Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.
Bent Life History for the Great-tailed Grackle - the common name and sub-species reflect the nomenclature in use at the time the description was written.
Great-tailed Grackle/Boat-Tailed Grackle
CASSIDIX MEXICANUS MEXICANUS (Gmelin)
Boat-tailed and Great-tailed Grackles were considered the same species at the time Bent was written.
Contributed by ALEXANDER F. SKUTCH
[AUTHOR'S NOTE: In recent years, according to the A. 0. U. Check List (1957) the races of Cassidix mexicanus have been spreading slowly northward. Phillips (1950) reported a specimen of the typical race from Cameron County, Tex., and we can suppose that in time others will reach southern Texas.] In Costa Rica the boat-tailed grackle appears to be confined to the Pacific coast, where it forages among the mangrove swamps, and is quite unknown in the interior. But in northern Central America and southern Mexico it spreads over most of the country, and to the local inhabitants is one of the best-known of feathered creatures. Most other birds of the region are given only general or family names; CHORCHA must suffice for many kinds of orioles, and CARPINTERO does service for a great variety of woodpeckers. The familiar grackle not only bears a specific name, but male and female are honored with distinct titles. The big handsome, yellow-eyed males, clad in sleek black plumage glossed with violet and blue, are called CLARINEROS (trumpeters); the much smaller females, soberly attired in shades of brown, are known to everyone as SANATES. And well may the boattailed grackles have two names, for more than any other bird of northern Central America, they seek the neighborhood of man. The palm trees of the town plaza are their favorite nesting place; in the evening one sees them streaming in noisy flocks from the surrounding fields, where they forage during the day, to the village shade trees, where they roost. They abound in the coastal towns; and the stirring whistled screech of the clarinero at once recalls to my memory some palm-shaded Caribbean port; but they are scarcely less numerous in the interior, and in Guatemala frequent the towns of the central plateau, up to at least 7,000 feet above the level of the sea. They are equally at home in the most humid districts of the Atlantic littoral and amid the cacti and thorny scrub of the scorching, semidesert regions of the interior and of the Pacific plain. But they are never found amid the forest .
But I have never remained longer than necessary in the towns, and only at Alsacia Plantation did I live on intimate terms with the grackles. The plantation house stood on the upturned end of a sharp spur jutting out from the mountains which form the boundary between Guatemala and Honduras into the level Valley of the Rio Morja, a tributary of the Motagua. Here on the hilltop, several hundred feet above the Valley floor, a numerous company of grackles established their headquarters in the tall coconut palms that shaded the house. From my arrival in February until the following July, I awoke every morning with their voices in my ears. In the earliest dawn the clarineros repeated over and over again, in a calm, subdued voice, a long-drawn note between a screech and a whistle, which sounded very pleasant and contented, and reminded me of one running up the entire scale on some stringed instrument with one deft stroke. How different from the shrill calls they uttered later in the day, at the height of their amorous passion! Then, as the morning grew lighter, with much commotion and clucking on the part of the females and excited calling by the males, they left their sleeping places among the coconut fronds and flew down to seek their breakfast. Many alighted on the Gonostegia, a melastomaceous shrub with small pink flowers that grew abundantly on the grassy hillside below the house, to eat the small, black, sweetish berries. Others settled in the cowpen and on the road, where they walked about seeking small, creeping things on the bare ground, or on the lawn to forage in the grass. One morning I watched four sanates perform an office of kindness to a gaunt old cow who stood alone in the pen. One bird alighted on her back and pecked at vermin among the hair. After a slight show of resistance, she allowed a second to settle beside her and share the feast. Two more sanates moved about on the bare ground at the beast's feet, and at intervals jumped up to pluck something from her flanks or belly. They clambered over her legs and tail, performing the same service, while the cow stood patiently still.
Many of the grackles, upon leaving their roost, flew directly down into the Valley. As the morning wore on the rest melted away, singly or in small flocks, to the banks of the Rio Morjti, which wound through the banana plantations half a mile away. Here they foraged along the moist shore or in the shallows, or searched among the piles of driftwood and washed-out banana plants stranded in the shoals. The clarineros walked sedately along the shingly beach and flicked small stones aside with their bills, to see what edible morsels might be lurking beneath them. On hot afternoons they delighted to bathe in the shoals at the margin of the steam, shaking wings and tail so vigorously that they sent up a shower of crystal drops which sparkled in the sunlight. One afternoon I saw a sanate approach a clarinero that was bathing and stand as close to him as she could, although there was an abundance of room elsewhere, seeming to enjoy the shower he was creating. She used him as the boat-tailed grackles of the towns sometimes employ the lawn sprinklers. Finally all the bathers flew up to the boughs of the willow and cecropia trees on the banks, vigorously shook the water from their plumage, and carefully preened their feathers with their slender bills.
As the sun sank low and the air grew cooler, the grackles flew up the hill in small flocks, sometimes cackling like a company of purple grackles, to congregate again in the coconut palms. On the way many would settle again in the Conostegia bushes for a dessert of berries before going to roost. From the time of their arrival until it was nearly dark, our hilltop presented a lively scene. The varied calls and squeaks of the males mingled with the constant chatter of the more numerous females. Many of the birds would settle upon the fronds of a single tree, but seemed unable to make themselves comfortable, and so flew out to alight upon another. Often they shifted back and forth a dozen times before at length adjusting themselves for the night. The fresh breeze that generally blew up from the valley at about sunset and tossed the great fronds of the coconuts made it more difficult for the birds to settle down. The long tails of the clarineros flagged back and forth as they perched on the leaves, causing them evident inconvenience. It was a delight to watch their graceful maneuvers in the wind, when they hovered, soared, and poised with dangling legs above the treetops, as sea gulls play above a windy shore.
On some particularly breezy evenings the clarineros engaged in spectacular if inconsequential sparring matches, meeting face to face and rising well above the treetops, until the wind took hold of them and twisted them around, and they were obliged to forget their opponents and devote all their attention to the maintenance of their own equilibrium. There seemed to be no point to these encounters, which were probably entered in a spirit of fun, the more to enjoy the wind by their vigorous exercise in it, as boys engage in sham battles in the water. The sun hung well above the western hills when the grackles began to congregate among the coconut trees; the last red glow was fading from the sky when finally they had all ensconced themselves out of sight among the inner fronds of the palms, and their final sleepy notes gave way to the awakening calls of the parraque. But the clarineros, especially at the outset of the breeding season, were light sleepers, and often awoke during the night to shatter the monotonous humming of insects with their shrill calls.
At first I was happy to have such active, spirited birds as close neighbors, but at length I began to wish them elsewhere; for like their northern relatives, the purple grackles, they ate the eggs of other birds. A number of pairs of tanagers, flycatchers, thrushes, and other small birds built their nests on our hilltop, yet few succeeded in rearing their young. The grackles kept all other large birds so well at a distance, that I strongly suspect that they themselves were responsible for most of the depredations, especially since I once surprised a clarinero standing over the nest of a tiny Bonaparte's euphonia (Tanagra lauta lauta) which he had just torn to pieces in order to remove the eggs.
Courtship: At "Alsacia" the sanates began to build their nests during the last week of February, and at this time the noise and excitement of the clarineros reached their highest pitch. The colony contained about a hundred birds, and there were at least two or three females for each male. The clarineros did not appear to have any particular mates, but formed merely random and temporary unions with the sanates. Yet although they shared the same territory and were idle, they never seriously quarreled. Sometimes two would stand side by side on the same perch, calling peacefully for several minutes, when of a sudden one would rush at the other and drive him away; but the bird thus threatened never turned to fight and the other forgot his animosity in a moment, so there never resulted any disagreeable encounters. The case was quite different with the sanates, who often came to grips in their disputes over their nest sites.
The clarineros were ardent in courtship. Often one flew down beside a sanate which was feeding or gathering material for her nest on the ground. He addressed her with wings half-raised and quivering, his great tail held level with his body and his head depressed, his contour feathers all fluffed out, making him appear larger tban he was, while with half-opened bill he uttered pleading calls. Sometimes his voice was shrill and insistent, sometimes soft and appealing as the peeps of a little chick lost from its mother in the grass; but no matter what language he used, the ardent suitor was sure to be ignored by the busy sanate, who went resolutely about her work. At other times he perched beside her in a tree and paid his court in much the same manner. So long as the sanate ignored him, his passion would die away almost as suddenly as it began.
The nuptial flights of the grackles were aerial displays of the most thrilling sort. They began when a sanate fled the attentions of a clarinero who addressed her on the ground or on a coconut frond, or when he tried to overtake her as she flew about her usual business, whether to find food or to gather material for her nest. As she fled from him he uttered his shrill nuptial calls and increased his speed to overtake her. She doubled and twisted and dodged and used every stratagem to escape him. Far out over the valley they went, until they were high above the tallest ceiba trees. Closely as he pressed her, she always managed to elude him; and I never saw one of these breathless pursuits end in a capture. The wild chase over, the twain doubled back to the hilltop separately or together, or continued their flight to the river.
Although the clarinero was so spirited in courtship, it was the sanate who decided when she desired his attentions, and this was usually about the middle of the afternoon. Then she vibrated her wings and called with pleading peeps much weaker than his. Sometimes she might continue this for a considerable period without attracting a clarinero, although several were in sight. When a clarinero responded, be flew to her with shrill, ear-piercing cries and quivering wings, and their union was completed in a moment. Then they separated, perched not far apart with wings still violently vibrating, and continued their calls; but their notes were weaker than before and soon died away.
Nesting: The nests of the boattailed grackles are usually built in colonies and are often placed near water, in willow trees or bushes along the banks of lakes or rivers, or among rushes and reeds at the marshy borders of lagoons. But often they are situated in the shade trees or clumps of bamboos about human habitations, sometimes at a considerable distance from water. At "Alsacia" all the grackles built well up on the hill, far above the river. A few of the sanates in this colony placed their nests in orange or lemon trees, or only 8 or 10 feet above the ground in low, thornless bushes growing in the pastures that surrounded the house. But the majority preferred to nest high up in the coconut palms where they roosted.
I wanted very much to see the nests, but at first was timid about climbing so high above the ground among the giant fronds of the coconut trees; for despite their tremendous size, they are only exaggerated leaves, and those of us who grow up in the temperate zones develop a prejudice against supporting our weight on leaves. At the beginning I sent up a slender lad to look into the nests and report their contents to me. But after I had watched the boy clambering in perfect safety among the fronds, I overcame my prejudices and ventured up myself. A man may climb by the aid of these giant leaves as though they were branches, provided of course that he keeps his weight fairly close to the trunk, and ascends to the top of the palm tree. The lowest dying leaf must be avoided, for it is on the point of becoming detached and may fall at the slightest touch. Above this the fronds are strong and safe. In their broad, cuplike bases fallen flowers and blasted fruits, shreds of decaying sheaths and misceilaneous debris, have accumulated and turned to mold, in which graceful pendent ferns, as well as grasses and various other plants, strike root and form a veritable aerial garden. Among these air plants hang the green dusters of ripe and ripening fruits, each larger than a man's head, and the whole bunch of some two dozen coconuts, weighing considerably more than a strong man can lift. Among these lower fronds ants establish their colonies, spiders spin their webs, and one expects to encounter, amid all this debris and decaying vegetable matter, scorpions, cockroaches, and other unpleasant creatures. Some trees swarm so with stinging ants that it is unhealthful to climb them. Few of the grackles nested among these lowest fronds.
Higher, where hang the young and the half-grown fruits, and from this point to the summit, the trunk and the bases of the fronds are enswathed by their sheaths, which soon dry to form a coarse fabric of loosely netted brown fibers, of much the texture and aspect of burlap. These sheaths tear and decay away while the fronds to which they belong remain green, with the result that the oldest are devoid of them. Here, in the axils of the younger fronds, against the coarse fabric of the sheaths, many grackles built their nests, among the white palm flowers covering the stiff upright branches of the spadix, each standing in front of its hooded spathe, fluted on the outer side.
But the place most favored by the sanates for their nests was in the very center of the palm tree's crown, between the two youngest of the expanded leaves, which stood upright face to face, providing between their broad green surfaces a cozy nook where the structures could be supported. Here the birds were in a verdant realm of their own, whence, through the narrow interstices of the fretwork made by the broad ribbons of the leaflets crossing at varying angles, they caught only imperfect glimpses of the outer world of plain and mountain that spread in a vast panorama about the lofty hilltop. The wind sent ripples along the pleated surfaces of these youngest leaves and tossed the older fronds below, the sun at high noon poured down its rays between the upright young leaves; but affairs on the ground below passed unseen and unregarded. A more attractive site for a bird's nest could scarcely be conceived. The first sanate to build in the coconut palm invariably selected this choice location, and sometimes allowed a friend to place her nest between these same fronds, but on the opposite side of the rachises. If any mishap befell one of these nests and left the position vacant, it was most likely to be occupied again so long as the grackles continued to build. Aside from its sequestered position, the nook between the youngest fronds offered many advantages, not the least of which was its cleanness, for here amid the fresh green leaves the birds were above the ragged sheaths and the vermin they harbored: above everything unclean save the droppings of the roosting grackles themselves.
It was only after these most favored sites had all been claimed that the sanates were content, perforce, to build among the mature fronds lower down. On the broad bases of the latter they found a firm and secure foundation for their nests. Five or six sanates frequently nested at one time in the same coconut palm.
As the sanates built, frequent quarrels arose among them, usually between birds which desired the same nest-site, or between those that had begun their nests too close together and were in each other's way as they worked. They menaced each other with open bills and high-pitched, irritated cries until at length one flew at the other, and the two sparred face to face as they fluttered toward the ground. Then they would separate and fly off to forage or to gather more material for their nests. These quarrels never resulted in injuries to the contestants, but caused the birds to scatter their nests in different parts of the tree rather than crowd them all in the same place.
Like oropendolas, the sanates often attempted to steal nest material. Often one bird would grasp the end of a long fiber that dangled from a neighbor's bill Perching side by side on a coconut frond, the two tugged at the coveted prize, until at last one or the other tore it from her opponent's grasp and flew to her nest with it. Sometimes one or even two birds would pursue a third who had found a particularly desirable piece of material. The sanate who had her fibres rudely torn from her bill never manifested resentment, but soon went cheerfully off to search for more. The clarineros took no part in building the nests and viewed with indifference the quarrels between the females from whatever cause they might arise.
The completed nests were large and bulky open cups composed of a variety of ingredients. The foundation was sometimes prepared by piling in the chosen site a quantity of coarse materials such as weed stalks, small grasses torn up by their roots, and miscellaneous vegetable material. Above this the bird wove a roomy cup of coarsely fibrous stuffs picked up from the ground, chief among which were uncleaned strips from the decaying outer leaf sheaths of the banana plants; but grass stems, bits of rag and string, and fibrous weed stalks made flexible by partial decay, were also employed. The nests built in bushes and dicotyledonous trees were suspended among the finer twigs by fibers twisted firmly around them and woven hack into the walls of the cup. In the coconut palms, the nests between the youngest leaves were attached by fibers woven around the leaflets. Those lower in the. crown of the palm were attached to the branches of an inflorescence if they happened to touch it; but most of these nests merely rested upon the broad bases of the leaf stalks, for usually the builders found nothing suitable to which they might bind them. The completed cup was plastered on the interior, to within an inch or so of the rim, with a substantial thickness of fresh cow dung or mud, and this in turn was lined with finely fibrous material. Those sanates which worked hardest finished their nests in 5 days, but others less hurried took twice as long. The ample cups measured from 4 to 5 inches in internal diameter and from 2% to 4 inches in depth.
Eggs: The female began to lay 3 or 4 days after finishing her nest. The earliest egg in the colony appeared on March 3, and during the next week many birds started to lay. Usually an egg was deposited each day until the set was completed, rarely 2 days elapsed between the laying of the first and second eggs in sets of two. Of 49 nests which we were able to reach at "Alsacia," 33 contained 3 eggs each, 15 contained 2 eggs, and there was a single set of 4.
The big, glossy eggs of the boat-tailed grackle are strikingly marked and usually very beautiful. The ground color varies from bright blue to very pale bluish gray, on which are dots, blotches and intricate scrawls of brown and black. The blue ground color of some eggs is locally washed with shades of brown or pale lilac. It would be tedious to describe all the diversities of pattern that fall within this general scheme; for the variation is so great that, if all the eggs in a populous colony were mixed together, each bird might conceivably be able to recognize her own by its distinctive markings. The measurements of 62 eggs temporarily removed from the nests at "Alsacia" average 33.6 by 23.0 millimeters. The eggs showing the four extremes measured 36.5 by 23.4, 32.9 by 24.6, 31.0 by 22.2 and 34.1 by 21.4 millimeters.
Incubation: As she had built alone, so each sanate incubated alone, without help from a clarinero. But long before the first egg hatched, calamities began to occur. The earliest builders, who had seized upon the most coveted nest sites between the youngest fronds, found to their sorrow that this supreme and most desired position had one disadvantage which to the sober-minded would have outweighed all of its manifold attractions. It was inevitably unstable; for here the nests were supported between two fronds which still grew and bent outward in opposite directions as new leaves pushed up between them at the apex of the palm. The coarse fibers of the outer wall of the nest were, as we have seen, wrapped around the ribbonlike segments of one or both of the supporting fronds. But these formed an entirely inadequate foundation; the slender ribbons sank down under the weight of the heavy, dung-lined structures, and the eggs rolled out even when the whole nest did not fall. The swaying of the fronds in the wind hastened the undoing of the nests. We attempted to save many by tying them securely with cord as close as possible to the original position; but even with this help it was difficult to make them remain in their precarious situations, and most came to disaster. Of the many birds which had built between the youngest fronds, only one to my knowledge succeeded in bringing out her nestlings alive, and then only because we tied up her nest when it began to lean. Yet despite the terrible example constantly before her, with infinite faith a sanate would begin a new nest in the top of the palm as soon as the expansion of a fresh frond had prepared another of these deceptive sites.
The sanates which, from necessity rather than by preference, placed their nests on the broad bases of the mature fronds, fared somewhat better; yet even with them the loss of eggs and nestlings was enormous. This was largely because the birds continued to roost in the same trees where they nested: an extremely unsatisfactory arrangement. As the clarineros and the sanates not actually engaged in incubation: they were always in the majority: settled in the palms for the night, the excitement and disorder which prevailed there was so great that I wondered whether the incubating females managed to remain on their eggs. The angry cries which at this time emanated from birds unseen in the crown of the tree were doubtless from sanates trying to protect their nests from intrusion. As the nesting season advanced, the number of grackles which went to roost in the orange and grapefruit trees growing beside the coconut palms increased, possibly as a result of the protests made by the females nesting in the palms. Not only was the safety of the nests jeopardized by the disorder so prevalent each evening, but they and their immediate surroundings were deified by the droppings of the roosting birds. Some queer things happened as a result of the grackles' disorderly habits. In one of the tallest of the palms was a nest which sheltered two nestlings. When they were nearly ready to take wing, one was found dead among the leaf bases in the vicinity of its nest, while the other in some mysterious manner made its way to a neighboring nest, where there was a single nestling 2 days younger than itself.
With the boat-tailed grackle the habit of colonial nesting is imperfectly developed, perhaps of comparatively recent origin; for conditions such as existed in the colony at "Alsacia" are a tremendous handicap to the reproduction of the species and therefore not likely to survive a long period of evolution. Oropondolas and caciques, birds of the same family which like the boat-tailed grackles nest in colonies that contain more females than males, arrange the matter much better. At nightfall, all the males, and all the females who do not remain in their nests, retire to roost at a considerable distance, leaving the incubating females to pass the night free from unnecessary disturbances. After witnessing the disadvantages with which the sanates must contend while attempting to rear a family in a crowded colony, one understands better why so many kinds of birds select a nesting territory which they zealously defend from the intrusion of all others of their own species.
Only rarely, in nests with two eggs, did both hatch on the same day. More often, one egg hatched each day, so that in sets of three the hatching of all the eggs required three days; or two might hatch on one day and the third on another day. In a few sets the eggs were marked as laid, and these hatched in the order of laying. The incubation period was measured from the laying of the last egg to the hatching of this egg. At four nests the incubation period was 13 days; at two other nests, 14 days .
Young: The newly hatched grackles had pale salmon-colored skin and bore a sparse but long gray down on the head, back, wings and legs. Their eyes were of course tightly closed, but they could already peep wildly and their bills when opened for food revealed a bright red interior. Their calls of hunger were heeded only by their mothers, for the clarineros were indifferent to this as to every other domestic claim. The only responsibility they assumed was that of guarding the nests. Whenever they espied a man approaching the coconut trees, their sharp tlick lick, tlick lick warned the females to flee from their nests, with the result that it was almost impossible to catch sight of them as they incubated or brooded. If we climbed into the crown of a tree which sheltered young grackles, the noise and excitement were immense. Clarineros and sanates, even those whose nests were safe in neighboring trees, circled around and filled the air with excited clucks. There was one particular clarinero, guardian of an isolated palm growing in the corral, who was bolder than all the others. While I rested in the crown of this tree to look at the nestlings under his tutelage, he ventured closer than any of the sanates dared to come, and often alighted near the end of the frond against which I leaned, bending it perceptibly under his weight and making me instinctively clutch another support. He interrupted his clucks with a little tinkling note rapidly repeated, and at times in his anger uttered an indescribably harsh, agonized call, which set the sanates, who all the while had been flying in circles around the tree and complaining in voices weaker than his, into faster movement and louder calling. A single female, mother of nestlings in this tree, perched on a frond and relieved her distressed feelings by giving it angry pecks .
No hawk or other large bird dared to fly close to our hilltop. Both clarineros and sanates joined in harrying the vultures, both the red and the black-headed species, which circled too near the palms that sheltered the nests or attempted to alight upon them. They pursued the carrion feeders far down the hillside, striking them repeatedly on the back until they retreated to a satisfactory distance. I am not sure whether they had a natural aversion to birds so unclean, mistook them for hawks, or whether the vultures would actually have eaten the nestlings if given the opportunity. But the grackles even attacked a curassow (Craz globicera), probably the first they ever in their lives saw, and certainly not a natural enemy; for these big gallinaceous birds come into the clearings as seldom as the grackles enter the forest where the curassow is at home. One morning, while I was in the Valley, my attention was drawn by a harsh cry to a male curassow flying heavily, with labored wingbeats, high above the hillside in front of the house. As he approached the top, two clarineros and several sanates flew out from the palm trees to buffet him. Flying "near his ceiling" and doubtless already fatigued by his unwonted journey, the big bird wavered in his course and lost altitude as his assailants beat down upon him, but managed to remain in the air until he rounded the brow of the hill and was lost from view.
Just as the historian must record both the pleasant and unpleasant events: alas! too often the latter: in the history of nations, so must the bird watcher reveal the disagreeable as well as the lovable traits of the birds which come under his notice; thus, I must record the following episode in the history of the grackles at "Alsacia." There was a nest, in the coveted position between the youngest fronds of one of the smaller palm trees, which as usual with such nests I found it necessary to support by tying. It had also been considerably damaged by a high wind, but the two nestlings that it cradled continued to thrive. One morning in this tree I saw a fight between two sanates, who clinched and fluttered to the ground; but I did not give much attention to their quarrel, for such flurries were of frequent occurrence. The next day, when I climbed into the crown of this palm tree, I found that grass and weed stems had been piled on top of the dilapidated structure which only yesterday bad been the home of two healthy, 10-day-old grackles. Removing the new accumulation, I found the cold, dead bodies of the nestlings interred beneath it. The intruder had apparently won the fight and must have begun her nest above the living nestlings, trampling or smothering them to death, for they were too fine and vigorous to have died during the night if they had been left unharmed .
The sanates found most of their nestlings' food on the ground and often bore it a long distance to the nest. Sometimes they flew from the river, half a mile away, bringing a morsel that they had found along the shore. The nestlings received grubs from among the grass roots, green caterpillars, and sometimes small lizards. Their eyes opened between their third and fifth days, but they continued to be very ugly little creatures until they were feathered at the age of 2 weeks or a little more. When from 16 to 19 days old, they would try to crawl from the nest if disturbed by one of my visits, but they could not yet fly. The rasping cry of distress which, at this stage of development, they uttered when touched, drove the adults to a frenzy. Those young birds which forsook the nest at the age of 19 days could not yet fly, but remained climbing around among the broad bases of the coconut fronds for 2 or 3 days longer. The full nestling period was from 20 to 23 days. At the time of quitting the nest the young birds of both sexes resembled the adult females, but their breasts were more grayish, their irises brown instead of bright yellow as in the adults, and their faces and foreheads still bare of feathers.
The destruction, during the course of cleaning the pasture below the house, of one of the isolated nests built 10 feet above the ground in an Inga tree, gave me the opportunity to make an experiment. Although the nest tree had been cut down, the two vigorous week-old nestlings were picked up unhurt from the ground. I placed one of these in a nest in a coconut palm which already held three 10-day-old nestlings; it was attended by their mother along with her own offspring. The other fallen nestling was deposited in another nest in the same palm tree, from which the original occupant had vanished a few days earlier. Apparently none of the four females which at the time were building or attending nestlings in this tree, nor any of the other grackles which frequented it, took notice of the foundling, for it died of neglect after a day or two. Each female appears to attend strictly to her own nest, and to ignore the nest and offspring of her neighbors.
Soon after leaving the nest, the young grackles began to follow their mother afield as she foraged, before long going even as far as the river, where they perched on a banana leaf arching above the bank while awaiting her return from her search along the shore; or else they pursued her along the sandy margin of the stream, begging for food with vibrating wings. In May and June, the young birds became an increasingly conspicuous element in the flock: for despite their numerous failures, the sanates succeeded by persistent efforts in rearing a goodly number of offspring: and the youngsters' halfpleading, half-imperious call, tuitit witit, mingled with the whistles and clucks of the older birds. The young males continued to solicit food from mothers larger than themselves. Once I watched two youngsters, a clarinero and a sanate, alternately beg for and receive food from their mother and help themselves to the ripe banana which she was eating. Sometimes, as the young birds waited for food to be brought them in the hibiscus hedge beneath the coconut trees they picked off the leaves and bright red flowers, or pecked at the unopened buds, seeming to try to find food for themselves before they could distinguish what was edible.
By the first week of July the nesting season was drawing to a close.
Since the grackles had begun to nest at the end of February, they had had time for rearing two broods. One sanate, who in some unknown manner had lost her tail and got a piece of red tape entangled around her right leg, making it easy to recognize her, built a second nest and hatched a second brood after her first had been successfully fledged; but how many birds actually succeeded in raising two broods to the point where the young could shift for themselves, I was not able to determine.
During the night of July 6 the grackles which roosted in the coconut trees were restless, shifting their positions and often crying out in the dark. After this the great majority of them withdrew from the hilltop which had so long been their home. There remained only a few sanates who still had young in the nest, one whose two eggs were just hatching, and two faithful clarineros. The early mornings were strangely silent after the grackles departed .
On the Pacific side of Guatemala, where the dry season begins in mid-October or early November, 2 or 3 months earlier than in the Caribbean region, the boat-tailed grackles begin to breed correspondingly earlier. At an altitude of 3,300 feet on the Finca Moca, a great coffee plantation situated on the Pacific slope, I found grackles feeding nestlings as early as the first week of January. These birds must have begun to build no later than the middle of December, more than 2 months before those at "Alsacia," which began to build in late February and had no nestlings before mid-March.
Food: Few birds, I imagine, subsist upon a greater variety of food than the boat-tailed grackle, or display greater ingenuity in procuring nourishment. "Everything is grist for their mill." Their diet includes both animal and vegetable products. Much of their food is picked up from the ground, where they extract the larvae of beetles and other insects from among the roots of the grasses, and capture small lizards. They are said to hunt in freshly plowed land, following close behind the plowman. They pluck ticks and other vermin from cattle, often alighting upon the animals' backs for this purpose. They spend much time foraging in the vicinity of water. On bare shingly fiats along the shores they turn over small stones by inserting the tip of the bill beneath the nearer edge and pushing forward, then devour the small crustacen, insects, worms, or the like that they find lurking beneath. It is chiefly the more powerful males that hunt in this fashion. Often the grackles wade into shallow water, where apparently they capture tadpoles and small fish. Or if the water be deep, they may adopt other modes of fishing; A. W. Anthony (Griscom, 1932) tells how at Lake Atitlan in Guatemala the grackles caught fish as they flew low over the surface of the water, seizing their prey by means of a quick snap and hardly wetting their plumage in the process. At other times, however, these grackles plunged boldly into the lake, like a tern or a kingfisher, immersing themselves to a depth of not more than 3 or 4 inches. Sturgis (1928) records that the great-tailed grackles frequent the most isolated rocks in Panama. Bay, where doubtless they devour a variety of small marine creatures. In Costa Rica, Carriker (1910) found the bird common among the mangroves of the brackish estuaries so numerous along the Pacific coast.
Like other grackles, this species pillages the nests of other birds, devouring their eggs or nestlings. In Guatemala, I surprised a male boat-tailed grackle resting upon a fence-post where a pair of Bonaparte's euphonias (Tancgra lauta lauta) had built a nest, well concealed in a cranny caused by decay. The roof had been torn from the little domed nest and the newly laid eggs had vanished. Although I arrived too late to catch the grackle in the act, the circumstantial evidence pointed strongly toward him as the despoiler of the nest and-devourer of the eggs. In Mexico, Chester C. Lamb (1944) saw a male grackle seize a female yellow warbler which had dashed into the face of the bigger bird in a vain attempt to save her eggs. The warbler was killed her skull crushed by the grackle's powerful bill.
Of vegetable food, the grackles are fond of ripe bananas and of small, sweet berries, especially those of the melastomaceous shrub Conostegia. They greedily eat maize, tearing up the germinating grains from newly planted fields. One Guatemalan farmer told me that his efforts to start a cornfield were frustrated by the grackles until he adopted the expedient of scattering a considerable quantity of grain about the edges of his field. This kept the hungry birds occupied until the planted maize had grown large enough to withstand their attacks. Yet this same farmer considered that the grackles, by destroying grubs and other insect pests, did on the whole more good than harm on his estate. Later, as the maize crop nears maturity, the grackles renew their depredations upon the milpas, tearing open the husks to reach the tender, milky grains, which the females at this season feed to their fledglings .
Behavior: The big male grackle glides downward with wings set, the tips of the primaries separated from each other and distinctly curved upward by the weight of his heavy body, and with his long tail folded together upward so that the feathers lie in a vertical plane, like that of the purple grackle, and vibrating from side to side in the breeze. Usually he flies upward with heavy, resonant wing beats, like those of the male oropendola; but at times he may fly silently. The flight of the female grackle is almost silent; but when laboring upward with long fibers for the nest streaming from her bill, her wing beats may be sonorous like the male's, but not so loud. Rarely she folds her tail feathers together in the manner of the male, but not completely. In sustained flights on a horizontal or ascending course, both sexes move with perfectly regular and rapid wing beats, neither folding their wings intermittently nor spreading them for gliding. On the ground, the grackles walk rather than hop .
Although I never witnessed a serious dispute between the male boat-tailed grackles in the colony at "Alsacia," in other regions these birds may be more pugnacious. While traveling by rail through southern Mexico, I saw from the train window two male grackles flghting in good earnest. They clinched and rolled on the ground, continuing their battle as long as I could keep them m view .
Voice: The range and power of the male grackle's voice are wonderful: he lacks only a set song. At one extreme, he utters a little tinkling note, rapidly repeated and very pretty, at the other, his calls are so loud that they are best heard at a distance. If one may say that a bird with so varied a language has one call which is most characteristic, that call is a single, long-drawn utterance, something between a squeak and a whistle, which rises through the scale. Then there is a resonant tuck tuck tuck, delivered while the bird is either in flight or at rest, and a spirited, rollicking tuck-a -lick tuck-a-lick which seems the outpouring of rare good spirits. There is also a rolling or yodeling call, very vigorous, and quite in contrast with the lazy, screeching note, like the slow swinging of a gate with rusty hinges, which is also a part of his varied vocabulary. Sometimes while perching the male grackle puffs himself up, swelling out all his feathers, and half opening his bill, slowly expels the air with a low, undulatory sound, such as can be made by whistling through the teeth .
As musicians, the grackles display a good deal of originality. They often invent new calls, and when they hit upon one which takes their fancy, repeat it over and over again. One bird fell in love with a pretty phrase, which sounded like wheet-t6ck, and uttered it constantly for a week or more, until at last, like a popular song, it grew stale and was forgotten. Another clarinero was much taken with a buglelike call that went ta-dee ta-dee ta-dee and was really very martial and stirring, especially when heard at a little distance, for it had great carrying power. After delivering a call, the grackles frequently perch with their long, sharp, black bills pointing straight upward, a pose which displays to good advantage the sleek glossiness of their purple necks. This position is also assumed on other occasions, and sometimes two splendid birds, perching side by side on a coconut frond, point upward at the same time and hold the pose for a good fraction of a minute, looking very self-conscious. The females, too, sometimes assume this attitude, but the trait is not nearly so strongly developed among them as among the males.
The female grackles are not only smaller but quieter than the males. Their most characteristic utterance is a rapid, clicking sound, a tuck tliclc tuck sharper and less sonorous than the corresponding note of the males. They use this while building their nests, quarreling with their neighbors, or flying. Single throaty clucks are also uttered by both sexes. Sometimes a female attempts to deliver the note that I ventured to call the most typical of the male, but hers is a weak, squeaky imitation .
Field marks: It is scarcely possible to confuse the boat-tailed grackle with any other bird of southern Mexico or Central America. The larger size of the male, his bright yellow eye, and his long fanshaped tail, easily serve to distinguish him from the other wholly black or blackish members of the troupial family that inhabit the region. Perhaps, at a distance, the giant cowbird (Psomocolar oryzivorus) might be mistaken for a male boat-tailed grackle. But in flight, these cowbirds with red eyes close their wings momentarily after each five or six beats, while the grackles fly with regular, uninterrupted strokes: peculiarities which will serve to distinguish the two species almost as far away as they are visible.
The members of this race are somewhat larger and darker, especially the female, than those of tile other races inhabiting the South Atlantic and Gulf Coast States.
Resident in the lowlands and tableland of Mexico from eastern Jalisco, southern Nuevo L6on, and southern Tamaulipas to Guatemala, British Honduras, EL Salvador, and northern Nicaragua; extending northward in recent years (a specimen from Cameron County, Tex., has been identified as of this race; this record has not yet been acted on by the A. 0. U. Committee on Classification and Nomenclature of North American Birds).
Sonoran Boat-Tailed Grackle
CASSIDIX MEXICANUS NELSONI (Ridgway)
Primarily a denizen of the coastal district of Sonora, and the interior of that province from Raneho Costa Rica southward, this race of the boat-tailed grackle has recently been reported from central-southern Arizona (Tucson). From Monson's boat-tail it may be distinguished by its smaller size, shorter tail, and the paler color of the female plumage.
Little or nothing has been recorded of its habits, but these are probably similar to those of the other races of this boat-tailed grackle.
Monson's Boat-Tailed Grackle
CASSIDIX MEXICANUS MONSONI Phillips
This recently described race occurs in the plateau of northern M6xico, in Chihuahua, and in recent years has spread northward to adjacent parts of the United States. It resembles the boat-tailed grackle, but has a less massive bill, a more slender tarsus, and the plumage of the female is noticeably darker in tone .
In its habits, as far as known, it does not appear to differ appreciably from the boat-tailed grackle.
It breeds from southeastern Arizona (Benson, Randolph), northcentral New Mexico, and western Texas (Brewster County), south to Chihuahua. It has been recorded sparingly in winter in Pinal and Graham Counties, Ariz., the Bosque del Apache Refuge, near San Antonio, N. Mex., and along the Rio Grande at Juarez, Chihuahua; it is presumed to winter mainly in Chihuahua, but has extended its winter range in the United States northward in recent years.
Mesquite Boat-Tailed Grackle
CASSIDIX MEXICANUS PROSOPIDICOLA Lowery
George H. Lowery, Jr. (1938), has given the above name to the large grackles of this species that are found in the "Gulf Coast region of central southern Texas, north to at least Port Lavaca, and south into northeastern Mexico in the states of Tamaulipas, Nuevo Leon, and Coahuila. In Texas it is closely associated with the range of Lhe mesquite (Prosopis glandiilosa Torrey)." He gives as its subspecific characters: "Resembling Cassidiz mexicanus mexicanus (Gmelin) more closely than any other form, but wing, tail, exposed culmen, and tarsus shorter; male in color almost indistinguishable, but female conspicuously difFerent from C. m. mexicanus, the under parts being decidedly lighter, ranging from Light Brownish Olive to Buffy Olive; also the pileum, sides of head and neck much lighter, tending toward olive rather than brown."
The separation of this subspecies removes the type race, Cassidix mexicanus mexicanus, from our list, and the bird that has for so long stood in our literature as the great-tailed grackle must now be called the mesquite grackle, and restricts it to eastern and southern M6xico, Central America and northwestern South America. However, papers by Allan R. Phillips (1940), Laurence M. Huey (1942) and Lawrence V. Compton (1947), to which the reader is referred for details, show that boat-tailed grackles of the Cassidix mexicanus species have been extending their ranges in the upper Rio Grande valley into New Mexico and into southern Arizona. From correspondence in 1945 and 1947 with Phillips and Lowery, I infer that there is much still to he learned as to the subspecies involved and their ranges. Roger T. Peterson (1939) also reported grackles of this species breeding in New Mexico. The species had been reported previously, as breeding in New Mexico, by J. Stokley Ligon (1926).
When I was in southern Texas, in 1923, I found the mesquite grackle to be astonishingly abundant from Matagorda Bay to the Rio Grande. It was unquestionably the most abundant bird all along the coast, as well as the noisiest and most conspicuous, almost a nuisance at times, especially in the heron rookeries.
Dr. T. Gilbert Pearson (1921) says: "One of the most noticeable, noisy, and abundant species of birds along the lower Texas coast is the Great-tailed Grackle. It possesses an astonishing repertoire of whistles, calls, and gutteral sounds and one sees or hears them everywilere. On islands surrounded by salt-water it is found and one may see it also about fresh-water ponds, or in the towns and on the high prairie or chaparral lands if water of any kind is in the vicinity."
Courtship: Mrs. Bailey (1902) gives the following account of this grotesque performance:
Seated on an oak top, where his bumble spouse could see him to the best advantage, an old male would begin by spreading his wings and tail to their fullest breadth and making a crackling "breaking brush" sound which he evidently considered a striking prelude. This done he would quiver his wings frantically and opening wide his bill emit a high falsetto squeal, quee-ee, quee-ee, quee-ee, quee-ee, perhaps attuned to the feminine blackbird ear. But his coup d'dtat, which should have wrung admiration from the most unappreciative mate, consisted in striking an attitude, his long bill pointed as nearly straight to the sky as his neck would permit. Poised in this way he would sit like a statute, with the most ludicrous air of greatness. Incredible as it may appear, instead of standing spellbound before him, his spouse, practical housewife that she was, whatever her secret admiration may have been, through all his lordship's play calmly went about gathering sticks.
Dr. Arthur A. Allen (1944) describes it as follows:
In the lone pine the grackles were executing their courtships, accompanied by such sounds as shatter an adult's nerves, but delight children when you draw your fingers over a toy balloon and let the air out at various speeds; first low squeals and then high squeals, followed by a crashing sound as if the bird were beating its wings on dry twigs. All this accompanied a display of plumage that was equally ridiculous, for the bird first threw his head back on his shoulders and inflated himself until he appeared twice his natural size, his feathers standing on end and his enormous tail spreading. In the bright sun the brilliant iridescence of otherwise black feathers shot out gleams of purple and green. Next he threw his head forward and, as he collapsed, he rapidly fanned the air with his wings, producing the crashing sound already mentioned .
Nesting: On the southern Texas coastal plain, from Matagorda Bay to Brownsville, we found the mesquite grackle nesting in enormous numbers in practically all of the heron colonies where there were trees or shrubs; there were sometimes a score or more nests in a single tree; nests were often built in the lower portions of the nests of Ward's herons, some were in prickly pear cactus, yuccas, and even in long grass. On May 9 and 10, 1923, we explored the heron colonies around Karankawa Bay, near Port Lavaca; the largest of these, at Wolf Point, was a densely populated colony of Louisiana, Ward's, and black-crowned night herons and reddish egrets, a few black vultures and, as I wrote in my notes at the time, "countless thousands of great-tailed grackles."
The willows, huisache, and other small trees and bushes were full of the nests of the grackles; the dense colony seemed to be much overcrowded. Many nests in the huisache trees were 10 or 12 feet from the ground, but many others in the bushes were only from 3 to 6 feet up. The nests were rather bulky structures, made of dry and green weed stalks, and grasses. We found nests with eggs and others with young during May .
Major Bendire (1895) writes:
The Great-tailed Grackles are more or less gregarious at all times, and generally breed in companies, often in considerable colonies, among the willow thickets and chaparrals bordering the streams and irrigation ditches, or in the tops of mesquite, ebony and colima trees, so common a feature in the lower Rio Grande Valley; they nest less often in hackberry, prickly ash, and oak trees, as well as in the extensive canebrakes bordering the numerous lagoons and fresh-water lakes and in the rushes in the salt marshes near the Gulf coast.* * *
According to Mr. Sennett, when breeding in swamps their nests are frequently placed within 2 feet of the water, and from 4 to 30 feet from the ground when in trees. Their nests, of which I have several before me, resemble those of the rest of our eastern Grackles in size, construction, and materials; some of them are almost entirely composed of Spanish moss, while others are mainly built of small, round stems of creeping plants which are flexible enough to admit of their being securely woven together. Mud is often used to bind the materials together, and the upper rim of the nest is generally securely fastened to the surrounding branches or reed stalks among which it is placed. Some nests show no traees of mud in their composition, but the materials forming the outer walls appear to have been quite wet when gathered. The lining usually consists of dry grass and fine roots, and when near towns bits of cotton cloth, feathers, paper, etc., are often found mixed among the other materials.
Nidification usually begins during the latter part of April; it is at its height in the first half of May and lasts through June. One and sometimes two broods are reared in a season. Young birds of various sizes and fresh eggs may frequently be found in the same colony.
Dr. Pearson (1921) says: "Near the main buildings on the Wolf Point Ranch in Calhoun County, the prairie is decorated by two 'motts.' In local usage the word 'mott' means a thick growth of slender live-oak trees. The combined area of these two motts is certainly not over an acre and a half in extent, yet they held on May 29, not less than 1,000 nests of the Great-tailed Grackle. The noise produced by the birds could be heard from the deck of the yacht where we lay at anchor half a mile distant."
Eggs: The mesquite grackle ordinarily lays three or four eggs, but sometimes five. Bendire (1895) describes them as follows:
The ground color is usually pale greenish blue, and is often more or less clouded over with purple vinaceous and smoky pale umber tints, which are usually heaviest and most pronounced about the smaller end of the egg. The markings consist mainly of coarse, irregularly shaped lines and tracings of different shades of dark brown, black, and smoky gray, and less-defined tints of plumbeous. In rare instances an egg is found which is only faintly marked with a few indistinct lines of lavender gray about the small end, the rest of the egg being immaculate. They are mostly elongate ovate in shape; a few are blunt ovate, while others approach a cylindrical ovate.
The average measurement of 93 eggs in the U. S. National Museum collection is 32.18 by 21.75 millimetres, or about 1.27 by 0.86 inches.
The largest egg in the series measures 36.58 by 22.61 millimetres, or 1.44 by 0.89 inches; the smallest, 28.19 by 20.57 millimetres, or 1.11 by 0.81 inches.
Young: There is no evidence that this race differs, in the care of the young, from the eastern or Florida races .
Plumages: The molts and plumages of the mesquite grackle are similar to those of the boat-tailed grackle, with due allowance for subspecffic characters.
Food: The food and feeding habits of this grackle are evidently similar to those of the boat-tailed. It seems to be equally omnivorous, feeding mainly on the ground or in shallow water on various forms of insects and their larvae, small crustaceans, little fishes, and whatever small aquatic animals, dead or alive, it can pick up around the shores. Some grain and small fruits are eaten, but no great damage to human interests is done. However, tbese grackles destroy large quantities of eggs of other birds in the colonies where they breed.
Behavior: George B. Sennett (1878) writes:
When I think of this bird, it is always with a smile. It is everywhere as abundant on the Rio Grande as is Passer domesticus, English Sparrow, in our northern cities, and, when about the habitations, equally as tame. This bird is as much a part of the life of Brownsville as the barrelero rolling along his cask of water or the mounted beggar going his daily rounds. In the towns or about the ranches, he knows no fear; is always noisy, never at rest, and in all places and positions; now making friends with the horses in the barns or the cattle in the fields, then in some tree pouring forth his notes, which I can liken only to the scrapings of a "cornstalk fiddle"; now stealing from porch or open window some ribbon for his nest, then following close behind the planter, quick to see the dropping corn. With all his boldness and curiosity, the boys of the streets say they cannot trap or catch him in a snare. He will take every bait or grain but the right one; he will put his feet among all sorts of rags but the right ones; and the boys are completely outwitted by a bird. He performs all sorts of antics. The most curious and laughable performance is a common one with him. Two males will take position facing each other on the ground or upon some shed, then together begin slowly raising their heads and twisting them most comically from side to side, all the time steadily eyeing each other, until their bills not only stand perpendicular to their bodies, but sometimes are thrown over nearly to their backs. After maintaining this awkward position for a time, they will gradually bring back their bills to their natural position, and the performance ends. It is somewhat after the fashion of clowns' doings in a circus, who slowly bend backward until their heads touch their heels, then proceed to straighten up again. It is a most amusing thing to see, and seems to be mere fun for the bird, for nothing serious grows out of it.
With all their familiarity, I have seen f~xese birds in the open chaparral as wild and wary as other birds, knowing very well when out of gunshot range. Their flight is rather slow, and when they make an ascent it is labored; but once up, with their great tails and expanse of wing they make graceful descents.
Baird, Brewer, and Ridgway (1874) tell the following story:
Captain MeCown states that he observed these Blackbirds building in large communities at Fort Brown, Texas. Upon a tree standing near the centre of the parade-ground at that fort, a pair of the birds had built their nest. Just before the young were able to fly, one of them fell to the ground. A boy about ten years old discovered and seized the bird, which resisted stoutly, and uttered loud cries. These soon brought to its rescue a legion of old birds, which vigorously attacked the boy, till he was glad to drop the bird and take to flight. Captain MeCown then went and picked up the young bird, when they turned their fury upon him, passing close to his head and uttering their sharp caw. He placed it upon a tree, and there left it, to the evident satisfaction of his assailants .
Voice: The vocal performances of the mesquite grackle are similar to those of its eastern relative, equally noisy and equally unattractive.
Captain McCown (Baird, Brewer, and Ridgeway, 1874) says that "these birds have a peculiar cry, something like tearing the dry husk from an ear of corn. From this the soldiers called them corn-huskers." Friedmann (1925) states that "the notes are very harsh and suggest the sound of the crackling of twigs."
Pearson (1921) remarks that this grackle "possesses an astonishing repertoire of whistles, calls, and guttural sounds." Charles W. Townsend (1927) was evidently better pleased with the voice of the mesquite grackle, for he says: "I had excellent opportunities to watch this bird and was struck with the great variety of its clear and at times musical notes and songs mixed with others that were not so pleasing, all so different from the songs of the Boat-tailed Grackle. I have recorded them as a clear almost Flicker-like week-it, week-it, and see, see, see; also a clear and pleasing wheet, whit-a, whit-a, whit, followed by whee-ee: ee, the last vibratory and pleasing.~~ Field mark8: The large, glossy black males are unmistakable, with their enormous tails which distinguish them from the smaller grackles and other blackbirds. The females are much smaller brown birds, with more normal tails; they are lighter brown than the females of other grackles, and decidedly lighter-colored than the females of the boat-tailed grackle, the sides of the head and neck and the under parts being light brownish olive or huffy olive.
Range: -The mesquite boat-tailed grackle breeds and is mainly resident from southeastern New Mexico (Carlsbad) and western, south-central, and east-central Texas (Toyahvale, Eagle Lake); south to southern Coahuila (Las Delicias, Saltillo), Nuevo Le6n (Monterrey, Montemorelos) and southern Tamaulipas (G6mez Farias) .
Casual records: Casual in winter on Gulf coast of Louisiana (Avery Island).
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