Northern Cardinal nest in backyard

 

This Northern Cardinal (Cardinalis cardinalis) has shown great taste in selecting a particularly showy spot: a thick liana of Trumper-creeper (Campsis radicans) vines only about two feet from my kitchen window. I should say "cardinals" as even though the female does all of the work regarding nest construction, the male assists with site selection, and feeds her while she is engaged in construction.

Here she is, busily weaving together her nest. This shot was made yesterday morning (June 11, 2026), and it's been about a week since I first noticed the commencement of construction. The nest appears to be nearly complete. While the nest is in a difficult area to avoid regular disturbances, I will do everything within my power to see that they have success.

While cardinal nests don't look like much at a glance, they are more complex than it appears. There are four distinct layers: a very rough twiggy outer layer, a loose leafy zone, grapevine strips, and a soft inner bowl of fine grasses. Interestingly, the rough-looking cup is not directly anchored to the branchy substrate, it is more or less just wedged into place.

As cardinals can nest quite early in spring, I imagine this is a second nesting.

A male Brown-headed Cowbird (Molothrus ater) performs his "Dracula" courtship display to a seemingly disinterested female. Cowbirds must be given credit for their interesting courtships, and this activity, if successful, leads to the production of cowbird eggs.

An ever-vigilant female cowbird, scanning her surroundings for potential host nests. As I am sure you know, cowbirds are parasitic in that the female dumps an egg(s) in host nests of unrelated species. Many species can serve as hosts, and the Northern Cardinal is a common victim/host.

Today, I was out back with a contractor doing some work for me, and we were about 30 feet from the nest. Suddenly a female cowbird flew in and landed on the ground, perhaps 10 feet from the nest. She then walked over to the base of the Trumpet-creeper vine and flew up to the nest. She didn't stay long, and after her departure I took a quick look within and she had not laid an egg. However, the cardinal has not yet laid any eggs, and as I understand it cowbirds mostly dump their egg (sometimes multiples) in nests that already have host eggs. My hunch is that she'll be back after some cardinal eggs appear.

This may be a case in which I will feel the need to intervene. While Brown-headed Cowbirds are not "invasive" or "nonnative" they have expanded their range tremendously. Why? Us. People. Cowbirds originally were tightly tied to bison herds, which they stayed with and depended upon for food. The cowbirds feed on insects and other fare disturbed by the bison's feet. One still sees this behavior, although cows are now the herding animals that they follow. When we opened up the eastern deciduous forest region, cowbirds aggressively pioneered new and favorable habitats and learned to exploit cattle.

As bison herds are quite nomadic and often not in one place for extended periods, the cowbirds evolved their nest parasitism habits. This freed the adult birds from the lengthy process of parental care. Just let someone else do the dirty work for you. Unfortunately, cowbirds are hard on their hosts. The young cowbirds often get a jumpstart on host species and outcompete the rightful young. While perhaps playing god a bit, I want "my" cardinals to have the greatest possible chance of successful reproduction.