Warblers: Mating Habits, Nesting & Eggs

warbler
The yellow warbler nest is made from several natural materials including grass, weeds, and leaves; some materials may even be taken from other nests. Female warblers will build the nest and raise up to two broods per mating season producing 1-7 eggs per clutch. 

Have you ever wondered where warblers build their nests and raise their young? These clever birds sometimes steal nesting material from neighboring nests and find inventive ways to combat the parasitic cowbird! Keep reading to find out about the mating and nesting habits of the cute warblers.

Warblers raise between 1-2 broods of young birds per year, and females play a significant role in raising their young. When the male warbler attracts a female, she builds the nest and incubates a clutch of eggs while the male brings her food. They nest high in the branches of deciduous or coniferous trees and construct nests of soft materials that are sometimes stolen from the nests of neighboring songbirds!

warbler eggs in nest

The Warbler’s Nest

Warbler nests are found in high branches of coniferous or deciduous trees constructed from grass, weeds, tree bark, and leaves. The inside of the loosely-built cup contains softer materials for delicate eggs, such as animal fur, to keep them warm and protected.

When the yellow warbler picks a mate, the female (and only the female) builds the nest. Female warblers are serious about nesting rituals and have been spotted stealing nesting materials from other birds’ nests!

Warbler Clutch and Eggs

Warblers lay between 1-7 eggs per brood. In a single breeding season, these songbirds only raise one or sometimes two broods yearly. Their eggs are small and delicate and measuring 0.6 inches long and 0.8 inches wide. Yellow warbler eggs look muddy with a greenish-gray hue accented with dark spots.

Warblers Nest Incubation

Once all the eggs are laid, the female incubates the nest for up to 12 days. During incubation, the female lays on the nest while the male brings her food. If cowbirds decide to slip in a few eggs on a warbler nest, the female reacts by tossing the foreign eggs from the nest, building another nest on top of the cowbird eggs, or deserting the nest entirely.

Cowbirds and warblers have a tense relationship. If a female warbler spots a parasitic cowbird lurking around her nest, she will attempt to scare it off by making a distinct ‘seet’ call. Warblers often fall prey to cowbirds just as much as vireos and house sparrows.

Warblers Mating Ritual

The yellow-rumped warbler mating ritual includes songs and unique mating rituals. When a male warbler spots a potential mate, it follows her aggressively while fluttering his feathers in a courtship display and singing a courtship song. If the female selects the male as her mate, they are seasonally monogamous. Seasonal monotony in warblers means they will stay together for the breeding season and find a different mate the following year.

warbler nest

How Do Warbler’s Care For Fledgelings?

Both parents care for their young when nestlings are old enough to leave the nest. Unlike the incubation period, the male warbler takes an active role in raising young birds during their nestling and fledgling stage. Male and female warbler will feed nestlings for up to 12 days, and after that, they leave the nest as fledglings.

Young juvenile warblers follow their parents, waiting for a good meal. They flap their wings and chirp while the parent brings them a juicy bug. Because warblers primarily dine on insets, they’re less likely to hang around backyard bird-feeders for their next meal.

Are Warblers Migratory Birds?

There are over 50 species of Warbler in North America, but the yellow-rumped warbler is the most abundant. This species of passerine breeds far north in places such as Canada and even as far up as Alaska. During the non-breeding season, it migrates south to parts of the midwest and as far south as Mexico.

Other popular species of Warblers include:

  • Yellow Warbler
  • Northern Parula
  • American Redstart
  • Pine Warbler
  • Orange-Crowned Warbler
  • Palm Warbler

Of the subspecies of warblers peppered throughout North America, almost all migrate to warmer climates in South America for the winter. Since they are primarily inset-loving birds, they migrate to find fresh food during the unforgiving winter months.

What To Do If I Find a Baby Warbler in my Yard?

If you find a baby warbler in your backyard, take note if it’s a nestling or a fledging. Nestlings are very young baby birds that can’t survive outside the nest. Nestlings are featherless and don’t have the tools needed to defend themselves. Fledglings, on the other hand, have space feathers and are recent graduates of their nests and don’t need human intervention. If the bird seems like a nestling that has fallen from its nest, there are a few things you can do to help.

Try and locate the nest to put it back

Warblers build nests between 10 and 40 feet, so finding the nest may be challenging. If you can’t find the nest, try and move the nestling to a safe and shaded location. Its parent will likely come looking for it, so keep your distance to ensure that the parent returns.

Try and keep your yard clear of predators

If you have dogs, don’t let your dogs into your backyard until you notice that the baby bird is back with its parent. When all else fails, contact your local wildlife rehabilitation center. They may not take the baby bird into their care, but they will provide valuable tips on what to do with your baby warbler.

Tara Summerville

Tara Summerville is a freelance writer that loves her backyard birdfeeders. She enjoys sitting on her deck with a cup of coffee, watching cardinals, blue jays, finches, and chickadees munch away at her backyard offerings. Her fascination with birds began as a child; spending afternoons at her grandma's house watching and identifying birds. She has since carried her love of songbirds into adulthood and ensures no bird in her yard goes hungry!

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