Hello! I wanted to take a moment today to talk about one of my favorite groups of birds, the Corvids. Corvids are birds that are members of the crow family, and are renowned for their intelligence. Myths and stories about corvids can be found in nearly all cultures. Only 3 species of Corvids nest in MN, though they can be found worldwide.
While Crows, Blue Jays, and Common Ravens are often thought of as bullies or signs of bad luck, I cannot stress enough what amazing birds they are! At our Lifelong Learner Lunch today, we discussed that corvids have very small brains for their body size compared to other kinds of animals. However those brains are packed with 2-4 times as many neurons as a primate brain, and are up to 3 times more efficient in their energy usage!! This helps to explain why they exhibit such high levels of intelligence compared to what we might expect from such small brains.
These large, magnificent birds are all Passerines, or song birds. Passerines are the only birds that sing, hence the name for this group. Instead of a larynx (the “voice box” in humans), birds have a syrinx. It sits at the bottom end of the trachea and branches into two parts. Passerines are the only birds to have a completely formed syrinx. The vibrations that they can produce through their syrinx are wide and varied, hence their complex sounds. Passerines have 4 muscles that control their syrinx. Parrots, on the other hand, are able to mimic due to the thick tongue that allows them to shape the sounds that they make. The difference in song and sound formation, combined with anatomical differences in the feet and beak, results in parrots being grouped independently of songbirds, despite their intelligence and ability to mimic sounds.
The defining criteria for songbirds is actually all about the feet. The feet of Passerines are built so that they perch while at rest with three unwebbed toes pointing forward and one toe pointing backwards. This has led to this group also being referred to as perching birds. When we look at their feet, it becomes clear why Corvids are placed in this category despite our perceptions on the musicality of their voices. The tendons in Passerine feet are arranged so that the default resting state of their feet is to clench the branch that they are perching on. This allows them to sleep while perching without risk of accidentally letting go. While owls and parrots also sleep while perched, the arrangement of their toes does not follow the three forward, one backward pattern of the Passerines.
The high flexibility in the variety of sounds that Corvids can make, combined with their amazing intelligence, has led to some exciting results. They can learn to reproduce sounds from other animals, including humans. This ability allows Blue Jays to clear out a landing zone when they approach a feeder, Steller’s Jays making you think that a Red Tailed Hawk is in the area, or an American Crow teaching children on a playground naughty words. Thanks to videos and social media, we have many examples of Corvids getting up to all sorts of highjinx as a result of their amazing vocal prowess.
One of the complaints that I hear most often is that Blue Jays are bullies at the feeders. While these large bodied birds can be intimidating, studies have found that they are usually the victims of bullying by woodpeckers when visiting feeder (https://www.allaboutbirds.org/news/when-136-bird-species-show-up-at-a-feeder-which-one-wins/). They do engage in their fair share of fighting at feeders, but I was surprised by how often they end up being blocked from food by smaller birds.
Crows and Common Ravens, on the other hand, are usually able to eat what they want without being troubled by woodpeckers. To be fair, there aren’t many creatures willing to stand up to the sheer size of a Crow or Raven. I made life size silhouettes of all three birds to help people understand the scale of them compared to the other nesting MN songbirds. The silhouettes are now on display in our education building, so please feel free to stop by and see them for yourself!
Corvids are incredibly social birds, and we are still working to understand their family and larger flock dynamics. Blue Jays, in particular, have complex familial relationships and interactions. Young Crows will stay to help rear siblings from subsequent hatch years. Similarly, Ravens are known to flock together as unmated sub-adults or teenagers until they find a mate. The increased social interactions of these birds is credited with their high success rates for foraging for foods. By learning how to successfully find food, and then communicating with and learning from others, Corvids are able to adapt to changing environments, such as urbanization, while still remaining successful.
One way that we see these social interactions expressed is through play. Crows and Ravens in particular have taken the internet by storm with videos of them swinging from towels on laundry lines, sliding down snowy roofs, or playing tug of war. Play is an extremely powerful learning tool used across many different species, including humans, and it always brings me joy to see videos of it.
I hope that this post has sparked your curiosity for these amazing birds. Be sure to keep an eye out for them as you are out walking or driving around. Have a wonderful day, and enjoy the end of Summer!
-Liz Sheppard
(Note: All photos in this post have not been altered from their original form.)