TERF17x/Mud Bay Chick (tracked 6/15/23-8/3/23)

[JudyB]

Update 2/27/24 -

The Mud Bay Chick was a young bald eagle who was banded and received tracker TERF17 while still a nestling. He or she was the second eagle to use that tracker, so we initially used the designation TERF17a for the young eagle. It was a hard year for young eagles in that area, and the Mud Bay Chick died before he or she was old enough to leave the area. The map at the bottom of this post shows the tracker data; I'm not sure if the youngster made a few flights, or if it only looks that way because of the margin for error when the data is uploaded. I do know that the farthest data point is no more than about 30 meters or 100 feet from the nest.

Because the eagle never traveled out of its home territory, it really doesn't fit in with the tracking project. The tracker has recently been redeployed on a new eagle (see viewtopic.php?f=95&t=724), and that eagle will be designated TERF17a. I am changing the designation for the Mud Bay Chick to TERF17x to help myself (JudyB) remember what that tracker was doing sitting in a tree for six weeks, since the master map shows everywhere the tracker has been (including the months it was stored at Hancock Wildlife headquarters). And I'm giving the young eagle a name - Mud Bay Chick.


BAEA23-06 - TERF17a TERF17x
Banding Date: June 15, 2023
USFW Band #: 0829-01874
ID: Blue marker K over 0 on left leg
Age: pre-fledge
Eye color:
Sex:

The tracker was previously assigned to young female adult TERF17 (her page is here) who sadly died in early May 2023. The map below shows where the tracker was when it was on the Mud Bay Chick; the combined map of all the eagles we’re tracking shows everywhere the tracker has been.

[JudyB]

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[JudyB]

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[JudyB]

Reserved

[JudyB]

Here are some maps for TERF17a - I tried to figure the distance to the furthest point as of July 9, and it's roughly 37 meters or 120 feet - so maybe more than the margin of error for the tracker, which means the eaglet might have fledged at this point, though is still staying close to the nest. I have had trouble finding time to work on this thread, but did take a few s'caps to show changes.

From June 24, before we split TERF17a's travels off from TERF17; I believe the place at the far left is where Myles parked his car to go to the nest, which I think is roughly where the red dot is, showing where the eagle was on June 17.

This is from July 1 after we removed the data from before TERF17a was banded and received the tracker; the dark green area that looks to me as if it may be trees between two fields with crops growing or something is about 10 meters or 30 feet.

From July 5:

[JudyB]

Sunday, July 9, 2023

A few more areas explored, but still staying quite close to the nest.

And here's a wider view - the red dot covers all the travels so far.

I wonder where the young eagle will go next.

[JudyB]

Here's a look at TERF17a's travels for the past two weeks using the Animal Tracker app - I'm including it because it uses Mapbox maps for a base rather than the Google maps used by the Movebank maps - and in this case provides a better idea of how far from the nest tree the young eagle may be going - although as I mentioned above, none of the distances are very far when compared to the distance up to the satellite that tells the tracker where it is, so there's definitely a margin of error, and the young eagle might actually still be in the tree and maybe branching.

[JudyB]

TERF17a's travels as of July 14:

No updates for a couple of days, which may mean that TERF17a has started exploring away from the nest, and is in an area with less cell towers. Hopefully he or she will "call home" soon.

[Lynne]

July 22nd tracker update - this young eagle continues close to nest tree

[JudyB]

August 16, 2023

I haven't gotten a report from Myles and David yet, but it looks as if young eagle TERF17a may have gotten into trouble.

This picture shows where TERF17a was exploring through August 3 - I think making some flights away from the nest tree, but staying fairly close.

I didn't have a sense of how far he or she was flying, so I looked at the area with a regular Google map, which has the ability to measure the distance between two points, and copied a line giving an idea of the distances involved and pasted that onto the map, with the legend box:

That suggests to me that the eaglet was staying within 15 meters or 50 feet from the nest, which I'm assuming is somewhere in the center of the lines. That's not very far, so I'm not sure if some of the apparent movement is within the margin of error for the app - 15 meters is a pretty small distance when you're looking down from the sky.

When the tracker uploaded data on August 4, it was partway to David Hancock's house, which is the home of Hancock Wildlife, and the tracker was there on August 5 and has been there since then:

We'll attempt to find out the rest of the story, but it is a very busy time for David and Myles, so no guarantee as to when we'll have an update.

[JudyB]

We've heard back from Myles, and sadly the eaglet did die.

Myles said "That chick perished - as did a number of other chicks this year. It appears several from starvation. I suspect we have breached the carrying capacity of BAEA [bald eagles] for our region and the population is likely going to experience a downturn before it stabilizes."

It seems likely that for at least some of the chicks that were lost, it's not just a matter of there not being enough food. Both Annie/TERF26 and her chick Bee/TERF27a ended up at OWL in June 2023, and both were underweight - even though there seem to be plenty of fish in the area Annie hunts, and the female in the neighboring territory (Harbour Sun/TERF31) was one of the largest/heaviest eagles David had seen when she got her tracker that same month.

Also, Tyr, one of the eaglets at the Surrey Reserve nest with cameras, was accidentally knocked from the nest in July; he was taken to OWL, where he was found to be severely underweight and died a few days later. There are plans for a necropsy, so hopefully we will learn what caused his death - those of us watching thought there was an adequate amount of food for both chicks, and Tyr often had a full crop. (More info starting here - viewtopic.php?f=114&t=640&start=9285#p691671).

Rest in peace, TERF17a - I'll picture you flying far above the sky, with Tyr and all the eagles who left too soon.

[JudyB]

February 27, 2024

Please see the update in the first post - the tracker has been redeployed on a new eagle, and you can follow his travels here.