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Posts Tagged ‘Tern chicks’

Although I may have spent the first few posts talking about songbirds and gulls, terns are our focus around here. These feisty seabirds are what bring us to Metinic, so it’s high time I let them have their “tern” as the center of attention.

Metinic’s terns, both Common and Arctic, had a rough season last year. Because of an unfortunate combination of bad weather and lots of egg-eating gulls, the terns were forced to abandon their nests shortly after they began laying eggs.

A Common Tern soars over Metinic - Photo by Zak

A Common Tern soars over Metinic – Photo by Zak

We were all holding our breath to see if the terns would take a chance on Metinic again this year. Even if they did, we had no idea how many would actually return.

After completing our annual tern census this week, we’re pleased to say we have 350 pairs of terns nesting on Metinic this year!

ARTE NEST

An Arctic Tern on the nest – Photo by Zak

We’ve also had chicks of both species start hatching – more than fifty of the island’s most adorable residents have popped out of their shells. The adult terns are already hard at work bringing in enough fish to feed their new chicks. It will be about a month before these little fluffballs are ready to fly, so the adults have their work cut out for them.

ARTE w Silver Hake

An Arctic Tern brings back a fish for its chicks – Photo by Zak

These days, Zak and I are out banding chicks in our productivity plots so we can chart their growth. Unlike tern parents, we can’t tell chicks apart without some kind of marker, so all productivity chicks are banded within a day or two of hatching.

ARTE baby banding

Amy banding a tern chick – Photo by Zak

We’ve also been trapping and banding adult terns. As with gulls, the best way to trap a tern is on their nest. We replace the eggs with wooden dummy eggs and set a trap that springs when the adult returns to incubate. We then band the tern and take a few measurements before releasing it. The dummy eggs are removed and the real ones are put back in the nest.  The terns aren’t too happy with the process, but they always seem to return to the nest within 15 minutes of being released.

ARTE Banding

Banding an adult tern – Photo by Zak

By banding adult birds, we have a better chance of seeing the bands again – any breeding adult has already proven its ability to survive at least one migration, so it’s likely that it will survive another year. Some terns can live to be more than thirty years old, and every time we see the band we add another piece of information about that bird’s life.

ARTE

An Arctic Tern – Photo by Zak

You may notice us wearing some strange looking hats in our photos. While we’d like to pretend these are the very latest in high fashion, they’re actually a practical method of tern defense. When protecting their nests, adult terns aren’t afraid to peck an invader, be it gull or eagle or human, on the head. They typically aim for the highest part of the body, so adding a flag to the top of you hat is a good way to keep your head from getting pecked.

COTE ATTACK

Tern attack! Adult Common Terns defend their nests from an invading mammal (aka Amy) – Photo by Zak

We’ve got a few more terns stories coming up, plus an update on some of our other seabirds, like Black Guillemots and Leach’s Storm Petrels, so stay tuned!

-Amy

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It’s only been a few short weeks, but our first few tern chicks are already taking to the sky. Although adult terns may make flying seem effortless, a chick has a lot to do and learn before its first flight.

First off, you can’t fly without feathers. Tern chicks are hatched covered in fluffy down. While these soft feathers may be warm and provide excellent camouflage, they aren’t very aerodynamic. Over the  weeks, our tern chicks have been going from this:

To this:

To this:

Their wings will grow from less than 20mm long to almost 200mm, mostly by adding long sturdy flight feathers. Their adult wingspan will be close to two and a half feet!

The chicks also grow tail feathers, but they won’t get the long, pointed streamers that mark an adult tern. As a result, you can spot a fledgling by the stubby-looking tail, even if you can’t see the unique color patterns on its back.

All these new feathers need to be kept clean and tidy, so soon-to-be fledglings spend a lot of time preening:

The next step is to build up muscle. Flying is hard work and for the first part of its life, a tern chick doesn’t use its wings for much. To make up for this, tern chicks flapping even before their wings are fully grown.

And of course, before a strenuous workout, it’s always good to do a bit of stretching:

No, not all tern chicks are green. This chick is part of a provisioning study, so he’s been color marked.

Once all their feathers come in, tern chicks start working extra hard to get airborne. It’s actually quite common to see a chick’s weight drop significantly just before it fledges.

It’s not uncommon to see them taking naps, either. Hey, all that flapping is exhausting!

Finally, for some chicks it might take a little extra encouragement. This fledgling wandered onto a neighbor’s territory and finally got airborne as he was being chased away.

While flying is a big step, these chicks still have a lot of growing up to do. Fledglings must master the delicate art of landing, figure out how to fly with a flock, and learn to catch their own food. In the mean time they can be seen begging food from their parents and making cautious practice dives into the water.

Feed me! Feed me! Feed me!

Like the terns, we’ve only got a got a short amount of time left on the island, but I’ve got a post or two more up my sleeve before we say farewell from Ship Island.

-Amy

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The infamous Roseate Tern!

There are currently four colonies with a total of 151 breeding pairs in the state of Maine. On Petit Manan alone, it’s been about a year since the last roseate tern was sighted and even longer since they last successfully nested.

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A Roseate tern nest sharing a space with a Puffin egg.

Roseate terns have either a full black or mostly black bill, a whiter coloration and considerably longer tail feathers then wing feathers in comparison to the arctic and common terns. They tend to nest along the vegetation line close to rocks of the intertidal zone. If not careful, too much activity could cause them to abandon their nests considering their sensitivity to human presence.

This year, we have two confirmed nesting pairs and another possible sighting further along the intertidal. The two nesting pairs each have two healthy chicks which we hope will fledge successfully. Their chicks have black legs and dark mottled down with fine black spots as opposed to the common and arctic tern chicks which usually have orange or pink legs with brighter down and black spots.

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A Roseate Tern chick being banded by our island supervisor Christa.

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An Arctic Tern chick being banded by my coworker Jordan.

Hopefully this means more nesting Roseate terns on Petit Manan island in years to come.

 ~Brittany

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Can you identify which of these birds are Roseate Terns? I’ll give you one hint, there are three in this picture.

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And now what we’ve all been waiting for (at all of us on Ship Island): tern chicks!

Hooray for tern chicks!

After a little more than three weeks of incubation, the first tern nest we sighted here on Ship became home to the first chick of 2012. This chick, affectionately nicknamed Fabio, was quickly followed by an as-yet-unnamed sibling about a day later. By the time the week was, out, we had chicks hatching out all over the colony

Fabio, on his hatching day

So what’s life like for a tern chick on Ship Island? Well, it begins as a ball of wet feathers and oversized pink feet. Usually, terns lay two or three eggs in a clutch, each about a day apart. As a result, the chicks tend to hatch about a day apart. This small difference in age is often enough for the first-hatched (known as the A Chick) to be noticeably larger than its siblings (called the B and C chicks respectively)

A fluffy A Chick next to a newly hatched B Chick, and an unhatched C Chick

After a few hours in the sun, the chicks dry out and become balls of fluff and feet. In less than a day, they can already make their way a short into the vegetation to hide. Tern nests are very simple and don’t offer a lot of shelter, so it’s important for chicks to get out of the nest as soon as possible. One in the vegetation, their natural camouflage kicks in and they become very difficult to spot.

A chick conceals itself in the vegetation

With a little luck, either Jill or I will spot these adorable little fuzzballs on a walk through the colony. If their legs are large enough (and they usually are) we put a band with a unique number on one leg. These bands allow us to identify the chick so we can track its growth over the weeks. Once the chick fledges, resighting the band will hopefully help us learn about migration and nesting patterns.  Terns will wear these bands all their lives

An adult tern with a band

For the next two and a half weeks, tern chicks spend their lives hiding in the vegetation and waiting for their parents to return with food. They have a lot of growing to do: a newly hatched chick weighs about 15 grams, while an adult tern will weigh as much as 145 grams. Chicks also have to grow a full set of flight feathers to replace their polka-dotted down. Fabio just reached 15 days of age, and his primaries (the long feathers at the tips of the wings) are really starting to grow! In less than a week, he should be flying around with his parents and learning to catch his own food.

Fabio sports his growing feathers

And just because I can, here’s one more picture of a chick:

Until next time,

-Amy

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They are so big now!

This chick is about 12 days old and is already almost 90 grams!  Soon his down will be replaced with the feathers that are forming underneath it, but getting a good picture of those is far more difficult then you would think.

Emerging feathers!

Feathered wings are starting to appear across the island, and even though these developing wings wont allow the chick to fly yet that doesn’t stop them from trying.  One of the highlights of our day is watching “jumpers” turn into the wind and flap as hard as they can while bouncing up and down.

Even tiny little tails have started appearing!

They haven’t made it anywhere yet, but any day now we expect to see one of our chicks fly by the blind.

-The Metinic Crew

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