Investigation Shows Laughing Gulls Do Little Damage to Seafood Products of the Eastern Shore of Virginia.

At the request of Colonel McDonald Lee, Commissioner of Game and Inland Fisheries, Richmond, Va., an investigation has recently been made of the Eastern Shore of Virginia for the purpose of making a detailed study of the black-headed or laughing gull situation. This investigation was started by persons on the Shore who wished to have rescinded the protection now given them under the Federal Migratory Bird Law. The survey was made by Dr. E. W. Nelson, of the Biological Survey, and he reports that they do no appreciable damage to any valuable seafood product. His report in full is as follows:

Pursuant to Letters of Authorization No. 86-Bi dated July 1, 1923, and allotments and instructions thereunder, I left Washington, D. C., on June 10th, to investigate sweeping complaints of damage to soft-shelled crabs, scallops, clams, and oysters by laughing gulls along the Eastern Shore of Virginia.

Arriving in Wachapreague I immediately got in touch with Mr. T. T. Bloxom, Federal Warden of the district. As no special locality was mentioned in the general complaints received, it was thought best to charter a boat with sleeping accommodations and investigate the relation of the gulls to valuable sea food products along the entire Eastern Shore. During the next three weeks I covered the Eastern Shore region from Chincoteague to the territory immediately South of Cobb Island collecting laughing gulls under numerous varying conditions, watching the birds in their colonies -- where occasionally notes on the food of nestlings could be obtained without harming the birds themselves, and interviewing old-time watchmen who depend upon the various sea food products for their livelihood.

The laughing or black-headed gull was found common or locally abundant as far north as the south end of Wallops Island but north of that island and at Chincoteague only a few of these birds were seen. Scattered nests were located on any available high marsh from Cedar Island southward although the only colonies of appreciable size were on the Gull and Eastward Marshes -- west from the north end of Cobb Island. I do not believe the total laughing gull population of the Eastern Shore of Virginia exceeds 10,000 individuals.

Not one of the numerous watermen interviewed had ever seen a laughing gull eat a scallop, clam, or an oyster, or even attempt to feed on these mussels. When first questioned several of the men stated the damage by gulls was great and offered detailed accounts of the methods used by the birds in breaking the shells of the mollusks. Further questioning, however, revealed that the damage without exception was caused by the herring gull, commonly referred to as the big gray gull, winter gull, and clam gull. Even the depredations of the herring gull assume importance only on the bedding grounds where clams are being planted. One individual, who plants upwards of a million clams each year, told me that the big gray gulls caused him an annual loss of probably $100.

Likewise no complaint against the laughing gulls as destroyers of fish were forthcoming. Belief was expressed by a few men that the birds in question did feed to some extent upon living fish but of species of small size and of no commercial value. On the other hand several people, wise in the ways of fishing villages, were of the opinion that the native gulls undoubtedly did a great deal of good in keeping the adjacent waters cleared of small fish discarded by fishermen operating pound nets. In fact, some even went so far as to say that if it were not for the gulls the odor of decaying fish would compel many of the villagers to move. However that may be, the fact remains that the only flocks of gulls I ever saw in the vicinity of Wachapreague were feeding on the dead fish brought in by the flood tide from the opened pound nets; at all other times but few gulls were seen near the village.

That the laughing gulls eat soft-shelled crabs is beyond question.

Yet, the only appreciable damage thus resulting is when the crabs are taken from the floats of a man who for the time being makes his living by shedding crabs. In this regard I may add that the business of shedding crabs requires a man's full time, as the floats must be visited and the crabs sorted each hour in the day and the gulls will not come near the floats when a man is around. Also the opinion is generally held that even severe depredations, allowing that such could exist, would be entirely checked by the simple procedure of covering the floats with discarded fish nets. At any rate it seems to me that it hardly behooves the natives to condemn the laughing gull for the occasional soft crab eaten when I saw in the fishing villages it was a common practice for the youngsters armed with sticks to straddle a gut and vie with each other in killing the crabs disturbed by the falling tide. And a little questioning brought forth the fact that no use whatever was to be made of the dozens of crabs thus killed.

Examination of the stomach contents of the laughing gulls collected revealed not a trace of a scallop, a clam, or an oyster, nor were any of the gulls seen attempting to feed on these shellfish. Even when a dozen small clams were spread out on a hard sand beach they were not disturbed by the flock of laughing gulls which had been attracted to the spot by bread floating at the water's edge and scattered among the clams on the hard shore.

Care was taken to avoid collecting gulls that were known to be feeding on dead fish or discarded refuse of any kind but otherwise the 25 birds taken were representative of the existing conditions, that is, they include single stragglers and small groups from colonies, collected both morning and afternoon along the beach, over marshes at high tide and at low tide.

The diet revealed by stomach examinations is as follows:

From the above table it will be seen that less than one-tenth of the laughing gull's food is composed of soft shelled crabs -- in fact only two of the birds collected had managed to find such food. On the other hand, more than two-thirds of the entire diet consists of small crustaceans of no commercial value -- chiefly fiddler crabs (Uca) and "oyster crabs" (Sesarma). At low tide it was common to see the laughing gulls in slow flight over the marsh suddenly dart to the ground and pick up the scurrying fiddlers; one stomach examined contained the remains of 23 of the marsh fiddlers (Uca pugnax) while another was crammed full with 12 whole ones and the fragments of 7 others.

The second largest item, nearly one-fifth of the entire food, is fish and was wholly contained in a series of 5 stomachs taken early one morning on the marsh at Cobb Island. Of these one contained the remains of a small goby (Cobiosoma bosci) and 4 were filled with silversides (Kirtlandia and Menidia); these small silversides or "spray fish" were being fed to the nestlings on Cobb Island late in June.

Occasionally the laughing gull eats small snails (Melampus Iineatus) for they composed nearly one-twentieth (4.38 per cent.) of the contents of the stomachs examined. These little banded mollusks live on the salt marshes and numbers of them are regularly found under gull nests or in any pile of wet drift.

Insects, chiefly beetles, are a minor food item (1.35 per cent.) of the laughing gull and were picked up only by birds feeding along sand beaches. The majority of these were ground beetles (Carabidae), leaf chafers (Scarabaeidae), and weevils (Curculionidae). Other insects eaten include a stink bug and a horse fly larva -- the latter being extremely common among the fibrous roots of the marsh grasses.

Prior to the passage of the Migratory Bird Treaty Act it was a common practice in the region for fishermen, boating parties and others to visit the colonies of laughing gulls, black skimmers ("flood gulls") and terns ("strikers") for the purpose of robbing the nests of eggs. Such action was presumably based originally on the law of necessity because of the remoteness of bases of supply. Such need, if in truth it ever existed, has long since passed so that the motives of present day eggers are either a personal predilection for the flavor of wild eggs over those of domestic fowl, or the hope of obtaining easy money through their sale in the nearby villages. The only argument advanced by the would-be eggers is that the birds themselves are of no value. In no place did I hear of any complaints against the birds other than their supposed uselessness but requests for the egging privilege were heard on every hand. However, I would like to state in defense of the majority of the native population that the present agitation is voiced by a small minority and the offenders against the law which prohibits egging are not the nearby islanders but the passing boatmen from "up shore" or the mainlander who expects to readily dispose of his spoils. Certain it is that egging is still carried on for I found many a nest which had recently been robbed. One locality which is readily accessible by boat I visited early in June and found a large colony of gulls and terns egg laying, some even with their sets already completed; yet two weeks later I again searched the same region and found the majority of nests held only one or two eggs, while the birds in a nearby colony -- whose nests were exposed to the same high tides but were not accessible by boat, were feeding young a week old. There is some excuse this year for the amount of egging done because without doubt some of the residents think all restrictions have been removed. In fact I was told that on two occasions the local papers carried notices to the effect that egging was again permitted. More critical readers, however, explained that the printed statements merely forecasted the possibility of the law being changed to suit eggers.

I do not believe the laughing gulls have any effect whatever upon the colonies of black skimmers, least and common terns. The three beach-nesting birds above mentioned I found in adjacent or intermixed colonies on the sands of Cobb Island, while in the edge of the marsh less than a quarter of a mile distant nested a colony of laughing gulls, yet the gulls were never seen among the nests on the beach. Nor were the passing gulls molested by the sand nesting species as would be expected of inherent enemies. Furthermore, no native with whom I talked had ever seen laughing gulls acting as vandals in the colonies of other birds.

A like situation was found to exist between the laughing gulls and Forsters terns and also between the gulls and clapper rails. In the gull marshes on Friday, June 13th , I saw laughing gulls and Forsters terns building nests on the same small pile of drift and in apparently perfect harmony. Later, on numerous occasions, I found gull nests with eggs located only a few feet (often less than 10) from Forsters tern nests also with eggs and an hour's watching disclosed no signs of fighting among the owners of the respective nests. Neither did I find any evidence that laughing gulls disturb the eggs of clapper rails, although rail nests with eggs (9 to 11) were frequently seen in close proximity to nests of gulls with eggs or young. In fact, on one occasion I came across a clapper rail's nest containing 11 eggs, which was only 2 feet from two laughing gull nests and four feet from two other laughing gull nests all of which contained eggs.

Fish crows were not abundant along the Eastern Shore but frequently one and sometimes two were seen in slow flight over the marsh apparently in search of food. One evening on the Gull Marshes I watched a certain fish crow for more than half an hour as it tacked back and forth over the colony looking for unprotected eggs. Time and again it dropped suddenly toward the ground instantly to be met by guarding gulls who chased the would-be robber high in the air. Finally after much searching an unguarded nest was seen and the crow alighted. Almost immediately it was again in the air and with an egg in its beak but the pursuing gulls followed closely and the chase became so hot that the crow dropped the egg and left the neighborhood. Not only the laughing gulls but the Forsters terns and even the willets were seen to chase crows away from the vicinity of their nests. Thus it may well be argued that the eggs of a clapper rail close to a gull's nest are better protected than are those somewhat removed from a gull colony. I did not see any fish crows flying over the beaches in the regions occupied by colonies of common terns and black skimmers.

On the ground near the nesting sites of fish crows I frequently found little piles of egg shells chiefly those of clapper rails and laughing gulls. Such proof of the marauding habits of the fish crow was particularly in evidence on Revell's Island. Yet shells of the eggs of the little green heron, the most abundant nesting bird on the island, were seldom seen on the ground even though their nests and the nests of fish crows were frequently found in the same trees. This may be accounted for on the assumption that the little green herons are capable of protecting their eggs and the same theory would explain the scarcity of remains of gull eggs relative to those of the clapper rail. But if such is the explanation why do the eggs of the black skimmers, large colonies of which are nearby, never appear beneath the nest of feeding station of the fish crows? It seems to me that the fish crows along the Eastern Shore on Virginia habitually cover the marshes and tidal flats in search of food and that the egg item of their diet whether large or small, is incidental to that search rather than the controlling factor as some people would have us believe.

Summary

I. -- The laughing gulls do no damage whatever to scallops, clams or oysters along the Eastern Shore of Virginia.

II. -- The laughing gulls should be considered beneficial to the fishing industry, as they act as scavengers in keeping the shores free from decaying fish while the few fish taken alive are small species of no commercial value.

III. -- The laughing gulls probably capture soft-shelled crabs at every opportunity but at most they can be classed only a nuisance to the man who makes a business of shedding crabs for market. Furthermore his crab floats can readily be protected by covering them with netting.

IV. -- Along the Eastern Shore of Virginia the laughing gulls live in peaceful harmony with other species of marsh and sand nesting birds.

Conclusion

The laughing gulls do no appreciable damage to any valuable sea food product along the Eastern Shore of Virginia and their colonies are in no way detrimental to the well being of other birds.