Status of the Snares Crested penguin
The Snares Islands are in many ways unique islands: they feature boreal forest in an subantarctic environment, were in the past little affected by humans and are the habitat of several endemic animal and plant species. One of those endemic (i.e. just on the Snares occurring) animal species is the Snares Crested penguin (Eudyptes robustus). An estimated 23.000 – 26.000 pairs breed on Northeast Island and Broughton Island. A recent census indicated stable if not slightly increasing population numbers.

Despite of that, the IUCN (International Union for Conservation of Nature and Natural Resources) considers the Snares Crested penguin a "vulnerable" species and lists it accordingly in the "red list" of threatened species (see http://www.redlist.org). Being confined to just the Snares as their only breeding site makes the penguins susceptible to many natural perturbations (e.g. changes in prey abundance, biotoxins that often come along with plankton blooms, climatic effects like the El Niño and La Niña phenomena) or human induced catastrophic events (e.g. oil spills, competition with fisheries).

To be prepared for conservation actions in the event of an emergency, we need to understand at least the basic biology of the Snares Crested penguin. And this is exactly what the Snares Islands Project sets out to achieve.

What do we know about Snares Crested penguins?
All in all, we don't know much about them. The amount of research that has been done in the past 30 years can almost be counted at one hand: only 6 publications deal with the biology of the Snares Crested penguin, some of these even mention the penguins more or less just on the side. Therefore, we know little more than the scientific name of Snares Crested penguins and what they look like.

However, from the few data that is available, a disturbing picture emerges. In 1988 a scientific publication indicated that annual survivorship of adult Snares Crested penguins up to 5 years of age was only around 50%. In 2001, another study reported the minimum survival rate of fledglings to be only 15% in their first year. And we actually have no idea which factors cause such low survival rates…

What are we planning to do?
Considering the fact that Snares Crested penguins are little more than an empty page in an unwritten book we have quite a bit of work to do. First of all, we need to determine the basic facts of the penguin's breeding biology: when do the birds arrive in their colonies; how long is the courtship period; when starts egg laying and how long is the incubation period; when hatch the chicks; how long are foraging trips during chick rearing; what is the length of the guard stage (i.e. the period from hatching until the chicks are left alone in the nest for the first time); and finally when fledge the chicks and how old are they at this time.

The project is planned as a long-term study nad aims at understanding the population dynamics in Snares Crested penguins. To learn about the variability of the penguins' reproductive outcome it is necessary to observe the breeding success over the next few years (how many eggs are laid each season, how many of these eggs produce chicks and how many of the chicks survive to fledge eventually).

Another thing we want to examine is the phenomenon known as "brood reduction" in crested penguins. All of the six crested penguin species generally lay two eggs, but most of the time only one chick survives. What sticks out, is that the first egg laid is always smaller than the second laid egg ("egg dimorphism"). And although the second egg quite often is laid up to six days later than the first egg, it usually is first to hatch a chick. Some reports indicate that crested penguins sometimes deliberately remove the first egg from their nest. Considering this, the question arises why crested penguins 'waste' a lot of energy to produce egg number one in the first place… Could it be that crested penguins reside – from an evolutionary view point – somewhere between Emperor and King Penguins (who only lay one egg) and the other penguin species (who always lay two eggs)?

A key factor to successfully raise a chick is the availability of food in the vicinity of the breeding colony. The adult penguins need to return to their nests regularly to feed their offspring and thus their foraging ranges are greatly reduced during the breeding period. We will try to determine how far the penguins have to travel to get their daily share of fish. For that, we're going to attach small data loggers (or rather incredibly expensive, waterproof mini-computers) that record data at different time intervals and store it on memory chips from where it later can be downloaded. Two different types of loggers will be used on the Snares: timed depth recorders (or just TDRs) will measure dive depth (via a pressure sensor), water temperature and light level, GPS loggers will record the bird’s exact position every time the penguin rests at the surface. From the position fixes stored in the GPS loggers memory it will then be possible to reconstruct the foraging route taken by the bird.