Thank you for your question.

I am not completely convinced this is a walnut tree.  Would you be so kind to send me a picture of two of the leaves that are on it?  Many thanks!!

Thanks for the picture.

I’m guessing that the tree died sometime in 2022 or 2023. If so, then the bark appearance would have sufficiently changed so to make me question it being a walnut. My apologies.

These are holes made by yellow sapsuckers. The holes have a unique appearance. See:

https://www.gardenia.net/pest/sapsucker

It is unlikely that sapsuckers directly contributed to the demise of the walnut. Instead, they were after insects that were either in the walnut bark or, more likely, directly under the bark. It was this insect infestation that started the whole process of decline for the tree. To a certain extent, the sapsucker might have prolonged the life of the walnut by consuming whatever insect pests were present. At this point, it would be impossible to ascertain exactly what those pests might have been.

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