In recent years, I have taken to watching flying fish along the Maine coast. Not the usual flying fish that skim over tropical seas, but fish dangling from the beaks of flying puffins. Puffins are famous for loading their colorful beaks with a dozen or more fish and winging home to feed their solitary, ravenous chick. In the late 19th century, spotting such overladen beaks was rare, as hunting for food and feathers had depleted most puffin colonies along the Maine coast. Their recovery took 40 years of dedicated conservation work—but the work isn't over. We still need to keep a close eye on puffins to learn how warming seawater and other aspects of climate change are affecting their populations and lifestyles. So each spring for the past forty years, I have migrated from Ithaca, New York to mid-coast Maine to observe the birds during their breeding season.
Puffins are colonial breeders, gathering in large groups to dig nesting burrows on coastal or island cliffs. Each pair typically lays a single egg during a breeding season, and the parents take turns watching the egg or chick and flying to catch food. Puffins may fly 20 miles in search of fish for their young and doing so burns a lot of energy, limiting just how far they can venture from their nesting island without jeopardizing their own health. They try to catch the healthiest (high in protein and fat) fish for their chick that are within reach.
Usually we check 60 nests in a colony once a week to see whether eggs hatch and chicks survive. But we've always wanted to be able to measure chick survival and feeding more carefully. So I was thrilled in 2012 when, through a partnership with Explore.org, I was able to place a HD live-streaming video cam inside of a puffin burrow at Seal Island National Wildlife Refuge, 18 miles off the coast of Rockland, Maine. With this new tool, I could determine in great detail when a pair of puffins laid their egg, when it hatched and when the chick left the nest (fledged), all without disturbing the nesting parents. Most useful, I was able to learn how many fish were delivered to the chick—and even the kinds of fish—much more accurately than I could observe from outside the burrow.
Often, it's the quality and kind of fish that determines whether a chick survives, as well as a sufficient quantity of food. One puffin chick, which we nicknamed ‘Petey,’ couldn’t swallow the oversized butterfish that his parents brought him. Helpless to advise them to choose smaller fish, I was saddened when the chick died surrounded by food that was too large for him to swallow. By the end of the season, we discovered that only about 30 percent of the puffin pairs had managed to fledge young because there wasn't enough nutritious small food around. Normally found further south, the abundance and size of the butterfish may have been related to the warmer-than-usual water: sea surface temperatures in the Gulf of Maine were the highest in 150 years in 2012.
This summer, we installed the camera in the same burrow. I was especially keen to follow the nesting success of Maine puffins in 2013 because last winter was tough on them. Many were found dead or starving on Massachusetts beaches among more than 400 other seabirds—the worst ‘wreck’ of seabirds in recent years. Autopsies of the birds showed that they had starved.
After that hard breeding season and harder winter, we discovered about a third fewer nesting pairs than typical at Seal Island, and most pairs laid eggs about two weeks later than usual. The puffin pair that lost Petey laid another egg, which hatched a chick nicknamed 'Hope.' The millions of viewers that tuned in online to keep an eye on the chick were relieved when Hope successfully fledged. But she was among the lucky ones, as only about 10 percent of neighboring pairs successfully reared a chick this past summer.
This time it wasn't the fault of butterfish. Again, the water was warmer than usual but, unlike 2012, butterfish were scarce; apparently so too were the puffins' usual foods, white hake and Atlantic herring. Herring are intensely fished for lobster bait and also fluctuate from one year to the next depending on water temperature, which in turn affects the herring’s food, tiny zooplankton. Meanwhile, white hake is among fish documented by NOAA to be shifting their range farther north and moving into deeper, cooler waters in the Gulf of Maine. These changes threaten to further reduce food supplies for puffins and other seabirds.
As you can see, observing the puffins isn't just about maintaining puffin populations: it can also provide clues of what's happening in the water around them. Their ability (or inability) to find ample fish of the proper size and nutritional quality to raise young can help us understand how climate change and warming water affects other species—and maybe even larger ecosystems. In the long run, this may even inform us about our success in mitigating the effects of climate change. So even after forty years, I am watching the fish in the puffins' beaks more closely than ever.