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Posts Tagged ‘Maine’

This past week on Ship Morgan and I both took our short breaks off the island. While Morgan was away I was joined by Kelby from PMI to work on predator control, productivity plot management, chick banding, and more!

We’re starting to see more and more chicks every day! Usually when we’re checking the productivity plots we can see when they start pipping. This is when their little beaks start to break open the egg. This lets us know that the next day we will definitely have some new arrivals to weigh and band if they’re dry and ready.

Before we start provisioning, we still have some time to re-sight birds from previous years. Typically, they will have a small silver BBL band on their ankle which contains either 8 or 9 numbers. We can use a spotting scope to see these numbers and enter them into a database where we can learn more information about that bird, such as it’s age. To make re-sighting easier, we put up posts for them to perch on so they aren’t being covered by the vegetation and are closer for us to see. While I was re-sighting from the blind, I spotted a tern that hasn’t been re-sighted in 19 years! I also found one with an orange band. This means that it was banded all the way in Argentina, which I thought was pretty cool.

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An example of a BBL band that can be found on the leg of a Common Tern. As you can see they are very small, which makes them difficult to read.

Now that the owl is gone, we are starting to see more birds come back to the colony. Many of them left during the time he was here and abandoned their nests. Thankfully now they’re starting to scrape the ground and re-nest. Chick age distribution around the island will surely be scattered, but at least they’re not giving up!

Now that I’m back on the island, there’s a lot more chicks running around and much more work to do!

-Amanda

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So far around the island we’ve come across Common Eider, Mallard, Savannah Sparrow, and Spotted Sandpiper chicks. Although a little behind schedule, we were beyond happy to finally find our first Common Tern chicks! Soon we will start banding them and taking measurements. Hopefully we will start seeing more every day!

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Our first Common Tern chick!

Our terns have been acting different than normal. Rather than settling down to incubate, many of them appear to be much more active flying around and leaving the island. We grew suspicious that there might be an owl around. In order to make sure it doesn’t disturb our terns, we set up a total of 17 foothold traps covering all sections of the island. When we placed the traps, we put them in areas that seemed suitable for an owl to land. If the owl lands on the platform that contains the trap, its leg will be caught. This trap doesn’t hurt the owl because it’s padded, but it allows us to capture it so it can be relocated. Though our minds were focused on an owl, we didn’t forget about our frequent Peregrine Falcon visitors. To prevent any unintended capture, we made sure to set off the traps during the day.

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The sign is lined with chicken wire at the top making the post with the trap the only suitable place to land

Only a few days after setting the traps, we caught the owl! Morgan and I noticed the terns were once again acting strange during our night stint, where we took shifts watching the colony between 6:00 PM and 12:00 AM. The next morning the terns were dive-bombing at the ground, and I could see through my binoculars that the trap wasn’t on the post anymore. It seemed unlikely that we caught an owl, especially since we weren’t completely sure we even had one, and last year it took over 2 weeks to catch it! We walked over expecting to find something like a gull caught up in our trap, but to our surprise it was a Great Horned Owl! We safely caught the owl, covering its head so it would stay calm, and removed him from the trap. It already had a band on its leg, so we suspect that it might be the same one from last year. The owl will be brought to a rehabilitation center to make sure it isn’t hurt, and it will be released somewhere far from our terns! We are so thankful we caught it in time, especially now that our eggs are hatching!

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Morgan about to cover the infamous Great Horned Owl with a blanket to keep him calm

 

Outside of bird research, we enjoy watching the Harbor Seals bask in the sun and swim around with their pups. The seals can be found on two adjacent islands. One pup decided to visit us on Ship this week. We were nervous when we didn’t see the mom around, but we were taught that after 3 weeks the pups begin to live on their own.

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Curious pup visiting our island

Ship has been very busy this week. We’re hoping to continue to wake up to new surprises every day, but only good ones!

-Amanda

 

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This weekend the Ship Island crew headed over to Pond Island to take part in a beach cleanup along the shore. Morgan and I, as well as several other volunteers, collected dozens of trash bags filled with lost buoys, cans, bottles, and more. This year is the first year the group will be able to actually recycle the plastic that was collected. Through the company, TerraCycle, our collection of plastics, no matter how dirty or broken they may seem, will be sent over to be thoroughly cleaned and re-purposed. Typically, most objects made out of recycled plastic only consist of about 30% reused material. Though it doesn’t seem like a lot, or maybe even not enough, if the concentration is increased then the new object becomes closer to the end of its lifespan and can no longer be reused. It was good to get off the island and spend some time with others working to keep our environment clean, but we’re glad to be back on Ship with our terns!

 

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Section of a boat that was found washed to shore. We needed all hands on deck to carry this one over!

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Beach Cleanup Volunteers

Back home on Ship, we’ve had problems with other birds predating on our Common Terns and their eggs. Currently, Great Black-backed Gulls, Herring Gulls, American Crows, Peregrine Falcons, and Northern Harriers are our main concerns. Almost every day we spend two hour shifts in the blinds to observe the tern behavior and keep an eye out for any of these predators that might pass by. During the evening we’ve been marking nests with predation sticks so we can notice if any eggs have gone missing. By doing this we are also able to get a good idea on how many terns we really have on the island. It doesn’t look like it, but so far we have counted over 500 nests, which means we have over 1000 terns! So far so good! In a few days we will be doing a GOMSWG census which will give us an even closer estimate on our tern population size. We’re excited to share the results with you next week!

-Amanda

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Petit Manan Island is in peak hatching season! The small, delicately speckled brown tern eggs are disappearing and being replaced by similarly patterned fluffy chicks. The oblong, white-brown spotted black guillemot eggs are opening up to reveal all-black downy chicks. Where once we were seeing large, gleaming white puffin eggs, now chicks with long grey down and white bellies are hiding quietly in their burrows. We even have found one razorbill chick (see photo below)! The only seabird still solely in the incubation stage are the Leach’s storm-petrels.

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One question that I often get asked is, why do some seabirds only ever hatch one chick (think puffins, razorbills, storm-petrels), while others can rear multiple chicks (terns, guillemots, etc)?

In general, seabirds have small clutch sizes compared to birds of other groups like most waterfowl, game birds, and some perching birds. This is because seabirds, unlike the groups mentioned previously, tend to have long life spans. This means it is not quite as critical for seabirds to have a successful nesting season their first breeding season or every year of their life in order to replace themselves in the population. Other bird species may only get one chance to successfully reproduce if annual adult survival is low due to high depredation of adults and/or other factors.

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But why lay only one egg instead of two or even three? There are multiple factors that influence seabird clutch size, and still many questions to be answered. Chick rearing is very energetically demanding for the parents, from egg formation to providing enough food for growing chicks. Right from when birds arrive on the breeding grounds, food availability is critical. After long migrations or rough winters, seabirds need to be able to find enough resources near their breeding colony to allow them to be in proper condition for breeding. Limited food resources during this period of time can cause birds to lay smaller clutch sizes, or even not nest at all.

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This still does not answer our question why puffins and other species only lay one egg, in both good and bad food years. For species with one egg clutches, it is more beneficial for the long-term survival and breeding success of the adults to raise only one chick at a time. Raising two chicks would probably not be impossible during good food years, but the energetic costs on the parents might make this not worthwhile in the long run. So puffins, razorbills, and many other seabirds prefer to take things slow, laying only one egg per season.

Currently, we have found 17 black guillemot chicks, 15 Atlantic puffin chicks, one razorbill chick, and a few hundred tern chicks!

-Jill

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Hello everyone!  The main focus on Metinic this week was our chick provisioning watches.  Essentially what happens is we are watching to see what the adults are feeding their chicks.  To set this up, we select a number of nests in good visibility from our blinds and mark them with numbered and color-coded tongue depressors. We then find the chicks that belong to each nest, band them, and then color a specific part of their body according to the hatch order and corresponding nest.  The first chick to hatch is called the “A” chick and is colored on top of its head.  The second chick to hatch is called the “B” chick and receives color on its chest.  The third chick to hatch is called the “C” chick and is colored on its back.

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One of our provisioning nests.  The color on top of the “A” chick’s head corresponds to the color on the tongue depressor.  When the egg hatches, the “B” chick will get the same color on its chest.

During each provisioning stint we watch each nest for adults coming in with food for the chicks.  We record the nest number, the arrival time of the adult, which chick receives the food, the departure time of the adult, the number of prey items, and the species of prey brought in and its size.  Prey size is determined based on the bird’s bill length.  For example, a fish can be recorded as 1 bill length or 1.5 bill lengths; size is measured to the closest quarter of a bill length.  All of this is often determined within a few seconds as the adults swoop in and the chicks gobble down the food quickly.  Each provisioning stint lasts 3 hours and we try to total at least 12 hours a week each.  All of this information will give us an idea of the amount of food coming in and its quality.

Besides the provisioning watches, we have also been continuing our productivity monitoring.  It is amazing to see just how quickly our chicks are growing up!  Right now the majority of them are in the process of replacing their downy fluff with feathers.  Another interesting thing to observe is the range in development.  A few of the chicks have mostly feathers and seem like they will be fledging soon, while others haven’t even hatched yet!

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One of the older chicks in our productivity plots showing off its feathers.  It is getting so big!

Provisioning and productivity take up the majority of the week, but Mark and I decided to take one afternoon to head down to the southern end of the island to see if we could spot any new species to add to our island list.  As we were walking along one of the southern cobble beaches we came across a bird washed up on shore.  At first glance it looked like a small gull, but as we got a closer look we discovered that is was a tubenose.  Upon further observation and investigation, we were able to ID it as a Northern fulmar!  Our species list is now up to 92 with the addition of a great cormorant, lesser yellowlegs, and a semipalmated plover!

That’s about it for this week, we will be celebrating the 4th of July with our seabirds!  So far, we have been enjoying the various firework shows going on miles across the water on the mainland, and who knows, we may even break out the small grill this evening!

Have a happy 4th of July!

Helen

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Petit Manan Island is well known for its seabird inhabitants, most notably our Atlantic Puffins and Arctic Terns. However, a total of eight species of marine birds return yearly to nest on Petit Manan Island. Most of these birds have conspicuous nests, such as the terns and Laughing Gulls which lay their eggs on the ground’s surface. The Alcids, such as Puffins, Black Guillemots, and Razorbills, lay their eggs in burrows or rock crevices, but the adults are still easily observed on the rocks and surrounding waters. But Leach’s Storm-Petrels, the smallest seabird denizen of Petit Manan, are a little bit trickier to detect.

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Jimmy holding an adult Leach’s Storm Petrel that was grubbed from a nearby burrow

Leach’s Storm-Petrels differ from the other seabirds on PMI in a variety of ways. Taxonomically, they are the only species representing a group of seabirds called the Tubenoses to be found on PMI. Also, they are nocturnal and nest in often long, twisting sod burrows.  The burrow entrances are smaller than the size of a fist, and tucked underneath rotting logs, debris and rocks. These life history traits make observing storm-petrels quite the challenge, and prevent accurate estimations of breeding pairs on nesting islands.

This summer we have been testing a new methodology to s
urvey for active storm-petrel burrows. Instead of just reaching as far into each burrow to feel for birds and eggs, we have been playing a recording of storm-petrel vocalizations outside of each potential burrow entrance. The results have been extremely exciting! The birds have been responding with their strange, goblin-giggling call from deep within their burrows. But more importantly, this method has allowed us to find more birds than just by feeling in the burrows. In fact, 63% of the storm-petrels we located only because we heard them – their burrows did not allow us to reach them. Overall, 93% of the adults we located using both methods responded to playback. Hopefully this monitoring technique will provide new insights into Leach’s Storm Petrels nesting on Maine coastal islands!

-Jill

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The beginning of the week started out slow and rough as the weather was not cooperative.  High winds made it so we could not go out to the tern colony as we wanted the adults to stay on their eggs and keep them warm from the howling winds.  Finally the weather broke Tuesday afternoon and we were able to do some trapping and banding of adult terns.  We do this by selecting a couple of nests, replacing the eggs with wooden ones so they do not get damaged, and placing a chicken wire trap over the nest with the door open.  When the adult walks into the trap, they step on a trigger platform that closes the door.  As the adult sits in the trap incubating the wooden eggs, we walk up and take it out of the trap through a hole in the top.  The adult is then placed in a bag where it is weighed using a spring scale.  We then band the bird and measure its wing chord and head-bill length before it is released to return to incubate its eggs which we have switched back to the real ones.

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A common tern checking out the trap

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Measuring wing chord length

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Measuring head-bill length

Wednesday we headed over to Matinicus Rock to help them with their tern census.  It was nice to get out to another island to see what was going on there; plus we got to see Atlantic puffins, razorbills, and common murres, three species that do not nest on Metinic.

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Atlantic puffins on Matinicus Rock

The next day it was our turn to census!  With the help of a few guests, we were able to count 608 nests in our colony of arctic and common terns!  We did this just in the nick of time as we came across multiple hatched chicks with more popping up every day!  The rest of the week was spent securing our productivity plots which are circles of fencing surrounding a number of nests.  When the chicks within the plots hatch, we record the hatch date and band them.  Every time we visit the plots, we weigh the chicks and keep track of how they are doing until they fledge.

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Pipping arctic tern egg

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A hungry chick waits to be fed

Throughout the week we have also come across savannah sparrow chicks and fledglings, and spotted sandpiper chicks running around on the rocks.  An identifying characteristic of spotted sandpipers is they bob their rump up and down as they walk; it is funny to watch the tiny fuzzy chicks do this as well!  We are looking forward to more chicks showing up in the upcoming weeks!

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A tiny spotted sandpiper chick

Until next week,

Helen

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