Evidence suggests that climate change is negatively impacting their breeding on the Antipodes Islands, making their egg-selecting habits a detriment to their survival The erect-crested penguin population has declined sharply in the last 50 years. They suggested that conservation marketing – raising public awareness and advocating for more research – could help conservation efforts. The scientists cautioned that, without more research attention into its population dynamics, the species will continue to decline until threatened with extinction. Rising ocean temperatures have already caused the population of eastern rockhopper penguins to crash and they are likely affecting the erect-crested penguin's ability to reproduce and feed as well. This may help the males to protect the nest and guard the incubating females from bullying by other birds.ĭespite these evolutionary traits that help the species survive, the population has declined sharply in the last 50 years.Įvidence suggests that climate change is negatively impacting their breeding on the Antipodes Islands, making their egg-selecting habits a detriment to their survival.Ī greater numbers of storms and mudslides in recent decades has wiped out parts of colonies and killing nesting penguins. Right: Mass of the second egg relative to its laying dateīlood samples taken from the penguins also showed how hormones affect the birds' behaviour.ĭuring laying, females had testosterone levels that were as high as the males but they dropped during incubation and rose in males. Left: Mass of the first egg relative to its laying date. This may be because females begin to form their first egg while still at sea and their second egg after reaching land, where it has fewer constraints and can grow bigger. It was discovered that the second egg laid by female erect-crested penguins is often larger than the first. However, the modern penguins now sacrifice their first egg as they can't provide enough food for both chicks. The researchers suggest that the erect-crested penguins have retained the reproductive habit of their ancestors, who laid and hatched two eggs. Therefore, it is now thought that the reason the first egg is sacrificed is because the chick inside is more likely to starve than the one in the larger second egg. They also discovered that the second egg laid by female erect-crested penguins is often larger than the first. The data shows that, typically, the penguin's first egg is lost either before or soon after the second egg is laid and parents sometimes deliberately break or reject it.Īround 40 percent of mating penguin pairs do not even bother to incubate the first egg, with steady incubation occurring only after the second egg is laid.Įven when researchers put a ring of stones around some nests to stop the first egg from rolling away - a common occurrence - it was still often broken or not incubated. They sought to learn more about the birds' strange behaviour and to provide a basis for future conservation efforts. However, the erect-crested penguin sacrifices its first egg - the reason for which was, up until now, unknown.Īs Professor Davis' 1998 data set was the most extensive published about the species, his team decided to reanalyse it to discover the answer. Other species of birds that do this lay a second egg as a form of insurance, in case the first chick does not survive. In this latest study, researchers noted that the erect-crested penguin engaged in what's known as 'brood reduction', where it produces more eggs than is possible to rear. The lack of research into the species could, in part, be due to its remote habitats. Prior to this work, published in in PLOS ONE, most of what was known about these penguins came from a 1998 study from lead author Professor Lloyd Davis.
0 kommentar(er)
