Archive for the ‘Ship Island 2012’ Category

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.



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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,


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Hello again from Ship Island! Jill and I have been off the island for about 4 days as part of a mid-season break provided for us by the refuge staff. Now that we’re back and catching up on our work, here’s the second part of  “Citizens of Ship Island”, as promised.

In my last post, I wrote about the songbirds that call Ship Island home during the summer. This time, it’s all about water birds of all kinds. While we have songbirds breeding right on the island, most of our seabirds and shorebirds are found on the three islands surround Ship: East Barge, West Barge, and Trumpet.

Take for example the Great Black-backed and Herring Gulls. Because both of these species of gulls will eat tern eggs and chicks, they aren’t permitted to breed on Ship itself. Both species, however, make (usually unwelcome) appearances on Ship and have nests on both the Barges and Trumpet. Great Black-backed Gulls are one of the biggest North American gulls, with a wing span of over 6 feet while Herring Gulls are a bit smaller. Check out the photo below for a comparison.

Great Black-backed Gull on the left, Herring Gull on the right

Also nesting on Trumpet are North America’s largest sea duck: the Common Eider. While the females may look like a standard brown duck, the males have flashy black and white plumage.

A handsome Common Eider male with two Common Terns on the beach of Ship Island

Most often we see these large ducks paddling around with their heads under the water before they dive down for mollusks and other invertebrates. As you can see, they are quite a bit bigger than a tern!

A male Common Eider on the left, a female on the right, and a Common Tern in the middle

Eiders are best known for the incredibly warm down they produce – the females actually line their nests with these soft feathers. Eider ducklings take to the water the same day they hatch. Females with ducklings will gather together to form crèches, made up of several females and their young, to help protect the ducklings from predators like gulls. Although eiders pose no threat to our terns, they find people a bit intimidating and so prefer to nest on Trumpet.

A female Common Eider and her ducklings

Out on West Barge, in addition to lots of Great Black-backed Gulls, we have a colony of Double-crested Cormorants. Like the eiders, the cormorants prefer to nest on human-free islands, but we see them every day in the waters around Ship.

West Barge’s Double-crested Cormorant colony

They also sometimes come to shore to gather seaweed for nesting materials, like the one flying off in the picture below. The colony on West Barge seems to be doing well – we’ve counted about 50 cormorants on the south side of the island.

A Double-crested Cormorant flies off with some nesting material.

Not all of the water birds find us so intimidating. We have several Mallards on and around Ship, including a female with her ducklings. We usually see this fluffy gang paddling around in a swampy depression in the middle of the island.

Female Mallard paddling with her ducklings. Photo taken by Jill

Finally, we have our beloved Spotted Sandpipers. The only shorebirds that nest on Ship Island, Spotted Sandpipers are easily identified by their “teetering” behavior: as they walk (or even when they stand), they bob their rumps up and down. The purpose of this behavior is still unknown, but it makes them easy to pick out of a crowd.

An adult Spotted Sandpiper on the shores of Ship Island

We have several pairs of these nesting on the island, and we recently spied our first chick running around on the beach. Compared to other young birds, Spotted Sandpiper chicks are quick and agile. This one was already practicing its teetering! Jill snagged a photo of him bobbing his way down the beach.

A Spotted Sandpiper chick out for a run on the beach

Next time, the terns will be back in the spotlight with fuzzy chicks galore!

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While our terns are busy incubating their eggs, I thought I’d take some time to fill everyone in on some of the other birdlife here on Ship Island.

Although they might be the most numerous, Common Terns aren’t the only birds that nest on Ship.  In fact, Jill and I usually wake up to the sounds of song birds, not sea birds. Six species in particular call Ship their summer home:  three sparrows, two warblers, and a swallow. Many local birders will find most, if not all, of these to be familiar Maine residents.

First up is the melodious Song Sparrow. Although they may lack the sleek elegance of a tern, they make up for it with a distinct voice. We estimate there to be about six pairs nesting on Ship, although they’re loud enough to be heard on every part of the island.

Our second sparrow is the sonorous Savannah Sparrow.  At first glance they look quite similar to a Song Sparrow, but they sport some flashy yellow eyebrows (technically called the supercilliam). Again, we believe we have about six pairs nesting on the shrubby interior of Ship Island. We often see both Savannah and Song Sparrows chasing each other around the island.

A Savannah Sparrow

Our third sparrow is the more elusive Nelson’s Sparrow.  We’ve only spotted two of these on the island so far, but we’re hoping to find more. Compared to the warbles, cheeps, and trills of the Savannah and Song Sparrows, the song of the Nelson’s Sparrow is quite distinct: a sharp hiss, which reminds me of a burger being dropped onto a hot grill.

A Nelson’s Sparrow

Besides those three sparrows, our most numerous non-tern residents are warblers: Common Yellowthroats and Yellow Warblers.

With their distinctive black masks, Common Yellowthroat males are quiet striking. They’re also far from the secretive tree-top dwellers many birders think of when they hear the word “warbler.” Our Yellowthroats are most often seen perched on the top of a bramble or other shrub, singing their hearts out like the fellow below. We’ve got at least three pairs nesting on the island.

A male Common Yellowthroat

Yellow Warblers are usually the first bird I hear in the mornings, probably because we’ve got a pair nesting right next to the cabin.  We’ve got perhaps four or five nests of these flashy little, and it’s not uncommon to see pairs of males chasing each other around the middle of the island.

A male Yellow Wabler

Our final bird for today is a change-up from the first five birds I’ve listed. Our seven resident Bank Swallows are in almost constant motion. They’ve set up shop under the bluff of the high side of the island. Presumably, they have a burrow there, but we haven’t managed to spot it. We’re keeping our eyes open, though. Until then, we’ve been enjoying the gurgling calls and acrobatic maneuvers of these zippy little birds. So far, they’ve proven faster than my camera, so here’s a shot of where we suspect they’re living:

Here’s the bank, but where are the Bank Swallows? So far, they’re too fast for my camera.

Stay tuned for Part 2: Seabirds, Shorebirds, and other Swimmers!

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Allow me to introduce you to the worst enemy of the Ship Island Crew: garlic mustard. Although this may sound like a tasty addition to your next sandwich, we can’t wait to see the last of it here on Ship.

A small stalk of garlic mustard showing its characteristic heart-shaped leaves

Garlic mustard, or Alliaria petiolata is a highly invasive plant species that has spread over several parts of the island and it is incredibly difficult to eliminate once it becomes established.  On its own, a stalk of garlic mustard may look harmless, but don’t be fooled: this stuff is a pain!

While the adult plant is easy enough to uproot, it is highly persistent in its other forms.  Garlic mustard is a biennial plant, which means it takes two years of growth before it flowers and produces seeds. The smaller first year plants can be difficult to find in all the other greenery of the island. Small single-leaf seedlings are even harder to spot.  On top of that, seeds can stay dormant for years before sprouting, so even if we were to pull up every stalk of garlic mustard, we would still see more sprout up next year.

So what are we doing about it? The Refuge has been working with Glen Mittelhauser , a private contractor, to determine effective measures for removing this invasive plant before it covers the island. To start with, we’ve been pulling up every flowering stalk we find. And there are A LOT of flowering stalks. See that picture below? That’s about half of what we’ve pulled off of our 11-acre island so far.

Next step is the application of one or more sprays to kill the seedlings and non-flowering stalks. Since we’re so close to breeding birds, we’ve been trying to avoid the use of strong chemical herbicides. After studying results from some test plots set up on the island, Glenn has us using vinegar and seawater in areas where we’ve pulled up the flowering stalks. Hopefully, if keep this up over the years, we’ll be able to deplete the seeds that have been stored up in the soil and rid the island of this unpleasant plant.

Garlic mustard has small flower with four white petals

So why is it so important to get rid of garlic mustard anyway? One of the most important parts of our job out here on these islands is to maintain a habitat that is conducive to healthy seabird colonies. Terns nest in or near vegetation, and the presence of invasive species such as garlic mustard may reduce the amount of suitable nesting habitat. Additionally, terns aren’t the only birds breeding on Ship Island: we’ve also got Savannah Sparrows, Song Sparrows, Common Yellowthroats, and Yellow Warbler. All these birds depend on a finding a healthy habitat on Ship Island so they can successful raise their young.

So wish us luck in fighting this mustardy menace!

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Greetings from Ship Island! 2012

Greetings from Ship Island!  Located in Blue Hill Bay just southwest of Mount Desert Island, Ship Island is part of the Maine Coastal Island National Wildlife Refuge and serves as a summer home and breeding grounds for over 150 pairs of Common Terns.  This year it will also be the summer home for a crew of two biologists: Supervisor Amy (Yours Truly) and Intern Jill.

Ship is actually quite a bit different from the Refuge’s other managed seabird colonies. It is the last island in a chain that begins to the north with Tinker Island, followed by Bar Island and Trumpet Island. Thanks to a winding sand bar, Ship and Trumpet are actually connected at the lowest tides.  Sand is another thing that makes Ship special: instead of nesting on rocks, terns at Ship nest on the edge of a sandy beach.  This means the Ship island colony is in a thin band between the sand and vegetation, 

Earlier this week, Jill and I arrived at the Refuge’s office in Milbridge, ME and got an exciting surprise. Previously, researchers living on Ship Island for the summer were based in a large canvas tent, but this year we would be the first crew to live in a newly constructed cabin! Complete with bunk beds and a storage loft, our 12 by 16 home will soon have an indoor kitchen and a small refrigerator.  In the meantime, we’ll be cooking outside and storing perishables in a cooler, but we’ve already come to appreciate a solid roof over our heads during the recent rainstorms.

 Like us, the terns have spent the week checking out the island and moving into their summer homes. So far we’ve seen about 70 Common Terns circling around the island and its surrounding waters.  These birds have migrated thousands of miles and will settle here for a few short months to raise their chicks. It will still be a few weeks before they begin to nest, but after that things will really pick up around here. Eventually, we may have over 400 adult terns and their chicks living on the island.

In the meantime, Jill and I are keeping busy by getting to know Ship and the surrounding islands. In addition to Trumpet, there are two smaller islands, East Barge and West Barge, which we keep an eye on throughout the summer. These three islands host breeding gulls (Greater Black-backed and Herring) as well as Double-crested Cormorants and Common Eiders. Gulls are predators of tern chicks, so they’re not allowed to nest on Ship, but there will probably be a few nests on these other islands.

I’d love to post photos, but the computer isn’t cooperating right now, so hopefully I’ll be able to post pictures of Ship and our lovely little cabin soon.

That’s all for now!

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