Private holdings were finally acquired by the Panamanian government, and the island was set aside as the country's penal colony. Only two, Catival and San Juan, located on the rivers of the same name, are inland. There is also one over to the opposite side of the island from Maria and Playa Blanca, crossing the lower elevation at the southern end of the island.
Many people seemed confused by the thin soil covering the mass of various rocks, which is the core of the island. Among the skins of the wood-pigeon Leptotila plumbeiceps battyi, confined to Coiba, is an imma-. No published report was made on the specimens obtained, which include some of the peculiar forms of the island.
THE BIRD LIFE
The differences that mark the resident races are mainly heavier, darker pigmentation, which can be explained in terms of more abundant rainfall, indicated by the significant drainage system seen in the numerous rivers of the island. The vast forests that clothe Isla Coiba, still practically unbroken except for a relatively small area, offer habitats suitable for any of the birds found in such abundance as for the species and individuals of the great lowland area between the southern Mexico and northern Argentina. Apart from these eight prominent families, there is no record of wood quails (Odontophorus), long-tailed squirrel cuckoos (Piaya cayana) or the great woodpeckers (Dryocopus and Phlococeastes).
From the southern end of the island to Punta Brava, on the western side of the Golfo de Montijo, the distance is about 32 miles. If the movement of the earth during the subsidence that formed the present contour of the land was fairly uniform and evenly distributed, then Coiba. Or the formation of the island may have come before the missing groups of birds began.
ANNOTATED LIST
Coiba's bird settlers generally seem to be the ones who are. Where several terms are used locally for the same bird, the term that in some cases appears to be the most general has been chosen. In numerous cases involving small, inconspicuous species, where no local name is available, one that seems well applicable has been chosen, sometimes on the basis of use in other countries, sometimes on the basis of a descriptive term that seems appropriate, and sometimes by translation of the name in English.
Above, in the account of my field work, mention is made of the crested hawk (apparently Spisaetus), of which I saw only the legs, killed by a hunter. Able to hide, they dived and disappeared, but looking carefully we could occasionally see one under the cover of the higher water plants. We secured an adult female, a fully grown juvenile but with a white throat and head stripes, and another half-adult.
1 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 34 of this petrel in the British Museum (Natural History) taken in
Near the mouth of the Rio Catival we found a mature male January 27 and saw several others. From here they jumped out to eat, so twice, at sunset, I saw a flock of a dozen flying low over the water of the bay past the Colonia Central on its way to a roost in the distant mangroves. The second specimen is cinnamon-dull below, with gray feathers of the adult coat appearing on the throat, foreneck and.
This hawk is undoubtedly more common on Coiba than any of the other species of its family. On the 6th of January I recorded Gulls at sea throughout the voyage from Balboa, and at Coiba one or two came daily to the beach in front of the Colonia Penal. Anise in the usual groups of 6 to 12 or so were found in the low thickets in abandoned fields, or around the borders of the pastures.
However, given the considerable individual variation in the Rough Night Lilac, it seems desirable to see further specimens on the continent before reaching a final decision on the Coibaseries. 9 birds ISLA COIBA, PANAMA — WETMORE 45 Three taken on January 10 and 15 are typical of the present breed. This large species was only found in the center of the white mangroves. in the marshy area bordering the estuaries of the San Juan and.
Hartert believed that a longer bill could be one of the characters of this breed, but this is not true. This was the least remarkable of the hummingbirds, the few that were noted being found in the forest or on the edge of the forest. They seemed more aggressive than other species of the family here, and especially towards other hummers.
The light ground of the bill, which is pale reddish in life, shows clearly as they move about, even in the dim light of the heavy forest. This beautifully marked hummingbird was one of the least common species in the family. On January 8, I found a nest in a small broad-leaved tree growing next to a coconut palm at the back of the beach.
50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134
It is interesting to note that there is a general similarity in the bilobed forms, which suggests that the darker color, perhaps a more primitive stage, has been preserved within the limited confines of the islands in the sea, while the modification has come over the wide range. continental. The study of birds from Coiba Island has led to an examination of the series of species now available from the entire range. It may be noted at the outset that the writer believes it useful to treat the Centurus group of species as a separate genus, instead of joining it with the united Melanerpes, as Petersand and some others have done.
In addition to the conformation of the pattern found on the barred back, the throat feathers are soft and mixed, unlike the hairs of typical Melanerpes. Another matter is that species of Centurus rubriventris Swainson differ from rubricapillus in having a much narrower septum on the back and a relatively much longer tail. I34Melancrpes Wagleri Salvin and Godman, Biologia Centrali-Americana., Aves, Melancrpes Wagleri Salvin and Godman, Biologia Centrali-Americana., Aves,.
The National Museum treats this extensive range in sufficient detail to show that none of the supposed varieties separated can be maintained, as there are no constant differences in color.
MALES
The tendency towards reduced red on the male head has occasionally been found in specimens of C. Catival, in higher, unbroken inland forests, usually starting from the grain on the lower branches of trees and at the edges of thickets. The subspecific name of the form described here is derived from the Latin adjective eremnus, swarthy or dark.
Some of the men who worked in the forest edge were familiar with the excited calls of these birds, but were unsure of their origin. The name "borreguito" is given to them from the light colored plumage of the male. It is primarily a forest species, found from the lower undergrowth to the interbranches of the taller trees, although I.
These flycatchers were found inscrub growth back of the beaches and in the border of mangroves, never in the densely shaded high forest. The mainland series, which is uniform, includes skins from the eastern side of the Azuero Peninsula (Paris, Parita, Monagrillo, Los Santos), the Canal Zone (Farfan, Corozal), and the eastern half of the Province of Panama (Chico, Chepo, Maje). They therefore seem to represent an ancient establishment of the species, perhaps from the time when.
These small birds roost in open perches on the tops of undergrowth, or on the lower branches of trees. It was common in the scrub near the beach line, also in the mangrove back swamps, and was regularly encountered throughout the interior high forest. They were encountered from mangrove margins inland, but always in forest cover.
Conditions on Coiba seem particularly favorable for the blue honeyeater, as it is one of the most common birds. The measurements of the type, male, are larger in the male series, where there is a difference in dimensions. Males resemble the latter in darker brown on the head and belly stripes, and the former in stronger stripes on the chest and sides.
NO. 9 BIRDS OF ISLA COIBA, PANAMA WETMORE 91 DENDROICA PETECHIA AMNICOLA Batchelder
92 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I34 orange in males, that flash as they dart out or drop through the
The generally darker color of the new breed corresponds to the general trend of the local breed son Coiba. There appear to be few of these grackles present, with those few spreading only in the southern part of the Bahia Damas in January. 9 BIRDS OF ISLA COIBA, PANAMA — WETMORE 95 on the webs to Venetian blue; belly and undertail coverts pale blue-gray; remainder of the lower surface of the body Alice blue, except the posterior parts of the sides and flanks, which are orientation blue;
A male taken at the edge of the tall forest on January 7th is an individual less than a year old, as shown by the dull grey-brown. This is another of the common birds on the island that used to frequent the trees and bushes around the residences, but was. 14.-Crimson-backed Tanager, Sangretoro Comun. The differences that distinguish the birds of Coiba from those of other parts of the species' range are detailed in the following.
Characters.-Darkest of the races of Ramphocelus dimidiatus;. male similar to Ramphocelus dimidiatus limatus Bangs,28 but deeper red throughout, especially on belly; female definitely darker. The lower surface of arestus is duller than that of the female of R. d.dimidiatus, while the crown is darker and the back is duller. The male of the new form corresponds to that of limatus in the limited black area on the middle of the lower chest and abdomen. it is certainly less than in the continental races.
Characters.—Darkest of the subspecies of Saltator albicollis; similar to Saltator albicollisisthmicus Sclater20 but darker, grey-green above; sides of head and stripes on lower surface decidedly darker sides of breast darker; edge of wing lighter yellow; under tail coverts slightly deeper buff. The grass was common along the borders of the grasslands and. on the edge of the forest, gather especially where tall grasses bore ripening seeds. Wherever tall grass and weeds grew on the borders of the cultivated fields and pastures, this grasshopper was found, and lived as usual in small bands, feeding in the open early in the morning and remaining under cover the rest of the day.
Arrocero prieto was found in small quantities in the borders of the swampy forests along the lower courses of the Catival and San Juan rivers, not far from the sea.
104 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I34 in the undergrowth of the high gallery woodland across the central
