Written by Stephanie Krueger, Aviary Zookeeper, North Carolina Zoo
Spring is here at the North Carolina Zoo, and breeding season has begun in earnest in the R.J. Reynolds Rainforest Aviary. Some of our most vocal residents, the yellow-rumped caciques, have been busy courting and building their elaborate hanging pendulum nest nearly 30 feet up in the aviary trees!
Native to South America with black and yellow feathers and bright blue eyes, yellow-rumped caciques are closely related to the red-winged blackbirds that we can find in our own backyards. Like our blackbirds, male caciques rely on their loud vocals and flashy feather display to attract mates.
Starting in early spring, our normally chatty cacique male will ramp up his singing even more as part of his courtship. Males make a variety of sounds, including gentle warbles, sharp barks, and may even mimic other bird calls when singing to females. Males, who are nearly twice as big as the much smaller females, will also do a courtship display to show off their striking black and yellow plumage. While singing, the male will find an ideal nesting site high up in the trees, fluff up the bright yellow feathers of his lower back (hence the name “yellow -rumped”) and shake his wings to draw attention. This signals to a female that he has secured a good nesting location and is a healthy, vibrant mate. Yellow-rumped caciques are polygamous, meaning one male will breed with several females and are colonial nesters with up to 250 nests in the same tree, so there is a lot of competition for the perfect mate and nesting site.
While the male cacique will find and secure the nest location, the female is the architect. Cacique females single-handedly weave intricate hanging nests, some of which can be over a foot long. Females make their own “thread” by finding a palm tree and stripping each frond into long thin fibers that they will use to weave a dense pendulum nest. Nest construction can take up to 20 days, but our female this year wove her whole nest in one week!
The nests have a small entrance hole at the top that drops down to a cavity at the bottom where eggs, and eventually chicks, will live. Nests are built high up in trees, sometimes as high as 40 to 50 feet up. Having a tunnel structure and being very high up helps protect eggs and chicks from potential predators such as primates, snakes, and even other birds.
Yellow-rumped cacique in our Aviary
Once the eggs hatch, it is totally up to the female to feed and care for the chicks. The male will stay around the nest site as both defender and cheerleader for mom, usually breaking out into a song and display each time she flies to the nest to deliver food.
While most songbird chicks take two weeks before they’re ready to leave the nest, caciques stay in their tunnel nest up to 40 days! When they emerge, they are fully feathered and able to fly, but still dependent on mom for food.
Aviary keepers are excited to announce that on May 10, Mother’s Day, two healthy cacique chicks emerged from the nest! Caciques usually lay two eggs, but only one tends to succeed because it takes so much time, energy, and food to raise both chicks. Hatching and raising two chicks to fledge speaks to the endless dedication our first-time mom has committed to her offspring.
To help out the family after such a monumental feat, keepers opted to move mom and the two kids to a mesh enclosure inside the aviary. This way, dad can still interact with and “protect” his family on the outside of the mesh. Mom can feed her chicks without competing with other aviary birds, and keepers can closely monitor the development of our newest editions!
