What evidence suggests the White-Eyed Vireo acts as an opportunistic feeder within its dense shrubbery environment?

The inclusion of small prey like snails and occasionally small lizards in its inventory.

The White-Eyed Vireo primarily consumes insects, but certain dietary inclusions demonstrate a willingness to take whatever high-protein items are available within its preferred dense habitat. While regular prey items include consistent staples like spiders, beetles, and various larvae, the inclusion of less common or structurally different items points to opportunistic feeding behavior. Specifically noted are the consumption of small snails, which require a different handling technique than typical insects, and the occasional capture of small lizards. These dietary additions suggest the vireo capitalizes on unexpected protein sources encountered within the thick undergrowth, rather than strictly limiting itself to known insect taxa.