Butorides virescens virescens (Linnaeus), Eastern Green Heron
No winter records for the occurrence of this species were available to Oberholser in 1938, the latest date cited by him being October 27. Recently, however, it has been noted several times in winter on the coast of Louisiana. Kilby and Croker (Aud. Mag., 42, 1940: 117) observed it at the mouth of the Mississippi River, near Pilot Town, on December 25, 1939, and Burleigh and I each obtained a specimen at Cameron on December 13, 1940. Another was shot by me at the same place on February 2, 1946. The species is therefore of casual occurrence in the state in winter.
Dichromanassa rufescens (Gmelin), Reddish Egret
Although previously reported only as a casual summer visitor along the coast, the Reddish Egret is known now to occur regularly in small numbers during the winter. Since Oberholser (op. cit., 56) cited only one specific record of occurrence in the state, all additional records are listed here. On East Timbalier Island, one to three were seen daily, August 16-19, 1940, and two to five were seen daily, November 15-17, 1940. In Cameron Parish, the species has been noted as follows (Lowery, et al.): two on December 14, 1940; one on January 3, 1943; three on September 3 and two on November 4, 1944; one on April 29, 1945. Several specimens were collected.
Plegadis falcinellus falcinellus (Linnaeus), Eastern Glossy Ibis
Plegadis mexicana (Gmelin), White-faced Glossy Ibis
Considerable confusion exists concerning the specific identity of the glossy ibises inhabiting Louisiana. The fourth edition of the A. O. U. Check-list (1931: 33) stated that falcinellus "breeds rarely and locally in central Florida and probably in Louisiana." In 1932, Holt visited the marshes of Cameron Parish in southwestern Louisiana where he studied the ibises nesting in a large rookery. Later he definitely stated (Auk, 50, 1933: 351-352) that the birds seen by him were Eastern Glossy Ibises (Plegadis falcinellus). It was doubtless Holt's identification that influenced Oberholser to list falcinellus as a fairly common local resident in the state (op. cit., 78). This, however, is contrary to the evidence at my disposal. My associates and I have studied thousands of glossy ibises in the marshes of southwestern Louisiana in the past ten years. These observations include numerous field trips into the region where ibises are plentiful throughout the year, especially during the breeding season. I have also visited a large nesting rookery in Cameron Parish, the only one in the state known to me, and the one which I have every reason to believe is the same colony visited by Holt in 1932. Although Holt identified as falcinellus the birds seen by him at a nesting rookery in Cameron Parish, I have never seen that species anywhere in Louisiana except at Grand Isle, 150 miles east of Cameron, as henceforth noted.
In winter when the White-faced Glossy Ibis lacks the white on its face, some difficulty might be encountered in differentiating that species from the Eastern Glossy Ibis. The perplexing thing, however, is that Holt made his observations in the nesting season when no possible confusion should exist; also he was in the middle of a nesting rookery with birds close at hand on all sides. This fact notwithstanding, the ibis nesting in the Cameron Parish rookery (known locally as "The Burn") on May 28, 1942, was the white-faced species (Plegadis mexicana), as evidenced by moving pictures taken by J. Harvey Roberts and by specimens of varying ages collected at the same time by me. In all, the Louisiana State University Museum of Zoölogy has 19 specimens of mexicana taken in Cameron Parish in April, May, November, December, and January. Field records are available also for the months of February, March, July, and September.
Aside from Holt's statement, Oberholser had only five other records for falcinellus in Louisiana, one being a market specimen with incomplete data and therefore of questionable scientific value. The remaining four specimens were taken by E. R. Pike near the mouth of the Mississippi River on November 13 and 17, 1930, and are now on deposit in the Chicago Academy of Sciences. Recently I borrowed these specimens for reëxamination with the following results. The three taken on November 17, 1930, are mexicana and not falcinellus as labeled and so reported by Oberholser. The single specimen taken on November 13 is, however, correctly identified as falcinellus. Alexander Wetmore kindly examined the material for me and confirmed my identifications. The occurrence of falcinellus in Louisiana thus hinged on Holt's statement and one preserved specimen. However, on July 23, 1944, in the marshes on Grand Isle, Jefferson Parish, Louisiana, I encountered a flock of 12 immature ibises that impressed me by their blackness in contrast to the color of glossy ibises with which I was familiar in Cameron Parish. Two specimens were collected and both proved to be falcinellus.
Holt's published observations cannot be positively refuted, for we cannot be sure that a colony of falcinellus did not exist in Cameron Parish in 1932, nor that the portion of the rookery under his observation did not consist of a segregated population of that species. However, ten years of field observations by other ornithologists have failed to disclose the species which Holt considered a common nesting bird in an area where we now know that only the White-faced Glossy Ibis occurs. The fact that Holt specifically stated that he failed to find the white-faced bird at any time in his stay in Cameron Parish is difficult to explain, but this much is certain—the present known status of falcinellus in Louisiana is that of only a rare and casual visitor.