PROCEEDINGS OF THE ACADEMY OF

The amount of change effected in the plumage at any particular molt varies considerably in different individuals of the same species and sex. Variability in the order of molting in remiges and the presence or absence of moths in the flight feathers at the end of the first. In wing fusion, feathers are separated one or two at a time and symmetrically from both wings.

118 PROCEEDINGS OF THE ACADEMY OF [1896

CHANGE OF COLOR BY ABRASION

The planing of the end portion varies with different feathers, while the planing of the end portion varies with different feathers, while the planing always takes place exactly on the boundary line of the colors. In the body feathers the tip of the feathers is less perfect in structure than that of the base, and many of the barbs are completely free at the tips, which obviously makes them more susceptible to rapid wear up to the point where the strongly pin-like structure begins. This is especially visible in the Snow Bunting.

Fig. 1 . Tips of several barbs from feather of Snow Bunting showing the difierence in structure between the light and dark portions (greatly en-larged ) Photograph by Dr

SEASONAL PLUMAGES

1896.] NATURAL SCIENCES OF PHILADELPHIA. 121

DIRECT CHANGE OF COLOR IN FEATHERS

As a matter of fact, these mottled feathers are for the time being permanent, and at each regular moulting a greater proportion of the mature feathers are assumed. A study of several of the more recent examples brought forward to illustrate the actual change of color in feathers will be of interest in this connection. This is especially the case in the treatment of Motacilla lugens,^^ in which he asserts, not only a change from gray to black in the plumage of the back, but also a remarkable change in the color of the primary and secondary of brownish to pure white, the mature feathers are, according to dr.

124 PROCEEDINGS OF THE ACADEMY OF [1896

Gatke says (p.163) that he "limits his description to what actually takes place, without starting any hypothetical assumptions." In this, however, I cannot agree with him; liedoes not claim to have seen the change in color actually take place in any individual feather, and to make the claim that feathers change color from one style to another when the only facts before him are that they have feathers that representing those color styles, one of which can change after another, involves too much of an assumption. Hist.,VIII,p- 1—8), in which he criticizes Griitke's statements on the same grounds as above. 126 PROCEEDINGS OF THE ACADEMY OF [1896,Gatke formerly repudiated, and old who other advocates of the.

126 PROCEEDINGS OF THE ACADEMY OF [1896, Gatke formerly repudiated, and oue which other advocates of the

1896.] NATURAL SCIENCES OF PHILADELPHIA, 127 pigment at all, as has been ascertained by careful microscopical

PLUMAGES AND MOLTS OF THE SMALLER LAND BIRDS OF EASTERN NORTH AMERICA

128 PROCEEDINGS OF THE ACADEMY OF [1896

A false specimen of either species exhibits a noticeably worn, moth-eaten appearance on the breast and flanks, probably reflecting some peculiarity in the habits of these individuals. The molting of the first plumage of the head and breast of this species continues throughout the fall and winter, and in a photograph taken on April 8 (Philadelphia, Pennsylvania), a few new feathers appear on the crown and throat. The adult plumage differs in that the throat is white, some individuals have the crown black, others red; Whether this is due to age or purely individuality, I cannot determine.

Without a satisfactory series I am unable to describe the detail of this bird, but it is apparently the same as the preceding species.

1896.] NATURAL SCIENCES OF PHILADELPHIA. 131 does not produce much effect upon the plumage but it loses the

1896.] NATURAL SCIENCES OF PHILADELPHIA. 135 At the end of the first summer the entire plumage of the young

136 PROCEEDINGS OF THE ACADEMY OF [1896

137previous costume, but the entire abdomen and rump and small wing previous costume, but the entire abdomen and rump and lower wing coverts are bright red-orange, while the black is more intense. All other wing feathers are jet black edged with white; the two middle regions are black, then the last pair are largely black, the others orange with mottled or less black on the base. The large series, which collects several hundred sheets, is contained in the collections of the Academy of Natural Sciences of Philadelphia, National Museum, American Museum of Natural History and the private collection of Mr.

The tail is also obscured with black, but as the specimen just referred to does not molt the tail, I believe that this change occurs at the previous annual molt.

138 PROCEEDINGS OF THE ACADEMY OF [1896

The young birds fuse wing and tail with the first plumage and assume the adult plumage in its entirety during the first winter. There is no spring molt and there is very little wear effect due to the uniform color of the plumage, so the nuptials are almost indistinguishable from the winter. A summary of the molting of the species of finch described below shows that thirteen species have no spring molt, while six species have a spring molt of the body feathers.

I have not been able to examine any molting specimens of Carpodaca, but a large series of winter and spring specimens indicates that spring molting occurs. The change to pink plumage is apparently due to the annual molt in the second year or so.

140 PROCEEDINGS OF THE ACADEMY OF [1896

From April to mid-May, but none of the wing feathers, not from April to mid-May, but none of the wing feathers, not even the tertials, are renewed at this time. During winter and spring the white edges on the tail and wing feathers are lost through wear, so that in summer breeding clothing the wings are almost completely black. Some abrasion occurs during winter and spring, causing the buff edges to the feathers to be lost and the markings in the breeding plumage to intensify and become more strongly accentuated with the white of the breast.

28th, (CapeMay, N. J.), the feathers of the throat and breast are much suffused with brown, so that the dark streaks are almost obliterated. There seems to be no spring in the Snow Bunting, but the remarkable change from winter to nuptial dress is effected entirely by shedding, which is probably more marked in this species than in any other.

142 PROCEEDINGS OF THE ACADEMY OF [1896

In April, the complete molt of the body plumage occurs, together with the tertials and sometimes the current; a specimen taken April 16 at AtlanticCity, N. After the spring molt is over, the birds are indistinguishable, except by close examination of the wing feathers, from the October specimens. Very soon the plumage again began to show the effect of fraying, and in August, just before the annual molt, the birds present wore such an appearance as is to be found among our species.

The wear and tear in the plumage of this species is undoubtedly due to its habit of living entirely among the coarse grass and edges of the salt marshes, which may also have something to do with the unusual extent of the spring molt. In this species, the spring plumage differs from the winter plumage only in wear, as there is only one moult per year. It seems strange that in this species there should be no shedding, while in its nearest relative, the Sharp-tailed Finch, it should be so extensive.

The difference between the second and third and fourth and fifth is often very small, especially in the case of the latter two. After the change to the first winter plumage, the bird has a fairly marked white throat, but the crown stripes are very mixed with brown and the center stripes are rather dull.

1896.] NATURAL SCIENCES OF PHILADELPHIA. 145 that of the old birds except in the purity and extent of the chestnut

There is apparently only one molt per year in the Towhee, and although the feathers are subject to wear and tear in winter. Female. Molts just like the male, the only difference in plumage is the replacement of brown with black plumage. There is no spring molt; the winter plumage shows extensive gray edging to the feathers of the back, lost through wear and tear during the breeding season.

The renewal of the flight feathers in the first autumn in this species is a matter of great importance (cf. . . 117). Female.—Breeds as in the male, a young female changing from the first to winter feathers (Tarpon Springs, Fla., Aug.

1896.] NATURAL SCIENCES OF PHILADELPHIA. 147 shows the wings beginning to molt as described above in the case of

148 PROCEEDINGS OF THE ACADEMY OF [1896

149feather molt, that they present an almost unbroken series from one feather molt, that they present an almost unbroken series from one extreme type of plumage to the other. It is therefore quite impossible to do more than to separate them into two groups, with brown and black bands respectively, the former representing birds a year old, the latter more than a year old.^". The brown wing feathers of the young are therefore retained until August of the following year.

Furthermore, all the brown-winged birds I have examined that show the annual molt progression have black young feathers. Birds in first winter plumage (ie, brown-winged) almost always molt the tertials with body feathers in spring, then they are black with white spots. An example of the other extreme is a specimen (No. 501 Coll. W.Stone), a bird of the year, shot in September, which has just finished it from the start.

Old birds do not usually renew the tertials in the spring, although some of the most feathered examples appear to have done so.

1896.] NATURAL SCIENCES OF PHILADELPHIA. 161 age of the female which I do not regard as belonging to the regular

152 PROCEEDINGS OF THE ACADEMY OP [1896

1896.] NATURAL SCIENCES OF PHILADELPHIA, 153 Above and below scarlet, tail jet black, wings brown, edged with

154 PROCEEDINGS OF THE ACADEMY OF [1896

From such series of this bird as I have examined, I should judge that it had no spring molt; whether the cubs at the end of the summer line flight feathers, I can not say, because none of mine. The lack of adults in winter plumage or during molting in the collections precludes a complete description of the molting of this species. New feathers appear on the chest, throat and back, and the tail is just starting to molt.

In any case, this raises one curious question: The outer regions are only 0.35 inches longer than the next pair (as in young summer birds). Now, all the spring birds I have examined have the feathers much longer (0.75-1.25 inches longer than the last pair), so there should be at least part of the tail in the spring. Female.— Two plumages of the female are found, one indistinguishable from the male, the other very dull and quite brown in the spring.

The latter, I believe, is the plumage of the first year; atanyrat, in one specimen, it is assumed certain at the molting of the first plumage.

156 PROCEEDINGS OF THE ACADEMY OF [1896

The young of most warblers in the first autumn differ considerably from the adults, and there is an extensive molt. Almost all warblers have probably had a spring molt at some point, but in many of them the molt is limited to the head and thorax after the first time. Adult male in all seasons and young of the year almost the same, Seiurus, Helmitherus, Sylvania mitrata (winter plumage with light points on black parts).

158 PROCEEDINGS OF THE ACADEMY OF [1896

I had thought that the dark-breasted individuals were birds of the second or third year, but Mister Birds in the first winter are very dull and gray-tinged, while adult birds in winter differ little from spring birds, except that all the feathers are broadly fringed are. with olive gray or yellow. The freshness of the flight feathers in some spring specimens seems to indicate that they are sometimes renewed with the rest of the plumage.

Old birds have more or less gray feathers on the back and black feathers in the center of the chest in autumn, but they all continue to molt. A spring bird, which I assume to be in its second or third year, has the black uniform on the breast, uninterrupted by white edges on the feathers. Adults differ from birds of the year in winter by the thick stripes on the sides of the body and the large black centers of the feathers on the back.

Spring molts are more extensive than in the last two species, and the adult plumage is always more distinct from the nuptial plumage, differing only from the bird of the year in the chestnut stripes on the sides.

1896.] NATUKAL SCIENCES OF PHILADELPHIA. 163 have more or less black on the head and perhaps sometimes attain

EXPLANATION OF PLATES

STONE. MOLTING OF BIRDS