Status of the Glossy Ibis in Mexico

DISTRIBUTION Status of the Glossy Ibis in Mexico Steve N. G. Howell and Barbara M. de Montes his paper details the first marshes near Emiliano Zapata, in able experience with both species be records of the Glossy Ibis for northern Chiapas. The bird was stud fore and after the sighting, Howell is TMexico and summarizes the ied for 20 minutes by the group, most certain that the red irises of a White status of Plegadis ibises in Middle of whom were very familiar with faced Ibis would have been apparent America. White-faced Ibis. The bird was at given the views obtained and that the The Glossy Ibis (Plegadis falcinel times within 70 meters and observed whitish-bordered loral skin is charac lus) is a notoriously nomadic wading through several telescopes in good teristic of the Glossy Ibis. bird widespread in Eurasia, Africa, light. It was an adult, as judged by The flood plain and marshes of the and Australasia (Cramp and Sim areas of retained purplish-chestnut Usumacinta River where the sighting mons 1977). In addition, it breeds feathering on the upperparts; other occurred are at the point where either commonly and is increasing in the plumage features, including the white- Plegadis might be expected to occur eastern United States, to which it may streaked head and neck, indicated that from time to time. We know of several have spread from the Old World in the bird was essentially in basic plu sightings of Plegadis sp. from the Usu the mid- to late 1800s (Palmer 1962). mage. The irises were clearly brown; macinta marshes since the early 1970s In the New World it also occurs lo the unfeathered lores appeared slate- including a report of 54 “dark ibis” in cally in the Greater Antilles, Central gray and were bordered both above July 1972 (Sprunt and Knoder 1980), America and northern Venezuela and below by a thin but distinct whi suggestive of a breeding colony. (See (A.O.U. 1983), a distribution in ac tish line, the upper line broader and below). cord with what one might expect from more striking. The bill and legs ap De Montes observed five Plegadis a transAtlantic invader; cf. the early peared grayish. Having had consider ibises at Isla Cancún, Quintana Roo, stages of the more spectacular and well-documented spread of the Cattle Egret (Bubulcus ibis) (Crosby 1972). The very similar White-faced Ibis (P chihi) breeds commonly in the Figure 1. Distribution of Plegadis ibises in Mexico and northern Central America. western United States, northern Mex ico (see Fig. 1), and locally in South America (A.O.U. 1983). In North America it winters south on the Atlan tic slope to eastern Mexico and on the Pacific slope to Guatemala, El Salva dor, and possibly Costa Rica (at least formerly). However, vagrant occur rences are documented from as far afield as Hawaii, British Columbia, and Massachusetts (DeSante and Pyle 1986) and thus demonstrate a consid erable potential for wandering. Records of Glossy Ibis in Mexico On November 30, 1985, while lead ing a Golden Gate Audubon Society tour, Howell found a lone Plegadis feeding in roadside freshw ater Volume 43, Number 1 43 on January 30, 1986. They were feed ing in mangroves with other wading February 1984: one at a brackish birds including White Ibises (Eudoci lagoon on Isla Cozumel, Quintana mus albus), Tricolored Herons Roo (Howell and Peter Pyle). (Egretta tricolor) and Snowy Egrets March 1986: three in freshwater (E. thula). Six birds were noted on marshes near Majahual, Quintana February 2 and March 28 at the same Roo (Arturo Lopez Ornat). location and a single bird was still January 1987: one at small fresh present on April 10, 1986. Photo water pool on Cancún Golf Course, graphs taken of the birds (Fig. 2) Quintana Roo (per. Howell). clearly show the whitish-bordered lo July 1988: one at Rio Lagartos, Yu res characteristic of the Glossy Ibis. catán (Howell and S. Webb). The third record of Glossy Ibis is a small flock seen along the road to Status of Glossy Ibis in Middle Palizada in the Usumacinta marshes, America Campeche, in February 1988 (R. A. Behrstock and K. J. Zimmer, inde Russell (1964) mentioned no rec pendently). At the time of observa Figure 2. Glossy Ibis at Cancún, Mexico, ords of Plegadis ibises for Belize (Brit tion, not all ibises were specifically February 1986. Photograph / Barbara M. de Montes. ish Honduras) but, by 1985, the identified but the observers’ notes plus Glossy Ibis was considered a rare per photographs (Fig. 3) indicate that of manent resident in the northern half about 20 Plegadis ibises, most were was seen at Kilometer 172. The bright of that country (Wood et al., 1986). Glossy but at least three White-faced red irises and plain gray lores of the However, the identification of birds as Ibises were also present. White-faced were striking in contrast Glossy Ibis is by presumption only The fourth record of the Glossy Ibis to the Glossies. In addition, groups up and breeding has never been proven is of a basic-plumaged bird found on to four-five Plegadis were scattered in in Belize (D. Scott Wood and Dora Isla Cozumel, Quintana Roo, on June flooded fields from Kilometer 173 to Weyer pers. comm.). 4, 1988 by Andres M. Sada. The Kilometer 156 (Palizada junction) but Monroe (1968) reported a single brown irises and contrasting bluish- none was found along the road to Plegadis ibis seen in the lower Sula white line along the upper lores were Balancan in adjacent Tabasco where Valley of northwestern Honduras, on seen clearly at close range. Howell and similar conditions prevailed. The rel November 29, 1953. In December it Sophie Webb relocated the bird, July atively localized concentrations and was joined by “a few others” which all 12, 1988, and agreed with the identi high percentage of juveniles indicate remained until February 1954. A fication. that a breeding colony of Glossy Ibises “white feathered area on the sides of Following the above scattering of exists close to the sites of our obser the face” was noted and hence at least records Howell and S. Webb were vations. It is also not inconceivable one bird was suspected to have been amazed to encounter 500–700 Ple that more of the birds were White a White-faced Ibis. However, given gadis ibises along Route 186 in south faced Ibises and that both species the time of year, it seems likely that western Campeche, July 18–20, 1988. might be breeding in the area. the white observed was the bare loral At Kilometer post 172 flocks totalling The fact that few birders visit south border and that the birds were, in fact, 300–350 birds were present in flooded ern Mexico in summer helps explain Glossy Ibises. fields near the highway; about 50% the seemingly dramatic discovery; We are aware of no confirmed or were alternate-plumaged adults and later in the year, birds presumably possible records of the Glossy Ibis 50% juveniles, many with bills not disperse more widely although a few from Guatemala, El Salvador, or Nic fully grown. All adults seen at close may be encountered close to the high aragua. There are several reports of range (minimum nine to ten birds) way. Plegadis sp., including specifically were Glossy Ibises: the brown irises As well as the confirmed records identified Glossies, in northwest Costa and dark blue facial skin with con detailed above, and earlier reports of Rica (A.O.U. 1983, Howell pers. obs.) trasting bluish-white borders were Plegadis sp. from the Usumacinta and there are several records of Ple quite obvious. At least one-two juve Marshes, there are several records of gadis sp., including one specimen re niles showed traces of whitish loral unidentified Plegadis ibises in the Yu ported as a Glossy, in Panama (D. borders, indicating they were also catán Peninsula (Fig. 1): Engelman pers. comm.; J. Guarnaccia Glossy. At Kilometer post 164 up to June 1976: 1 in roadside marsh at pers. comm.; Ridgely 1981). Records 375 Plegadis ibises were seen with Tulum, Quintana Roo (Hector Cebal- from Costa Rica and Panama are 35% adults and 65% juveniles. All of los–Lascurain). mainly in the northern winter months 45 adults seen well were Glossy Ibises October 1977: one in mangroves at but there are also records during the as were at least three-four juveniles. Celestun, Yucatán (de Montes). northern summer. Most if not all juveniles at Kilometer May 1982: two in freshwater marsh 164 appeared to have fully grown bills north of Vigía Chico, Quintana Roo and a few had traces of white streaking (Arturo Lopez Ornat). A Note on Field Identification about the head. No immature (year- June 1983: one, possibly two, in old) Glossies were identified but at freshwater marsh near Vigía Chico, Criteria for distinguishing between least one immature White-faced Ibis Quintana Roo (Ingrid Olmstead). the Glossy and White-faced ibises are 44 American Birds, Spring 1989 and Kevin J. Zimmer for allowing us to include their unpublished observa tions; Robert A. Behrstock for per mission to include his photograph; and Dodge Engelman, John Guarnac- cia, Dora Weyer and D. Scott Wood for help in researching records in Cen Figure 3. Mixed flock, in tral America. Howell would very cluding White-faced Ibises much appreciate further information (top and right hand flying on the distribution of Plegadis ibises birds), Glossy Ibises (stand in Mexico and Central America, in ing birds), White Ibises, cluding comment on the breeding and Great and Snowy egrets along road to Palizada.

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