The FIELD TREE WARBLER, or WILLOW WREN (_Phyllopneuste Trochilus_), is
a slenderly-formed bird with long wings, in which the third and fourth
quill exceeds the rest in length. The tail is of moderate size, and
slightly incised at its extremity; the beak is delicate, broad at its
base, and compressed at its tip. The lax plumage is of an olive green
upon the upper parts of the body, and white on the under side, the
breast being tinged with greyish yellow; a yellowish-white stripe passes
over the eyes, and the cheek stripes are deep grey; the quills and
tail-feathers are grey, edged with green, and the lower wing-covers light
yellow; the eye is brown; the beak and legs grey. After the moulting
season the under side becomes a pale yellow. This species is four inches
and eleven lines long, and seven inches four lines broad; both wing and
tail measure about two inches. The sexes are alike in colour; the young
are greyish green above and yellowish-white on the throat; the rest of
the under side is white, tinted with yellow.
[Illustration: THE FIELD TREE WARBLER, OR WILLOW WREN (_Phyllopneuste
Trochilus_).]
The Field Tree Warblers inhabit the whole continent of Europe, a large
portion of Northern Africa, and some parts of North America. During
their migrations they also occasionally visit India and Northern Africa.
For the most part, however, such as quit Northern and Central Europe
for the winter do not wander farther than its more southern countries.
These birds alike frequent highlands and lowlands, and usually pass the
summer months in disporting themselves about the leafy summits of lofty
trees. In autumn, on the contrary, they come down into the brushwood and
beds of reeds or rushes, or, in Southern Europe, alight in the fields
of maize in quest of food; dense forests they appear almost entirely
to avoid. The song of this species is pleasing and flute-like; its
chief beauty, however, consists in the delicacy of intonation and rapid
swelling and sinking of sound in which the male indulges, as he sits
with drooping wing, inflated throat, and raised crest, upon a projecting
branch, or flutters rapidly from bough to bough, in order to attract the
attention of his intended mate; at such times the female also utters a
faint twittering kind of song. Like the Tree Warblers, these birds are
particularly active among the foliage; they do not creep in the quiet
mouse-like manner above described, but flutter about with a constant
brisk agitation of the tail that cannot fail to betray their presence to
an observant eye. While perched the body is usually held erect, but is
kept somewhat bowed down as the bird hops upon the ground; this latter
mode of progression is accomplished with some difficulty, each long hop,
or rather leap, being followed by a succession of rapid gesticulations
with the head before another effort is made. Their flight is capable of
being long sustained, but is somewhat inelegant, and appears unsteady,
as it is usually undulating and carried on by a series of very irregular
efforts. The same restless activity is also observable in the conduct of
these birds towards all their feathered companions; the slightest injury
or annoyance is resented with much fury, and even the sportive exercises
in which they frequently indulge usually terminate with a series of
violent flappings and peckings given on either side, rather in downright
earnest than in play. The nest is carefully concealed in a hollow in the
ground or in the trunk of some tree, and built entirely by the female,
who commences her operations by hacking at the hole or aperture till it
is of the requisite depth. The utmost caution is displayed by the anxious
mother to prevent the discovery of her future abode. For this reason she
seldom works except during the early morning, and at other times never
remains near the scene of her operations. The nest itself is cone-shaped,
with thick walls, in one side of which a hole is left for entrance; dry
leaves, stalks, moss, and grass are employed for the exterior, while
the interior is snugly lined with feathers, those of partridges being
usually preferred. From five to seven eggs form a brood; these are laid
about May, and are oval in shape, smooth, glossy, and white, more or
less spotted with light red. During the period of incubation the female
displays much anxiety for the safety of her eggs, and even when alarmed
will not leave them until she is forcibly removed. At mid-day her mate
takes his place on the nest for an hour or two, but with this exception
gives her no assistance; both parents, however, combine to rear and
protect the nestlings, and endeavour to attract the attention of any
intruder on their privacy and divert it to themselves, by hurrying to a
distance and uttering cries of distress. The young are fledged by the end
of May, and a second brood is produced in June.
* * * * *
The LEAF WRENS (_Reguloides_) constitute a group inhabiting Southern
Asia and the provinces of the Himalaya. In these birds the beak is
comparatively shorter than that of the true Tree-Warblers. The wings are
long and more pointed, and the legs shorter and weaker. All such species
as inhabit India frequent mountainous districts.