Of these 366 species, 217 breed or are formerly native to the island; 11 out of 217 are shorebirds of Gatun Lake and not land birds. Nine of the 217 resident species immigrated to the island from nearby lowland areas since the early 1950s, but four of the nine are now extinct. Most of the extinct former inhabitants have been lost due to forest growth and consequent loss of second-growth habitats.
FORESTS. The island's forests can be divided into old forest and young forest. Forest streams on the island dry up or become chains of pools in the dry season, as does a forested swamp of wild pineapple north of Armor Trail on the island's central and flat basalt cap. Birds believed or known to have been bred on the island in the 1930s (Chapman number 199 species, plus 9 species restricted to the lake or grassy marshes along the island's shores.
Four of the nine immigrants (green-brown kingfisher, common grebe, brown warbler and dark-faced tanager) apparently failed to maintain the population and left the island again. Due to the preservation of the forest, the island remains wetter during this season than many nearby mainland areas. With such a stream occupying part of the forest surface, several forest species could be lost.
Sixteen of the lost species are woodland or woodland birds, which would disappear from central Panama if forests other than those on Barro Colorado Island were cleared.
Annotated List Family TINAMIDAE: Tinamous
Fry flying together over the lake on 14 Feb 1940
One can easily see 50 or 60 species around the clearing and another two dozen in the forest, but finding other species is difficult. The preservation of large areas as natural areas would represent only a small reduction of the area available for human use. Since half of the world was not even known to humans a few thousand years ago, from a geological point of view, it is not inconceivable to remove a part of the world from human use again.
Rare along the lake shore, more common September to May, when northern breeding birds arrive. Formerly common along the lake shore, now almost extirpated, apparently due to food competition with peacock bass. Sometimes along the lake shore or forest streams, usually in the shade of the forest; rarely seen.
The Shining Ibis, Plegadis falcinellus, now a regular migrant to Panama, would be hard to tell from the Green Ibis and is more likely to be in the Canal Zone, at least in the northern winter. Occasional in lake near island, especially near Burrunga Point, from hydrilla growth; quite common in other parts of the lake. Occasionally, one to four hover over clearings and woods or dead animals floating on the forest floor.
A bird of the lower layers of forest edge and secondary woodland, but also of forest. Formerly quite common in small and noisy groups in the forest canopy and edge; last seen 29 Aug 1963 (Willis). This species disappeared from nearby Panamanian forests around the same time, so loss from Barro Colorado may be related to general loss rather than to the small size of the island.
A few groups remain near the lakeshore, particularly at Barbour and Burrunga Points; a bird of forest edge and other growth. Occasional in the forest or summoning treetops; not seen, but noisy calling bird present 18 Aug 1970 to 9 Jan 1971 (Willis) and others seen since, as species re-waded successfully. Common in grassy marshes in Gigante Bay and the south-west coasts of the island.
Mar 1966 (Slud)
Common in laboratory clearings and tree fall clearings, but often confused with a female of the previous four species. Common in lower and middle forest levels, often behind army ants. Very common, looking for dead leaves hanging on the forest floor, often in mixed clumps.
A few pairs in the laboratory clearing and along the lake shore; rare in the forest.
Apr 1961 (Eisenmann); 1973 (M. Perrone) to 1977 (Willis and others) increasing and nesting along the lake
13.-18. May 1961, one in the canopy of tall second growth along Gigante Bay opposite the end of the Shannon Trail (Willis). Common, forages from high to low along clearings and lake shores; in some places also at the top of the crown.
March-17 Apr 1935 (Skutch in Wetmore 1928;
Fairly common, at least in the dry season, to fly over the lake and clean up; the dark-rumped, dull-throated northern migratory serripennis is seen, as well as the pale-rumped breeding race uropygialis (Eisen-mann). Formerly "occasional in thickets around pits" (Eisen-mann) and in the 1960s on Mona Grita Island. Breeding: A female vireo-like moss cup 14 m up as male sang and watched, 15 May 1966 at Madden Forest Reserve (mainland) (Willis).
Notes: An oft-repeated phrase of three whistles, peeea, peeea, peeea, or pee, pee, suggestive of the call of the North American Soft Titmouse, Parus bicolor. Common transient autumn resident and unusual winter resident in treetops, 11 October (1961, Willis) to 12 March (Skutch); sings persistently in autumn. Once a rare breeder in clearing; seen singing there 16 March 1974 (Eisenmann), possibly a vagrant; common in open forests in Frijoles.
Very common in the treetops, often the center of mixed herds there or in groups of its own kind. Often in the canopy and at forest edges; rarely seen or absent during the post-breeding period, September 8 (1958, molting male) to November 10 (1962, full plumage male; Eisenmann). Occasionally at forest edges or in the treetops, first recorded on February 8, 1951 (Collias), but probably previously overlooked.
Common autumn migrant, fairly common winter and spring along the lakeshore and in clearings and cover; recorded October 8 to April 23 (1961, Willis). Fairly common winter visitor and transient, especially in clearings and along lake shores, 18 Aug (1965, Willis) to 4 May (1926, collected, Van Tyne). Common winter visitor on or near the ground in lighter forest, less common in old forest; recorded Sep 4-Apr 18 (1961, Willis).
Sep 1951 (Bourliere) and 5 Jan 1977 (N. Brokaw)
Common in small groups around clearings and by lakes, usually in treetops. Fairly common in clearings and along lake shores, rare in forest canopy. From March 28, 1966, only stray young males (Slud) reach clearings and lake shores; previously, a few pairs nested in the clearings.
Until 1961, irregular in the clearing; a bird of scrub and semi-open areas on the edge of moist forests. Fairly common in the canopy and occasionally at the edge of the clearing, often in mixed groups.
Sep 1964, occasional around the clearing; common in woodland edges and second growth, as at Frijoles (mainland)
General and successional ecology of the tropical lower rainforest on Barro Colorado Island, Panama. Geographical and climatic relations of avifauna with special reference to comparative distribution in the Neotropics. Manuscripts intended for serial publication receive substantive review within their originating Smithsonian museums or offices and are submitted to the Smithsonian Institution Press with the approval of the appropriate museum authority on Form SI-36.
Review of manuscripts and art by the Press for series format and style requirements, completeness and clarity of copy, and arrangement of all material, as described below, will govern, at the discretion of the Press, acceptance or rejection of manuscripts and art . . Frontispiece (before text) should include: title page with title and author only and no other information, abstract page with author/title/series/etc., following established format, table of contents with bullet points reflecting headings and paper structure. The first page of the text should bear the title and author at the top of the page and an unnumbered footnote at the bottom consisting of the author's name and professional mailing address.
Formal tables (numbered, table headers, box headers, stubs, rules) should be submitted as camera copy, but the author should contact the Press Series section for editorial attention and preparatory assistance before final printing the issue. Taxonomic keys in natural history documents should use the indented-couplet form in the zoology and paleobiology series and the multilevel indentation form in the botany series. Synonymy in the zoology and paleobiology series should use the short form (taxon, author, year page), with a full reference at the end of the paper under "Literature Cited."
Footnotes, when few in number, whether annotative or bibliographical, should be typed at the bottom of the text page on which the reference appears. If bibliographical footnotes are required, use the short form (author/short title/page) with the full reference in the bibliography. Use the colon bracket system for volume/number/page citations For alignment and arrangement of elements, follow the format of the series for which the manuscript is intended.
Legends for illustrations should not be attached to the art nor included in the text, but should be submitted at the end of the manuscript—with as many legends typed, double-spaced, on a page as is convenient. If several "figures" are treated as components of a single larger figure, they should be indicated in lowercase letters (italicized in copy) on the illustration, in the legend, and in text references: "Figure 9JD.". Keys to any symbols within an illustration must appear on the art and not in the legend.
