Bird nests come in all shapes and sizes. Few, however, are as remarkable as the oriole nest.
Orioles are known for their hanging, sock-like nests.
Of course, not all oriole species are the same. Their nests differ depending on the environment they live in.
Some species, such as the Altamira oriole, have nests as long as 24 inches. The orchard oriole, on the other hand, weaves nests just 3 inches deep.
This article will aim to explore the intricate engineering of the oriole nest, and why they go to such lengths to create such remarkable nests.
What Are Orioles?
Okay, okay, okay, pay attention – unnecessarily complicated taxonomy incoming.
Technically, there are two groups of orioles.
We have the Old World orioles, which are found across Europe, Africa, Asia, and Australia. This group belongs to the family Oriolidae.
Then we have the New World orioles, which are found across the Americas. These belong to the family Icteridae, which also includes members of the blackbird family.
Here’s the confusing part – the two groups, despite both being called orioles, are not closely related.
The icterids of the New World were first called “orioles” by early European settlers due to their resemblance to the true orioles of Europe and Africa.
Males are typically black with plumage of either orange or yellow, depending on the species.
But, as we now know, this is simply convergent evolution – where two non-related species have evolved similar traits to exploit a particular niche.
So, whilst the two bird families look physically similar in size and color, and often share habits and dietary preferences, they are not closely related to one another.
For this article, we’ll be exploring the New World Orioles.
What Does An Oriole Nest Look Like?
Oriole nests are unique among North American birds.
These are no ordinary nests – most oriole nests can be found hanging, suspended midair from the canopy of deciduous trees.
Think a basketball net, or a woven sock made of twigs or grasses, extending from a branch or a fork in the tree.
Of course, not every oriole species has the same approach to nesting.
Travel to the Southwest or into Northern Mexico, and you may find nests sewn to the underside of large overhanging leaves of palm or yucca plants. This is probably the nest of a hooded oriole.
If you see a nest hanging from a yucca or Joshua plant, it could well be the nest of Scott’s oriole (scientists evidently got lazy with the species naming in the Southwest and named things after their mates).
On the Great Plains, where fewer large structures and trees are found, orchard orioles build cup-shaped nests in low shrubs to shield them from the wind.
How Do Orioles Build Their Nests?
Orioles, unlike some other bird species (cough cough pigeon), take a lot of time and care over their nests. Depending on the species, orioles can spend anywhere between 7 – 15 days constructing their intricately weaved, hanging nests.
Most oriole nests are built in three stages.
First, the female creates a sturdy outer bowl using strong yet flexible fibres.
Then, using softer, more springy fibers, an inner bowl is created. This maintains the sack-like shape of the nest.
Lastly, the female creates a cushioned lining to incubate and protect the eggs.
I haven’t gone into too much detail about the particular types of fibers used. But there’s a reason for this: nest materials depend on the oriole species and what materials are available around the nesting site.
For example, Baltimore orioles forage for the fallen fibrous fluff (say that 5 times) of the cottonwood tree, whereas Scott’s oriole picks off pieces of the Joshua tree in which they nest in.
Some individuals ditch the plant-based materials altogether and use human-made materials, such as yarn or even discarded fishing gear – a form of pollution that causes the fatalities of many birds each year.
Other species use a resource that can be found almost everywhere: grass.
From April, the start of the breeding season, it’s common to spot female orioles starting the weaving process of nest construction.
What Makes The Oriole Nest So Remarkable?
It seems incredible to us that these small birds can create such masterpieces of engineering – with just the use of their beaks.
Female orioles tangle long fibers over branches to first anchor the nest in place. This is the starting point of the nest.
Then, using her bill, she begins to poke holes into fibers.
More fibers are added and weaved together. With the addition of the holes she has poked, the fibers tangle together forming a strong bond. She continues this process to create the three components of her nest.
The nests are so strong and durable that, in one study, it was found that 85% of all nests remained intact after a year.
But why do orioles make their nests like this in the first place?
Well, the obvious answer is to make it harder for any potential predator to get to the eggs or chicks.
However, the shape of the nest also deters any brood parasite – such as cowbirds – from accessing the nesting chamber.
Some nest entrances measure just 2 inches wide.
However, the depth of the nest depends on the oriole species.
Those with more concealed nests, such as species found across the Great Plains, have shallow pouches, rarely exceeding 4 inches in depth.
In contrast, the Altamira oriole, which is the largest oriole species in the US, can build nests as long as 24 inches. It’s not uncommon to see these nests hanging from power lines.
Interesting Facts About Oriole Nesting
- Before nest construction can begin, the male must court the female. To do this, he moves around the female, bowing deeply as he goes. He’ll also point his bill towards the sky and sing softly. If the female is interested, she will reciprocate.
- Nest sites are selected by females within a territory that is defended by her mate.
- Most orioles breed throughout April – July. However, their nests remain throughout fall, owing to their durability.
- While orioles do not reuse the name nest twice, they recycle nest material to use in the construction of new nests.
- Females are the main nest builders. Males occasionally bring materials to the female, but they will not help with the construction or weaving processes. Only the females do this.
- Female orioles can lay up to 7 eggs in a clutch.
Final Thoughts
Orioles are eye-catching passerine birds found throughout North America.
However, it’s not always their striking colors of black, oranges and yellows that capture our attention.
Orioles construct some of the most intricate and complex nests in the bird world. These hanging nests are thought to deter predators and brood parasites.
Some species can create nests that are up to 24 inches in length, weaved together with nothing but grass.
In other words, orioles are engineering powerhouses.
