Warblers are arriving and birders are all a flutter. These birds have a reputation as challenging the most experienced birdwatchers. In this post I focus on understanding their habits, hopefully making the spring warbler-watching season a fun one.
Warblers of the World
Warblers are classified in two categories by western scientists, Old World (Sylviidae) and New World (Parulidae) birds. The Old World includes Eurasia, Africa, and Australia. The “New World” includes the Caribbean, North, Central, and South America.
“New World” Warblers are small, arthropod-eating birds of Central, South America, and the Caribbean which breed in North America north of Mexico. During spring they migrate as far north as Canada.
The Wood Warblers
The Parulidae family is called the ‘wood warblers’. The Parulidae are split into two subfamilies, the ‘wood warblers proper’ (Parulidae) and the ‘banana quits’ (Coerebinae). The bananaquits have one species in the Caribbean. This post focuses on the Parulidae, wood warblers of the Americas and the Caribbean.
There are about 116 species of wood warblers that breed in North America, give or take a few. Scientists debate amongst themselves as to how they decide a bird fits into the Parulidae family. It still is one of the largest bird families.
A female yellowthroat bathing in the Vale of Cashmere in Prospect Park, Brooklyn. Early in the video there’s also a female American redstart.
Video courtesy of Rhododendrites, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Warbler Traits
One hundred sixteen species are categorized as Parulidae and all those species share a number of traits.
The wood warblers are small, anthropoid eating perching birds. Species lengths range from 4 to 7.5 inches long. They have skinny little legs that look like toothpicks.
Most have short, pointy slender or flat beaks. They eat arthropods which include insects, spiders, and crustaceans. They search for food in tree bark, among tree leaves, and on the forest floor.
Many are colorful. The most common plumage colors are yellow and olive. But also red, black, gray, and green feathers on some species.
The males have brighter and sharper color plumage that females. The females being nest sitters have duller more subdued coloration. The young fledglings, both male and female, share the plumage of their mothers but a bit duller.
Very Colorful Wood Warblers
- Golden Swamp Warbler (Protonotaria citrea)
- Northern Parula (Parula americana)
- Blackburnian warbler (Dendroica fusca)
- Red-faced Warbler (Cardellina rubrifrons)
- American Redstart (Setophaga ruticilla)
And they have lovely songs. The males are the singers in all but a few species. When warblers are return to their breeding territories I believe their beautiful songs greatly enhance the dawn chorus.
Learning the songs and calls of spring warblers, particularly the most common species, may be your best bet in identifying them, because you may not actually see them.
They constantly move. On many occasions I have heard birders, call out, “Hold still!’ while trying to focus their binoculars on warblers hopping through the trees.
Warbler Migration
May is the height of warbler migration. Most American warblers of Central and South America, stay in tropical forests all year around. but some take part in Neotropical migrations and move to northern ecosystems to breed and raise young.
Neotropical migratory American wood warblers breed and raise their young in forests of higher latitudes. This includes the woods and forests of Alaska, Northern and Southern Canada and the United States.
They birds take advantage of the abundance of anthropoids (insects) and more choices of nesting sites than are available crowded tropical areas.
When to Go Birding, I mean Warbling
It is during migration that birders in North America get a chance to see neotropical birds. Otherwise, you would have to travel to the tropics to see them. Birding during spring migration is when the birds save us an expensive overseas trip.
Warblers migrate at night, from dusk to dawn the next morning during spring and fall. During the day they stop to feed. This is when birders get to see them: from dawn all day until they take off at dusk and continue their migration. Unless your area is their breeding territory.
During migration several species may feed in the same area, creating a bonanza for excited birders.
Breeding
At least 52 species of American Warblers breed within the central and eastern portions of North America from about the middle half of the United States to the southern half of Canada.
Several species can breed in the same stand of trees but feed in different parts of the tree canopy, on the surface of tree bark, or on the forest floor.
Identifying Wood Warblers
In spring, the different species of spring warblers are easy to identify. The males are brightly colored and they sing species distinctive songs. The female plumages are similar to the males, but the colors are more subtle.
In fall, things get a bit more challenging. Some species change their plumage and can look very different than they did in the spring. The males aren’t singing either. The work of breeding and raising young is over, so there is not need to attract a mate.
Adding to the difficulty, in fall that the plumage of juvenile warblers is similar to their mothers, but duller.
Very Common Wood Warblers
These warblers are common in many areas of North America.
- Yellow Warbler (Dendroica petechia)
- Common Yellowthroat (Geothlypis trichas)
- Yellow Breasted Chat (Icteria virens) – the largest species of Warbler
- Yellow rumped Warbler (Dendroica coronata)
- American Redstart (Setophaga ruticilla)
Keeping a Life List or Birder’s Journal
Mystery Bird in the Middle of the Atlantic Ocean
Habitats
Wood warbler choice of habitats contribute to making they hard to see. They like thickets, dense shrubs, and hopping along branches high in the tree canopy. Because of their preferences look for warblers along woodland and forest edges. They can also be found in marshes and swamps.
Photographing Warblers
Getting photographs of these small, hyperactive birds is a challenge. I would love to get a great photo or two of at least two species of warblers. It takes research and practice way before you hit the birding trail.
An article by Bill Palmer appeared on the North American Nature Photography Association blog entitled, Chasing Spring Warblers
From the article:
“Most of us are pretty adroit at photographing eagles, hawks, pelicans, ducks and other large birds, but what about photographing small, hyperactive, secretive birds such as warblers? Adding to the challenge, when you do get a chance to see one, it may only be visible for a few…”
The tips in this article also help with spotting the warblers on birding trips.
I share it here because it has such excellent advice. Highlights from the article
- learn the calls and songs of the species you are most likely to see and hear
- learn which warbler like which habitat
- spring warbler migration starts in late March through May in North America
- warblers fly over the Gulf of Mexico back into North America
- Magee March in Northwest Ohio is called, “The Warbler Capital of North America”
- the technical stuff of photographing warblers – camera, lens, flash, etc. is covered
- hints and tips of getting the shot
Conclusion
I hope this post has shed a little light on how to observe warblers. In researching this article I learned some tips on how to up my “warbler game”.
I do get excited when I actually “see” one of these birds on a branch or tree limb. Spotting one feels like a major accomplishment. They are a challenge. That’s why birders love warbler season.
This is an updated post originally published March 4, 2020.
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