Tag: Geolocators

Pigeon Guillemots are a coastal species that are locally common, meaning they are common in areas suited to their needs. You won’t spot them on sandy beaches, but in places with rocky outcrops and where they like to nest in inaccessible rocky crevices. To Lindquist, this speaks to the different survival strategies adopted out here: Common Murres nest in large colonies, seeking protection as group; Cassin’s Auklet’s are nocturnal and nest in burrows; and, Pigeon Guillemots use the rocky crevices for protection while breeding. Image Credit: Julie Chase/ACCESS/NOAA/Point Blue

The Western Gulls are residents of Farallon Islands and they’re quite abundant. Unlike the other birds out here, they forage in the wild, but they also come very close to human activities and interact with people. Western Gulls are much less isolated than the other species studied on the islands. Image Credit: Julie Chase/ACCESS/NOAA/Point Blue

Kirsten Lindquist is the ecosystem monitoring manager for the Greater Farallones Association (GFA); she is also the birder for this ACCESS cruise. She’s awestruck by ocean creatures that live in such extreme environments. Image Credit: Julie Chase/ACCESS/NOAA/Point Blue

Common Murre are ubiquitous here, nesting by the thousands. While cruising through the area, we’ve encountered large rafts of them floating out in the open and the cry of a father Common Murre searching for his baby chick can be heard frequently. Image Credit: Jenny Woodman/ACCESS/NOAA/Point Blue

The Cassin’s Auklet live offshore, you won’t see them as they are not a coastal or near-shore species. They come on land at night to breed and nest in burrows underground. The rest of the year they live out in the open ocean. They are fans of krill, the small shrimp-like crustacean that lures so many critters to the region. “Since Auklets are a lot more abundant than Blue Whales, we can use Cassin’s as indicators,” says Kirsten Lindquist, birder on this ACCESS cruise. They are underwater flyers; some birds swim with their feet and keep their wings retracted underwater. Using their wings, Cassin’s and Common Murres fly underwater. Image Credit: Point Blue Conservation Science

Rhinoceros Auklet are similar to Cassin’s Auklet in foraging and nesting, but they are less abundant in the area. They eat fish, not krill, primarily what’s available. Juvenile rockfish are the preferred food choice, but they will eat larger anchovies, which can be problematic because they may be too large for chicks to consume. Image Credit: Farallon Islands Foundation

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The sound is deafening — a symphony composed of 350,000 seabirds screeching and calling to each other. Ask a table full of scientists in the mess hall what it sounds like when you first set foot on the Farallon Islands and they answer in unison: cacophony.

The islands are home to the largest nesting colonies of seabirds south of Alaska.

Competition for real estate on the Farallons is minimal because each species has different needs. Pigeon Guillemots nest in rocky crevices and talus slopes, while the Common Murres find safety in numbers, perched atop steep cliffs and outcrops by the thousands. Rhinoceros and Cassin’s Auklets come on land at night and burrow underground to lay their eggs.

After decades of observations, scientists have learned a great deal about these creatures, but much of the research only occurs when the birds come ashore to breed in the summer. How do we know about birds that spend the vast majority of their lives out in the open ocean where few humans visit?

Some information is gleaned by sending teams on scientific expeditions like this ACCESS cruise, undertaken via a partnership between North-Central National Marine Sanctuaries and Point Blue Conservation Science. Wildlife observers spend most of each day conducting visual surveys, counting seabirds and marine mammals with a level of precision that is impressive to a non-scientist watching from the sidelines.

At various points each day, the ship stops to collect water and biological samples to understand food distribution in the region. By comparing the visual counts of animals with the samples collected, scientists can help determine predictable locations where food in the ocean lead to birds and mammals aggregating. Identifying where these hotspots overlap with human activity may help reduce negative impacts such as ship strikes and entanglements.

Adding tagging technology to these data sets enriches the picture even more.

Researchers can combine tracking and dive patterns to show when birds are going to forage and where they’re finding food. The types of dives and how deep they’re going can tell you how deep the prey is, according to Kirsten Lindquist.

Lindquist is the ecosystem monitoring manager for the Greater Farallones Association (GFA); she is also the birder for this cruise and has conducted field work on the islands. “We only know food conditions when they are breeding,” she said.

According to Lindquist, data gathered over the years has revealed details such as clutch size, diet, nesting timing and success, but this information only reflects what is happening during the summer.

In Far from Land: The Mysterious Lives of Seabirds, Michael Brooke writes, “It can be quite rare for observers to see the birds actually feeding. Is this because the birds manage to catch enough food to last, say, a couple of days during infrequent bouts of gorging, or is it because much feeding happens at night when they cannot be seen?”

“How do you tell the story of fledging on into the next spring? Where are these birds going?” Lindquist asks. Breeding season is one window – it’s just a snapshot in time, she explains.

In other words, the lives of seabirds remain a bit of a mystery.

Jaime Jahncke, California Current Group director for Point Blue Conservation Science, points out that data from GLS tags on Cassin’s Auklets during the non-breeding season has shown that birds from the Farallon Islands disperse much farther than the scientists on the Point Blue team originally thought.

“A single bird can go as far south as Baja, California and others have gone as far north as Oregon,” said Jahncke. “This makes conservation efforts a real challenge.”

While breeding on the islands the birds are protected by the U.S. Fish & Wildlife Refuge. When foraging, they’re protected within the Sanctuaries. Discovering the birds range is extended after the breeding season puts these conservation scientists in uncharted territories, because they don’t know what threats these birds face beyond the protected boundaries previously studied, said Jahncke.

Elsewhere, observations are also captured in the field by scientists like George Divoky. Each summer, he lives alone on a barrier island in the Arctic with a small colony of breeding Mandt’s Black Guillemots. He visits all the nests daily, weighing chicks and collecting data. In spite of the longevity of his 44-year study, each season seems to bring new insights, especially as the technology aiding this work gets smaller, faster, and smarter.

When unexpected snow and cold in Alaska delayed the arrival of Divoky’s Black Guillemots in June, he looked at previous year’s data from geolocators and determined that they were most likely waiting in nearby Nuvuk and would arrive as soon as their nesting boxes were clear of snow, which they eventually did.

Every spring when the guillemots return, he removes the geolocators to download data about where the birds have been spending time over the winter. In addition to aiding his own research, this data is being used by several graduate students and organizations such as SENSEI (a French research group funded by BNP Paribas) seeking to better understand the impacts of climate change in the Arctic.

Using GPS or Geolocator (GLS) tags reveal different information. The GPS used on a Rhinoceros Auklet from the Farallon Islands offered a very detailed map of where the seabird traveled during one four-day period, whereas a GLS tag helped researchers map the places seabirds traveled from month to month during the non-breeding season. “One is more fine scale movements in a foraging area and one is less fine scale trying to get data over winter,” said Lindquist.

To scientists like Divoky, Jahncke, and Lindquist, technology may hold the key to a deeper understanding of the lives of seabirds where they spend most of their time — at sea.

Lindquist said, “I’m drawn to deep, untouched wilderness and the wild things that make their home there. The ocean has a lot of that close to shore.” She explained that they can leverage the number of years of seabird data and new information from technology to tell the story of the species and the pressures they are facing in a rapidly changing world.

Jenny Woodman, Proteus founder and executive director, is a science writer and educator living in the Pacific Northwest. Follower her on Twitter @JennyWoodman.

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