Research that measures the stress levels in seabirds using their feathers can help to chart the effects of climate changes on threatened populations
A single seabird feather is like a strand or hair and hides many secrets.
It can reveal the hardships and challenges that a seabird has experienced over the past year and how climate change is affecting the environment. Feathers can be used as evidence in forensic work to show that the sea was unusually warm that year, or to warn that a population of seabirds is at risk.
Climate change has a significant impact on the ocean and consequently, on food availability for seabirds as well as their chicks. These powerful flyers can travel amazing distances to find food. They can glide above the water for tens to thousands of kilometres, looking to spot squid, crustaceans, and sometimes fish, ready to dive for the hunt. They can have a lot of stress because they are often not able to find quality meals in warm waters.
Although it may sound odd, the stress response of seabirds is very similar to our stress response as humans. Imagine your daily shopping for food being uncertain. Regular items are either unavailable or in poor condition. You search for an alternative supermarket farther away, and you spend more fuel to go grocery shopping every week.
If the crisis continues, food shortages will eventually become more widespread. Research shows that chronic stress can cause you to catch more colds or become sicker more often. Long-term, it can lead to many health problems and limitations. A stressed population of seabirds can become sick and have difficulty raising their young.
What happens when a whole generation grows up in an environment that promotes scarcity? It’s likely we would see adults in poor physical condition as soon as a decade in. They would be weak physically and far from their cognitive potential.
This is how climate changes directly affect seabirds. Stressed animals are more prone to raise malnourished chickens, which then turn out to be inefficient breeders. A declining population of birds that struggle with breeding will likely lead to population declines.
Losing seabird populations in Auckland is a serious problem. This city is the seabird capital of New Zealand. This is where you will find the highest diversity of these birds, right in your backyard in Auckland. They play a vital ecological role as what scientists call ’ecosystems engineers’.
Seabirds bring nutrients that have been deposited in their feathers, eggs and faeces to shore. Their burrowing habits change the soil and allow marine-sourced nutrients to be incorporated into our coast. Their presence is crucial for the survival of coastal forests and islands. However, many seabird species are in danger and rapidly declining. We must act quickly to rescue these birds, and our coast.
Here is where you will find the seabird feathers.
Stress hormones are deposited in the birds’ developing feathers as they grow up. Seabirds produce stress hormones in the same way as humans when their environment is difficult. Variations in hormone levels can indicate changes in the environment, and can be a sign of trouble in the population.
We can easily collect seabird feathers from the sea and measure stress hormones in labs. This information can be used to make critical decisions before the effects of climate change are too late.
We need to thoroughly test this tool in order to make the most of it.
In our research on seabird feathers, and specifically the feathers of grey-faced petrels I study at the University of Auckland, our aim is to quantify the pattern of stress hormone deposits in the birds’ feathers. We then compare what we find to the birds’ overall population stability and what we have already measured as effects of climate change.
The findings of the feathers and their findings are a key piece of the puzzle of seabird ecophysiology. They also offer promising opportunities for how we might use these new data to monitor the impacts of climate change on the oceans and biodiversity. Monitoring the ocean health is vital, but it’s expensive and difficult with rapidly changing environmental conditions and critical seabird populations.
Low-cost, non-invasive tools, such as stress signs embedded in feathers, can help us to understand our environment and how it affects our lives. This new monitoring technology can be used with precision, confidence, and my research has validated it. It engages some of New Zealand’s most underestimated birds as a promising solution to complex problems.
Innovative applied science can help us protect our taonga species, their habitats and all of the critically important it plays roles in nature. A simple seabird feather could be the key to a healthier Auckland for all.
*I use feathers of stressed grey-faced petrels, a seabird native to Aotearoa New Zealand.