The beginning of the end

The milky way over PMI, photo by Jenna Lutes

This past week on PMI has transformed from a tern chick takeover to flight school for fledglings. Over the past few weeks during our feeding studies we could observe our tern chicks flapping their feather-less wings, or at least attempting to. As time passed and they gained more feathers this flapping became a very large jump… and typically a crash landing. However their practice has paid off, our skies are now filled with fledglings getting ready for their migration. As exciting as this is the crew is now racing the clock to band as many chicks as possible before everyone is flying away.

PMI crew each holding a tern fledgling during a banding sweep.

We also have a few brand new additions to our island family. Last week we found our first Leach’s Storm Petrel chick. LHSP chicks will be brooded by their parents for up to twelve days and after that the adults will only come back every other day and can be gone for up to 3 days based on weather. They will stay in their burrows till they fledge at about 8-9 weeks of age.

Leach’s Storm Petrel chick (Oceanodroma leucorhoa)

We also found our first Razorbill chick last week and were able to grub him from the burrow on Friday. As of right now we only know of the one chick, but we are hoping to find more. This little bundle of fuzz will head out to sea with its dad at around 18-20 days old!

Our Razorbill chick (Alca torda), we have decided to name it Jasper

As our tern chicks begin to fledge and the rest of our sea bird chicks put their work into growing so they can head out to sea; we have one more member of our island family preparing to leave. One of our fellow island techs Micaela Griffin (known for her love of puffins and stellar gopro skills) will be leaving us this Friday. We hope you have enjoyed her blog posts as much as we have, she will be missed as we finish the next two weeks here on PMI. Much like many of our birds this is her first island season, and we are so proud of how easily she adapted to island life and field work.

Micaela weighing a puffin chick on puffin point

That’s all for now!

-Kelby Leary on PMI

 

The Lingering Effects of a Nocturnal Predator

It has already been over two weeks since the Great Horned Owl roamed the surface of Ship Island looking for a late-night snack. You would think that over time, the terns would settle down and begin to behave “normally.” But that’s not the response we’re seeing. Even today most of the colony begins to sweep high above the island soon after sunset, then disappear quietly out over the ocean. It seems that small numbers do come back to warm their chicks and eggs, but the majority aren’t seen again until sunrise.

The owl caused full colony abandonment during the nights on the island. This occurred for over a week straight, which might have led to some long-term effects on chick physiology. Many of the eggs didn’t end up hatching since they weren’t incubated during the nights. But, some eggs were still able to make it. Typically, eggs hatch after 21-23 days of incubation. With the owl disturbance, incubation length increased, which is why our chicks arrived slightly behind schedule.

Although we have many healthy chicks all around the island, there are a select few that are showing what we assume to be the negative consequences of this over-exposure to the cold and wet nights on a Maine island. When terns incubate, they are constantly rotating the eggs around. This allows for even nutrient and heat distribution throughout the egg as well prevents the embryo from sticking to the shell, allowing it to float in the middle and develop successfully. Without this constant rotation, it’s possible that the chicks could have developed certain physical defects.

 

Chick with one defective leg

Chick with two defective legs

Not only are we seeing odd chick appearances, but we are also seeing a huge change in colony behavior. The terns have been extremely sensitive to any presence that might seem or sound threatening. This even includes species that are not considered predators. In order to protect themselves, terns often mob, dive-bomb, or attack the predator. They also might flee, just as they did with the owl. Their actions depend on the level they feel threatened themselves versus how threatened their young are. We’ve observed terns going after Common Eiders, Dowitchers, and Harbor Seals. They were even frightened by the sound of a nearby fishing boat. Although we can see that these species are here to do no harm, it’s still good to see the terns working hard and being extra protective.

These actions displayed by the tern colony isn’t uncommon among populations who are or were at risk of nocturnal predation. In fact, it has been witnessed in several other Common Tern studies where owls were present. Looking at a well-known colony observed by Monomoy NWR in particular, you can read how they experienced very similar results years ago (Nisbet and Welton, 1984).

It’s amazing how a single bird can influence an entire colony in only a few days. This owl left an impression on the terns to last the entire season. The fate of this years fledgling was greatly altered and we can only hope that next year the colony works to make up for this years loss.

On a better note, we’re still waking up to a few more chicks every day, and we’ve already seen a few fledge! Based off of our provisioning efforts and weight measurements, our current chicks are growing at a steady rate and being fed a healthy diet, which mostly consists of Atlantic Herring. Some chicks are being fed so much that they actually have to lose weight in order to lift themselves off the ground and fly! We’re glad to finally start seeing our chicks transform into successful adults!

One of my healthy provisioning chicks. Not quite ready to fledge yet!

Chicks that were recently born. Only a couple days old!

Only one more week until the island closes. This season really flew by! I’ll keep you updated on any more unusual or exciting events happening on Ship!

-Amanda

Approaching Flight

Measuring wing chord on a black guillemot chick

It’s hard to believe that we only have one week left on Metinic Island. It seems like yesterday that we arrived in the chilly May weather.  As we count down the days, we have been busy collecting our last stretch of data before the birds too leave the island.  The terns that just hatched weeks ago are taking flight from our productivity plots. The forage fish held out during July and we are expecting a high rate of overall survival. The black guillemot chicks in our study burrows are also doing well. We have been monitoring their weight and wing growth since hatching. Black guillemots tend to gain lots of weight before they shift to wing growth. The chick pictured here is 278 grams and has a wing chord of 84 millimeters.

Black guillemot chicks attempting to hide in their shallow burrow.

The last few days have been plagued with fog which means limited work out with the birds. But we have been keeping busy from the cabin entering all the data we have collected into excel spreadsheets and Microsoft databases. We have also had to keep an extra eye on the window as the number of nuisance sheep has increased to seven! Herding them away from the tern colony has become a daily routine.  Tomorrow we are greatly looking forward to a day trip out to Seal Island to see some puffins!

Cheers to a wonderful season!

Ravin

Arctic tern chick approaching fledging!

Chicks are Ready for Takeoff at Metinic!

Hello again from Metinic!

We have just two weeks left here on the island, and it has been amazing how much things have changed since we got here.  Most of our little fluffy chicks have grown in actual feathers and some of them have even begun to fledge!  It has been a truly unique experience being able to watch them develop from an egg to a bird that will make a journey all the way down to Antarctica.

A box of common tern chicks waits patiently as we weigh and record other prod plot chicks.

We have also been busy monitoring our black guillemot burrows and marking their location on our GPS.  They have also grown a lot, some weigh over 200 grams!  Sometimes when we approach a burrow, the adult is in the burrow with the chicks and we band the adult as well.  They require a bit more force to handle than the chicks, we need to use both hands when handling them!

Ravin with an adult black guillemot

In other news, as our large crop of wild strawberries begins to dwindle down, we anxiously await the ripening of the wild blueberries, raspberries and blackberries that litter the island.  We ordered a few mason jars from the mainland in hopes of making wild berry jam!

Till next time,

 

Aya

Hatching Chicks and More Eggs on their Way

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.

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

Puffin Chicks on PMI!

Greetings from Petit Manan!

This week we have been focused on monitoring the productivity and provisioning for the chicks on the island. The tern chicks in our productivity plots have been growing strong, many now weighing over 100 grams. So far during our provisioning stints, we are seeing tern chicks mainly being fed herring, hake and sand lance. These are good food sources for the chicks!

Common tern feeding its chick a sand lance

We have also seen many adult puffins flying into burrows with fish, which means more puffin chicks may have hatched this week. So far we have confirmed that 3 puffin chicks have hatched, but we are seeing puffins enter some of the deeper burrows carrying fish, which suggests more may have hatched as well.  We will begin puffin productivity this coming week, where we will do a more thorough search to determine how many chick have actually hatched! Unlike terns, which usually only bring one fish at a time when feeding chicks, puffins are able to carry multiple fish in their beaks at a time! This makes provisioning a bit trickier, since rather than having to identify one fish, there could be multiple. Also, the puffins tend to duck into their burrows quickly after landing with food for their chicks which can also make identification difficult. We decided to try putting a GoPro in one of our puffin boxes this morning to see if we could possibly use GoPros in some of the man-made puffin boxes to add to our puffin provisioning data. We were able to take some pictures of a puffin chick being fed by its parent!

Puffin chick being fed by its parent

Puffin chick checking out the GoPro

The puffins are my favorite birds on the island, so I look forward to finding more chicks this week!

~Micaela

 

Fish and Chicks!

Aya reaching for 2 black guillemot chicks at a numbered burrow

We are currently in full swing of tern feeding studies and productivity checks for terns and black guillemots chicks! The majority of the tern chicks have hatched and are doing well. Our feeding studies reveal that the adult terns are continuing to bring in hake and sandlance as the primary food for the chicks. Both of these fish are very high in nutrients which means the chicks are getting nice and plump. Warmer water temperatures could change the fish composition for the worse so our fingers are crossed that it stays the way it is as the chicks approach fledging in the next few weeks.

 

Arctic tern chick with a BBL band on the birds right leg and a field readable on its left. 

We have begun banding the older arctic tern chicks with field readable bands, so they can be easily identified as adults. This allows the Refuge and our partners to collect information on the importance of each island as a nesting location for specific individuals and to determine adult survival. We have been reading field readable bands on adults during resighting stints throughout the summer and will continue to identify as many birds as we can for the rest of the season.

We have also returned to the Leach’s storm petrel burrows that we flagged earlier in the season to determine if they are active by playing the call of a petrel on our phones and waiting for a response from an adult. So far, we have located 41 active burrows! Most of them are deep in the old stone walls that are scattered across the island and impossible to reach but we did find one that we were able to reach into a feel one adult with one egg. We will return in late July to check hatching success.

Yesterday evening we had a spectacular view of the mainland fireworks and enjoyed some of our own sparklers for 4 of July celebrations!

Until next time,

Ravin