1.1M views · 4.2K shares | Why does the coral cardinalfish nest its eggs in its mouth? | National Geographic | Facebook

Northern Cardinal nesting in our backyard.. | Renzbu

Northern Cardinal singing (Cardinalis cardinalis)

125K views · 10K reactions | Unlike with most songbirds where the singing is left purely to the males, with Northern Cardinals, both the males and the females sing. Here are a few beautiful duets between a female (on camera) and her partner (heard singing in the background.) This singing is important in pair bonding, and usually happens after the males have established territories and before nesting has begun. | Jocelyn Anderson Photography | Facebook