Part 71

Eggs.--The jacana’s eggs are as unique as the bird itself, and can not be mistaken for anything else. They are ovate to short ovate, or even rounded ovate, in shape; and they are decidedly glossy. The ground colors vary from “buckthorn brown” or “Isabella color” to “chamois.” They are well covered with fantastic scrawls and tangled, fine, pen-like lines of black; these markings are usually quite evenly distributed, but they are sometimes concentrated more thickly at either end or in the middle. The set almost invariably consists of four eggs, but I have records of a few sets of five and of three; Mr. Gillin’s series consists of 37 sets of four and one set of three. The measurements of 50 eggs average 30.1 by 23 millimeters; the eggs showing the four extremes measure =31.8= by 23.3; 31 by =24.1=, =28.3= by 22.2, and 30.3 by =21.7= millimeters.

=Young.=--Mr. Gillin says in his notes:

The young run as soon as hatched, and in one case, when I came upon a nest in which the young had just hatched, they dived into the water and swam under the water for several feet before they came to the surface.

Plumages.--The young jacana in natal down is beautifully marked with rich colors. A narrow frontal line, the sides of the face and the entire underparts are white; the crown and nape are “ochraceous orange,” centrally browner, with a black “crow-foot” on the occiput, and with a black line from the eye to the hind neck, which is dusky black; the central area of the back and rump is “burnt sienna,” bordered on each side by a band of “ochraceous buff,” below which is an indistinct dusky band; the thighs and the inner joints of the wings are “burnt sienna”; the outer joint of the wing is white; the tail and sides of the rump are jet black; and the tibia are dusky black. The bright colors become duller as the chick grows older.

In fresh juvenal plumage the crown and occiput are “warm sepia,” the feathers faintly tipped with “cinnamon”; the back and sides of the neck are brownish black; the back, scapulars and wing coverts are from “sepia” to “Saccardo’s umber,” the feathers broadly tipped with “tawny” and with a subterminal dusky bar; a black stripe extends from the eye to the back side of the neck and a broad stripe of “cream buff” from the lores, over the eyes to the nape; the sides of the head, chin, throat, and underparts are white, suffused with “cream buff” on the breast. A partial postjuvenal body molt takes place during the fall, or else the edgings entirely wear away leaving only the plain colors of the upper parts, the juvenal wing coverts and some of the scapulars. In late winter or early spring, from January to April, a nearly, if not quite, complete prenuptial molt takes place, which produces a plumage which is practically adult, including the frontal shield. I have no data on the molts of adults. In this plumage the female is decidedly larger, is somewhat more brightly colored and has a larger frontal shield.

Food.--Mr. Gillin says in his notes:

The food of the jacanas must consist of minute insect life that they are able to find on this floating vegetation as they are very active and seem to spend practically all their time feeding, which would lead to the conclusion that their food is secured in very small morsels or else they require a great amount of food.

Behavior.--P. L. Jouy says in a letter:

When standing in reeds or sedge they frequently stretch the neck up straight on the lookout. They also have a curious habit of extending the wings and raising them up over the back until they meet. This, I suppose, is a kind of signal, the green of the primaries being conspicuous for a long distance when in this position. On wounding one of these birds I found that it was a very fair swimmer, and when I overtook it, it dived, to my astonishment, with as much confidence as a grebe, and I never saw it again.

Mr. Gillin writes:

On three different occasions I had wounded birds submerge themselves about a foot below the surface of the water for several minutes before I could locate them and secure them by hand. They clutched whatever was available with their feet and from above looked just as comfortable under water as a quail or grouse would be crouching in the leaves of a briar patch.

Voice.--Mr. Jouy says that “these birds have a noisy, cackling voice when they take flight.” Mr. Gillin refers to their note as “a plaintive call of alarm.”

Fall.--In September he found them “in flocks, flying around and feeding on ponds where” he “was sure that they had not bred.” The records of this form in Texas and the West Indian form in Florida were probably due to such post-breeding wanderings.

DISTRIBUTION

Range.--The Mexican jacana is found in Mexico and the lower Rio Grande valley in Texas. The range extends north to Sinaloa (Mazatlan); and southern Texas (Brownsville). East to Texas (Brownsville); Tamaulipas (Alta Mira, and Tampico); Vera Cruz (Jalapa, Alvarado, Tlacotalpan, and Cosamaloapam); Tabasco (Barra de Santa Ana, San Juan Bautista, and Teapa); and Quintana Roo (Cozumel Island). South to Quintana Roo (Cozumel Island); Chiapas (Tonala); Oaxaca (Zanatepec and Santa Efigenia); and Guerrero (Acapulco). West to Guerrero (Acapulco); Michoacan (Lake Patzcuaro); Colima (Rio Coahuayana, and Manzanillo); Jalisco (Zapotlan, Ocotlan, and Guadalajara); Nayarit (Tepic, San Blas, and Santiago); and Sinaloa (Mazatlan).

In October, 1899, a specimen of jacana was killed on Pelican Bay, Lake Okeechobee, Fla. (Mearns, 1902); and H. H. Bailey (1925) reports another seen by his father in Osceola County, Fla., in March, 1911. The first of these has been tentatively referred by Ridgway (1919) to Jacana s. violacea, a race found in Cuba, Haiti, Jamaica, and Porto Rico.

Egg dates.--Northeastern Mexico: 68 records, April 25 to August 15; 34 records, May 28 to July 13.

REFERENCES TO PUBLICATIONS

AIKEN, CHARLES EDWARD HOWARD, and WARREN, EDWARD ROYAL.

1914--The Birds of El Paso County, Colorado.

ALEXANDER, WILFRID BACKHOUSE.

1926--Notes on a Visit to North Queensland. The Emu, vol. 25, pp. 245–260.

AUDUBON, JOHN JAMES.

1840--The Birds of America, 1840–1844.

AUGHEY, SAMUEL.

1878--Notes on the Nature of the Food of Birds of Nebraska. First Report U. S. Entomological Commission, Appendix 2.

BAILEY, ALFRED MARSHALL.

1925–26--A Report on the Birds of Northwestern Alaska and Regions Adjacent to Bering Strait. Part 6. The Condor, vol. 27, pp. 232–238.