Читать книгу Life Histories of North American Jays, Crows, and Titmice - Arthur Cleveland Bent - Страница 39
HABITS
ОглавлениеSome birds are so thoroughly typical of certain habitats that one looks for them almost automatically when passing through such places. Perhaps of no species is this more true than the Florida jay. Indeed, so true is it that the local term for the habitat is applied to the bird itself, and thus we have the “scrub jay,” the universal name of the species in Florida.
No visitor to that fascinating State can have failed to notice the topographical divisions that distinguish it, and the “scrub” is essentially Floridian. The scrub consists, according to Arthur H. Howell (1932), of a type of vegetation peculiar to Florida that occupies scattered areas of whitish sand in the lake region, a narrow strip along the east coast, and smaller tracts on the west coast from Manatee County south to Collier County. The characteristic plants of the scrub are the sand pine (Pinus clausa) and shrubby oaks of several species (Quercus myrtifolia, Q. geminata, Q. catesbaei). These oaks, with saw palmetto and rosemary (Ceratiola ericoides), form dense and almost impenetrable thickets.
Proceeding south from Jacksonville one encounters the scrub just south of St. Augustine on the seacoast. Along the Ocean Shore Boulevard the great stretches of saw palmetto behind the dunes of the sea beach reach away illimitably in front of the car.
Here and there roadside signs, advocating the advantages of hotels, camps, and fishing guides, rear themselves above the gray-green fronds, and on these structures, as well as on the lines of telephone wires, one is almost certain to see that characteristic blue and gray dweller of the low growth perched in plain view of pedestrian or motorist, its crestless head and long tail in sharp silhouette against the sky. As many as two dozen “scrub jays” may be seen between St. Augustine and Daytona Beach any day from a speeding car, as an introduction to Florida’s thrilling bird life.
Yet, a person could very well spend a lifetime in Florida and never see a single specimen of this bird. It is so partial to the type of vegetation it inhabits that it is utterly useless to look for it anywhere else. In former years it was possible to meet with it almost from the State line at the St. Marys River, southward along the entire east coast, but this is the case no longer. There has been a gradual recession of the range to the north and south of Jacksonville probably because of the elimination of the typical habitat—as S. A. Grimes (MS.) says “to make room for beach houses.” This recession is to be noted in even short periods of time, for, as he adds, “the northern limit of the range has receded 20 odd miles within the past year (1939-40). I am no longer able to find a single jay in Duval or northern St. Johns Counties. Ten years ago there were five or six pairs in Duval County.”
The present northern limit of the bird’s distribution, therefore, is St. Augustine on the east coast. From that point southward along the coastal scrub it is quite common. There is considerable scrub on Merritts Island south of New Smyrna, and Hugo H. Schroder (MS.) states that he has “found more of these birds on Merritts Island than anywhere else in the State.” The narrow scrub area between the Indian River and the tracks of the Florida East Coast Railway is doubtless the best part of the State (including Merritts Island) for the visitor to study this interesting species. Quoting Schroder again, “Florida jays are quite numerous south of Indian River City between the highway (U. S. No. 1) and the railway tracks.” In my monthly trips to Florida throughout the year, with the exception of midsummer, I have found this to be invariably true. However, in 6 years of intensive field work on the Kissimmee Prairie I have yet to see a single specimen. This is strange, as much of that country seems well suited to their needs and inclinations. Nevertheless, they do not occur there. Records exist only in one area about Lake Okeechobee, that of the Fish-eating Creek section in Glades County on the west side of the Lake. On the east coast, this jay is found as far south as Miami, Dade County, but stops at about that point. Many observers have not noted them that far. The southernmost record comes from what was once known as Rockdale, a station on the Florida East Coast Railway, 10 or 12 miles south of Miami (Howell, 1932).
On the west coast, doubtless because of the abundant mangroves and scanty scrub, it occurs only as far south as Naples, Collier County, according to all records but one. This one, representing the southernmost point of the west coast, is an observation by Edward J. Reimann, a former Audubon warden of the Southwest Coastal Patrol. He writes me that on nearly 2 years’ duty in the field from Fort Myers to Cape Sable he saw the Florida jay but once, and that was on Marco Island (Collier County) on October 27, 1936. Marco is about 15 miles south of Naples. Concerning this occurrence he states: “I saw this individual near the cemetery on the north end of the island and am inclined to believe it was a straggler. I searched the same locale numbers of times and also the piny woods a great deal, with the sole purpose of digging up resident birds. Near Caxambas (southern end of Marco) are wonderful live-oak thickets where I hunted them to no avail.”
Here and there throughout Florida in suitable areas, inland as well as coastal (some in the very middle of the State), one can find this species up to Gainesville (interior) and Pine Point (west coast) just to the north of the mouth of the Suwannee River. It does not occur at all in the western “handle” of Florida. It is also absent from the open Everglades as well as the Kissimmee Prairie—Lake Okeechobee region. It has been noted sparingly in the Big Cypress Everglades about the village of Immokalee.
There are no records of this jay outside of Florida. I can find but one instance of a sight record beyond the confines of that State and that is considered unreliable by contemporary and present ornithologists. Not only is this jay confined to Florida exclusively, but very definitely to certain portions of that State.
Courtship.—Nothing in the literature I have seen throws any light on the courtship of coerulescens. Even those who live in its range and know the bird intimately say nothing about it. Personally, I have seen no evidence of it, and cannot speak from experience. S. A. Grimes, of Jacksonville, who knows the bird as well as any ornithologist living, states that it is his belief that pairs remain mated throughout the year. This is very probably the case and would account to a large degree for the lack of any literature on this phase of the bird’s habits.
Nesting.—The Florida jay is gregarious in its nesting habits to the extent of gathering in small, scattered colonies. Perhaps half a dozen pairs will sometimes occupy a tract of scrub of limited extent, but again a nest may be found at some distance from any other pair.
Material is usually the same in all cases, viz, oak twigs of varying shapes and thickness, formed into a substantial, thick-walled cup lined with fine rootlets. It is much like the nest of the blue jay (Cyanocitta cristata) in appearance and structure but, unlike that species, does not occupy such elevation, for it is usually constructed at 4 to 12 feet above ground. Probably a high Florida jay nest would be about at the elevation of a low blue jay’s. Necessarily, it is rather limited in the choice of a site because of the sameness of the scrub, but the myrtle (Myrica cerifera), sand pine (Pinus clausa), and various oaks (Quercus) are the shrubs and trees most used. S. A. Grimes (MS.) states that the wild olive (Osmanthus) “seems to be the favorite site, for it affords the best cover. It is a thick-branched and densely foliaged plant when the dune vegetation is in the ‘scrub-jay stage’.”
The seasonal range of nesting is extensive, a characteristic of many of the Florida forms, and this jay may be found any time between late March and late May, with eggs. Strange discrepancies in dates may be noted in the same locality, fresh eggs being possible in a nearly 2 months’ range of time.
Both parents are assiduous in all domestic duties. Grimes (MS.), who has paid much attention to the scrub jay, writes that “both gather nest material and work it into the nest; both incubate; both brood; both feed and attend the young in and out of the nest. I have seen the adults swallow the cloacal sacs of the nestlings and at other times carry them away and drop them. The female probably does the greater part of the incubating, but the male sees to it that she does not want for food while she is so engaged.”
Incubation occupies a little more than 2 weeks, 15 to 17 days. Again quoting from Grimes’ notes: “One nest that I kept under observation was in use 45 days, including the ten it was under construction. The last egg in this set of five was laid on April 1, and the three eggs that hatched did so in the night of April 16-17. The young left the nest on May 5.”
One interesting fact noted by Grimes in the northern limit of the range (Duval County) is that there is always a percentage of unhatched eggs. “In fact,” he writes, “I have never known all the eggs to hatch in a set of scrub jay. If that condition is general, it must indicate some form of decadence in the species. Perhaps it is a normal condition at a border extremity of range, due to inbreeding.”
In his comments on the recession of this jay’s range from its former northern limit about Jacksonville in the past few years, Grimes has noted another unusual condition. “When the Florida jays,” he says, “were down to the last five or six individuals here, for two successive seasons I found three birds attending one nest. Two were males. Even so, in the nest that I followed up, only two eggs out of four hatched.”
Though evincing tameness to a degree at times, under almost any conditions, the Florida jay is particularly indifferent to human beings about its nest. Its behavior under these circumstances is often remarkable. When investigating a nesting coerulescens, one is reminded strongly of the primitive unconcern displayed by the noddy (Anous stolidus) on the Dry Tortugas. It is quite possible to handle the bird freely, and in certain cases there is not even an attempt made to peck at the intruder. Neighboring birds occasionally show more concern than the sitting individual!
Well illustrative of this trait are some interesting notes sent to me by Hugo H. Schroder (MS.), who says that on “April 25, 1932, I found a female on nest in scrub oak and vines about 5 feet up, in Orange County, northwest of Orlando. She remained while vines were opened so nest and occupants could be photographed, and she allowed herself to be picked up and placed in a different position whenever we desired her to be in a better pose; she uttered no protest and made no attempt to bite when picked up. Even when she hopped from the nest she allowed us to replace her, when she remained. The male came to scold while we were handling his mate, and once he came within a foot of my head. A number of neighboring jays added their voices of protest and one of these allowed me to reach within a foot of his body without moving away.
“May 3. Same nest, two young nearly ready to leave. Female allowed herself to be handled but did make a weak attempt to peck at my finger. One of the youngsters wanted to leave the nest, and I held him down while a photo was made; the female was perched on the other side of the nest at the time, her feathers puffed out a little but otherwise giving no sign of resenting the effort to restrain her youngster. Several times when I picked her up she uttered a very soft, low-pitched sort of song.”
The Florida jay sometimes shows a decided preference for the nest even after the young have left. Both adults and young return to it for varying periods, and observations on this trait should be more extensive. An interesting instance is furnished by Wilbur F. Smith (MS.), who has had 9 years of experience with this jay near Englewood, Fla., on the lower west coast. He says: “My most thrilling experience with it was about four years ago when a pair built their nest in a hedge of Cherokee roses in a friend’s yard. The nest was placed well in the middle of the hedge where light conditions prevented a picture. Three young birds hatched, and when they were about grown I took a friend to see them. We found the nest empty and no birds in sight, though the young had been in the nest the day before. The old birds had been fed all winter and were very tame. The owner of the place had left for his Kansas home, and no doubt the jays missed the daily supply of food, so it was not so surprising that one of them appeared on a wire above us, looked down expectantly, and dropped to proffered food in an outstretched hand. Then the other bird (adult) appeared, and on looking again at the nest we found that two of the young had climbed through the vines and were sitting on the edge of it, while the third was nearby.
“One of the old birds went to the nest with the young and resented my trying to so part the vines as to let light in for a picture. So I braved its displeasure by bringing the nest forward about 2 feet to the outside of the hedge on the chance of the birds following. The inclosed photo shows both birds sitting on the nest in the changed position and one of them taking food from the hand, when we stood, without any effort at concealment, about 3 feet away. We ran out of film, when the nest was returned to its old site, and before we left two young had climbed back into it.”
Eggs.—According to Bendire (1895), “the eggs of the Florida Jay range from three to five in number, and their ground color varies from pea green to pale glaucous green. They are blotched and spotted with irregularly shaped markings of cinnamon rufous and vinaceous cinnamon, these being generally heaviest about the larger end of the egg. They are usually ovate in shape, though an occasional set may be called elongate ovate; the shell is smooth and compact, and shows but little gloss.”
The measurements of 46 eggs average 27.5 by 20.3 millimeters; the eggs showing the four extremes measure 30.8 by 20.6, 26.9 by 21.3, 24.6 by 20.1, and 27.0 by 18.6 millimeters.
Plumages.—Immature Florida jays are much like the adults in appearance, but the colors are duller, with less blue on the breast, and the top of the head is lighter. The sexes are alike in all plumages.
Food.—The Florida jay maintains the family tradition for a rather wide choice of food, deserving the term omnivorous, but leaning toward selections of animal matter to an extent of somewhat more than 60 percent. The tendency of this bird to become familiar with humanity and accept its offerings leads to the inclusion of many items that would not otherwise appear, notably such food as bread, cake, and peanuts, which are invariably accepted with apparent avidity. Any such food, however, is highly artificial in nature and should not enter strictly into any summary of normal consumption. So strongly has the bird become entrenched in many parts of its range as a semidomestic species that these items are mentioned because of their frequent offering and equally accepted status.
Dr. Clarence Cottam, of the U. S. Fish and Wildlife Service, has kindly furnished me with a detailed account of the stomach findings of 16 specimens of coerulescens taken in January, March, April, May, and September. The conclusions from this study reveal that the food is: “Animal matter 60.63 percent, plant matter 39.37 percent, gravel 6.38 percent, trace of feathers.” The breakdown of the above is worthy of note. Though the exact percentages are not given, the findings include the remains of grasshoppers, locusts, crickets, termites, burrower-bugs, squash bugs, leafhoppers, earwigs, beetles, weevils, butterflies, moths, caterpillars, cutworms, bees, wasps, ants, anglewings, flies, millipeds, and centipedes. Also included were spiders, scorpions, ticks, mites, mollusks, snails, turtles, frogs, and lizards. Vegetable matter was represented by wheat (Triticum), crowfoot grass (Dactyloctenium aegyptium), acorns (Quercus), purslane (Portulaca), milkwort (Polygala), huckleberry (Gaylussacia), blueberry, cranberry (Vaccinium), and fogfruit (Lippia). Portions of vegetable debris and indeterminate matter (mast?) and wood pulp were also present.
Audubon (1842) states that the seeds of the saw palmetto are a favorite food, so much so, indeed, that “no sooner have the seeds of that plant become black, or fully ripe, than the Florida jay makes them almost its sole food for a time.” He adds that the method of feeding is like that of the blue jay, for coerulescens “secures its food between its feet, and breaks it into pieces before swallowing it, particularly the acorns of the live oak, and the snails which it picks up among the sword palmetto.” Nuttall (1832) also gives the seeds of the saw palmetto as being eaten “largely.”
Bendire (1895) adds another item in his summary of the food as “offal.” He also mentions wood ticks specifically, as does Maynard (1896), the latter stating that “upon examining the contents of its stomach, found that it was filled with ticks or jiggers which infest the skin of all quadrupeds in this section of Florida.” These references to ticks substantiate, without saying so, of course, the observations of N. B. Moore on the habit of this jay of alighting on the backs of cattle and securing ticks in that manner. “Jigger” is the universal name of the red-bug in the southeast, an even worst pest than ticks in many ways.
Another food habit of this jay, not hitherto mentioned and something of an indictment against the bird, is its fondness for the eggs and young of other birds, and even of poultry. Just how much this is indulged in does not seem clear, but there is certainly abundant evidence that predation of the sort occurs. Bendire (1895) states that this jay is “charged with being very destructive” in this way. A writer whose name I am unable to determine, but whose initials are C. S. C., writing in the Chicago Field, says that they “eat and drink with poultry, having an eye on eggs and young chickens.” M. M. Green (1889) states: “Stomachs of two shot contained insect food. The birds’ bills were smeared with yolk of eggs. Several people told me that the jays were nest robbers.” Nuttall (1832) notes that it “destroys the eggs and young of small birds, despatching the latter by repeated blows on the head.”
Grimes (MS.) says: “I know they like crickets for I saw a male pass up four, one after the other, to his sitting mate. * * * In the fall and winter they feed to a large extent on the little acorns of Chapman’s oak.”
Behavior.—The Florida jay is a true representative of its family in traits and character. Individual variations occur, but essentially it resembles its better-known relative Cyanocitta cristata, in actions and habits. As its local name implies, it is not a high-ranging bird in any sense. One of its outstanding characteristics is its love of the ground and low elevations, which must impress anyone observing the bird for any length of time. Along roadsides it is frequently seen on the “shoulders” of the highway, particularly in sandy stretches, where it feeds commonly. Passing cars often flush it from such situations, whence it dashes off amid the scrub palmetto or ascends to a convenient telegraph wire. The flight is strong and without particular character unless the frequent sweeps with wide-open wings could be called such. The long tail is often fully expanded. On the ground it hops with strong, sure jumps, planting the feet firmly. In searching for food under such conditions it is given, according to Howell (1932), to probing the loose sand with the bill.
One often sees the moods of the bird expressed in the action of the tail. Usually, in repose, it hangs fairly straight down, offering a good field mark, but under stress of excitement this member is jerked and twitched in a highly expressive manner. Approach is not difficult most of the time, though easier during the nesting period. Sometimes an almost utter disregard of the human intruder is evidenced. In former years these birds were caged, and they proved easy to keep. Audubon (1842) gives an account of a pair he saw in captivity at New Orleans(!), which he states “had been raised from a family of five, taken from the nest, and when I saw them had been two years in confinement. They were in full plumage, and extremely beautiful. The male was often observed to pay very particular attentions to the female, at the approach of spring. They were fed upon rice, and all kinds of dried fruit. Their cage was usually opened after dinner, when both immediately flew upon the table, fed on the almonds which were given them, and drank claret diluted with water. Both affected to imitate particular sounds, but in a very imperfect manner. These attempts at mimicry probably resulted from their having been in company with parrots and other birds. They suffered greatly when moulting, becoming almost entirely bare, and required to be kept near the fire. The female dropped two eggs in the cage, but never attempted to make a nest, although the requisite materials were placed at her disposal.”
A reference to the adaptability of this species to captivity is referred to by Nuttall (1832) when he states that it is “easily reconciled to the cage.” Since caging of wild birds is now a thing of the past, the above may probably be all we will know about this species in private captivity, but successful attempts to tame it at large have been often accomplished. A striking example is noted by Howell (1932) just 100 years after Nuttall’s observation, as follows:
Miss Edith Werner, who in the spring of 1923 was operating a tea house on the shore of Lake Jackson, near Sebring [Fla.], has been remarkably successful in taming the Florida Jays, which are abundant in the scrub close to her house. She whistles a bright little tune and in a few minutes the Jays appear from all directions and without hesitation alight on her arm or shoulder to take the pieces of bread she offers them. She told us she had been a year or more taming the birds, and that it was a month or more before she could get them near her. At the time of our visit however, they had become so used to strangers that they allowed us to feed them and even alighted on our heads and shoulders. On hearing a note of alarm from one of the Jays in the brush, they all deserted us and flew into the scrub. Miss Werner says the birds always have a lookout posted on a high bush, which sentinel remains there while the rest are feeding and gives warning of danger. She added that they often frolicked together in the morning, at which times they snap the bill continuously as they shake their bodies. Occasionally they sing very softly, under their breath, “like a canary.”
The indifference of the Florida jay to human presence is alluded to by Hugo H. Schroder (MS.) in the following note: “While I was eating lunch beside the road south of Indian River City, Fla., a male jay landed on ground near my car. When I threw down some bread he picked it up and flew off with it. As soon as he returned, I threw more pieces of bread; each time the bird would fly off with it. More than a half dozen pieces were taken away; whether each one was eaten I could not see.”
Wilbur F. Smith (MS.) states that “Florida jays become tame about the houses of winter visitors, taking peanuts and bread from the hand or on the head, or even from between the lips of some.”
This bird appears to run true to corvine traits in its predilection for making away with odds and ends of property. This is a characteristic overlooked by many, or at least not referred to. Such articles are, as usual with avian thievery, bright and shiny as a rule, easily seen and attractive. Buttons, tops of small tins, spoons, bits of glass, china, and the like are among the hoards. A reference to this habit, the only one in fact that has come to my attention from the literature, appears in the Chicago Field of May 1880 and states that these birds “bury such food as they cannot immediately consume, and also spoons, thimbles, or any shining object that attracts their attention.”
Another interesting habit is also apparently not well known and may have been more frequently indulged in during past years than now, though I know of no reason why it should have now ceased. This concerns the picking of ticks from cattle, a habit shared by some of the Florida herons. I have never observed it, nor can I find anything in the literature about it, but N. B. Moore (MS.) in writing of this jay says: “A common habit of this species during the time when cattle have many ticks upon them, and this happens through the greater part of the year, is to perch upon their backs, move or hop upon their rumps and hip bones, and pick them off and eat them, or, if they have young, carry them to the nest or to a tree or fencepost, where the young are perhaps waiting for food. It reminds one of the habits of the Buphaga of Africa to see this jay riding about on the backs of cattle and feasting on these disgusting parasites. The jay often obtains the ticks by hopping on the ground about the legs of the cows jumping by the help of its wings up to the buttocks, flanks, or brisket and seizing the most palatable ones. The cattle seem not in the least annoyed by those on their backs, and yet the pretty constant switching of their tail and throwing back their horns keep the jays constantly on the alert, and they often quit their place to avoid a blow, perching either on another cow or on a tree or a fence.”
With the even greater prevalence of cattle in Florida today than when Moore wrote (about 1870), it seems strange that this habit has not been commented on more by recent observers. To many persons’ surprise Florida is one of the greatest cattle-raising States in the Union, but in recent years there has been a definite effort, attended by marked success, to eliminate ticks, and this may have resulted in such a sharp decrease in the parasites that the jays have largely abandoned this source of food and the method of obtaining it.
On monthly investigations on the Kissimmee Prairie, I see literally thousands of cattle, but as mentioned previously the jay does not occur on the open prairie and therefore could not be expected in the largest cattle concentrations. It is known that the Florida crow (Corvus brachyrhynchos pascuus) procures ticks and other insects from the backs of cattle, and occasionally some of the smaller herons do the same thing, which reminds one of the African cow heron.
Somewhat contrary to the accepted opinion that jays are domineering and quarrelsome, there is evidence that coerulescens is an exception to the rule. Though at times seen to drive off such species as blackbirds and mockingbirds, it appears to live in considerable harmony with its avian neighbors, with little bickering and interference. Wilbur F. Smith (MS.) in noting this trait says: “The Florida jay has far better manners than other members of the family. I have photographed it with quail (Colinus virginianus fioridanus), ground doves (Columbigallina passerina), meadowlarks (Sturnella magna argutula), red-winged blackbirds (Agelaius phoeniceus mearnsi), and grackles and have never seen it bully or disturb these birds, a fact worth noting in view of the family reputation. In the section where I have known it for nine years [Englewood, Fla.] it is a general favorite, giving ground only to the quail that feed about the homes.” It is supposed that in his expression “giving ground” Mr. Smith refers to the popularity of the quail over the jay, not that the jay retreats before the other.
Voice.—Notoriously noisy as are most of the jays, this species is not unusually so. Compared at least to Cyanocitta and its forms, it is decidedly less vocal. The notes are essentially jaylike, which is not too general a term to employ for quick recognition, but are given at greater intervals and not so constantly. Certain calls are loud and have a harsh, rasping quality, and it is probably some of these that Howell (1932) likens to notes of the boat-tailed grackle (Megaquiscalus mexicanus major) and that he terms “churr.” I cannot say that they ever impressed me in such a way, but bird calls sound different to different hearers.
The song, if one can designate the attempt as such, is widely at variance with the call or alarm notes. It is a rather surprising performance really, and would puzzle many not seeing the singer. Wetmore (MS.) describes it as “a mixture of low, sweet-toned calls, high in pitch, mingled with others that were variously slurred or trilled in utterance.” It is next to impossible to describe most bird notes in words. However, the above seems to me to be as good an interpretation as can be given. Not in character or similiarity, but in that one would not expect such a song from such a bird, it recalls some of the performances of the loggerhead shrike (Lanius ludovicianus)! On some occasions, I have heard low, subdued notes that cannot be described otherwise than as a chuckle, delivered rather rapidly and having an abrupt quality. It is an agreeable delivery and imparts the distinct impression that the bird is in a thoroughly contented mood at the time.
Field marks.—The outstanding field marks of this species, aside from the characteristic color pattern, are the crestless head and the long tail. The name “Aphelocoma” is from the Latin meaning “smooth hair,” referring, of course, to the lack of a crest in a crested family; “coerulescens” refers to the prevailing color, blue.
