Grim reaper cuts swathes through the Little Penguins of Perth

Little Penguins off the coast of Perth are being found dead - starved, battered, and in some cases almost completely beheaded - as elements both natural and manmade conspire against them. Penguin Island, 50 kilometres south of Perth and just 600 metres offshore from a rapidly growing urban area, is home for a very special colony of Little Penguins, which are the smallest of the penguins with an average height of 33 centimetres. Penguin island is not only the largest colony in Western Australia, but it also has the highest conservation status of all major colonies in Australia. In addition, there are no Little Penguin colonies further west in the world. In the Perth region, a smaller colony is also found on Garden Island, just seven kilometres north. It lies at the western edge of Cockburn Sound, the busiest bay in Western Australia. The two colonies together are regarded as one “metapopulation”

The pathology and pathogenicity of a novel Haemoproteus spp. infection in wild Little Penguins (Eudyptula minor)

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

Poorer breeding by little penguins near Perth, Western Australia is correlated with above average sea surface temperatures and a stronger Leeuwin Current

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

The foraging behaviour of Little Penguins Eudyptula minor at different light levels

The role of vision in the prey-catching behaviour of Little Penguins Eudyptula minor was tested using four captive penguins in a swimming pool. A live fish was placed in the pool with a penguin at various light intensities before and after dawn and dusk. The penguins' behaviour in the morning was the same as in the evening. As the light decreased, the percentage of fish chased by the penguins decreased, and no fish were caught at a light level less than 0.01 μeinstein/m2/s (which occurs approximately 25 min before sunrise and after sunset at latitude 37d̀S). The time the penguins spent searching for the fish also decreased with decreasing light. The probability of a penguin pursuing a fish was found to be dependent on the amount of light, such that log,(p/1 - p) = 6.323 + 2.08 × log,(light level), where p= the probability of pursuing a fish