A Northern Cardinal Nest

Female Northern Cardinal in Arkansas, November 5, 2013.

Male -- also November 5, 2013, in Arkansas.

If you live in eastern or central North America and spend any time outside, chances are good that you’re familiar with the Northern Cardinal.  Cardinals are so common, in fact, that I confess I tend not to pay them much attention—especially if there are more unusual birds nearby.  But a couple of summers ago, a pair of these birds nested in the thorny elaeagnus shrub near the house, right outside the living room window.  Naturally, I had to pay attention to that!

The cardinals began nesting in the thorny elaeagnus shrub right around the time that the White-eyed Vireos that I wrote about previously were nearly fledged.  I first noticed the female cardinal carrying twigs in her bill to the nest site, which was a few feet higher in the shrub than the vireos’ nest had been.  This was typical behavior.  Female cardinals construct the nests and incubate the eggs, while males bring food to the females during incubation and assist in feeding the young after they hatch.  

As you can see, cardinals build their nests on top of limbs, unlike vireos, which suspend theirs from forks in the branches.  Whenever the female cardinal added new material to the nest, she bent it with her bill and pushed it into a cup shape with her feet.  The outside layers were constructed from twigs, bark, and leaves, while finer materials, such as grasses and pine needles, formed the lining.

June 19, 2016 -- Cardinal building the nest!

Checking early-stage nests too frequently can lead to the parent birds abandoning the site, so I was cautious about getting photos at that point.  By June 28, there were two eggs in the nest, but, since I had been avoiding the nest, I assumed that they had probably been there for two or three days.  Cardinals lay anywhere from one to five eggs, with two to three being more typical.

According to Birds of North America Online, incubation takes 11-13 days.  The eggs were definitely hatched on or before July 7, when I photographed the slightly downy nestlings for the first time.

By July 11, the young birds were much larger and more heavily feathered.  You can see how their bills are starting to turn dark, a characteristic of juvenile cardinals.  Their beak color doesn’t change to red or red-orange until late in the fall.

July 11, 2016

On July 14, the nestlings were nearly ready to fledge.  Although it’s difficult to determine exactly how heavily feathered the average dinosaur might have been, this is what I tend to imagine juvenile dinos looking like.  (On the anatomical level, though, modern birds and the dinosaurs from which they evolved differ very little—so I’d guess that quite a lot of dinosaurs may have had full plumage.)

July 14, 2016

I think that these cardinals fledged on July 15 or 16.  Fledging usually occurs after about nine or ten days, so this estimate seems reasonable.  You can just barely make out one of the nestlings in the center of the photo below.  That photo was from July 15, and the one of the empty nest was taken the next day.  This might have been the second brood of the year from these nonmigratory birds, but I can’t say for certain.

July 15, 2016 -- at least one young cardinal still on the nest

July 16, 2016

This cardinal nest and the young in it were from two summers ago.  There haven’t been any birds nesting in the thorny elaeagnus (or thorny olive) this year, though, since it’s only a bit above waist height at the moment.  A recent windstorm damaged the shrub, causing it to lean heavily to one side, so we pruned it.  It’s a more manageable height now, with no long shoots threatening to grow over the roof (see photo below).  In its native range in Asia, this species often “climbs” by entwining its upper branches with the limbs of the trees above it.  Although I miss being able to see birds nesting so close to the house, I don’t bemoan the fate of the thorny olive.  I intend to elaborate a little on invasive plants—including this species—in a future post.

June 22, 2016