Little penguin Eudyptula minor at Middle Island, Western Victoria : current status

We examined the status of the Little Penguin Eudyptula minor at Middle Island on the west coast of Victoria during the species' 1999/2000 breeding season. The vegetated upper surface of the island had 292 occupied burrows at a density of 0.02/m². Peak dusk arrival occurred in January with 502 penguins coming ashore during a one-hour period. Little Penguins at Middle Island displayed important differences in breeding ecology from penguins in other Australian colonies. Early breeding combined with heavier adult and chick weights resulted in high breeding success. However, as Middle Island is a popular destination for day visitors, during the 1999/2000 Little Penguin breeding season, tourism ·was found to cause detrimental effects, including deaths of some eggs and chicks. There are also concerns for the conservation of the Little Penguin colony as faxes or dogs may readily access the island.

Determining the sex of Little Penguins (Eudyptula minor) in northern Bass Strait using morphometric measurements

In avian species with no obvious differences in plumage or body size between the sexes, such as penguins, discriminant function analysis (DFA) of morphometric measurements that display sexual dimorphism can provide a simple and rapid means of determining sex in the field. Like most other penguin species, the Little Penguin (Eudyptula minor) displays sexual dimorphism in bill shape and size. In the present study, discriminant functions (DFs) were developed for sexing adult Little Penguins at two colonies in northern Bass Strait, Victoria, Australia, and their accuracies were compared with those obtained previously in other parts of the species' range. Backwards stepwise DFA indicated that birds at Phillip Island can be sexed with an accuracy of 91% using a single measurement of bill depth (>13.33 mm classed as males). Similar analyses at Gibson Steps produced a DF incorporating bill length, bill depth and head length [although the model with the greatest accuracy when applied to birds from Phillip Island (91%) also contained only bill depth]. Published DFs derived in New Zealand had accuracies of 50–85% when applied to birds from Phillip Island and Gibson Steps, supporting earlier suggestions that DFs are not applicable across subspecies of the Little Penguin. In contrast, there was little difference between the accuracy of the DFs in the present study and that previously derived for the same subspecies in Tasmania when applied to birds from Phillip Island (89%) and Gibson Steps (92%). However, as the degree of variation in bill size within a subspecies is unknown it may still be prudent to derive colony-specific DFs.

General practitioners' competence and confidentiality determinations with a minor who requests the oral contraceptive pill

The right of minors to make medical treatment decisions is an issue that is not explicitly addressed in the legislation of most Australian jurisdictions. While recent common law decisions allow competent minors to consent to treatment, current legislation in Victoria does not provide adequate guidelines on how competence is to be measured. It is also unclear whether the duty of confidentiality is extended to competent minors. The current study explored general practitioners' competence and confidentiality decisions with a hypothetical 14-year-old patient who requests the oral contraceptive pill (OCP). Questionnaires were sent to 1,000 Victorian general practitioners, 305 of whom responded. General practitioners were asked to determine whether "Liz" was competent to request the OCP, and whether they would maintain her confidentiality. A total of 81% of respondents found the patient competent, while 91% would have maintained her confidentiality. Results indicate that the majority of general practitioners used rationales that generally did not conform to current legal principles when making competence and confidentiality determinations regarding this patient.

Synchronized group association in little penguins, Eudyptula Minor.

Most seabirds form groups on land and at sea, but there is little information whether seabird groups are formed deliberately or randomly. We investigated whether little penguins formed groups composed of the same individuals when they crossed the beach each day over four breeding seasons (2001–2004) using an automated penguin monitoring system (APMS). We used an association matrix to determine the number of times any two birds crossed the APMS in the same group. The number of these group associations or ‘synchronized parade’ behaviour was determined for every possible pair of individuals, giving a total association value for each pair of birds during the postguard stage of the reproductive cycle. We concluded that a penguin group was composed of 5–10 individuals within 40-s intervals. Penguin groups were formed nonrandomly in years of high breeding success (2002 and 2003), but not in years of low breeding success (2001 and 2004). Age of birds was a significant factor in composition of groups. Little penguins with higher association values shared similar characteristics or ‘quality’, which in turn may increase the functional efficiency of their groups, especially if they are also foraging together. However, low association indices indicated that seeking the same associates was not a priority. It is costly for any animal to synchronize their attendance with the same individuals, so it could be beneficial to display synchronized parade behaviour in good breeding years but it could result in intraspecific competition for food during poor breeding years.

Sexing little penguins eudyptula minor using bill measurements

In Little Penguins Eudyptula minor there are no reliable plumage or body size differences that can be used visually to distinguish the sex of individuals. However, sexual dimorphism of morphometric measures has been noted, with males always being a little larger than females. In this study, differences between E. minor sexes at eight colonies in south-eastern Australia were determined statistically via discriminant function analysis (DFA) and through the utilization of DNA-based techniques developed for non-ratite birds. The DFA correctly determined gender in 91.1% of cases and molecular methods were 100% accurate. Our DFA success rate of classification is similar to that previously published for Little Penguins in Victoria. In this study statistically significant differences in mean bill depths and lengths were found between Little Penguin colonies at St Kilda, Phillip Island and Gabo Island, compared to colonies at Kangaroo Island, Granite Island, Middle Island and London Bridge. As birds in eastern populations (St Kilda, Phillip Island, Gabo Island) exhibit statistically significantly smaller beaks (bill depth and bill length), separate discriminant functions were investigated for each phenotypically distinct geo-spatial cohort. Interestingly, cluster analysis for bill length identified three groups: western (Kangaroo Island and Granite Island), eastern (St Kilda, Phillip Island and Middle Island) and the London Bridge Little Penguin colony, which constituted a separate group. We conclude that while there is a slight increase in DF power for colonies west of Cape Otway and for some specific colonies, colony-specific DFA is not required to identify the sex of Little Penguins in south-eastern Australia.

A neural networks learning algorithm for minor component analysis and its convergence analysis

The eigenvector associated with the smallest eigenvalue of the autocorrelation matrix of input signals is called minor component. Minor component analysis (MCA) is a statistical approach for extracting minor component from input signals and has been applied in many fields of signal processing and data analysis. In this letter, we propose a neural networks learning algorithm for estimating adaptively minor component from input signals. Dynamics of the proposed algorithm are analyzed via a deterministic discrete time (DDT) method. Some sufficient conditions are obtained to guarantee convergence of the proposed algorithm.

Foraging behaviour and habitat selection of the little penguin Eudyptula minor during early chick rearing in Bass Strait, Australia

Knowledge of the foraging areas of top marine predators and the factors influencing them is central to understanding how their populations respond to environmental variability. While there is a large body of literature documenting the association of air-breathing marine vertebrates with areas of high marine productivity, there is relatively little information for species restricted to near-shore or continental-shelf areas. Differences in foraging range and diving behaviour of the little penguin Eudyptula minor were examined from 3 breeding colonies (Rabbit Island, Kanowna Island and Phillip Island) in central northern Bass Strait, southeast Australia, during the chick-guard stage using electronic tags (platform terminal transmitters, PTTs, and time-depth recorders, TDRs). Although there were large overall differences between individuals, the mean maximum foraging range (16.9 to 19.8 km) and mean total distance travelled (41.8 to 48.0 km) were similar between the 3 colonies, despite different bathymetric environments. Individuals from all 3 colonies selected foraging habitats within a narrow sea surface temperature (SST) range (16.0 to 16.4°C). While there were significant differences in mean dive depths (5.4 to 10.9 m) and mean durations (13.2 to 28.6 s) between the different colonies, the mean diving effort (vertical distance travelled: 936.3 to 964.3 m h–1) was similar. These findings suggest little penguins from the 3 colonies employ relatively similar foraging efforts yet are plastic in their foraging behaviours.

Contrasting genetic structuring between colonies of the world's smallest penguin, Eudyptula minor (Aves: Spheniscidae)

The Little Penguin, Eudyptula minor, is a seabird that nests in colonies throughout New Zealand and southern Australia. Individuals from different colonies in southeast Australia differ significantly in morphology and ecology, suggesting that some genetic structuring may exist among colonies. In contrast, the marking of individuals with flipper bands has revealed some, albeit infrequent, movement between colonies. To determine the extent of genetic structuring, we tested the null hypothesis of substantial gene flow within southeast Australia by examining patterns of genetic variation across seven colonies separated by up to 1,500 km. Phylogeographic structuring was absent for mitochondrial control region sequences (2–3 individuals per colony). Microsatellite allele frequencies at five loci and mitochondrial haplotype frequencies (50 individuals per colony) were also homogenous among the majority of colonies sampled, although two colonies at the western periphery of the sampling range were distinct from those to the east. The genetic homogeneity among the majority of colonies can be explained by low but consistent contemporary gene flow among them, or a recent founder event in Bass Strait following the last marine transgression. The genetic break towards the western end of the sampling distribution appears best explained by differences in sea surface temperature and, consequentially breeding phenology, the latter hindering genetically effective migration.

Food utilisation and digestive ability of aquatic and semi-terrestrial crayfishes, Cherax destructor and Engaeus sericatus (Astacidae, Parastacidae)

Both Engaeus sericatus and Cherax destructor are omnivorous crayfishes consuming a variety of food items. Materials identified in the faeces of both E. sericatus and C. destructor consisted of mainly plant material with minor amounts of arthropod animals, algae and fungi. The morphology of the gastric mill of C. destructor suggests that it is mainly involved in crushing of food material while the gastric mill of E. sericatus appears to be better suited to cutting of food material. Given this, the gastric mill of E. sericatus may be better able to cut the cellulose and hemicellulose fibres associated with fibrous plant material. In contrast, the gastric mill of C. destructor appears to be more efficient in grinding soft materials such as animal protein and algae. Both species accumulated high amounts of lipids in their midgut glands (about 60% of the dry mass) which were dominated by triacylglycerols (81–82% of total lipids). The dominating fatty acids were 16:0, 16:1(n-7), 18:1(n-9), 18:2(n-6), and 18:3(n-3). The two latter fatty acids can only be synthesised by plants, and are thus indicative of the consumption of terrestrial plants by the crayfishes. The similarity analysis of the fatty acid patterns showed three distinct clusters of plants and each of the crayfish species. The complement of digestive enzymes, proteinases, total cellulase, endo-β-1,4-glucanase, β-glucosidase, laminarinase and xylanase within midgut gland suggests that both C. destructor and E. sericatus are capable of hydrolysing a variety of substrates associated with an omnivorous diet. Higher activities of total cellulase, endo-β-1,4-glucanase and β-glucosidase indicate that E. sericatus is better able to hydrolyse cellulose within plant material than C. destructor. In contrast to E. sericatus, higher total protease and N-acetyl-β-d-glucosaminidase activity in the midgut gland of C. destructor suggests that this species is better able to digest animal materials in the form of arthropods. Differences in total cellulase and gastric mill morphology suggest that E. sericatus is more efficient at digesting plant material than C. destructor. However, the contents of faecal pellets and the fatty acid compositions seem to indicate that both species opportunistically feed on the most abundant and easily accessible food items.

Range-wide phylogeography of the Little Penguin (Eudyptula minor): evidence of long-distance dispersal

The Little Penguin (Eudyptula minor), a colonial-nesting seabird that is widespread in New Zealand and southern Australia, has high dispersal potential but exhibits regional variation in morphology, coloration, and breeding phenology. We present a distribution-wide survey of mitochondrial DNA variation in the Little Penguin to document phylogeographic relationships and genetic structuring and to test for concordance with intraspecific taxonomy. Phylogeographic structuring was absent among Australian colonies (27 localities, 94 individuals), but the distribution of haplotypes among colonies was significantly nonrandom (ϕST = 0.110, P < 0.01). The Australian individuals exhibited close phylogenetic relationships with a subset of New Zealand birds (4 localities, 22 individuals), whereas the remaining New Zealand birds (20 localities, 106 individuals) were phylogenetically distinct, with ≥7% sequence divergence, and exhibited greater levels of genetic variation and geographic structuring (ϕST = 0.774, P < 0.05). These patterns are consistent with earlier suggestions of an origin in New Zealand followed by recent colonization of Australia and back-dispersal to New Zealand. Extinction and re-establishment processes may have been important factors in the development of genetic structuring across a range of spatiotemporal scales. The genetic data are consistent with suggestions that a single subspecies exists in Australia, but not with the subspecies distributions within New Zealand that have been suggested on the basis of morphology and coloration.

A unified learning algorithm to extract principal and minor components

Recently, many unified learning algorithms have been developed to solve the task of principal component analysis (PCA) and minor component analysis (MCA). These unified algorithms can be used to extract principal component and if altered simply by the sign, it can also serve as a minor component extractor. This is of practical significance in the implementations of algorithms. Convergence of the existing unified algorithms is guaranteed only under the condition that the learning rates of algorithms approach zero, which is impractical in many practical applications. In this paper, we propose a unified PCA & MCA algorithm with a constant learning rate, and derive the sufficient conditions to guarantee convergence via analyzing the discrete-time dynamics of the proposed algorithm. The achieved theoretical results lay a solid foundation for the applications of our proposed algorithm.

Little Penguin (Eudyptula minor) variability in south-eastern Australia

This research examined the ecological, morphometric and genetic variability of the Little Penguin (Eudyptula minor) between seven colonies in south-eastern Australia. Significant differences in breeding ecology and morphology were noted for birds between colonies. However, most colonies were genetically homogeneous with respect to each other, with the exception of the Kangaroo Island colony.