French Frigate Shoals (Kānemilohaʻi):Tern Island Blog: New Bird Videos and Sound Clips

Short but sweet this week: Dan Rapp, who is practicing recording at burrow entrances and artificial nest boxes with a night-vision trail cam, has shared some videos of nocturnal seabirds in front of artificial nest boxes on Tern Island. Nocturnal burrowing seabirds can be very difficult to monitor, so it is difficult to track if their populations are increasing, decreasing, stable, or gone. Night vision is one way we may be able to 'see' these animals without accidentally crushing burrows, sticking our arms or equipment into their burrows, or otherwise disturbing them. Few people will ever get to see these birds -- so this is pretty cool to see!

Tristram's storm petrel video (sound at end)

Tristram's storm petrels live only in the northwestern Hawaiian Islands and the Bonin Islands of Japan. These giggly little seabirds flutter and patter over the ocean when they feed. (If you watch the video, keep watching to the end -- the sound actually comes after the bird moves out of sight.)

Dan Rapp checking on trail camera at Tern Island.

Tristram's are actually quite large for storm petrels, which are usually the smallest of all the seabirds. Birdlife International lists Tristram's as 'near threatened'; because we really don't have a reliable population estimate by any stretch of the imagination, their conservation status is really unknown, but they certainly are not widespread nor numerous. They're active at night, and nest in burrows or artificial nest boxes. Over this last year, Sarah Youngren and Dan Rapp found that Tristram's chicks are among the hardest hit by plastic ingestion (along with the more well known Laysan albatross). Tern Island is the only place in the United States, and perhaps the world (we're not sure what's going on in the Bonin Islands right now), where Tristram's are actively monitored -- so its important that we do a good job with this species.

Bonin petrel video

Bonin petrels also live only on only a few islands in the Pacific, with a largest portion in the northwestern Hawaiian Islands. They feed both when sitting on the water and by dipping for prey. Bonin petrels used to breed in the main Hawaiian Islands, but rats killed them off there. They were almost eradicated from both Midway and the Bonin Islands, but since rats have been elimiated there, the Bonins are coming back.

Like many of these seabirds, Bonin petrels can live to be pretty old: Last year, Dan Rapp and Sarah Youngren found the oldest recorded Bonin Petrel in the world living right here on Tern Island! That bird was banded 30 years ago on Whale-Skate Island -- an island about 3 miles southeast of Tern that no longer exists. Imagine a bird that is older than most of the people reading this blog..... Over 50% of the world's Bonin population still live in the U.S. Pacific islands, so knowing about this bird's status is very important to us.

Sarah Youngren setting up acoustics array. There's a microphone, cell phone (for relaying the signal to the computer & satellite dish), and other innards attached to the solar array, which powers the equipment. After calibrating this equipment, we may be able to use it in remote locations and sensitive locations such as Nihoa or Gardner Pinnacles, where people can't stick around to monitor seabirds. The acoustics allows us to obtain a relative number of seabirds active in an area -- and hence to follow trends in breeding populations.

Sarah Youngren has recorded the night sounds on tern Island, with support and equipment from Matthew McKown (UCSC) and Martin Lukac (Nexleaf Analystics). Like the night-vision camera, the acoustics recorders can share some sounds that very few people will ever hear -- like this Tristram's storm petrel and albatross from Tern.

Tristram's storm petrel -- or inebriated elf?

Albatross Soundbite

Brown Noddy Soundbite

(I have to say, I can't stop laughing when I hear the Tristram's!)

Finally, some photos from this week...