Cardinals & Gold Fish & Their Interspecies Behavior

Humans aren't the only inhabitants on Earth that take care of other species. There are a good-number of well-documented cases of certain species taking care of another they feel are in need. From Dalmatian canines adopting lambs, to gorillas taking care of kittens, interspecies care occurs both in the wild, as well as in domesticated scenarios.

Male Cardinal feeds gold fish . . .

One of the latest example of this type of behavior was discussed in a 2017 National Geographic feature, where a black-headed cardinal was caught on video feeding goldfish.  

Originally filmed on YouTube in 2010, this footage shows the scarlet bird hopping alongside a goldfish pond, before dropping what appears to be seeds into their waiting mouths.

This cardinal would also return to the pond as often as six times a day to feed the fish.

Why would a bird feed an entirely different species?

Princeton biologist Christina Riehl has a suggestion.

“My best guess is that the appearance of the goldfish’s open mouth at the surface of the water is just similar enough in size and shape to the open mouth of a baby bird that it triggers the instinct in the adult bird to provide food to it,” says Riehl.

Nestlings tend to have vibrantly colored mouths, often bright red and yellow. This acts like a bull’s-eye for the parents—a visual cue that says “Feed me here!”

Doting Males

As many know, male cardinals are both doting husbands and fathers. Unlike a lot of other species, cardinals are monogamous and usually form long-term relationships with their mates.

Males engage in a courtship ritual where he searches for seed and worms and feeds the female, even before they establish a nest. He will then continue to bring her food both before and after she lays eggs.

Ode to the Cardinals

Ron Callari's Cardinals


Recently, a male and female cardinal pair took up residence outside of our back porch. So, my family and I have had the opportunity to see them care for their hatchlings, up close and personal. This poem is my tribute to them and is dedicated to my mother-in-law who brought them to our attention.  In it, I describe how they typically take care of their own young versus other species.

Coffee with our Cardinals
by Ron Callari
Dedicated to Queenie

A blaze. A fury.
Like caffeine in my mug
He stirs it up in a hurry.

Oh Cardinal
In Scarlet you're dressed
You hop along my porch rail
Protecting your blessed nest

Nature has reasons
Why your color's bold,
Marked different from your mate,
Blending into your threshold.

Her armor. Her camouflage.
Hidden with her hatchlings,
Her entourage.

A Hunter. A Gatherer.
A sharp pointy beak.
Collector of worms & seeds.
Fledgling meals he seeks.

Feed Her. She feeds them.
This pact was imprinted years ago.
Each family member, a role:
Mama. Chicks. Generalissimo!

I sit.
I demure with each new sip.
Coffee with our cardinals,
a unique relationship.
He’s set the rules.
There’s boundaries.
Getting too close,
Will show him ill at ease.

Big Red can get ruffled.
Better to pour another cup of Joe,
Than face 'angry bird' in a scuffle.

A blaze. A fury.
Like caffeine thru the looking glass
A blaze. A fury.
Our cardinal is a potent blend of


PRIMARY SOURCE:  National Geographic