Hermit Thrush

Catharus guttatus

Introduction

With spotted breast and reddish tail, the Hermit Thrush lives up to its name. It is a quiet and unobtrusive bird that spends much of its time in the lower branches of the undergrowth or on the forest floor, often seen flicking its wings while perched and quickly raising and slowly lowering its tail. This thrush is one of the most widely distributed forest-nesting migratory birds in North America. Its extensive breeding range includes the northern hardwood forest, as well as most of the boreal and mountainous coniferous forest areas north of Mexico. In migration, the species moves southward and spreads out to winter over much of the southern United States, through Mexico to Guatemala. It is the only species of Catharus that winters in North America.

Identification

Adult Male (spring/summer)

Head and face dull brown; complete eye-ring; dark malar stripe; dark bold spots on throat and upper breast; olive-gray flanks and white undertail coverts. Reddish tail contrasts with dull brown nape, back and wings. In flight underwing axillaries and underwing coverts are gray and buffy.

Adult Female (spring/summer)

Sexes are similar.

Juvenile

Shows pale speckling on head and back.

General Information

General:

Chubby Thrush with complete white eye-ring. Length: 14-18cm. Wing: 25-29cm. Weight: 23-37grams.

Behaviour:

The Hermit Thrush forages on forest floors, in forest clearings, along forest roadways and trails. It picks up and kicks loose vegetation looking for insects. Its habit of cocking tail upward and flicking wings (tail lifted rapidly and lowered slowly) is distinctive among similar Catharus species. Its breeding diet consists mainly of arthropods and wintering diet is heavily supplemented with fruits.

Habitat:

The Hermit Thrush uses a broad spectrum of forested and edge habitat. It is described as a forest interior bird that favors internal forest edges. For example: margins of pond or meadow within forest patch; small clearings within wooded areas created by disturbances such as logging, drilling, road-building, utility cuts, wind, and fire; and mountain bogs and glades bordered by native or transplanted conifers.

Information:

During winter the Hermit Thrush may be found foraging with mixed flocks of kinglets, chickadees and Brown Creepers. For such a widely distributed species, surprisingly little is known about its basic demographic characteristics such as life span, basic breeding biology and factors that influence reproduction and survival, and fidelity to breeding and wintering areas. Even the well-known song of the Hermit Thrush has been studied little. Birds east of the Rocky Mountains typically nest on the ground and those west of the Rockies nest off the ground in shrubs and tree branches. The nest is a cup made up of vegetation and mud lined with fine materials. 1-2 broods. Clutch size is 3-6 light blue brown spotted eggs.

Similar species:

Swainson’s Thrush, Veery, Gray-cheeked Thrush, Wood Thrush.

Conservation Status:

Listed as Least Concern with populations rising since 1966.

Maps & Statistics

Capture Rates

The first of the Catharus thrushes to arrive in their summer range, the Hermit Thrush is also the last to leave in the fall for their short distance migration south. This species breeds at higher elevations therefore capture rates (2010-2012; standardized as birds captured per 100 net hours) occur in April/May then again in September/October coinciding with their movement through the lower level coastal areas during spring and fall migration.

Ageing and Sexing (Band Size: 1B, 1)

Molt Summary:

PF: HY partial; PB: AHY complete; PA absent
Preformative molt includes some to all med covs and 0 – 4 inner gr covs, but no terts or rects

Juvenile

June - August

Juveniles have the feathers of the upperparts with buff fringes. Juvenile M=F

HY / SY

September - August

Hermit Thrushes are relatively short distance migrants wintering in the southern US and south to Central America but some remain further north along the pacific coast and they are always the first of the Catharus thrushes to return.

Like all Catharus thrushes aging Hermit Thrushes is relatively easy with first year (HY/SY) birds often showing buffy tear drops on retained juvenal greater coverts.

These buffy tear drops on retained juvenal greater coverts can often be seen in the field allowing the bird to be aged as a first year bird, as in this second year (SY) bird in March.

This HY in September is showing a clear molt limit between the retained outer and replaced inner greater coverts (indicted with the red arrow).

This second year (SY) bird of unknown sex is again showing the typical buffy tear-drop pattern of retained juvenal greater coverts in this genus. Note the molt limit between the 7 retained outer greater coverts (red arrow) and 3 replaced inner greater coverts which have chocolate brown edging and lack these buffy tear drops.

The blue arrow points to primary 10 (P10) which is a vestigial feather in Catharus thrushes, the characters having lost their original function through evolution. This tiny feather which has probably little use to the bird is of great use to banders in making their age determinations. In addition to the molt limits on the wing mentioned above the length and shape of this feather varies with age being longer and more rounded in first year birds and shorter and more sharply pointed in adults (see below).

As with other Catharus thrushes, the shape of the small, vestigial outer primary (P10) is helpful in determining age, this feather being broader, more rounded and longer in first year birds, often extending beyond the primary coverts as in the photo below.

P10 is narrower, more tapered and shorter than the primary coverts in adult birds as in this photo of an ASY bird in May.

This SY bird in April is again showing a molt limit between the replaced inner GC’s without buffy tips and the 7 outer retained GC’s showing prominent buffy tips or tear drops.

This SY bird in May is also showing a molt limit between the replaced inner GC’s without buffy tips and the 7 outer retained GC’s showing less prominent buffy tips due to wear on these feathers.

This SY bird in May is showing a more subtle molt limit between replaced inner GC’s and retained outer GC’s (red arrow).
The replaced inner GCs are longer with the visible ‘step’ in between replaced and retained feathers but the outer retained GCs lack the buffy tear drops of the birds above.

Replaced feathers are often longer than the retained ones producing this ‘step-in’ between replaced and retained coverts and is typical of all Catharus thrushes (see also Swainson’s Thrush).

Rectrices of first year birds like this SY in April are typically thinner and more tapered than adults, often with pointed tips as in the photo below.

AHY/ASY

AUGUST - July

Adult wings like this ASY in April are uniformly adult, the greater coverts without distinct buffy tips. The primary coverts are broad and truncate and relatively fresh, and dusky brown with distinct, broad, brown edging.

P10 is narrower and shorter than in first year birds normally not reaching the length of the primary coverts.

Rectrices are broad, rounded and truncate with a corner to the inner edge and relatively fresh with little wear compared to first year (HY/SY) birds. Note that some adult rectrices do show tiny points on the terminal end of the feathers.