It’s always a pleasure seeing a cardinal around, especially during winter when everything is grey and drab. The bright colour of a male cardinal is so pretty and attention-grabbing (which is the point) that I can’t help but watch these birds when they come in my yard. Still, I don’t really know much about them, so it’s about time they got a blog post.

Northern cardinals are found all over eastern North America, from southern Canada to Central America. There are introduced populations in California, Hawaii, and Bermuda. Cardinals are well-adapted to live in suburban environments, preferring to live on the edges of woods or in trees surrounding houses. They are non-migratory, sticking around even in the horribly cold throes of winter.

A female northern cardinal. Look at that beak!
Image by Eric Kilby from Somerville, MA, USA, CC BY-SA 2.0, via Wikimedia Commons

Cardinals aren’t huge birds, with adults being between 20 to 24 cm in length. Males are the brightly coloured ones, with red plumage, and a dark face. Females are quite a bit more drab, being brown or green-brown with some red streaks. Both sexes have large orange-red bills and a distinctive crest on top of their heads.

The colour of male cardinals is derived from carotenoid pigments (the same things that make carrots orange). Carotenoids vary in shade from yellow to orange to red, and some birds will change colour based on the type of carotenoid in their diets. Male cardinals, on the other hand, are able to use carotenoid pigments of different colours and still make their feathers red. The vibrant red colour, though, can only be maintained with red carotenoids — if a male cardinal eats only yellow pigments, his colour will change to pale red.

Northern cardinals are serially monogamous, sticking with the same mate for a breeding season or more. The males have the tough job of trying to win over females, not only using their bright plumage but also their song and numerous courtship displays, often feeding the females seeds to try and woo them. Male cardinals are highly territorial, and will aggressively attack other male cardinals that enter their territory. Unfortunately for these birds, they often get confused by their reflections, and attempt to drive them away.

The best picture I've been able to take of a cardinal. I will try better this spring.
The best picture I’ve been able to take of a cardinal. I will try harder this spring to get a better one. 

Breeding occurs from March to September, with the cardinals raising two broods a year. Between one and five eggs are laid, and are incubated solely by the female for almost two weeks. During this period the male isn’t completely useless — he brings his lady food to keep her alive. Once the chicks have hatched both parents feed them until the chicks have fledged.

Because of their beautiful plumage and pretty song, cardinals have long attracted the interest of the pet industry. They are now protected in the US and Canada, and their adaptations to urban living mean that the species is common and doing well. Which makes me glad, because I really like seeing the ones that come to my backyard.

Cover image by FWS, Public domain, via Wikimedia Commons