In my own experience, whenever I detect something AI generated I lose the ability to evaluate how much I can "trust" something. Compare an article on Medium with a published book on the same topic; both are human-originated but the substance of one implies authority, quality etc. Generating a website and pictures with AI requires very little effort and care, and I have no interest in carelessness. Like most humans, I can't help but evaluate the author alongside the art.
The whole point of the site is the images and facts.
I don't mind it at all for decorational images, but in this case I would mind. I suppose I would mind the inaccuracy, the worry that the creatures might not look exactly like the real world ones look.
Not that it actually matters but if those images were generated it would feel pointless to me, even if I can't tell the difference.