How did the Hermit Warbler get its name?

Thanks for the question, Jim D. in Delvan, WI.

Answer:

Perhaps the reason relates to how it’s often easier to hear than see them, as Hermit Warblers typically forage individually high in the tree tops — hence, the common name that John Kirk Townsend first described when collecting this species in 1837 near Fort Vancouver (now Vancouver, WA).

Considered part of the Black-Throated Green “super species” — along with Black-throated Green (Dendroica virens), Golden-cheeked (D. chrysoparia), Black-Throated Grey (D. nigrescens) and Townsend’s (D. townsendi) warbler — the Hermit Warbler breeds in coniferous forests of the Coast, Cascade, and Sierra Nevada mountain ranges of southern Washington, Oregon, and central and northern California.

Where it occurs with Townsend’s Warbler within the s. Washington Cascade Mtns., Olympic Mtns., and central Oregon Cascade Mtns., Hermit Warbler may be losing populations as it is replaced and outcompeted by its first cousin. Studies by S. Rowher and C. Wood from 1994 to 1996 in this region indicate that 80 percent of adult Townsend’s and only 53 percent of adult Hermit paired and maintained their territories long enough to reproduce successfully. Other data relating to aggression behavior and hybrid zone analyses further supports Rohwer and Wood’s conclusions. Another reason for the reduced local populations of Hermit’s may be the result of reduced suitable breeding habitat in portions of its home range.

Nonetheless, in other portions of its range where Townsend’s Warbler does not breed, Hermit Warbler population densities appear to be stable, according to Breeding Bird Surveys (BBS) conducted in the last 30 years. However, it’s important note that BBS surveys are limited to routes where roads occur, so more comprehensive surveys of the Hermit’s total abundance do not exist. In addition, given the Hermit Warbler’s inherent small population worldwide and narrow geographic distribution, it is not considered abundant or common in most portions of its home breeding range.

Latest Warbler Quiz Answers

Below, you’ll see correct answers to recent quizzes that appear on the right side of this page (in order, from the most recent quiz to older ones):

Which "New World" wood-warbler species has the most extensive breeding area?

Answer: Yellow Warbler

Unlike Blackpoll that undertake a long migration (see 1/8/09 article), which wood-warbler has populations that do NOT migrate?

Answer: Common Yellowthroat

What behavior displayed by American Redstart is different than most other songbirds?

Answer: Some females sing

Which wood-warbler species spends the winter in large numbers in higher latitudes than any other wood-warbler?der members?

Answer: Yellow-rumped Warbler

Returning Wood-Warblers In The Bay Area

Birders are reporting the initial appearance of northbound migrating wood-warblers to the Bay Area this week.

Newly-arrived ORANGE-CROWNED WARBLERS are currently joining brave over-wintering populations, with Oak-Bay woodlands one of the best habitats to hear and seem them.

Note the annual date range of first-returning migrants for this species in Marin County (the initial county north of the Golden Gate Bridge) is 2/18 (earliest detection) through 3/16 (latest detection), according to Dave Shuford’s “The Marin County Breeding Bird Atlas.”

Soon, other nesting wood-warblers of the Bay Area shall also appear, with their identities and date range of arrivals in parentheses below:

- WILSON’S (3/10 – 4/8) (shown above)

- BLACK-THROATED GRAY (3/31- 4/27)

- YELLOW (4/8 – 4/23)

- MACGILLIVRAY’S (4/3 – 4/30)

For a comprehensive list of arrival dates for Marin County landbirds, feel free to visit my Web site (www.warblerwatch.com) where there’s a button that provides access to the Atlas’ chart (page 39).

Who’s ready for a brief wood-warbler quiz?

It’s the Q and A portion of the day, so feel free to satisfy your wonderment with the following questions (answers appear far below):

1. To which family do some taxonomists believe is most closely related to wood-warblers?

2. If you include North, Central, and South America, and the West Indies, how many wood-warblers exist?

3. Although most wood-warblers possess small bills, which two species have more robust ones?

4. Which common wood-warbler has rictal bristles (like flycatchers) to help it sense prey while pursuing insects?

5. Although most songbirds have ten functional primary flight feathers on each wing, how many do wood-warblers possess?

6. Among the 53 typical annual breeding North American wood-warblers, what’s typical about their breeding behavior in contrast to Central and South American wood-warbler species?

ANSWERS:

1. Some taxonomists place wood-warblers closest in relation to the tanager family, Thraupidae (sometimes treated as a subfamily, Thraupinae, of Emberizidae). Other researchers believe they are nearest to the New World finches family, Emberizidae.

2. 126 species amidst 28 genera.

3. Yellow-breasted Chat and Yellow-Rumped Warbler.

4. American Redstart.

5. Nine.

6. North American wood warblers remain monogamous for the breeding season, while Central and South American pairs may persist together for longer periods.

Wilson’s Warbler: Abundant, Yet Vulnerable

You might think the Wilson’s Warbler is one of the most abundant warbler species while traveling through Alaska, most of Canada, and south through the western USA to southern California and New Mexico. Your supposition would largely be correct.

But long-term trend analysis indicate recent population declines, especially in the western portion of the species’ range. The most likely problem is large-scale destruction of riparian habitat.

Nesting on or near the ground at elevations that vary from sea level to the alpine zone, the three subspecies of Wilson’s Warbler encompass a wide geographical area that spans from eastern Canada to Alaska and portions south into Utah, New Mexico and central California.

Interestingly, the subspecies may occur together in non-breeding range, with all three subspecies possible in Panama.

Although it shares its genus name – Wilsonia -- with other wood-warbler species – (Canada and Hooded), Wilson’s is by far the most common. All three species possess rectal bristles (small , highly-sensitive feathers at the base of the bill) that are utilized during “flycatching,” a foraging behavior that can sometimes help with field identification.

Mr. Warbler, what’s the difference between “New World” and “Old World” warblers?

Thanks for the question, Barbara S. in Spokane.

Noting the New World is a geographic designation corresponding to the Western Hemisphere, Old World warbler species live within the Eastern Hemisphere areas of Europe, Asia, and Australia – with only a few species (e.g., gnatcatchers) existing in the New World/Americas.

Approximately 350 Old World warblers occur in the Sylviide family. New World warbler species total around 120 species and most of them are in the Parulidae family.
(Approximately 52 are annually seen in the USA north of Mexico, with the most common being Yellow, Common Yellow-throat (above photo), Yellow-Rumped, among others.)

In fact, the Olive Warbler (the sole Peucudramidae family member) is the only non-Parulidae family species among North American wood-warblers to occur north of Mexico.

Note there’s also the Australasian warblers in the Acanthizidae family that include gerygones, thornbills, and scrubwrens,.

This family is native to Australia, Indonesia, New Zealand, and the south-west Pacific. Australia hosts 35 endemic Acanthizidae family members and New Guinea 15. A single species is found in Vanuatu, New Caledonia and the Solomon Islands, and three species occur in the New Zealand region, including endemic species in the Chatham Islands and Norfolk Island. In Asia two species are restricted to Indonesia and another is found in the Philippines and on mainland Asia. Most species are not migratory, with the exception of the gerygones.

Which wood-warbler travels the longest migration route?

Thanks for the question, David in Studwell, MN.

The answer: Blackpoll

Autumn studies of the routes south-traveling Blackpoll take have been extensive. Through banding at stations where the same individual has been studied, researchers have determined some Blackpolls travel more than 5,000 miles one way from Alaska to Brazil.

For many Blackpoll migrating populations, migration occurs over the Atlantic Ocean from the northeastern United States to Puerto Rico, the Lesser Antilles, or northern South America.

This route averages 1,500-2,000 miles over water, necessitating a potentially non-stop flight of up to 88 hours. To complete this migration feat, many Blackpolls nearly double their body mass and prefer to take advantage of a shift in prevailing wind direction to direct them to their destination.