Is it a Monarch butterfly? How to tell the difference.

As a kid, I called every large butterfly a monarch because it was the only name I knew. Now I know more.

With the growing concern about monarch butterflies, how can we easily distinguish them from others? Part of the key is knowing which ones are lookalikes. First, let’s establish what the monarch’s features are. They are bright orange with prominent black line markings and white spots on the wing edges.

Not all orange butterflies are monarchs. This week, here in New England, I’ve seen many Pearl Crescent and Great Spangled Fritillary butterflies. Both can be on the larger size, and both are predominately orange. But they don’t have this distinct black-and-white strong pattern of the monarchs.

In the western United States, the California tortoiseshell and the Western Tiger Swallowtail are two that look like the monarch. Two other lookalikes are the Red Admiral and the Painted Lady, sometimes called American Lady.

But the ultimate lookalike is the viceroy. First, the viceroy is a bit smaller, but the key indicator is the black line across the viceroy’s hind wings. Another clue is the number of wing flaps per second. The average butterfly flaps its wings about 20 times per second. However, the monarch only flutters 5-10 times each second. They glide at a slow speed, undulating pattern.

You can learn to identify a monarch in the field with practice and a keen eye.