One of the most intriguing species of bird that I have the pleasure of working with is also one of the most overlooked: the sociable weaver. Their exhibit is located in the San Diego Zoo’s Lost Forest, across from the gibbons. It’s easy to pass right by them, since at first glance their appearance is not that impressive. They look very similar to the common house sparrow, so what could be that interesting about them? Please allow me to enlighten you.
Despite their small size, they are capable of completing an extremely large task. They create the largest communal nest of any bird in the world! These nests are often referred to as “apartment complexes,” as they are used for both roosting and breeding. A single colony nest can weigh up to a ton and may house over a hundred birds. There are several chambers in the nest, and the colony may use it for many generations.
In the interest of being efficient, these birds are constantly communicating with each other and constantly building! You can hear all the chatter as you approach their exhibit. You’ll also notice a large pile of nesting material on the ground that they can pull from throughout the day. As their keeper, it is my job to keep the material coming, and it has been a challenge to provide the proper items.
In the wild they would have access to a variety of plants, and each item they add to the nest serves a different purpose. Sociable weavers prefer rigid material for the roof, chambers are made stable with various dried grasses, access to these chambers are usually surrounded by straw, and the chambers are lined with soft materials (grasses, feathers, cotton, etc.) for comfort. Over the years they have been offered feathers, silk floss, camel hair, small sticks, pine needles, Bermuda hay, and dried grasses. I have worked with this colony for 4½ years now, and I have learned that their favorite items are pine needles, Bermuda hay, and dried Pennisetum grasses. And they certainly keep me busy with the challenge of providing them with plenty of material every day!
Recently the nest was the largest that it has ever been. Due to its ever-increasing size, as well as the weather, portions of the nest have started to fall. This is a natural process, and the birds have already begun investigating other potential nesting locations. They may also choose to repair the areas where chunks of the nest have been lost. Whatever the outcome may be, the colony benefits as they have the opportunity to renew their nest and start with fresh material. A healthy nest helps to maintain a healthy colony of birds.
The next time you’re walking along Monkey Trail in Lost Forest, take a moment to watch these active birds. I’m sure you’ll be impressed by their nest-building skills. And since the San Diego Zoo is home to the only sociable weaver colony in the United States, you won’t want to miss the opportunity to see them up close!
Athena Wilson is a senior keeper at the San Diego Zoo. Read her previous post, Welcome to the World, Screamers!