Given that people learn historical and scientific facts from media (movies and books), we owe it to our audience to at least teach them something that's accurate.
Unless you're writing fantasy, chances are you want to lend a hint of realism through your setting. Something as simple as a cardinal singing in a jack pine can help bring a scene to life. But what if cardinals don't actually live in said location? Or jack pines for that matter? Well, now you can find out for sure, without booking a plane ticket, driving all day, or pestering your facebook friends who live kinda-sorta near there.
Discover Life is a fabulous site to use to research plants and animals of all kinds (something you may need to do whether you write fiction or non-fiction; I found the site while researching a non-fiction article). The site has a mapping feature that allows you to enter the type of organism and search for places where it has been recorded.
The easiest way to use Discover Life is to search for the plant or animal on their home page. (If you have trouble, google the species by common name, then copy and paste the genus species epithet—e.g. Cardinalis cardinalis for cardinal—into the search box.) Most of the species pages come up with a map of locations. Each point on the map is the location where a specimen was collected by a scientist; all are registered with various official museums and collections, so you know the information you're getting is accurate.
If you've got a cardinal singing in the jack pine, let's hope your story isn't set in Idaho. Neither cardinals nor jack pines can be found there. This resource can save you from an embarrassing email from an Idaho-based fan one day.