Baltimore Oriole Nesting (Behavior, Eggs + Location)

Baltimore Orioles (jaundice), named for the yellow-orange and black of the Baltimore coat of arms, is a common icteric blackbird in North America. Male Baltimore orioles are brightly colored and hard to miss in their deciduous forest habitat.

Here, we investigate the nesting of the Baltimore Oriole, including habitat, nest appearance, construction, and more.

The Baltimore Oriole’s nest is very special, consisting of a pendulous sac the size of a baseball. Nests are often precariously attached to drooping branches of deciduous trees. Although the nest appears to be exposed to the elements, it is sturdy and kept away from predators.

The female builds the nest, a process that requires determination, patience and skill. First, she weaves together strong fibers such as strips of bark, flexible branches, rope, and milkweed silk, which are attached to the branches and strengthened by rolling the material together.

The edge of the mouth is made first, and then the female bird hangs upside down to build the cup.

Baltimore oriole nests are some of the most spectacular of all North American birds – read on to learn more about them!

The Baltimore Orioles nest is very special, consisting of a pendulous sac the size of a baseball

nest location

Where did the Baltimore Orioles nest?

The Baltimore Oriole lives in Canada and east of the Rocky Mountains in the United States. They usually nest in deciduous trees and tall mature shrubs in open woodland or forest edges. They usually avoid deep forests.

Nests are built on narrow shafts of long, drooping branches.

Do Baltimore orioles nest in the same place every year?

Baltimore orioles don’t usually nest in the same place every year, although they do return to the same breeding grounds.

Others claim they may return to the same tree every year – especially if they raise successful offspring there. Bird’s nests are sometimes recycled as material, but are rarely reused.

Do Baltimore Orioles Nest in Backyards?

Baltimore orioles typically nest in the upper branches of deciduous trees in wooded areas. They rarely nest in backyards unless the backyard has properly mature deciduous trees.

Close up of a nesting Baltimore Oriole

Do the Baltimore Orioles use nest boxes?

The Baltimore Orioles build incredible pendulum-shaped nests that don’t fit in nest boxes. Instead, they prefer to build their nests from grasses, leaves and twigs from deciduous trees and, rarely, tall shrubs.

What tree do Baltimore orioles nest in?

Baltimore orioles typically nest on the outer branches of deciduous trees such as oaks, maples, elms, and fig trees, as well as fruit trees such as apples and cherries. They choose slender, drooping branches for their nests, which look like a very unstable structure!

How Tall Are Baltimore Orioles’ Nests?

Baltimore oriole nests are usually built 10 to 30 feet above the ground, but some have been recorded as high as 90 feet.

This means the nests are difficult to spot with the naked eye, as they are usually well hidden in mature trees.

Baltimore oriole nest hanging from a tree in early spring

Nest Appearance

What is a Baltimore oriole nest like?

Baltimore oriole nests are cup-shaped hanging or pendulum structures made of grass, twine, and other plant fibers, lined with softer materials such as hair and feathers.

They usually hang from fallen branches or dangle from shrub branches. The den is usually the size of a baseball and looks like a hanging bag or sock.

They are certainly one of the most striking nests of any North American bird, looking very precariously suspended between drooping deciduous branches.

However, their strength belies their appearance, as some Baltimore oriole nests have been documented for more than a year. In fact, in one study, 85% of nests lasted more than a year.

How big is a Baltimore oriole nest?

Baltimore oriole nests are very small. They measure approximately 4 to 6 inches wide by 4 to 8 inches deep with a 2 – 3 inch wide opening. They are compact and comfortable inside.

Inside the Baltimore Oriole’s Nest

phenology

When Do Baltimore Orioles Nest Every Year?

The Baltimore Orioles stick to their traditional spring breeding season, which runs from late April through July. Nesting peaks in May, especially further north as the weather is colder. Nesting time is earlier in the south and the weather is milder in early spring. If the weather is bad, the nesting time will be delayed.

How Long Do Baltimore Orioles Nest?

Baltimore orioles nest for two to three months at most. During this time, the males occupy a territory, while the females begin building complex nests, which can take up to three weeks to complete.

Egg laying and incubation take about 12 to 14 days, and the chicks fledge after a few weeks. There was no interruption and the whole process took just over a month. In fact, nesting may be delayed by bad weather, or nesting may fail.

If the lair fails early in the season, the matchmaking won’t try again – the lair is too hard to build – so they can only fight once per season!

Female Baltimore Oriole outside the nest

What month do the Baltimore Orioles lay eggs?

In most areas, the peak spawning season is in May. Generally, it is later in the north and earlier in the south. In any case, spawning may be delayed due to inclement weather, which makes it difficult for the female to build a nest.

Where do Baltimore orioles nest in winter?

The Baltimore Oriole migrates during the winter, often traveling to the Gulf Coast, the Antilles, and Central America, as far south as Panama and remote areas in the far north of South America.

Female Baltimore oriole collects nesting material

nest

How did the Baltimore Orioles build their nest?

The Baltimore Oriole builds its nest on the branch of a deciduous tree, usually on a drooping branch high up in the tree. Women are master builders and do most of the work, while men sometimes deliver materials.

First, female orioles gather strips of plant material such as grass and twigs, thin strips of bark, fine fibers, and cotton-like materials such as hair or wool.

The fibers are initially tied to the branches and gradually weave together in turns and coils – some nests are thought to involve around 10,000 individual “stitches”. The nest is usually divided into two halves or from top to bottom. Then sew the separated parts together.

The resulting pendulum-shaped nest is sturdy, though it appears to be floating in the air without a platform or support. Additionally, the females seem to “stress test” the nest from time to time to ensure its strength.

In one study, 85% of nests lasted at least a year, a testament to the females’ enormous capacity. Nest building takes 40 hours, or two to three weeks.

Female Baltimore Oriole Weaves Nest

What did the Baltimore Orioles build their nest with?

Nests are made from a variety of materials, including vine bark, milkweed silk, wool, park tape, soft twigs, horse hair, and man-made fibers such as twine, cellophane, twine, and fishing line. A complete nest is lined with feathers, wool, and other soft fibers.

Do male or female Baltimore orioles build nests?

Female Baltimore orioles build nests, and males occasionally provide material. Women are definitely the masterminds of this complex process.

Female (left) and male (right) Baltimore oriole breeding pairs nest together

Baltimore Oriole Eggs

What do Baltimore oriole eggs look like?

Baltimore oriole eggs are blue-gray with brownish-black markings concentrated at the larger end of the egg. Some marks are spotted, while others are webbed.

How many eggs do the Baltimore Orioles lay?

Female Baltimore orioles almost always lay 4 to 5 eggs, rarely 3 to 6 eggs.

Do male Baltimore orioles sit on eggs?

Female Baltimore orioles hatch while the males keep an eye out, often hovering near the nest. He sometimes feeds the females and drives away parasitic cowbirds and other intruders.

Baltimore oriole chick peeking from the top of the nest

fledgling and parental care

When do Baltimore baby orioles leave the nest?

Baltimore baby orioles fled after 12 to 14 days. Both males and females intensively feed their young during this time.

How many litters do Baltimore Orioles have?

Baltimore orioles have only one brood. If that brood fails, they will not try again because the nesting process is too complicated and lengthy.

Who Feeds Baltimore Oriole Chicks?

Both males and females contribute equally to feeding the chicks. Chicks are usually fed ruminant insects.

Close-up of a recently fledged Baltimore oriole chick

common problem

Will the Baltimore Orioles Abandon Their Nest?

During the early breeding season, Baltimore orioles typically wait for the bad weather to subside before the females begin nesting.

Once built, nests are virtually invulnerable to land predators, but are still vulnerable to other birds, such as the tauren that lay their eggs inside the oriole’s nest. However, cowbirds often have difficulty laying their eggs inside the oriole’s brood pouch.

They won’t abandon the nest unless it fails irretrievably.

Do Baltimore orioles nest on the ground?

Baltimore orioles nest high in deciduous trees, usually at least 30 feet high.

Where Do Baltimore Orioles Nest At Night?

The female sleeps in the nest during incubation. Otherwise, they sleep in treetops.

How to Attract a Nesting Baltimore Oriole?

Baltimore orioles are sometimes attracted to flowers and fruit trees, such as oranges. Provide them with fresh water, mealworms, and fruit. Milkweed silk and cotton help them build their nests.