis contributes to the body of literature on the anthropology of tourism, environmental anthropology and wildlife tourism.Theoretical conclusionsThe need for a holistic framework encompassing all the stakeholders in any wildlife tourism venture is proposed. This approach to wildlife tourism is best serviced by examining perspectives, values and concerns of all members of the wildlife tourism community at any given destination. It is only through this type of holistic and situated focus that we can hope to effectively understand, and then manage, in the best interests of all parties. …

Prevalence of Leucocytozoon spp, in the endangered yellow-eyed penguin Megadyptes antipodes

Yellow-eyed penguins on Stewart Island were identified with a Leucocytozoon spp. of a novel lineage in association with a high regional incidence of chick mortality (n=32, 100% mortality) during the November 2006 to January 2007 breeding season. Fourteen chicks from Stewart Island were examined post-mortem and histologically for Leucocytozoon infection. In addition, a survey of blood to detect Leucocytozoon spp. infections using PCR was performed on 107 yellow-eyed penguins from 4 distinct nesting areas on the South Island (Oamaru, Otago Peninsula, and Catlins) (n=95), and Stewart Island (n=12). The results of the study revealed that 2 of the 14 (14%) chicks necropsied showed severe, disseminated megaloschizont formation in the liver, spleen, lung, kidney and other tissues characteristic of leucocytozoonosis. Eighty-three percent (83%) of blood samples collected from Stewart Island penguins contained Leucocytozoon DNA, whereas samples from the 3 other nesting areas were negative for the blood parasite. Leucocytozoon spp. DNA sequences isolated from blood and tissues of adults (n=10) and chicks (n=7) were similar and grouped with other published Leucocytozoon spp. sequences but in a distinct cluster together with closely related isolates from a Western march harrier (Circus aerginosus) and common loon (Gavia immer). These findings suggest that yellow-eyed penguins on Stewart Island are infected with a regionally isolated, host-specific Leucocytozoon spp. which may contribute to the high chick mortality observed during this period.

The role of early diagenesis in the sedimentary steroids around Penguin Island, Antarctica

The role of lipids in polar environments is of primary importance for understanding the cycling of carbon organic and associated elements. Thus, the knowledge of the nature and quality of organic matter is necessary to evaluate the overall impact in this area and to model the carbon cycle. The aim of this study was to determine the transformations of organic matter in the marine environment by analysis of a specific group of lipid biogeochemical markers, the sedimentary steroids. Sediment cores were collected during the 2007/08 austral summer in the vicinity of the Penguin Island (2 cores). In general, the cores were sectioned at 1 cm intervals and the steroids analyzed by gas chromatography with flame ionization detection (GC-FID), after Soxhlet extraction, adsorption column chromatography and derivatization. The results showed that organic matter had been subjected to extensive degradation and transformation with depth in the two corers and the general increase of the stanol/ stenol ratio may have represented the progressive reduction of stenols to stanols within the deepest sediment layers. According to the linear regression (R2) applied, the process at Penguin Island is governed by a natural supply, and a random pattern in the concentration values with increasing depth. These results contribute to the understanding of the current processes of organic matter transformation in this important region of Antarctic environment.

Asperelines A−F, Peptaibols from the Marine-Derived Fungus Trichoderma asperellum

Fermentation of the marine-derived fungus Trichoderma asperellum, collected from the sediment of the Antarctic Penguin Island, resulted in the isolation of six new peptaibols named asperelines A-F (1-6), which are characterized by an acetylated N-terminus and a C-terminus containing an uncommon prolinol residue. Structures were determined by extensive 1D and 2D NMR ((1)H-(1)H COSY, HMQC, HMBC, NOESY) spectroscopic data analysis combined with ESIMS/MS fragmentation. The absolute configurations of the amino acid residues possessing a chiral alpha-carbon and of the prolinol residue were determined to be L and S, respectively, using a new method of (1)H NMR spectroscopic comparison of complexes formed between the chiral reagent Ru(D(4)-Por*)CO and amino acids derived from the peptaibols with those formed with reference standards.

Ticks Associated with Macquarie Island Penguins Carry Arboviruses from Four Genera

Macquarie Island, a small subantarctic island, is home to rockhopper, royal and king penguins, which are often infested with the globally distributed seabird tick, Ixodes uriae. A flavivirus, an orbivirus, a phlebovirus, and a nairovirus were isolated from these ticks and partial sequences obtained. The flavivirus was nearly identical to Gadgets Gully virus, isolated some 30 year previously, illustrating the remarkable genetic stability of this virus. The nearest relative to the orbivirus (for which we propose the name Sandy Bay virus) was the Scottish Broadhaven virus, and provided only the second available sequences from the Great Island orbivirus serogroup. The phlebovirus (for which we propose the name Catch-me-cave virus) and the previously isolated Precarious Point virus were distinct but related, with both showing homology with the Finnish Uukuniemi virus. These penguin viruses provided the second and third available sequences for the Uukuniemi group of phleboviruses. The nairovirus (for which we propose the name Finch Creek virus) was shown to be related to the North American Tillamook virus, the Asian Hazara virus and Nairobi sheep disease virus. Macquarie Island penguins thus harbour arboviruses from at least four of the seven arbovirus-containing genera, with related viruses often found in the northern hemisphere.

Preliminary Quantitative Data on Behavioural Responses of Australian Pelican (Pelecanus conspicillatus) to Human Approach on Penguin Island, Western Australia

The heightened popularity of islands amongst tourists along with increasing recreational activity on small nearshore islands has resulted in the need to acquire data on the potential effects recreational activities may be having on the breeding behaviour and ultimately the reproductive success of seabird colonies. This paper quantifies the differences in behaviour elicited from two colonies of Australian pelican (Pelecanus conspicillatus) at two different stages of incubation on Penguin Island, Western Australia when approached repeatedly by a researcher. Three response indicators were chosen for comparison: (1) behaviour during an approach; (2) the pre-flight initiation distances; and (3) behaviour following an approach. Although preliminary, these data are strongly indicative of major behavioural changes by nesting pelicans in response to human approach. Observations also indicated that breeding Australian pelicans exhibited short-term habituation to human approach over both phases of the breeding seaso...

Preliminary Quantitative Data on Behavioural Responses of Australian Pelican (Pelecanus conspicillatus) to Human Approach on Penguin Island, Western Australia

The heightened popularity of islands amongst tourists along with increasing recreational activity on small nearshore islands has resulted in the need to acquire data on the potential effects recreational activities may be having on the breeding behaviour and ultimately the reproductive success of seabird colonies. This paper quantifies the differences in behaviour elicited from two colonies of Australian pelican (Pelecanus conspicillatus) at two different stages of incubation on Penguin Island, Western Australia when approached repeatedly by a researcher. Three response indicators were chosen for comparison: (1) behaviour during an approach; (2) the pre-flight initiation distances; and (3) behaviour following an approach. Although preliminary, these data are strongly indicative of major behavioural changes by nesting pelicans in response to human approach. Observations also indicated that breeding Australian pelicans exhibited short-term habituation to human approach over both phases of the breeding season tested. Results from this study suggest that setback distances, that are designed to separate humans from Australian pelicans, should be precautionary, being based upon the longest pre-flight distance recorded during the most sensitive stage of the breeding season.

Few genetic differences between Victorian and Western Australian blue penguins, Eudyptula minor

Blue penguins, Eudyptula minor, breeding on Penguin Island, Western Australia are considerably larger than other blue penguins in Australia. If genetic isolation is the cause, it may have implications for the conservation status of some blue penguin populations. We compared the sequences of two mitochondrial gene regions (cytochrome‐b and the control region) from Western Australian blue penguins with other populations of blue penguins from Australia and New Zealand. We found few differences between sequences from Western Australia, Phillip Island, Victoria and Otago, New Zealand, although all three differed considerably from other New Zealand blue penguins. Sequences for the control region from the Western Australian blue penguins and 30 more birds breeding at various Australasian sites provided further support for two major clades within Eudyptula; an Australian clade (including Otago) and a New Zealand clade.

Diving behaviour of Little Penguins from four colonies across their whole distribution range: bathymetry affecting diving effort and fledging success

Little Penguins, Eudyptula minor, breed in several small colonies in New Zealand and Australia. In this study, we compare the birds’ diving performances at different sites situated throughout their breeding range. Environmental conditions and breeding success vary drastically amongst colonies, but all birds feed on similar types of prey and face similar limitations on their foraging range. We examined several diving parameters and calculated the proportion of foraging zone available during breeding to examine whether oceanographic and geographic factors in the foraging zone can explain variations in diving behaviour and fledging success among the different colonies. In colonies with high fledging success, Penguin Island and Oamaru, penguins made shallow dives <50 m depth and had lower diving effort. More than 90% of the foraging zone was in waters <50 m depth in these colonies. Motuara Island also has shallow waters with 95% <50 m depth, but the fledging success was low. Phillip Island has only 42% of waters <50 m and comparatively low fledging success. Thus, penguins dived deeper and showed a higher diving effort in colonies with lower fledging success (Motuara Island and Phillip Island), indicating that they were disadvantaged compared to conspecifics from other colonies that dived shallower and with a lesser diving effort. We concluded that bathymetry is an important factor, but not the only one, which influences fledging success.

Micromelia in Little Penguins (Eudyptula minor)

Two cases of unilateral micromelia are described in wild juvenile little penguins (Eudyptula minor). The first bird was found at San Remo, Phillip Island, Victoria, Australia. The bird's left flipper was reduced in length, and radiography demonstrated severe shortening and dysplasia of the humerus. The second bird was found having difficulty swimming off the coast near Fremantle, Western Australia. Clinical examination revealed that the bird was underweight (0.55 kg) but otherwise in good condition with subadult plumage and had probably only recently fledged from nearby Garden or Penguin Islands. The left wing was markedly reduced in size and had limited range of elbow and carpal joint movement but sensation and motor control were normal. Radiography demonstrated a severe reduction in size and distortion of the humerus and shortening and fusion of the ulna, radius, metacarpals, and phalanges. The furcula was asymmetrical because the left clavicle was slightly thinner and more radiolucent than the right and was also slightly deviated to the right side. Necropsy results of histopathologic examination revealed no other significant external abnormalities other than a mild focal heterophilic ulcerative proventriculitis from a mild burden of Contracaecum eudyptulae. Concentrations of heavy metals in kidney, liver, and brain were: cadmium, <6 mg/kg; mercury, <0.05 mg/kg; lead, <2 mg/kg; and selenium, 1.30 mg/kg. Possible causes of unilateral micromelia in these penguins are discussed.

Decline of the breeding population of Pygoscelis antarctica and Pygoscelis adeliae on Penguin Island, South Shetland, Antarctica

This work is a quantitative analysis of the population of breeding pairs of Pygoscelis adeliae and Pygoscelis antarctica, which use Penguin Island as a breeding area. There was a decrease in the populations of P. adeliae and P. antarctica by 75 and 66%, respectively, from the breeding season of 1979/1980 to 2003/2004. A mixed breeding colony of both species was also documented, according to published data which has existed since 1979/1980. The P. antarctica has an advantage over P. adeliae in this mixed breeding situation, where the breeding pairs of the former increased by 127%, indicating an interspecies competition for nesting ground.