Yellow Warblers

Many warblers have at least some yellow, but I imagine if there's one that deserves the name of the color, it's the Yellow Warbler (Setophaga petechia).

The spring migration has come and gone, and now we have to be content with the summer residents that remain. Robins seem to be everywhere, and unfortunately so are the starlings and grackles. High in the tree tops, you might hear an oriole; they seem to prefer big cottonwoods here. If you have orioles near you, what trees do they prefer?  Orioles can be relatively common, but seldom do we get a good look at the male's flashy orange and black.
 

male Yellow Warbler at the Allegany Nature Pilgrimage (southwestern New York,
always the first weekend after Memorial Day) during a bird-banding demonstration

Another colorful songster, though relatively common, is likely to be overlooked unless you’re in the habit of scanning shrubby wetlands and thickets while listening for its "sweet, sweet, sweeter than sweet" song. Check the tops of shrubs and dwarf willows for a bright but tiny spot of yellow. With binoculars, look for rusty-red streaking on the breast. This is the male Yellow Warbler, one of 51 North American species of wood warblers – many of which are now uncommon or quickly pass through on their way north. The Yellow Warbler on the other hand is relatively common and a widespread nester from coast to coast across the northern 2/3rds of the U.S., Alaska and most of Canada with breeding populations extending down through coastal California and central Mexico. (If you're submitting an eBird report, you can use the "Add Details" button, and then the "Breeding Code" button to record any breeding behavior you observe or hear.)
 

female Yellow Warbler at Montezuma National Wildlife Refuge, NY

Warblers are small birds, generally four to five inches long, with slender, straight-pointed bills used like tweezers to collect insects. Warblers are very active and it’s hard to get a good look at any of them. Most prefer woodlands in various stages of growth from scrub to mature forest and for this reason they are referred to as wood warblers. Within these habitats, some warblers stay in the treetops (giving birders "warbler neck"), some hide on the ground and the majority travel in-between. Yellow Warblers are somewhat unusual in preferring more open settings. Willow thickets and isolated shrubs in cattail marshes seem more to their liking, but any thicket will do in a pinch.

male Yellow Warbler checking its reflection for a rival in our camper window

The Yellow Warbler is a common summer resident that begins returning at the end of April. The remainder trickles in throughout May. Aptly named, they are yellow on the head and underneath, olive-yellow on the back, and a mix of olive and yellow on the wings. Males are brighter with reddish streaks on the breast. The more aggressive and dominant males have darker streaks. Females are duller with faint rusty streaks on the sides. If you get a close view, look for yellow tail spots that are usually missed.

Brown-headed Cowbird egg in Yellow Warbler nest (Bradford County, PA)

The Yellow Warbler is one of the species most frequently parasitized by cowbirds, but they have developed a defensive strategy against the blackbirds. After a cowbird egg is deposited, the Yellow Warbler builds a new nest on top of the old and lays a new batch of their own eggs. If the cowbird returns, the warbler repeats the process. The record is a six-story nest (although there is an unconfirmed report of a 10-story nest near Cayuga Lake, NY, in 1923).

As a species, the Yellow Warbler is perhaps the most widespread of the warblers, but there are three distinct groups with four subspecies. Together they span the continent and range from the Arctic down through Mexico and the Caribbean to the northern reaches of South America. You can find an interactive range map on eBird.
 

pair of Yellow Warblers at Montezuma National Wildlife Refuge, NY

On their territories, Yellow Warblers sing two types of songs with a number of individual variations. One song type is used to attract a mate, while the other is used to defend territories against other males. With wetlands being a limited resource, there is intense competition for prime nesting space. After mating, recognition of individuals becomes important, so minor variations in songs become important. You can find more information along with a static range map and recordings of Yellow Warbler songs on All About Birds.
 
Yellow Warblers have only one brood per year and as soon as the young are independent, the species begins its southward migration. They are one of the earliest summer nesters to leave. Some are gone by the end of July and (almost) all have left by the time goldenrod is in full bloom.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com or connect through my Facebook page and photo page. There's also a community-type page for The Northeast Naturalist. Other nature and geology topics can be found on the parallel blogs Adirondack Naturalist and Heading Out.

Rhododendron

Great Rhododendrons (Rhododendron maximum) grow wild in scattered colonies across New York and New England as far as southwestern Maine, but it's found primarily in the Appalachians from Pennsylvania to northern Georgia. Beyond that it has been widely planted as an ornamental. Wherever there is sufficient moisture, these evergreen members of the heath family can form dense thickets generally reaching a height of 13 feet, but old bushes are capable of growing to a height of 30 or even 40 feet and a crown diameter of 12 feet, essentially becoming small trees. The main requirement is acidic soil with a high organic content.

The concave leaves are long and leathery and curve down to smooth edges that may curl under during dry or cold weather. Most of the leaves are clustered in whorls around the end of twigs and surround the showy, rose-pink to purple, sometimes white, flower clusters that open between March and August, depending on the local climate. Our ornamental version opens in late May here in the northern Finger Lakes region.

In the wild, rhododendron is an understory plant and does well in the shade of taller trees. Combine that factor with the shrub's dense, evergreen foliage and you can understand why it's difficult for smaller plants and wildflowers to grow underneath rhododendrons.

This species has a number of alternate common names including Late or Summer Rhododendron, Great, Bigleaf or Deertongue Laurel and Rosebay. It's the state flower of West Virginia. The name Mountain Laurel is reserved for its smaller relative, Kalmia latifolia.

Corrections, comments and questions are always welcome at

northeastnaturalist@yahoo.com or connect through my Facebook page and photo page. There's also a community-type page for The Northeast Naturalist. Other nature and geology topics can be found on the parallel blogs Adirondack Naturalist and Heading Out.

Picris hieracioides

This is an invasive, alien weed and I generally pull it out when I have time. It resembles a tall, multi-headed dandelion with rough-hairy, almost bristly, stems and leaves. Indeed it is a relative and like dandelions, comes from a foreign land. This one is native to the mountains in southern Spain and northern Portugal. In addition to growing in my yard, I find it proliferating along roadsides, often intermingled with its close relative, blue Chicory. The combination is colorfully attractive. All these plants are in the Aster (Daisy) family and generally considered invasive weeds.

I learned it's name as "Hawkweed Picris" from a botany professor, but the rest of the world now seems to call it "Hawkweed Oxtongue." Sorry, that just doesn't have the same ring (or is it just habit)?  The scientific name is Picris hieracioides. The genus name (Picris) comes from a Greek word for bitter, referring to the plant's roots. Members of this genus are called "oxtongues." The species name indicates its close resemblance to hawkweeds, genus Hieracium.

We've described the flowers as dandelion-like, but look closely and notice that the tip of each yellow ray has five "teeth." With age, the blossom becomes a fuzzy seed head. Without adequate sunlight, though, the plant never reaches the flowering stage and remains a basal rosette of leaves (on the ground).

The lower stem leaves are long, lance-shaped and wavy-edged, or they have short teeth separated by scalloped sinuses (see the last images before the photo notes). The upper leaves are shorter, alternate, long arrow-shaped and hug the main stem. Side branches arise from the points of attachment [axils].

Picris is a biennial, taking two years to reach maturity in sunny, open yards, fields and roadsides, and sometimes it survives another year or two as a short-lived perennial. It is related to Chicory (genus Cichorium) and both are in the Chicory subfamily (Cichorioideae).

Picris is found in isolated pockets across the Northeast into Canada, but primarily in New York and Pennsylvania. There is a disconnected invasion, again highly localized, in the Northwest from Washington to Alaska and another in Hawaii.

Photo notes: To make a leaf stand out, cast a shadow into the background. Use a tripod and a cable release [or the self-timer]. After aiming and setting the exposure [manual works best], move to throw your shadow into the background. After taking the shot, check the result and adjust as needed. I've also used notebooks and shirts to create shadows where I need them.
Lenses for this project were the 18-55mm kit lens and 100mm macro on a Canon XT.

Corrections, comments and questions are always welcome at northeastnaturalist@yahoo.com Connect with me on Facebook. In addition to my personal page (with the Gaillardia flower at the top), there is a photo/artist page, Dave Spier (photographic naturalist).