do robins steal other birds nests

The Discussion: Jessy makes a valid point in that eating baby birds is probably not a regular habit of American Robins (Turdus migratorius). However, most birds are opportunistic, and robins have been documented eating fish and snakes and even a shrew, so it doesn’t seem a stretch that they would eat a baby bird if given the chance. And though I had not heard of different species of birds truly sharing a nest, who knows what behaviors might be out there that we don’t yet know about. (We’re not, of course, talking about nest parasitism, such as is practiced by cuckoos and cowbirds, where females of one species lay eggs in the nest of another species and then abandon them to let the second species raise the chicks.)

With help from Jessy, I was able to find a source that described an incident of nest sharing between American Robins and Northern Cardinals (Cardinalis cardinalis). The authors of a 2009 article in the Wilson Journal of Ornithology observed a female robin and a female cardinal alternating at a nest where both laid eggs. This photo of the nest, in an arborvitae bush in a suburban neighborhood in Iowa, clearly shows three blue robin eggs and two speckled cardinal eggs.

The authors detail their search of the scientific literature for similar cases, and mention reports of sharing between two female cardinals and even a case of a cardinal feeding American Robin chicks. They state that “American Robins, however, are less tolerant of nest violations, generally rejecting Brown-headed Cowbird eggs, and have not been observed to exhibit intraspecific cooperative brood care.” They go on to say that actual nest sharing between two different species of birds is not common. One documented example, however, noted a tree cavity nest that included nestlings of both Red-breasted Nuthatches and Mountain Chickadees, after adults of both species were seen bringing food to the tree hole nest.

The rest of the brief article describes observations of the interactions between the birds at the shared nest. Apparently, the two females shared the nest fairly peacefully at first, but the interactions became more aggressive over time. The female cardinal would sit on the female robin’s back “… and scratch and kick until the robin fled the nest.” Eventually, the eggs began to hatch, with the result that two fledglings were seen, which turned out to be robin chicks. One cardinal egg was found on the ground and the other disappeared.

The authors suggest that scarcity of good nesting sites in this area might have led to the birds competing over that site, a contest that was eventually won by the robins.

Over the course of several days, Jessy monitored the joint nest in her yard and kept me updated by email. She wasn’t able to see whether there were eggs from both species, but as in the case documented in the Wilson Journal, the two eventual hatchlings were robin babies, as far as she could tell. The adult cardinals continued to hang around, and Jessy saw the male bringing food to the area of the nest, although she was unable to see if he was feeding the chicks or his mate. At one point, she noticed one of the hatchlings on the ground beneath the nest and she replaced it. A few days later, there was only one chick in the nest and shortly after that, Jessy found a dead chick on the lawn. She also found part of a wing of an adult bird, possibly a robin. The nest was empty and all the other adults were gone.

Jessy’s speculation is that a cat or raccoon or other predator might have ended the experiment in joint parenting.

So I guess I should modify my original answer about a robin hanging around a cardinal nest. I still think a good possibility is that a robin around a cardinal nest might be looking for unattended hatchlings to snack on. But another possibility is that it may be trying to compete for the nest. Unfortunately for the cardinals, in the two examples we have, that doesn’t seem to go well for the cardinals.

Sources: Govoni, P W, Summerville, K S, & Eaton, M D. (2009). Nest sharing between an American Robin and a Northern Cardinal. The Wilson journal of ornithology, 121(2), 424-426.

Sallabanks, Rex, and Frances C. James. Birds of North American Online. American Robin Turdus migratorius. Issue No. 462.APAMLAHarvardVancouverChicagoIEEEAsk a Naturalist® (March 28, 2024)

We’ve had robins nesting in a tree next to the garage for a long time. this year there was a dove. she had 2 eggs. After roughly two weeks, we discovered the nest halfway down the tree and the eggs broken on the ground. The following day, a robin had made her nest in the same location (there were no weather issues). Are robins sufficiently hostile or possessive to demolish another bird’s nest in order to assert their territory?

The authors describe how they searched the scientific literature for cases similar to their own, citing instances where two female cardinals shared food and even one instance where a cardinal fed American Robin chicks. They report that “American Robins, on the other hand, have not been observed to exhibit intraspecific cooperative brood care, and are generally less tolerant of nest violations, rejecting Brown-headed Cowbird eggs.” They continue by saying that it is uncommon for two distinct species of birds to actually share a nest. In one recorded instance, however, nestlings of both Mountain Chickadees and Red-breasted Nuthatches were found in a tree cavity nest after the adults of both species were observed feeding the tree hole nest.

Sources: Summerville, K. S.; Govoni, P. W. (2009). Nest sharing between an American Robin and a Northern Cardinal. The Wilson journal of ornithology, 121(2), 424-426.

The Discussion: Jessy is right when she points out that American Robins (Turdus migratorius) probably don’t eat baby birds on a regular basis. Nonetheless, since most birds are opportunistic—robins, for example, have been observed consuming fish, snakes, and even shrews—it doesn’t seem unlikely that they would consume a baby bird if given the opportunity. Furthermore, even though I had not heard of any bird species actually coexisting in a nest, you never know what hidden habits there might be. (Of course, we’re not referring to nest parasitism, which is carried out by animals like cowbirds and cockoos, in which females of one species deposit eggs in the nest of another and then leave the eggs there to allow the second species to raise the young. ).

With help from Jessy, I was able to find a source that described an incident of nest sharing between American Robins and Northern Cardinals (Cardinalis cardinalis). The authors of a 2009 article in the Wilson Journal of Ornithology observed a female robin and a female cardinal alternating at a nest where both laid eggs. This photo of the nest, in an arborvitae bush in a suburban neighborhood in Iowa, clearly shows three blue robin eggs and two speckled cardinal eggs.

Sallabanks, Rex, and Frances C. James. Birds of North American Online. American Robin Turdus migratorius. Issue No. 462. APAMLAHarvardVancouverChicagoIEEEAsk a Naturalist® (March 28, 2024).

FAQ

What birds steal other birds nests?

Crows and other corvids (magpies, jackdaws, rooks, ravens and jays) are probably the most common predators of bird nests. They actively search hedgerows for nests and scan the ground from trees for nesting birds.

Do robins take over nests?

While robins might repair or build on top of a previous nest, most of them build a new nest. This is best for many reasons. A used nest is a mess, stretched out and often home to insects or parasites and possibly poop. Take the nest down and the site will be ready for the next robin.

Are robins aggressive around nest?

Parents very aggressive in defense of nest. Young leave the nest about 14-16 days after hatching.

Do cardinals steal other birds nests?

Is this true?” Male cardinals occasionally feed nestlings or fledglings of other species, although not because they have taken over another bird’s nest. This may happen because another chick is begging nearby, and the birds might get confused.