I can't find that photo on Getty so I'm not sure if it's mislabeled, or the editor just searched for "warbler", or got it from somewhere else and forgot to change the photo credit from an article template or something.
Edit: It seems to be from Shutterstock and is labeled correctly https://www.shutterstock.com/image-photo/yellowbrowed-warble.... My best guess is an overworked web producer was told to find a photo for this article, searched for "warbler" in some integrated stock photo search engine, picked this one and copy/pasted the wrong credit.
The reason? It's one of the first images that pop up when you punch 'chigger' into Google, and it appears to be licensed (and mislabeled) by Getty. Tracking the image back to its original source, it was clearly identified as a red velvet mite.
I wish publications wouldn't do this. A completely random lede image would be better than showing a picture of an animal that people will now believe is the one the article was talking about.