Notes on the Birds of Cobb's Island, Virginia.
A series of relatively small, outlying islands extends practically from southern New Jersey and Delaware to the Carolinas, Georgia and beyond, and is largely responsible for the now well-known "inside course to Florida." Most of these islands amount to more or less naturally "developed" sand-bars; many of them treeless, but all with their allotment of salt-marsh on the inner or "bay" side. The majority of them, remote enough to escape profitable conversion into summer resorts, are virtually uninhabited, except for the invariably present crews of the coast-guard, and a few sporadic gunners and fishermen. Lacking some of the hazards on the mainland, on many of these islands isolation conditions are favorable for breeding and migrating Gulls, Terns, shore-birds and waterfowl, and consequently these birds frequent them annually in great numbers. Curiously others, apparently equally favorable, are practically abandoned and barren of all bird-life, at least during the breeding season.
For many years, probably one of the best known of these islands to ornithologists as well as sportsmen, has been Cobb's Island; perhaps best described as a strip of sand some seven or eight miles in length, with fairly sizeable dunes, and an extensive area of salt marsh and tidal flat on the inner or landward side. In relation to the mainland, it is approximately eight miles off the Virginia coast and nearest to the small fishing town appropriately termed "Oyster," which in turn is roughly equidistant to either Cape Charles or Eastville. Though naturally somewhat remote and isolated it is, at the present time, remarkably accessible. From Cobb's Island, one is within easy striking-distance of several other islands, such as Smith's [Island], and directly below and across the channel, is Cordwell's Island; about a mile in length, of very recent "origin," upon which, at the time of our visit, about half the skimmers and a fair proportion of the breeding gulls, Terns and shore-birds were to be found.
Relatively little has apparently been written concerning the birds of Cobb's Island since the visit of Dr. Chapman,
about 1900, although it has been visited by several different parties of observers, within the past five years. During the last twenty-five or more years, owing largely to protective measures, the status of almost all of the local breeders has altered so materially that it seems of interest to summarize the results of two visits to Cobb's Island, recently made by my brother Richard and myself; the first, June 22 to 25, 1927, and another in September 5 to 13 of the same year.
Perhaps a brief comparison of present conditions with the immediate past would illustrate graphically what protective measures can accomplish, if properly directed. Less than thirty years ago, the Least Tern, for instance, was practically extinct as a breeding-bird on Cobb's Island, and the ranks of many of the other Terns were greatly depleted, owing to the extent to which plume-collecting for commercial purposes, was being practiced. "Egging" and spring-shooting vastly decreased the numbers of breeding Skimmers, and shorebirds, such as the Oystercatcher, Willet, and Wilson's Plover; particularly the latter "sport" since the spring shooting-season is said to have frequently coincided to some extent with the bird's actual breeding period. Consequently by 1900, Dr. Chapman found the breeding-birds of Cobb's Island, in addition to the Skimmers, consisted of: "....several hundred Common Terns, a small number of Forster's, about eight pairs of Gull-bills, a pair each of Oystercatcher, Willet, and Wilson's Plover, and several hundred Laughing Gulls." Fortunately however, with increased protection, the local breeding-birds are increasing, apparently in regular progression. At the present time, the Least Tern is again well established, and practically all of the other breeders, including the Oystercatcher, Willet and Wilson's Plover, are evidently appearing annually in larger numbers. There seems to have been a particularly marked increase in breeding-birds over the last five year period, judging by the reports of others who have made surveys in June, during that time. However, lest we become unduly optimistic, it is well to remember that Cobb's Island is not, at the present time, a sanctuary for birds, and despite the efforts of Capt. Cobb and others, certain abuses, such and "egging," are still practiced to some extent. Also the sheep which are now kept at large on the Island, doubtless un-
wittingly break-up many nests annually, and destroy innumerable young birds. In addition, the natural hazards must of course be considered, such as unusually high tides, storms, etc. which yearly take their toll of bird-life from any sea-coast breeding resort.
The present breeding birds of Cobb's Island might be thus briefly summarized: Laughing Gull 750 (est.). Caspian and Royal Terns probably no longer breed on the Island but either species is occasionally noted flying off the Island in June, and doubtless breed nearby; perhaps, as has been suggested, somewhere in the vicinity of Smith's Island. Common Tern, plentiful, 275 (est.); Roseate Tern, sparingly, 10; Least Tern, well established, 50; Forster's Tern, numerous on salt marsh, 40; Gull-billed, well distributed, 32; Skimmer, 550 (est.); Clapper Rail, abundant; Willet, 10 pairs, mostly at the eastern end of the Island, where the species is locally plentiful; Wilson's Plover, 12; Oystercatcher, 25. Owing to the difficulty of differentiating the sexes of many of the above species in the field, it was thought expedient to state the total number of adult birds present, rather than the probable number of breeding pairs. There is said to be a decided fluctuation in the numbers of certain of the breeders from year to year, so that the observations of any one year are probably not an absolute index of what can be found there, at any particular time, thereafter.
Cordwell's Island being only about an eighth as large as Cobb's, naturally has a somewhat smaller breeding total, but certain of the breeding species, such as the Skimmer, are more abundant there in proportion to the amount of available environment. In June, stretches of sand on the lower end of this island are literally strewn with the remarkably handsome eggs of the Skimmers. The following "counts" are of interest by comparison with those given above: Laughing Gull, 150; Common Tern, 25; Roseate Tern, 6; Least Tern, 15; Forster's Tern, 18; Gull-billed Tern, 12; Skimmer, about 450 (est.); Willet, 6; Wilson's Plover, 8; Oystercatcher, 6.
An interesting and rather unexpected feature of the June trip was the relative abundance and variety of certain of the shore-birds. On June 22, there were some 15 Dowitchers (in breeding plumage); about 250 Knots (mostly in winter plumage); Semipalmated Sandpipers, 300 (est.), and Least Sandpiper, 16; Hudsonian Curlew, 30;
Black-bellied Plover, 12; Ring-necked Plover, 10; and several Turnstones. There was a very marked increase in the number of Knots on the 23rd (at least 450 being present), but by the 24th they had decreased to about 150. No perceptible change in the number of Dowitchers was observed, but most of the other varied noticeably from day to day, suggesting the possibility of migration. Of course, some are almost sure to have been summering non-breeders, but it has been suggested that if the birds were in regular migration, the Knot, Semipalmated Sandpiper, Black-bellied and Ring-necked Plover, and Turnstone were probably north-bound; while the Dowitcher, Least Sandpiper, and Curlew were south-bound migrants. However, whether or not these birds were regular migrants, is probably largely a matter of speculation, and the present data are too fragmentary to warrant any positive assertion. Mr. J. T. Nichols has further suggested that some relation is thought to exist between summering and wintering shore-birds; at least to the extent that certain species are apparently somewhat more apt to be found in summer localities in which a few may winter. This is an exceedingly interesting hypothesis, but unfortunately we do not know to what extent any of the species in question may winter. Judging by the reports of the local inhabitants, some shore-birds are found on the Island in winter, but it is not always clear to which species they belong. However, it does not seem altogether rash to assume that a few "enterprising" Redbacks, Sanderlings, Knots, or even Black-bellied (not to mention Killdeer) Plovers, may linger well into winter, or even spend the entire season; especially in view of their occurrence in recent years much further north, along the New Jersey coast in December and early January.
On June 24, two Comorants (sp.?) were noted flying in a northerly direction off the beach, apparently in regular migration. No less than six American Scoters were observed on the same date (three of them adult drakes). These birds were very likely non-breeders since about the same number was found there in September.
The relative proximity of much favorable habitat for land-birds along the adjacent mainland, makes a trip to the vicinity of Cobb's Island, in the breeding season, more attractive. There is a stand of pine-woods just south of Eastville, and on the west side of the
highway, which is probably characteristic of that particular section of tide-wide Virginia. In June, it fairly rings with the songs of Mockingbirds, Cardinals, Titmice and Carolina Wrens. The Summer Tanager, Yellow-throated, Pine, Prairie, Kentucky, and Southern Parula Warblers are also present in numbers, in addition to the Gnatcatcher, and Acadian Flycatcher, and in the evening it is frequently possible to hear Chuck-wills-widows "performing." Nearby the Brown-headed Nuthatch and Red-bellied Woodpecker can usually be found, but both of these species are probably more apt to be observed in a rather interesting place directly east of the village (Eastville). Here in a somewhat secluded inlet, the Yellow-crowned Night Heron can occasionally be found. In June several were observed, and in July of the previous year they were reported by others in larger numbers. Limitations of space prevent a more detailed treatment here, but by way of indicating the relative abundance and variety of bird-life, the fact may be cited that it is not particularly difficult to record over one hundred species, as a combined list for both the island and the neighboring mainland in June.
A trip to Cobb's Island in September is naturally interesting by comparison with one in the breeding season, and also because of the shore-bird migration. The return or fall flight of Curlew is apparently a regular feature of the early autumn on the Island, and is obviously well-known to the local inhabitants. According to their reports, the birds seem to collect on the neighboring islands during migration periods, and as the majority appear to roost on Cobb's Island, there is consequently a perceptible evening flight to, and an early morning flight away from, the Island. The birds probably reach their peak of abundance locally in late July or early August, depending upon general conditions, and are then said to be present literally "by the thousands." During these times, the Curlew, we were told, frequently outnumber all other shore-birds combined. To give some idea of the abundance of the species locally, it is perhaps of interest to note that on the evening of September 9, probably long after the main flight had passed south, over 1500 birds were present.
While it is true that shore-birds are frequently more abundant numerically in July and August, nevertheless probably a greater
variety can occasionally be found on this coast later in the season. For instance, it was not particularly difficult, during early September, to see on Cobb's Island, twenty species of shore-birds in a day; the "record," so to speak, was twenty-three on September 10, and the total for the period from September 5 to 13, was twenty-eight species. Some picture of the relative abundance of certain of the more prominent species, may be gained from the following numbers, many of which were probably obtained long after the actual period of greatest abundance had been reached: Stilt Sandpiper, 10, September 9; Dowitcher, 50, September 6; Knot 1200, September 5; Pectoral Sandpiper, 35, September 9; White-rumped Sandpiper, 12, September 10; Least Sandpiper, 50, September 11; Semipalmated Sandpiper, 1400, September 10; Sanderling 550, September 12; both Yellow-legs unprecedentedly scarce; Willet, 25, September 10; Curlew, 1500 (est.), September 9; Black-bellied Plover, 3500 (est.), September 7; Ring-necked Plover, 450 (est.), September 8; Turnstone, 56, September 10; also Wilson's Plover, 12, September 5; Oystercatcher, 42, September 9; Baird's Sandpiper, satisfactorily observed on September 7; Upland Plover, 1, on September 10; Western Sandpiper, 5, on September 12. Two Golden Plover on September 9 and 10, under very satisfactory conditions, seem unusually early.
Both Caspian and Royal Terns were more conspicuous than in June; the former being about twice as numerous as the latter; the maximum number of Caspian Terns was eighteen on September 9. The other Terns were mostly less numerous individually than in June, and the Gull-bill was conspicuous by its absence. At least 3500 "Shearwaters" (as the Skimmers are known locally) were observed on September 10 and 11. Southern Herons had been unusually scarce all season, and there were practically no other rare summer "vagrants," from further south. Parasitic Jaegers were occasionally noted flying off the beach, and on September 11, at least one fine Pomarine Jaeger was satisfactorily observed from the beach. None of the other pelagic birds was sufficiently close to shore to be identifiable from the beach. About 175 Double-crested Comorants were noted flying in a southerly direction, offshore, on September 9, and smaller numbers were observed under the same conditions, on several successive days.
In summing up, we may say that a trip to Cobb's Island in June, will well repay the effort involved, particularly to one interested in breeding birds. However, a visit at any other time ought to prove equally interesting from the view-point of the student of migration. It is perhaps pertinent to add that such trips as these, besides being of positive value, and a source of much real and genuine enjoyment, also widen the scope of ones field-experience, and in that way form a valuable basis for other excursions of a somewhat more extended nature.
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