Warblers Part 1

 

Prothonotary Warbler (Protonotaria citrea).
Rowan County, North Carolina. 

Spring is coming and birds that spent the winter in the tropics are heading north.  The most eagerly awaited of these neotropical migrants are the new world warblers, the Parulidae. These small birds are active, often brightly colored and each sings a distinctive song.  This family has 117 species and all are restricted to the New World.  Many warblers are tropical but over 35 species regularly occur in eastern North America.   

 

Pine Warbler (Setphaga pinus).
Rowan County, North Carolina.

Pine Warblers (Setophaga pinus) are present year-round of the Piedmont of North Carolina.  As their name suggests they are closely associated with pines (Pinus sp.) where they feed, breed and nest.  Yellow-rumped Warblers (Setophaga coronata) migrate from the north and spend the cold months with us.  This species breeds in northern forests and winters throughout the south and into the tropics. Yes, Yellow-rumped Warblers do have yellow rumps. This gives rise to their nickname, butterbutts.

Male Yellow-rumped Warbler (Setophaga coronata) in spring.
Rowan County, North Carolina. 

 

Female Yellow-rumped Warlber in winter,
showing her yellow rump,
Rowan County, North Carolina. 

Other warblers arrive from the south in the spring and breed in our area.  One of the first of these early birds is the Louisiana Waterthrush (Parkesia motacilla).  Despite the thrush in its name, this bird is really a warbler.  Both male and female Louisiana Waterthrushes are brown on the back with a white eye line and a white breast with brown streaks.  They also have the habit of bobbing their tails while perched or walking on the ground.  Male Louisiana Waterthrushes sing on their breeding territory near water in hopes of attracting a mate.

 

Louisiana Waterthrush (Parkesia motacilla) singing in spring.
Mecklenburg County, North Carolina.

Common Yellowthroats (Geothylpis trichas) are warblers that breed near creeks, ponds and marshes.  Males have a black mask, a brilliant yellow throat and brown back.  Females have similar coloration but lack the black mask.   Males sit on exposed perches and sing their distinctive song, witchity-witchity-witch. 

Male Common Yellowthroat (Geothlypis trichas).
Rowan County, North Carolina. 

American Redstart (Setophaga ruticilla) males are brilliantly colored, black with flashes of orange on the wings and tail.  Females are grayish brown and with yellow markings. These active warblers are constantly fluttering among the leaves and fanning their tails while chasing insects.  American Redstarts will chase insects through the air and often look like falling leaves as they pursue their prey. 

 

Male American Redstart (Setophaga ruticilla).
Palm Beach County, Florida. 

Female American Redstart.
Palm Beach County, Florida. 

The Black-and-white Warbler (Mniotilta varia) has a very descriptive name.  These warblers are striped black and white and behave like little woodpeckers, crawling along tree trunks and branches looking for food.   

Male Black-and-white Warbler (Mniotilta varia).
Dry Tortugas National Park, Florida.

The smallest warbler we have in the area is the Northern Parula (Setophaga americana).  This tiny creature is brightly colored with blue on the back, yellow on the throat and breast and an orange collar.  Northern Parulas have white wing bars, a broken white circle around the eyes and a green saddle on the backs.  They build their hanging nests high in trees.  Northern Parulas use of lichens as nest material in our area, but further south they make their nests with Spanish Moss. 

We saw this Northern Parula (Setophaga americana) in New Mexico,
well outside its normal eastern range.  It was feeding along the edge of a
marsh which is atypical habitat for the species.
 This bird probably took a wrong turn on migration.
Bosque del Apache National Wildlife Refuge, New Mexico.  

Yellow-throated Warblers (Setophaga dominica) are boldly patterned black, white and yellow birds.  Males and females have similar plumage and they spend their time creeping along branches in search of their insect prey. 

 

This Yellow-throated Warbler (Setophaga dominica) 
was hanging around our bird feeders and acting sick. 
It tumbled to the ground and died later that day. 
Rowan County, North Carolina. 

Ovenbirds (Seiurus aurocapilla) are warblers with strikingly large eyes and spend a lot of time on the ground.  They look like tiny thrushes with a gray-green back, white breast with black stripes and a crown streaked with orange.  Ovenbirds get their name from their dome-shaped nest.  They build  nests on the ground that resemble an old-fashioned clay oven with a side entrance.  This ground nesting habit makes their eggs and young vulnerable to predators like snakes, squirrels and chipmunks.

Ovenbird (Seiurus aurocapilla) feeding on the ground.
Mecklenburg County, North Carolina. 

Ovenbird.
Mecklenburg County, North Carolina. 

I think the most dazzling member of the Parulidae is the Prothonotary Warbler (Protonotaria citrea).  Prothonotaries are bright yellow and seem to glow with an internal light in their swamp habitat.  They are one of only two cavity nesting warblers and use old woodpecker holes or nest boxes.  Their odd name comes has an ecclesiastical source.  The First Notary (proto-notary) was a Catholic Church official who traditionally wore yellow robes.  When Europeans started naming North American birds, they found a red-robed Cardinal and, yes, a yellow-robed Prothonotary.  Our friend Dr. Joe Poston is doing a long-term study on Prothonotary Warblers in Salisbury, North Carolina.  He traps the birds and marks them with colored leg bands.  Each bird has a unique combination of colors so they can be identified through binoculars.  In the spring of 2021 we found a male Prothonotary singing on his territory. Based on his legs bands this warbler was at least 5 years old.  The oldest known Prothonotary lived 8 years. We hope to find this guy singing again this spring on his way to breaking that record.  

Prothonotary Warbler bringing food to nestlings. 
Rowan County, North Carolina. 

A male Prothonotary Warbler with colored leg bands.  This bird was
at least five years old in the spring of 2021.
Rowan County, North Carolina. 

There are so many warblers, and I will not be able to cover them all. But the next blog with have another selection of these most appealing birds.

A Thorny Subject

 

Thorns of Trifoliate Orange (Poncirus trifoliata).
Rowan County, North Carolina. 

It happens all the time.  Hiking through a field, I get pulled up short by a Blackberry cane and come away with a bloody scrape.  Plants that grab and slash are said to be armed and botanists have precise terms for these armaments; thorns, spines and prickles. 

Wounds from Blackberry (Rubus sp.) prickles.
Rowan County, North Carolina. 

Thorns are modified branches that come to a point.  These sharp structures defend the plant from the attention of herbivores.   Sweet Acacia, Vachellia faresiana, is a shrub in the bean family, Fabaceae.  It has a world-wide distribution and in the US it grows in the west and Florida.  We found Sweet Acacia flowering in the deserts of southeastern Arizona.  The thorns are arranged along the stem and protect the delicate leaves and bright yellow flower clusters. 

Sweet Acacia (Vachellia faresiana).
Cochise County, Arizona. 

Honey Locust (Gleditsia triacanthos) is a tree in the bean family.  It is native to the Mississippi valley but has been introduced to many areas around the world.  Honey Locust has impressive, 3 inch, multi-pointed thorns that probably evolved to protect the tree from giant ice age mammals that are now extinct.

 

Giant thorns of Honey Locust (Gleditsia triacanthos).
Rowan County, North Carolina. 

Another small tree with impressive thorns is Trifoliate Orange (Poncirus trifoliata).  Trifoliate Orange is a close relative of oranges and lemons.  It is native to northern China and Korea and has been naturalized in many countries.  Trifoliate Orange is cold tolerant and is used as root stock to graft  species of Citrus.  Because of its thorns Trifoliate Orange is planted as a natural fence.  

Leaves and thorns of Trifoliate Orange.
Rowan County, North Carolina. 

Members of the family Cactaceae have spines.  Cacti have reduced their leaves through evolutionary time to spines.  This change lowered the leaf surface area and cut down on water loss from the plant.  The spines have lost their photosynthetic ability and the cactus stem has taken on that function.  The stems also store water, and the spines protect that precious resource from thirsty desert creatures.   

 

The aptly named Fishhook Barrel Cactus (Ferocactus wislizeni)
has hooked spines..
Portal, Arizona.

Prickly Pear Cactus (Opuntia ficus-indica) with spines.
Arizona-Sonora Desert Museum, Arizona.

Saguaro (Carnegiea gigantea) with rows of spines.
Arizona-Sonora Desert Museum, Arizona. 

Some armed plants have structures that resemble thorns or spines but are extensions of the epidermis called prickles.  Both thorns and spines have vascular bundles running down their center, but prickles lack this tissue.  Blackberries (Rubus sp.) and Roses (Rosa sp.) have hooked prickles on their stems.  Greenbriar (Smilax sp.) is a vine that also bears prickles.  Besides protection the prickles help these viny, rambling plants to climb over other vegetation. 

Blackberry (Rubus sp.) armed with prickles.
Rowan County, North Carolina. 

Prickles on Multiflora Rose (Rosa multiflora).
Rowan County, North Carolina.

Greenbriar (Smilax sp.) showing its prickles. 
Rowan County, North Carolina. 

You often hear people talk about thorns of the rose.  This combination of beauty and pain have made roses a powerful symbol of love over the centuries.  But roses have prickles, not thorns. This misuse of terms is common. Thorn and spine are used interchangeably by most people and prickles are hardly mentioned at all.  But to botanists, thorns, spines and prickles have a precise meaning that the rest of the world ignores, at its peril.