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Posts Tagged ‘hatching’

Hello everyone, this is Bobby writing to you from Ship Island with some breaking news.

The bird word must have gone around, because as of Thursday, July 11th, 321 nests have been found and marked with more being discovered every day! The chaos on the tern nesting beach area is beginning; the eggs laid in late June have begun to hatch this week. Soon our island will be filled with extremely adorable fuzzy chicks who love to run and hide in whatever grass or shelter they can find!

fuzzy boy

One of the first chicks on Ship, easily one of the softest objects one could ever hold.

These toddler-like chicks are extremely curious and will wander away pretty far from their nests if given a chance. With them running around all over, it can be difficult to tell how the colony chicks are doing health wise and how many of these chicks are surviving to adulthood. This is answered through a protocol that all of the islands perform known as productivity plots. This may sound like a fancy term, but essentially Colin and I determined a group of nests with eggs that were laid earlier in the season (in our case in late June) that neighbored each other and constructed fencing around them to enclose this area.

 

COTE on colins head

Colin (pictured) and I constantly had terns going at our heads to protect their nests while we constructed productivity plots. This one very nicely went feet first to our heads instead of the usual sharp bill first.

This keeps the chicks from our nests of focus from running all over the beach getting into trouble, that way we can determine how many chicks are surviving to adulthood and the size increases of each chick from each nest within our plots. To determine which chick is which, we put stylish metal BBL bands on their right legs that give them a unique identification number for life in a large online database. Colin and I then check each nest in each plot every morning to monitor the eggs and chicks. I am not a parent, but I imagine how I feel when we look for the chicks every morning it is similar to the stressful situation of a parent trying to find their misplaced kids, as Colin and I are really attached to our chicks in the plots. It has been amazing to see the transformation from egg to chick, and soon from chick to fledgling. Watching them grow up has been so special for Colin and I, and we can’t wait to see each chick’s journey continue. More updates coming soon!

wet baby tern

One of the many chicks hatching this weekend, this one hatched within the hour before this photo with a big world to explore!

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For the past few weeks, a lot has been going on with Petit Manan’s tern colony!  We have been focusing much of our time on trapping and banding both Arctic and Common Tern adults, which is an essential part of our research.

In order to capture terns, we use two types of traps—the bownet and treadle trap—to catch adults on their nests.  First, we temporarily remove the eggs from the nest so that the bird does not crush its eggs if it struggles in the trap.  The real eggs are replaced with painted wooden ones, and a trap is set over the nest. Trappers then hide out in a blind and wait for terns to return.

The bownet is a spring trap that is set behind the nest cup and triggered when the adult sits on two monofilaments stretching over the “eggs.”  This trap has a metal frame and netting which springs harmlessly over the bird to contain it.  The treadle is a small cage trap with a door, which the tern must walk through to trigger its closing mechanism.

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a Common Tern being removed from a treadle trap

When a tern is captured, a researcher runs out from the blind to retrieve it and replaces the fake eggs with the real ones.  Each tern receives a metal band with a unique number on one leg.  Every Arctic tern also receives a field readable band with an alphanumeric code on the other leg, so that it can be easily resighted from a distance.  We take several measurements, including mass, wing chord (wing length), and head/bill length before releasing the tern.

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Julia banding an Arctic Tern

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Wayne releasing an Arctic Tern

By banding these birds, we can learn about their migration paths, longevity, nest site fidelity, and productivity.  Banded birds may be re-trapped or resighted in the future.  If a banded bird is found along its migration path or on wintering grounds, we can learn about where it has been travelling.  If a bird that was banded as a chick is later found as a nesting adult, we know that it has lived to breeding age and laid eggs.  Speaking of chicks…

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first Common Tern chicks hatched on 6/20

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first Arctic Tern chicks hatched on 6/22

We found our first tern chicks of the season on June 20!  Every day we are finding more chicks, and banding them as well.  As the season continues, we will be closely monitoring their growth, survivorship, and diet to learn about the colony’s overall health.  Stay tuned for more posts about these little cuties!

-Anna

 

 

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