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Posts Tagged ‘Productivity’

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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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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Hello again from Ship Island! Mark and I are back at home base after visiting beautiful Petit Manan Island! While saying goodbye to puffins is not easy, we are excited to come back to a thriving population of Common Tern chicks. These little bundles of fuzzy feathers are just delightful and it’s hard to keep a straight face every time you see them scampering around the colony. With chicks, however, comes hard work.

Mark bands our first chick!

Mark bands our first chick!

Before the chicks began to hatch, we set up productivity plots. Productivity plots are essentially a group of nests that have fences around them. These plots allow us to closely monitor a subset of tern nests, which gives us insight into the success of the colony this season. On Ship we have six plots with a range of 5 to 11 nests in each plot. We visit the plots every day, monitoring nests that have yet to hatch, taking daily weight measurements of and banding chicks. From time to time, we see eggs that never hatch and chicks that don’t make it. While sad, this is part of why these plots are important. Our productivity plots let us know the effects of severe weather or can clue us in to potential predators. With this in mind, we’re very happy to report that we have a strong and growing chick population this year on Ship!

Common tern with herring

Common tern with herring

With so many chicks running around, we’re able to begin our provisioning studies here on Ship Island. These provisioning (feeding) studies are set up by designating several nests that are easily seen from the blinds. As the nests hatch, chicks are banded and colored according to nest number and chick order. For example, Nest 1 is green, so the A chick is marked green on its head, the B chick green on its breast and the C chick green on its back. Each nest has its own color and the chicks are marked in the same pattern. Once the provisioning study is under way, we wait for adults to return to their chicks with food in their bills. When they arrive, we record what they’re bringing in and who they’re feeding it to. Identifying the fish isn’t difficult; trying to see what it is before a hungry chick swallows it whole is the hard part! So far we’ve seen plenty of herring coming in, some hake and sandlance, and the occasional pollock. Again, all good news for the colony and its chicks!

B and C chicks beg for food while A chick gobbles down a herring

B and C chicks beg for food while A chick gobbles down a herring

That’s all for now! Hope you’re enjoying the weather and we’ll be back next week!

-Sarah

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Tern on an egg (through the spotting scope)!

Life and death unfolds at an alarming rate here on Petit Manan Island. Thousands of eggs hatch every summer. At the peak of the season, Common Terns, Arctic Terns, Atlantic Puffins, and Black Guillemots (just to name a few) can be found on almost every surface and in every crevice on the island. But a whole host of predators are fully aware of this phenomenon – in June, PMI is ripe with adult birds, chicks, and eggs all ready for the picking. Peregrine Falcons, Bald Eagles, Harriers, Greater Black-backed Gulls, Herring Gulls, and Laughing Gulls are just a few of the predators that have already found a few meals on PMI this summer.

The Crew (minus Christa) painting popsickle sticks

The PMI Crew (minus Christa) painting popsicle sticks

In all this madness and mayhem, the research team is trying to get a gauge on the effects of predation on some of the species nesting on the island – especially Arctic and Common Terns. How many eggs are being laid and how many are being predated for each species? With several hundred nests already established, it’s a little difficult to keep track of such details! So over the years, the Refuge staff has devised a method of labeling nests with small wooden stakes – more commonly known as Popsicle sticks!

Stake indicating the nest number, species (COTE = Common Tern), date inserted and number of eggs, and the number of eggs at the check date

While observing the tern colony from the blinds scattered around the island, whenever we notice a nest we place a Popsicle stick (which we paint purple so that we can easily spot it on the ground) nearby that indicates the stake number, the date that the nest was discovered, the tern species, and the number of eggs in the nest. As that number changes (because more eggs are laid or because of a predation event), we update the stakes accordingly. At the end of the season we use this data to calculate success rates for each species.

Arctic tern on its nest, marked by a purple stake

The stakes will also come in handy when we do the big island-wide census, which is coming up soon! Check back for updates!

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