I contacted the person thru Facebook. She said, "the bird is still missing, and we assume now that the transmitter died, so I am completely relying on sightings."
If you see the bird Aria, please contact Caitlyn Anne
(425) 319-6622.
The bird looks like this...

Her original post on Facebook
PLEASE BE ON THE LOOKOUT FOR MY BIRD IF YOU ARE ON THE WHATCOM COAST.
I had a radio telemetry signal on my harris hawk (who chose to take a hormonal adventure in a misguided attempt to find a mate outside of her native range) at 10:30 this morning in Squalicum Harbor and had to leave for work. Her signal was pretty much on top of some active trains and it was too dangerous for me to cross. I assumed she was on the other side. When I got back this evening the train was gone and for the first time her signal was completely gone. She knows that area inside and out and wouldn’t leave that fast that soon.
Her transmitter was not low battery. If the transmitter is dead it’s a freak occurrence, and if somehow she is somewhere where the signal is completely blocked from every angle I will eventually find out and update this post. If it got zapped or pulverized there’s nothing I can do. But in case she did hitch a ride on that train, it’s going along the coast up to Canada.
I am humbly asking anybody in Whatcom or further north into Canada with radio equipment to turn your receivers on to 216.035 when you can for the next few days, and to please keep an eye out for unusual crow activity that would indicate an unfamiliar predator. This bird is special to me. I am baffled by this whole thing and devastated that her signal is gone. I am desperately holding out hope that someone will find her.
She has green paracord equipment on her legs (designed to be flown with safely) and a black transmitter with my phone number printed on it. Attached is a picture of exactly what she looks like in a tree, with everything she’s got on her legs now.
Edit 6/30:
The more I hear from people the more I wonder if her telemetry has failed. There have been NO CONFIRMED sightings of Aria in a few days now. However, people claim to have heard her in the bay, and one person picked up a weak signal also in the bay. Given this information it’s difficult to determine whether her telemetry is working or not, and whether she is still in Squalicum Harbor or not. There have also been suspected sightings of her in Ferndale, which the train
would have passed.
If you believe you heard Aria, please listen to this video, because it’s exactly what she would sound like. No other bird in Washington will sound like this. If you do hear this noise, please message me right away.
https://youtu.be/CAOIMB5tkuU?si=awAdIaTRQalARkHf
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Also, someone from FB group Lost pets of Whatcom County saw the bird today (Sunday) around 1 pm in Fairhaven:
I saw this hawk at approximately 1pm flying above my balcony. It was 100% this hawk because I took note of how strange it was to see it in this area. I live on 32nd St. in Bellingham close to the Sehome Haggen area. Hope they find it!
Let's keep our eyes on the sky and the trees!
Mariko