Article and photos by Bronwyn Clear, Certified Texas Master Naturalist
“… I like worms and bugs and dirt
I think they make a fine dessert” – by Arlo Disarray
At the very heart of it, swarms of insects and lots of worms are absolutely crucial to the survival of our birds. The importance of these food sources to our bird world is greatly underappreciated.
Birds are sometimes classified by what they eat. Herbivores feed on plants, berries, fruit and seed. (They can be split up endlessly into granivores, nectivores and other definitions.) Carnivores eat flesh and insects (and can also be split into insectivores, piscivores, etc). And finally there are omnivores, who eat it all! We humans are omnivores, and the reality is that most birds are too.
Rarely if ever will you see a bluebird at your seed feeder since they eat mostly insects and worms. Except…there’s that ‘except’ word…what birds eat depends on the season, what is readily available, if they are raising chicks, and what they like to eat. For example, in spring and summer the diets of our Eastern Bluebirds are 80% insects and worms because bluebirds like them, and they need high protein for breeding and raising their chicks. Also, insects and worms are plentiful during that time. But in winter an Eastern Bluebird’s diet switches to mostly fruits and berries, such as hackberries, wild grapes, yaupon berries or poison ivy berries. There are not as many insects in winter, and in the cold temperatures birds go to high sugar food sources to fuel their metabolisms. Therefore bluebirds are true omnivores, but you probably will never see them at your seed feeders.
A different example is the Northern Cardinal. They love seeds better than insects. When available, seed makes up most of their diet, and you will see them at your seed feeders in droves! But they also eat insects and worms. When feeding chicks they give them insects of all sizes, big and little! So cardinals are omnivores too, but unlike bluebirds you will definitely see them at your seed feeders.
In the springtime a damp healthy yard should have 10 worms per cubic foot. This provides a good worm supply for birds and for robust gardens. However, determining a healthy supply of insects is harder to do. Since so many insects are annoying and even dangerous to us humans, we are happy to eliminate them. Some studies indicate that our insect populations are declining, but if they decline, our bird populations will likely decline with them. This would be disastrous! Most birds need insects and worms, even the birds that eat mainly seed. As you use insecticides and pesticides on your yards and gardens this year, please keep in mind that there needs to be a balance between keeping humans safe from disease, and also keeping birds safely fed. Bugs and worms are extremely important to our bird populations and our ecosystems.
Learn more about the incredible nature in our area by joining a chapter of the Texas Master Naturalist organization. To find a chapter close to you, or to read about the state program, go online to www.txmn.org. Volunteer and get involved!
It took 5 minutes for the male Eastern Bluebird to wrestle his worm into submission. He has a family to feed, and worms don’t fight back!
A caterpillar meal is just exactly what this bluebird momma’s chicks need.
This large handsome juvenile Yellow Crowned Night Heron slurps up worms like they are spaghetti. For the better part of an hour he sucked down worms, and added some side dishes of insects.
A bright green insect caught this Mockingbird’s attention.
Although they prefer larger catches, crows eat worms and insects too. Here this crow thought he had a worm, but all he found was a skinny brown stem.