Contributed by Alexander Sprunt, Jr.
[Published in 1942: Smithsonian Institution United States National Museum Bulletin 179: 489-508]
It has always seemed to me that literature has been somewhat chary of the purple martin. Song and story have long stressed the advent of robin, bluebird, and goose as heralds of spring, and so they are, but is the martin any less so? True, it comes somewhat later than these others, but who can fail to thrill when, on waking early one morning, one hears the rich, gurgling calls of the first martin! It is a signal that spring is really at hand, indeed, at one's very door. When the martins come, can summer be far behind?
This largest of the swallows, in its handsomely glossy livery, whether slurred by literature or not, has been a favorite with humanity for many generations. Even before the white man came to America's shores it was a dooryard bird in Indian villages, and its status as such is unchanged today. It is, beyond all doubt, the "bird-box" species of this country. Its range is extensive, almost universal indeed, and it occurs from coast to coast and border to border. Young and old admire it, encourage it, and protect it, and those who have a word of criticism for it are few and far between. Alexander Wilson said that, in his day, he never found but one man who disliked the martin, and many a modern ornithologist will have had the same experience, if indeed it can be matched!
Some birds occupy high pedestals in human regard, typified by the robin in the North and the mockingbird in the South, but in North and South the purple martin comes and goes as a welcome arrival and regretful departure; an always invited avian neighbor. Few are those anywhere who would fail to subscribe heartily to the wish--may its tribe increase.
Spring.--The martin makes its appearance in the United States from late in January on through April. The vanguard of the migratory hosts from South America cross the Gulf of Mexico and make landfall in the South from January 20 (Florida, Howell, 1932) to 29 (Louisiana, Oberholser, 1938). It is, therefore, one of the very earliest migrants.
There is not, however, the marked regularity of appearance that is characteristic of many other northward-bound species. Early February would fit the Florida arrivals, on the average, better than late January. For instance, at Melrose, Fla., the arrival date for 12 years averaged February 9 (Howell).
In the Charleston, S.C., area, Washington's Birthday is about the time to expect this welcome summer resident, though the earliest record is February 6, and Arthur T. Wayne (1910) has also noted them on the 7th and 16th of that month. There are at least three dates for the 16th. Strangely enough, they appear not to reach North Carolina until "the latter part of March, while in most of the state the earliest dates are about the middle of April, with only an occasional March record" (Pearson, Brimley, and Brimley, 1919). In the vicinity of Raleigh, N.C., it has been seen in March but once in 25 years! At Cape May, N.J., the arrival varies from March 27 to May 2, with the great majority of first dates occurring in April, throughout the month (Stone, 1937). In New York and the Hudson Valley, late April sees them arrive (Chapman, 1912), while the species appears in Massachusetts and other parts of New England from April 14 on (Forbush, 1929). Taverner (1934) gives no specific dates for arrival in Canada but mentions in another connection that they arrive "early in spring" and are often caught by unseasonable frosts and cold rains. The spring migration appears to be about parallel in dates across the country; in Minnesota, for instance, the birds sometimes arrive late in March but mostly early in April (Roberts, 1932).
It will be seen, therefore, that the martin moves northward rather leisurely, for a range from late in January to early May would cover the extremes from Florida to the northern portions of the range. April appears to be the time throughout much of the northern half of the whole range across the country. As a general rule, the males arrive in advance of the females and spend the interim in establishing themselves at old nesting boxes, feeding and preening, all these activities being accompanied by a vociferous indulgence in vocal effort.
Nesting.--Before the advent of the white man the martin used natural cavities in trees and cliffs for nesting sites. But even in those distant days there was some bird-house nesting, for the Indians were fond of these birds and, as Wilson (1832) says, "even the solitary Indian seems to have a particular respect for this bird." He gives an account of the methods used by the "Choctaws and Chickasaws" who "cut off all the top branches from a sapling near their cabins, leaving the prongs a foot or two in length, on each of which they hang a gourd, or calabash, properly hollowed out for their convenience." Forbush (1929) adds that "when saplings were not conveniently situated the Indians set up poles, fastened cross-bars to them and hung the gourds on these cross-bars." ***
Instances of strictly primitive nesting are still to be seen in remote parts of the country. Roberts (1932) gives an account of martins breeding among large boulders on Spirit Island, Lake Milles Lacs, Minn. Howell (1932) mentions two or three examples in Florida, one near La Belle and another at Naples. A unique situation came under his observation on Anna Maria Key in May 1918, when he found a pair using a hole in a palmetto piling over water, the cavity being about 3 feet from the surface.
I have seen one instance of primitive nesting in Florida, that of a small colony of about five pairs utilizing a tall, dead pine perforated with woodpecker holes. This tree stands near the banks of the Kissimmee River, near the hamlet of Cornwell, in Highlands County, Fla., and martins were using it late in March 1940. Shown to several participants in the Wildlife Tours undertaken in that region during the early part of 1940 by the Audubon Association, it never failed to elicit the greatest interest. Flickers and bluebirds, as well as a red-bellied woodpecker, were also using this avian apartment house. I have had it reported that martins use the hollows in very old cypresses in some of the large river swamps of South Carolina, along with chimney swifts, which is certainly very likely, though I have not seen this association personally.
Today, the purple martin is unknown to the great majority of people in this country except as a dooryard bird. Its popularity is tremendous, and nesting houses throughout the various states must run into the thousands. It is not a "choosy" species as regards the type of box, for anything from a boy-manufactured cigar-box home to the most elaborate miniature mansion is utilized, and, in the South at least, the martin is as partial to gourds as anything else. The number of rooms in a martin house is simply up to the owner who maintains it; these vary from 1 to 20 or 30 as a rule, but some houses have as many as 200.
After the males have arrived and located themselves, they await the arrival of their consorts, and when they appear mating takes place soon. This may vary by locality, those birds breeding in the southern part of the range not mating so soon as those occupying the northern sectors. The immature birds mate later than the adults anywhere. Both sexes build the nest, and it is a most animated sight when a colony is engaged in such construction. A great deal of vocal effort accompanies it, and the gurgling chatter goes on throughout most of the daylight hours.
Nest material differs rather widely. In most parts of the South, it is often confined simply to grass and leaves. In other localities, twigs, feathers, mud, rags, paper, string, straw, and shreds of bark have been noted. S. F. Rathbun mentions a nest on the water tower of a building in Seattle, Wash., which was "composed entirely of bits of rubber insulation from electric wires; this was lined with pieces of wood." Occasionally, a rim of dirt is placed in front of the nest to keep the eggs from rolling out of the entrance. F. W. Rapp states that he has "seen some of these mounds built up to 2 1/2 inches, while others make hardly any attempt to do so." Both sexes incubate the eggs, the female, however, assuming the greater part of this duty. The incubation period varies with locality apparently, being variously noted as from 12 to 20 days.
Forbush states that only one brood is raised in New England, and this is the case throughout the greater part of the range. It holds for the Carolinas certainly. Audubon (1840) insisted that two broods were raised in his day and that in Louisiana three were brought forth. In coastal South Carolina, though martins are abundant by the end of the first week in March, nest-building does not commence until the last of April, and it is usual that eggs are not laid until the middle of May. Since the birds are not through until early July, there would be time for only one brood.
The usual nesting box is placed upon a pole, the height of which is commonly 15 or 20 feet. Many of the poles are hinged to facilitate cleaning, painting, etc. The measurements recommended are: individual compartments, about 8 by 8 inches; entrance, about 2 inches in diameter and 1 1/2 inches above the floor. The house is placed in fairly open situations. On erection in spring it is well to put up the house as the martins arrive; otherwise it gives English sparrows and starlings opportunity to become established therein. Forbush (1929) gives an instance of a friend of his erecting the house as the martins arrived, and "they were so glad to see it that they could not wait until it was up. While it was going up they flew around it, singing and fluttering about it, and when it was half-way up, they all alighted upon it and rode up with it."
The homing instinct in the martin must be very strong, as the foregoing incident well illustrates. One of the most striking examples of a returning martin colony I ever heard was related to me by Alston Clapp, of Houston, Tex. While in his yard on one occasion he showed me his colony and said that the year previous he had taken down the house to paint it. Something delayed him and it was not up when the martins arrived. Attracted by a great chattering one morning, he went out into the garden and saw the birds fluttering and circling about in the air where the house should have been, at the exact elevation occupied by it when placed!
Elevations vary, of course, some houses being placed much lower (or higher) than others. The lowest I ever saw was a large, rather elaborate house holding a thriving colony in Warrenton, Va. It was only 9 feet from the ground. The primitive nesting site noted by Howell (1932) on Anna Maria Key, Fla. (3 feet), may be regarded as the extreme in low elevation. The highest that has come to my attention is recorded by S. F. Rathbun in Seattle, Wash. Speaking of it he says that "a rather high brick building in the lower business district was surmounted by a tall flagpole capped with a ball. This ball was as a height of about 130 feet above the street. One day when I was watching martins glide above the building one of them flew directly to the ball and disappeared. By the use of a pair of field glasses a check or crack could be seen in the side of the ball, which accounted for the bird's disappearance; it was using the ball as a nesting place. Use of it continued for a number of years, until the ball was replaced by another."
Walter Faxon (1897) records martins nesting on top of street lights in Cambridge, Mass.
Another unusually low nesting site was seen by S. S. Dickey at Seth, a mining village on the Coal River, Boone County, W. Va. He found that some boys had erected crudely made, one-room boxes, 8 to 9 feet above ground, and had painted them brightly, one being red, white, and blue! This same correspondent has also witnessed, as have others, the use of buildings by martins as nesting sites. "While I was in Madison, Wis.," he writes, "I was entertained by several colonies of martins. They were building in cracks in the wooden eaves of business buildings in the city square, facing the capital building."
It is entirely possible that in some residential districts martins are disturbed by the actions of small boys, who are thoughtless enough to cause the birds trouble. For instance, in the case of the low-nesting house in Warrenton, Va., mentioned above, the owner had noticed that the birds used the rooms on the far side of his residence, the yard being "infested" with boys and dogs! Wishing to see more of the birds' activities, he turned the box so these occupied rooms could be seen from his own house, but the martins promptly deserted their already occupied nests and rebuilt in rooms on the far side!
There are, throughout the country, several particularly noteworthy colonies of martins, but one of the best known, as well as a very populous one, is established in Greencastle, Pa. It is hardly correct to say "one," however, for the martin population is spread here and there over town, in many boxes, but, to the citizens, who take great interest and pride in the birds, it is the Greencastle Martin Colony! Those who have never seen it have something in store for them. The outstanding attraction of this colony is the tameness of the birds and the intense interest of the citizens in their welfare. The houses are by no means elaborate, simply plain wooden boxes as a rule, with many compartments. They are at low elevations, about 8 or 9 feet, attached to telephone poles around the square in the heart of the business district, as well as on hotels and stores. The birds seem to prefer the rush and bustle of the retail district rather than the quieter residential sections.
These Greencastle martins go back into history. There are records to show that they have been there since at least 1840. One curious lapse occurred in this long tenure, 10 or 15 years after the Civil War. The martins did not return to Greencastle for nearly 15 years! It was a mystery that has never been completely explained, but G. F. Ziegler (1923), whose article on these birds should be read by everyone interested, considers that the hiatus occurred at the time the English sparrow was most rapidly multiplying and that these two events are connected. Now, however, the martins are again, and have long been, the town's great attraction. The first arrivals appear about the middle of March, and by the second week in April most of the boxes are occupied.
Eggs.--[AUTHOR'S NOTE: The purple martin lays from 3 to 8 eggs, usually 4 or 5; the larger numbers are rare. The eggs vary from ovate to elliptical-ovate. They are pure, dead white and practically without gloss. The measurements of 50 eggs average 24.5 by 17.5 millimeters; the eggs showing the four extremes measure 26.4 by 16.3, 25.4 by 20.3, 22.7 by 16.0, and 24.9 by 15.8.]
Young.--The period of incubation has been recorded by various observers as 12, 13, 15, or even 20 days; probably the normal period is 12 or 13 days. Incubation apparently is performed by the female only, but both parents assist in the feeding and care of the young. Under favorable circumstances two broods are raised in a season; Audubon (1840) says that sometimes three broods are raised in a season in Louisiana.
The young usually remain in the nest 24 to 28 days, but Forbush (1929) says that "the young sometimes remain in the nest for about six weeks. . . . Many of them return to the nest night after night for a week or ten days, especially if the weather be windy and stormy." Of the feeding, he says:
Among the insects brought were some large dragon-flies; some were brought by the wings, and the young bird leaning forward snatched the insect and swallowed it, often with difficulty, leaving the wings in the beak of the parent. Some were held by the body in the beak of the adult bird and were swallowed wings and all by the young bird, though the ends of the wings stuck out of its mouth for some time afterward. In some cases small snails and egg-shells are fed to the young along with their insect food.
Excessive heat and swarming parasites in summer often cause the death of young Martins in the nest, or they are killed by falling to the ground, in their attempts to escape from suffocation or the tormenting parasites in the nest. When a young bird falls to the ground it is soon deserted by its parents, who give up the attempt to preserve its life, and if not killed by the fall it is soon picked up by some cat or other prowler.
Charles Macnamara (1917) writes:
By the first of July most of the doors are crowded with little heads, and the whole front of the house blossoms suddenly with enormous yellow mouths whenever an old bird sweeps in with a beak full of insects. Numerous counts made at different times of the day during the first two weeks of July, 1917, showed that, with remarkable regularity, a parent arrived with food every thirty seconds. This year nine pairs occupied the house, and assuming that each pair had four young, and that they were fed in turn, then each nestling was fed every eighteen minutes. A similar count for a whole day, from 4 a.m. to 8 p.m. cited in Chapman's Handbook of Birds of Eastern North America, when reduced to the same basis as my results, gives a feeding every twenty minutes. . . . As the young grow up, however, they are not fed so often. After the middle of July the pace slackens considerably, and the old birds have more time to sit around on the verandahs and nearby trees, and gossip and scold.
Plumages.--[AUTHOR'S NOTE: The sexes are much alike in the juvenal plumage, except that the young female has the whole top of the head gray, whereas in the young male the forehead only is gray. Dwight (1900) describes the juvenal male as "above, including wings and tail, sooty or clove-brown, the forehead and a nuchal band grayish, the feathers of the head and back indistinctly dull steel-blue. Feathers of the wings with very narrow whitish edgings. Below, white, mouse-gray on chin, throat, breast, sides and tibiae, the feathers of chin, lower breast and abdomen with narrow dusky shaft streaks." This is worn until after the birds leave for the south, where a molt, probably complete, produces a first winter plumage.
In the first winter plumage the sexes are more readily distinguished. The male has acquired considerable steel-blue plumage on the upper parts, is generally darker, and is much like the adult female in coloration, but the chin, throat, breast, and sides are pale gray and the abdomen whitish. The young female is duller, the upper parts less glossed with steel-blue, and the under parts are more extensively white. This plumage is worn, apparently without much change, for practically a year, or until the next postnuptial molt; this complete molt takes place after the birds have gone south and produces the well-known adult plumage of each sex.]
Food.--The whole diet of the purple martin can be fully covered by one word--insects! When that is said, all is said, for that is what the bird subsists upon and nothing else. However, since the same can be said for other birds, some elaboration is necessary in regard to specific kinds of insects. Prof. F. E. L. Beal made an exhaustive study of the martin's food (1918) and found only a few spiders besides true insects. These creatures are so close to insects, however, that, in many minds, they are identical. The Hymenoptera composed the greatest item, amounting to 23 percent, ants and wasps figuring mostly, with a few bees. To accusations that martins destroy honeybees, he had a definite answer that in only 5 out of 200 stomachs did honeybees appear, and every one of them was a drone.
Flies amount to 16 percent of the total food and include some of the house-fly family as well as numerous long-legged tipulids. The Hemiptera, or bugs amounted to 15 percent and included stink bugs, treehoppers, and negro bugs. Beetles composed 12 percent and are represented by May, ground, dung, cotton-boll, and clover weevil beetles. Moths and butterflies were found to some extent. Dragonflies seem general favorites and were found in 65 stomachs, some of which contained nothing else.
In connection with this habit of eating dragonflies, Forbush (1929) states that "adult dragonflies are considered to be useful, as they destroy harmful smaller insects, including mosquitoes, but the young of dragonflies are destructive to small fishes, and this habit may neutralize the beneficial habits of these insects. As Martins are said to feed heavily at times on mosquitoes, their destruction of dragonflies may be immaterial."
He says further that "in some instances a great decrease of mosquitoes is said to have followed the establishment of Martin colonies, but I have had no opportunity to investigate these reports." Certainly, it would be logical to suppose that the area about a thriving martin colony would be freer of mosquitoes than one without these birds. T. S. Roberts (1932), after listing such insect prey as ants, wasps, daddy-long-legs, horse flies and robber flies (which prey on honeybees), bugs, beetles, moths, dragonflies, and spiders, ends with the somewhat remarkable statement that the martin is "rather neutral from an economical standpoint but worthy of protection." He appears to be in an isolated position among most writers, who are entirely commendatory of the martin's economic value. Junius Henderson (1927) quotes some interesting data from Attwater in saying that a quart of wing covers of cucumber beetles were found in one martin nesting-box. Henderson says rather vividly, in comparison with Roberts' opinion above, that since "Martins are very active, requiring a large amount of food, and a considerable part of each insect is indigestible, the number of insects they destroy in order to get sufficient nourishment is 'not only beyond calculation, but almost beyond comprehension.' The food is often compressed into a hard mass, so it is wonderful how much a stomach may contain. The mass of insects contained in a Swallow or Martin would, before compression, equal or exceed the bulk of the bird's body."
Audubon (1840) says little of the martin's food, mentioning only that "large beetles" figure in it, and that the birds "seldom seize the honey-bee." Alexander Wilson (1831) devotes more space to this phase and states that he "never met with more than one man who disliked martins and would not permit them to settle near his house. This was a penurious close-fisted German, who hated them because, as he said, 'they eat his peas.' I told him he must certainly be mistaken, as I never knew an instance of martins eating peas; but he replied with coolness, that he had many times seen them himself 'playing near the hife; and going schnip, schnap' by which I understood that it was his bees that had been the sufferers; and the charge could not be denied!"
Relative to the enormous numbers of insects destroyed by this species, as well as the assiduous care of the young in providing them with food, is the now classic example given by Widmann (1884). He watched a colony of 16 pairs of these birds from 4 a.m. to 8 p.m. and during that time the parents came to the young 3,277 times, or an average of 205 times for each pair. The females made 1,823 visits, the males 1,454.
John A. Farley (1901b) records that about the cranberry bogs of Plymouth and Barnstable, Mass., the martin devours numbers of the imagoes of the fireworm (Rhopobata vacciniana), which is a highly beneficial act, since cranberry growers estimate that over a term of years, they lose 50 percent of their crops by insects, chiefly the fireworm.
F. L. Farley writes from Camrose, Alberta, that martins are very fond of bits of eggshells, so much so that "they are as crazy for these shells as are cedar waxwings for ripe fruit." He continues: "Mrs. Farley saves most of her eggshells for one of our friends who has about 30 pairs of martins nesting. He just breaks them up and throws them down on the ground under his boxes and before he reaches the house there are numbers of martins on the ground, feeding on them and even taking bits up to the young. The first time it was noted that martins liked shells was when a man saw them holding on to a stucco house and pulling away at oystershells that were protruding from the cement. The party told me he tried to feed them eggshells at once, and from that time on all the martin men in town have been doing this." No doubt it was the lime that attracted the birds. Farley adds the interesting item that "our purple matins have increased now (1939) to more than 200 pairs in our little town, from a single pair that nested here in 1918."
The food is, of course, procured mostly on the wing and in the usual swallow fashion of darting, swooping, and wheeling in erratic flight, but graceful in the extreme. Sometimes, late in the afternoon, or early in the morning, martins skim the surfaces of ponds and rivers, dipping down expertly for drinks. Occasionally they pick up food from the ground by walking about. In any summation of the martin's food habits and economic value Taverner's (1934) statement is eminently fitting. Under the heading "Economic Status" he says: "The Martin like the other swallows is a bird with no bad habits, and with so many good ones that every effort should be made to aid its increase." Here is no betwixt and between statement, but a straight declaration of a fact that should be apparent to every student of this valuable species.
Behavior.--The purple martin essentially typifies the grace that makes the swallows famous. Beautifully proportioned, trim, and streamlined, it looks like a miniature plane as it sails overhead on outstretched, sable wings. Master of the air, as are all the family, it is not so spectacular in aerial evolutions as are some much larger birds, but this is by no reason of inability. Because of its small size much of its performance aloft is not easy to see and watch, as with a bird of larger wing expanse. Martins do not usually fly at a great speed but are perfectly capable of such at need. Any bird that catches such swift insects as dragonflies must, of necessity, be a finished flier. Feeding is accomplished largely on the wing, but martins can and do resort to the ground at times, where they feed on ants and other terrestrial insects.
Francis H. Allen says that the "flight consists of a rapid flapping of wings, alternating with periods of sailing, either in a straight line or in a long, sweeping curve or arc. The bird often flies high, and his mellow, staccato song can be heard distinctly when the singer is hard to find in an expanse of sky."
Witmer Stone (1937) gives a graphic picture of the martin's flight as follows:
The martin on the wing is deserving of careful study: a glorified swallow. . . . His flight is at all times a wonderfully graceful performance. I stood on the edge of the meadows, one day in June, while twelve males were skimming the tops of the salt grass, tilting now to this side now to that to maintain balance in the air. Now one of them turns in his course and passes close to my head, swift as an arrow and uncanny in his blackness, which has no relieving spot of white, not even on the belly. . . . His call uttered either in greeting or in protest as he passes is a harsh 'zhupe, zhupe.' Again he will mount upward with rapid strokes of his narrow pointed wings only to return again to the lower level on a long sloping sail. Sometimes at the very summit of the ascent he will come about into the wind and remain stationary, on rapidly beating wings, before sliding away on the long downward sail. When flying high over the town, late in the summer, the Martins' mastery of the air is particularly noticeable. They come in against the wind on set wings like small three-cornered kites, steadying themselves now and then with two or three short wingbeats, and then, apparently tiring of this sport, they will drop through considerable distances and, flapping rapidly, regain their former altitude. While Martins flying low over the meadows are undoubtedly engaged in seeking food, many of their aerial evolutions, like those of other expert fliers, seem to be for the sheer joy of flight. . . . I watched a single Martin associated with a band of Swifts maintaining a position directly over Congress Hall hotel, in the face of a strong south wind, for at least half an hour. The birds would often remain absolutely stationary in the air for several minutes at a time, evidently supported by the upward currents of air deflected by the walls of the building. Here was no search for food but some sort of enjoyment or play.
While at rest the martin sits rather erectly and with an alert carriage, often uttering the characteristic note of contentment. Preening occupies considerable time, and several may be engaged in this at once, offering a never-ending variety of poses. They are fond of bathing and often do so on the wing. Audubon (1840) describes this process unusually well: "They are very expert at bathing and drinking while on the wing, when over a large lake or river, giving a sudden motion to the hind part of the body, as it comes into contact with the water, thus dipping themselves in it, and then rising and shaking their body, like a water spaniel, to throw off the water."
The behavior of martins in storms has been commented upon by early and recent writers. Audubon says:
The power of flight possessed by these birds can be best ascertained. . .when they encounter a violent storm of wind. They meet the gust, and appear to slide along the edge of it. . . . The foremost front the storm with pertinacity, ascending or plunging along the skirts of the opposing currents, and entering their undulating recesses, as if determined to force their way through. . .all huddled together in such compact masses as to appear like a black spot. Not a twitter is then to be heard from them by the spectator below; but the instant the farther edge of the current is doubled, they relax their efforts, to refresh themselves, and twitter in united accord, as if congratulating each other on the successful issue of the contest.
S. F. Rathbun writes that on the night of August 1, 1931, at Seattle, Wash., "not long after midnight there was a heavy thunderstorm with a rather strong wind. I arose to close a window that faced the storm, and the outdoors showed a pitchy darkness. To my surprise, I heard the calls of martins, and for a short time whenever there were flashes of lightning I could see a number of these birds playing in the air in advance of the dark clouds. The martins drifted by with the storm, which was only of short duration."
The purple martin is a fearless bird in defending its territory. This characteristic has been noted for as long as man has had to do with the species and accounts for his original desire to have the birds as neighbors. The Indians and later the Negroes both induced martins to nest about their wigwams and cabins because of their readiness to drive away any winged intruder that might attack poultry. Crows, hawks, eagles, and vultures are quickly set upon and driven away, the whole colony combining in a mass attack that rapidly puts the invader to rout. Wilson (1831) says that the martin "also bestows an occasional bastinading on the king bird when he finds him too near his premises; though he will, at any time instantly cooperate with him in attacking the common enemy."
Another trait of the martin that has long attracted attention and produced much writing is its communal roosting habit late in summer, when the species gathers in great flocks preparatory to and during migration. Concentrations up to 100,000 birds have been noted, and the attendant noise sometimes results in such a nuisance to people that direct efforts are made against the birds and many killed through various methods. To some degree these roosts are a parallel to those of the vanished passenger pigeon in that branches of trees are broken by the weight of the birds and, as Arthur T. Wayne (1910) puts it, "the noise produced by such a multitude resembled the sound of escaping steam." In 1905 a huge roost at Wrightsville Beach (near Wilmington), N.C., was attacked by irate citizens and 8,000 to 15,000 birds were killed. The North Carolina Audubon Society succeeded in convicting 12 of the offenders, who were fined.
G. Clyde Fisher (1907) describes a roost near Quincy, Fla., which he estimated to contain 5,000 birds and, like Wayne, was impressed with the noise, which he also described as being "much like escaping steam."
A typical roost, and a very well known one, was that at Cape May, N.J., written of in detail by Witmer Stone (1937). Students should peruse his account with great interest. It is too long to quote here, and since 1936 the roost has been deserted not only by martins but by robins, starlings, and grackles. However, it may sometime again be instituted, and extracts of Stone's account are given herewith:
For many years it [the roost] was located on the Physick property on the principal street of the town. Here there is a grove of silver maples about thirty feet in height and covering an area of some two acres, growing so close together that their tops join one another, making a dense canopy with constant shade. . . . Were it not for this roost, the only one in South Jersey so far as I know, Martin history at Cape May would come to a close early in August when the last of the fledglings become self dependent and sail away with their parents. But as it is, though there may be many days in August when practically no martins are to be found for miles around Cape May from sunrise to sunset, they will gather in ever increasing numbers to pass the night in this small grove which, so far as our eyes can detect, offers no advantages over hundreds of similar groves past which the birds must have flown. It would seem that most of these Martins must have come from areas far to the north of New Jersey, as the local breeding Martins could not have yielded such a crop of young. I estimate that there are not more than fifty pairs of birds in Cape May and perhaps twice that number elsewhere in the peninsula and these hundred and fifty pairs could not produce more than six hundred offspring, making some nine hundred Martins in all, and yet at least 15,000 of the birds come to Cape May every night to roost. In the New York area, including northern New Jersey, Ludlow Griscom states that the Martin colonies are very locally distributed and that the birds are rare as transients, which further complicates the question of where our Martins come from! Another fact of interest is that on July 23, 1926, before any of the young had left the Cape May nesting boxes one thousand Martins had already assembled at the roost.
Later in Stone's account of this same roost he says that while the birds gather together and settle on the twigs of the trees for the night "their calls produced a constant twittering like escaping steam, now swelling loudly and then dying away again." The italics are mine, this being the third author to refer to escaping steam!
Voice.--Though unable to lay any claim to being a musician, and therefore incompetent to judge music, I cannot but feel some slight resentment toward writers who characterize the voice of the martin as "unmusical." True, some of the notes are such, but there are many others that are decidedly pleasing. All writers seem to agree that on the whole the vocal efforts of the species are "pleasing," which, in itself, denotes that they are musical rather than otherwise.
Certainly, they are pleasing. This fact has undoubtedly a great deal to do with the attraction of a martin colony about one's home. People generally enjoy hearing them. The bird has no specific "song," such as many species possess, but the varied medley of notes has a definite quality of imparting satisfaction and enjoyment to human ears.
The outstanding impression always left upon me is that of contentment. In few birds is this so typified. The gurgling chatter of a group about its nesting box gives one the complete assurance that, so far as the martins are concerned, "all's well with the world!" There is a restfulness about the notes that is distinctly relaxing; they can be listened to at a time when a person is reclining on a porch in an easy chair in springtime and fit perfectly with the droning of bees about a flowering vine, the sighing of a breeze through moss-hung oaks, and the distant calling of willets over the salt marshes. The notes of the martins simply "fit" a spring and summer picture, and while such a description may be exactly what a nonmusical ear would produce in words, i.e., very inadequate, it is certainly something of a tribute to the birds!
As has been so often and rightly said, it is difficult, not to say impossible, to render any idea of a bird's notes by written words. Yet that is about the only way to be specific, and while one's own interpretation may differ from another's, it continues to be done, and has to be. In the case of the martin, Audubon (1840) did not attempt a word translation. He simply says that "the note of the martin is not melodious, but it is nevertheless very pleasing." Wilson (1831) went farther and produced the following: "Loud musical 'peuo, peuo, peuo'." Forbush (1929) quotes W. M. Tyler as describing a "loud, rich chirrupping." Many authors describe some of the lower notes as "guttural," which is accurate enough. The alarm note is stated by Tyler as "kerp," and he adds a "low-toned 'kroop' song and several throaty notes followed by a spluttering trill."
Francis H. Allen says that the "call notes uttered in flight are a low, mellow but somewhat husky chip; a ye(r)p, and a kew." The similarity between Tyler's kerp and Allen's ye(r)p is at once apparent, and this note can hardly be described in a better way.
S. S. Dickey has this to say: "Purple martins, which scarcely can be called songsters, usually utter loud, penetrative twitterings. They give vent to exclamations of singular delight." This last is a rather happy expression and fits my idea exactly! He adds that "as the nesting season advances they, by spells, break almost into song; spick-spack-spitter-spee-spack are the syllables. When troubled by English sparrows, bluebirds, and starlings, they swoop in downward curves in pursuit of the nuisances, and utter buzzing sounds as spiz-spiz-spiz." Dickey concludes with the statement that these "outcries are not to be confused with those of any other swallow. The utterances have a character of their own, and it is good to hear them if you chance to be one fond of past association and summer excursions." One can easily subscribe to the last thought; it at once brings to mind a dreamy summer afternoon in the side yard, but some of Dickey's "sp" interpretations are rather difficult to follow. Evidently this sound has impressed him considerably, for he uses it consistently.
During the great gatherings at roosts late in summer the birds are extremely vociferous, and their notes at such times have been likened to "escaping steam" by some authors. This imparts a rather hissing impression that is certainly characteristic of these communal gatherings, but the simile leaves one a little cold. At such times the vocal efforts of the birds are neither musical nor pleasing and often result in becoming a nuisance because of monotony and volume.
While the martin is not, in any sense, nocturnal, its notes are sometimes heard after dark. One such instance is recorded by Abby F. C. Bates, of Waterville, Maine (1901). She heard martins plainly about 10 p.m. on the moonlight night of August 8, 1900. Mr. Bates heard martins on June 15, 1930, between 2 and 3 a.m. as he was returning home from a late train. These auditors seem to consider this a highly unusual thing, but in the South I have frequently heard martins at night. I once lived across the street in Charleston from a friend who maintained a large martin colony, while just over the back fence was another. I recall hearing the birds now and then, but I never made any series of observations or records of it. However, on looking up my notes under this species, I do find the following: "heard martins 'singing' in E. A. Williams' bird-house at 11 p.m. tonight." This entry was under date of May 1, 1933. These night notes are of a lazy, sleepy character, which one might expect from birds aroused by some slight disturbance. In no case have I ever heard them in an alarmed or excited nature, simply a low chuckle, or gurgle, indicative of restlessness or temporary wakefulness.
Enemies.--The enemies of the purple martin appear to be confined to a few other birds and the weather. Certainly man is extraordinarily absent as such unless the occasional outbursts of impatience at the roosts can be so construed. Though in so many cases man is Enemy No. 1 to bird life, this is a happy exception indeed.
The natural enemies of this species are those importations among avian circles, the English sparrow and the starling. Bluebirds have been listed as enemies in that they sometimes compete for nesting boxes, but it is difficult to conceive of a bluebird being an "enemy" of anything, and such interference is inconsequential. However, that the sparrow and starling are, is beyond all doubt. Both of these interlopers cause endless trouble to martins and human friends of the latter who dislike to see their favorites usurped. I often have questions put to me as to how to get rid of them!
The quarrelsome dispositions of these trouble-makers are too well known for elaboration. There are instances by the legion where they have appropriated nesting boxes. Specifically, J. K. Jensen, of Wahpeton, N. Dak. (1918), mentions that in that area English sparrows entered the compartments of a martin colony freely and destroyed so many eggs that few of the swallows could be raised. Many others in various parts of the country have seen similar occurrences.
The rapid spread of the starling southward and westward has resulted in its becoming pretty much Enemy No. 2. Its larger size and even more efficient methods make it as much if not a greater menace. Various means are resorted to in attempting to drive out these invaders such as shooting, noises, water-cures, etc., but it is often hard to make an impression, and more than one martin colony has been lost.
Adverse weather bulks rather largely in a martin's life at times. Martins are very susceptible to cold, and unseasonable spells of it play havoc with them. After a cold spell has depleted a colony, it is usually a long while before they return to that locality. It is, of course, a lack of food supply as well as the weather itself that reacts detrimentally on the birds in these cases. An insectivorous bird's digestion is very rapid and demands that it be more or less constantly eating, and two or three days of severe cold so eliminates insects that starvation not infrequently occurs. These spells sometimes take place as late as mid-April.
In the Charleston area, where I have lived all my life, sudden cold, which is very rare in spring, sometimes affects the martins. My old friend Arthur T. Wayne (1910) states that he has known the species to be affected seriously only once. He says that "on Tuesday morning, February 14, 1899, the temperature registered 6 above zero at Charleston. . .followed again by a very severe cold wave accompanied by snow. . . . On April 14 and 15, 1907, however, large numbers died from cold and starvation during the prevalence of gales and cold weather." One of these spells provided Wayne with a very beautiful albinistic specimen of this species, which he found dead under his "swallowhouse" as he invariably called it.
Rains, cold ones and even protracted ones in warm weather, occasionally wreak havoc. F. B. Horton, of Brattleboro, Vt. (1903), writes that in June 1903 long rains resulted in the death of 30 young and 2 adults in a colony there. The remaining martins deserted the place leaving 12 unhatched eggs.
Forbush (1929) quotes Dr. Brewer as describing a cold rain spell that eliminated martins in "eastern Massachusetts" and as a result none have returned there "to this day." The rain of June 1903 mentioned in the Horton note above extended into Massachusetts and is mentioned also by Forbush, who says that it destroyed "most of the Martins in Massachusetts and contiguous parts of New England." He brings out the fact that when martins do come back after such a spell to the locality they find their houses occupied by English sparrows. He also adds that excessive heat and vermin constitute enemies of this species. The latter at all times kill the young birds outright. Heat, in the restricted space of a martin house, utterly exposed to the sun as it is, must be a factor certainly. One would think it unbearable at times. Forbush (1929) states that the "parents have a habit of collecting many green leaves and placing them in the nest, a practice which may tend by evaporation to reduce the heat." This is a very interesting observation and one that has been made also by P. A. Taverner (1933).
Apparently there is rather little specific data on migration casualties, but there is little doubt that such occur. Wintering in South America, the northward migration of the birds is very deliberate, as has been pointed out, covering the time from late January until into June. Thus, there are perhaps less mass movements over the Gulf of Mexico than are true of other birds, and it follows that casualties would be fewer, but bad weather over that body of water must result in the loss of some. Lighthouse victims do not figure largely.
S. S. Dickey writes that in his observation "screech owls are the worst foe" of martins. He states that he "made it a practice to frequent the vicinity of occupied boxes well into the night, and every once in a while a screech owl would come shadowlike, alight for a moment on the runway or porch of a bird-house, then begin a scrambling kind of noise. By the use of a strong flashlight I was enabled to get some conception of how Asio performs his pillaging. He peers intently into an occupied room, then leans sideways, lifts his face skyward, and reaches as far as he possibly can with one leg into the orifice. Shortly he creates consternation. The squeals of the inmates resound. He brings forth squirming birds. With the prey in his talons, he flits to the nearest tree or shed roof, there to devour his bill-of-fare. I have known him to continue such ravages for an hour at least, taking as many as a half dozen martins to appease his ravenous appetite."
Fall.--The martin is an early migrant. Sometimes the roosting habit of late summer is noted on the part of certain birds before young have left the nest boxes. Stone (1937) mentions this, and again speaks of barren or nonbreeding birds "roosting" as early as June 25. After the young have flown the southward movement really takes place. This seems to be very general over much of the martin's range. Forbush (1929) gives September 30 as the latest date for New England. F. M. Chapman (1912) gives departure dates from Cambridge, Mass., as August 25; Ohio, September 5; Illinois, September 10; Minnesota (SE.), September 9. In Michigan, Barrows (1912) states that "it is one of the first of our swallows to move southward in autumn, usually disappearing about the middle of August and rarely seen as late as September 1." The migration in New Mexico is even earlier, Mrs. Bailey (1928) stating that "only stragglers being left after the first week in August." At Cape May, N.J., that great funnel point of migration, Stone (1937) has noted the last individuals from September 3 to 15 over a long period. About Charleston, S.C., the last martins are seen approximately at the same time, though a marked reduction in the numbers of the species occurs from mid-July on, when many begin to migrate.
Proceeding southward, the last ones leaving Florida are recorded by Howell (1932) as from late September to October 2 about Pensacola and Tallahassee, while down in the Keys, at the jumping-off place, they were noted at Sombrero Key on October 6. A rather late flight was recorded at St. Marks (south of Tallahassee on the Gulf) on November 10, 1912. Again, in another November flight, Howell states that Mrs. Hiram Byrd saw "great flocks of swallows over the glades" on the 11th, of which "some were Martins." A flight seen by this observer on November 4 was described by Howell as being "between Royal Palm Hammock and Homestead." Here again Howell confuses Royal Palm Hammock with Royal Palm Park, the latter being Paradise Key in Dade County, while the former lies across the Tamiami Trail in Collier County, an hundred miles or so to the westward. Though in this case he says "hammock," he means "park" for he quotes Mrs. Byrd as saying that the martins were "circling over a glade at the edge of the Park." She estimated this flock to cover 9 miles of territory and to contain "anywhere from a hundred thousand to a million or more."
H. W. Ballantine noted three birds at Orlando on December 18, 1915, which Howell says "may be considered wintering birds." This is a parallel case to his statement that gray kingbirds must sometime winter in Florida because of a single specimen seen in Royal Palm Park in December. Rather it would appear that, like the kingbird, these three martins at Orlando were belated migrants, for in six years of constant field work in southern Florida I have never seen a single specimen, not even in the Keys. It is my confirmed belief that the birds leave the country entirely, and there is nothing to offset this except the single exception of the December Orlando birds above, if that can be considered an exception. Oberholser (1938) gives the departure date (latest) from Louisiana as October 22. Definite knowledge of its winter home in Brazil has resulted from banding, and Lincoln (1939) gives an example of a specimen "found" in December 1936 (the same month in which the Orlando "wintering" birds were seen) near Ttaituba, Para, Brazil, which had been banded at Winona, Minn., on May 30, 1934.
Thus, it will be seen that the autumnal migration of the martin
is almost as leisurely a matter as is the spring movement. It
covers a rather long period.
Purple Martin* Progne subis
*Original Source: Bent, Arthur Cleveland. 1942. Smithsonian Institution United States National Museum Bulletin 179: 489-508. United States Government Printing Office