The area covered by this book—Mexico, Belize, Guatemala, and El Salvador—is rich in bird life, readily accessible for the most part, and almost unique in its mixture of many typically temperate-zone species with many distinctively tropical birds. Although the area of Mexico, Belize, Guatemala, and El Salvador combined is considerably smaller than that of the United States, many more species of birds occur regularly in those countries than in the contiguous United States (the lower 48). The Atlantic lowlands of Mexico, Belize, and Guatemala (sometimes called the Gulf-Caribbean Lowlands) and the adjacent lower mountain slopes, up to about 5000 feet (1500 meters) above sea level, are richest in variety of species and numbers of typically tropical species, as compared with other parts of Mexico and Guatemala and as compared with El Salvador. Within these lowlands, especially from about 200 miles south of the U.S-Mexico border and farther south and southeast through northern Guatemala and Belize, the observer can encounter a host of distinctively tropical species, among them parrots, hummingbirds, motmots, toucans, woodcreepers, and tropical species of hawks, woodpeckers, jays, tanagers, grosbeaks, buntings, and orioles. Likewise, because of the varied topography, a birder in Mexico or Guatemala (and to a lesser extent a person in Belize or El Salvador) need travel only a couple of hours, up or down the mountain slopes, to find an assortment of birds quite different from those around the starting point.
In contrast to the second edition, which covered only the birds of Mexico and all its islands and territorial waters, this third edition has extended full coverage to Belize, Guatemala, and El Salvador, in addition to Mexico, while restricting coverage of species that occur only on remote islands or over ocean waters far offshore. Birds in the latter category have been gathered, in this edition, in a special list at the end of the main text.
Specifically, the main text of this edition covers all the birds that we believe occur regularly (not casually or accidentally) on the mainlands of Mexico, Belize, Guatemala, and El Salvador; in their coastal waters and islands out to a distance of three miles from the mainland; on Cozumel Island, Mexico; or on the readily accessible cayes of Belize.
How to Use This Book
It is important, first of all, for the user to develop a concept of the different physiographic features, the elevations, the types of vegetation, the behavior patterns of certain kinds of birds, the seasonal changes, and the distribution of various species within each country.
For example, a dull, brownish bird, slightly smaller than a robin, flying across the road in rather open, dry, highland areas in northern or central Mexico, may quite likely be a Canyon Towhee. A similarly plain brownish bird, about the same size, in the humid lowland forests of southeastern Mexico and Belize and Guatemala, might be a Rufous Piha, a Rufous Mourner, or one of the ovenbirds or woodcreepers. It is difficult to imagine even a remote possibility that a Canyon Towhee would ever be found in the lowland humid forests or that a Rufous Piha would ever be seen flying across the road in arid, semidesert, mountainous areas.
To assist you in making the necessary choices when attempting to identify a particular bird, we have divided Mexico and Guatemala into regions (and in Mexico, subregions), divided Belize by habitat types and location within the country, and divided El Salvador by location within the country.
The Regional System in Mexico and Guatemala
Within Mexico the regions, in sequence from west to east (followed by subregions from north to south, in parentheses), are: Baja California (nBajCal, sBajCal), Pacific (nPac, cPac, sPac), Highlands (nHi, cHi, sHi), Atlantic (nAtl, cAtl, sAtl), and Yucatan. (See map, plate IV.) Separate modifiers are also employed to make the subregional range statements more precise when appropriate, for example, n.nBajCal (northern nBajCal), s.nPac (southern nPac), and se.cAtl (southeastern cAtl). A period separates the directional modifier and the subregion.
The Baja California (BajCal) Region, in the northwestern part of Mexico, includes the entire Baja California Peninsula up to the U.S. border on the north and the Colorado River on the northeast and thus includes elevations from sea level to 10,000 feet or higher, on the tops of the highest mountains. The region is divided into the northern (nBajCal) subregion, from Tijuana south to Guerrero Negro, and the southern (sBajCal) subregion, from Guerrero Negro south to Cabo San Lucas.
The Pacific (Pac) Region in Mexico includes all of the Pacific coastal plain (outside Baja California) and the adjacent lower mountain slopes, up to approximately 5000 feet (1500 meters) elevation, and is divided into three successively smaller subregions: northern (nPac), extending from Puerto Peñasco and Nogales southward to Puerto Vallarta; central (cPac), from Puerto Vallarta southeastward to Tehuantepec; and southern (sPac), from Tehuantepec southeastward to Tapachula.
The Highlands (Hi) Region in Mexico includes the mountain ranges and relatively high plateaus above 5000 feet (1500 meters), except in a few lower areas in the northern part of the Central Plateau, forming the backbone that runs more or less northwest to southeast down the center of the country (and on through central Guatemala and parts of El Salvador). The Highlands is divided into three successively smaller subregions: northern (nHi), extending southward from the vicinity of Agua Prieta (opposite Douglas, Arizona), Ciudad Juárez (opposite El Paso, Texas), and the Sierra del Carmen (opposite Big Bend National Park, Texas) to Guadalajara, Guanajuato, and Pachuca; central (cHi), extending southeastward from there through Mexico City, Jalapa, and Oaxaca, almost to the Isthmus of Tehuantepec; and southern (sHi), divided into two narrow segments, one extending near the Pacific coast from the Isthmus of Tehuantepec to the Guatemala border and the other beginning near Tuxtla Gutiérrez and extending through San Cristóbal de las Casas to the vicinity of Comitan. Within those subregions the reader might frequently encounter the designations w+e.nHi (referring to the western and eastern mountain ranges of the northern Highlands), w.cHi (western portions of the central Highlands), or se.cHi (southeastern portions of the central Highlands).
The Atlantic (Atl) Region includes the shores and coastal plain of the Gulf of Mexico and the Caribbean Sea (except the northern half of the Yucatan Peninsula) and the lower slopes of the mountain backbone up to about 5000 feet elevation. Even though it is not nearly as extensive as the Pacific Region, it is divided into three subregions: northern (nAtl), extending from near Ciudad Acuña (opposite Del Rio, Texas) and Matamoros south to Ciudad Valles and Tampico; central (cAtl), extending from there southeastward to Coatzacoalcos; and southern (sAtl), extending from there (the Isthmus of Tehuantepec) to the Guatemalan border on the Southeast, to Campeche on the north, and across the base of the Yucatan Peninsula to Belize and the Caribbean Sea.
The Yucatan (Yuc) Region includes the low flatlands of the northern part of the Yucatan Peninsula and extends from Champotón (south of Campeche) and Felipe Carrillo Puerto on the south to Progreso and the vicinity of Cancún on the north. Because of its relatively small size it is not divided into subregions, but there is a noticeable difference in vegetation, and therefore bird life, between the drier western half (w Yuc) and the wetter eastern half (e Yuc). (A space rather than a period separates directional modifiers and region abbreviations.)
Within Guatemala only three regions are designated: Pacific, Highlands, and Atlantic, with no subregions. Occasionally a modifier is used, such as ne Atl (the area around Puerto Barrios) or nw Atl (the Petén). The abbreviations Pac, Hi, and Atl represent the same locational and elevational data as they do in Mexico: Pac extends from the shores of the Pacific Ocean to the 5000-foot (1500-meter) level on the slopes of the mountains; Hi represents the highlands from there up to the tops of the highest mountains; and Atl extends from the 5000-foot (1500-meter) level on the other side (north side) of the mountains, on down to the shore of the Caribbean Sea, and to the Belize-Guatemala border and the Guatemala-Mexico border.
Bird Distribution in Belize and El Salvador
If we applied the same major regional designations to Belize (Blz) that we apply to Mexico and Guatemala, all of the country would fall into the southern Atlantic subregion, because it borders the Caribbean Sea and because the highest mountain in Belize falls considerably short of the 5000-foot (1500-meter) upper limit of the Atlantic Region. Most of the birds of the sAtl subregion of Mexico (and the Atlantic Region of Guatemala) are to be found in Belize, along with some of the birds that occur mainly in the Yucatan. Occasional parenthetical modifiers following "Blz" indicate that birds occur only in the coastal areas (cstl), only in the cayes, in both the coastal areas and the cayes (cstl + cayes), in the pine woods or pine ridge in general (pine), in the mountain pine woods only (mt pine), mainly in the north (n), or mainly in the south (s). If the country is listed without any modifiers, the bird is to be expected more or less throughout the country in suitable habitat.
El Salvador (El Sal) has one mountain peak rising about 9000 feet (about 2700 meters) above sea level and several above 6000 feet (about 1800 meters), as well as lowlands extending to the shores of the Pacific Ocean. It would fit into the regional system used in Mexico and Guatemala. For more precise designation of range the text sometimes uses parenthetical modifiers following the country abbreviation: (n) refers to birds occurring mainly or only in the northern part of the country; (w) to those restricted mainly to the western part; (e) to the very few species restricted to the eastern part; and (cstl) for birds restricted mainly to the coastal area (up to three miles inland or up to three miles offshore). As in the case of Belize, if no modifier is used, the bird can be expected in most parts of the country where suitable habitat exists. The affinities of the birds of El Salvador are mostly with the birds of the Pacific lowlands and adjacent lower-mountain to mid-mountain slopes of Guatemala and Mexico.
Reading the Species Write-ups
Most parts of the species write-ups, other than the range designations, are self-explanatory, but in case there is any doubt, here is a sample write-up, followed by an explanation of each portion in succession:
BLUE-CROWNED MOTMOT  Turco Real Momotus momota
Range Mex-SAm. Res Mex (sPac, c.nAtl-sAtl, Yuc), Blz, Guat (Pac, Atl), ElSal.
Habitat River-border woods, dry or humid forest, overgrown orchards.
Voice A low-pitched hoot, hoot.
Field Marks 16" Green above, or with some rufous; olive-green or rufous below; crown pale blue with black border (nAtl, n.cAtl) or crown with black center, then blue circle, then black border (s.cAtl, sAtl, sPac, Yuc); short bare space on racket-tipped tail; black ear streak and chest spot.
- Blue-crowned Motmot
- Each entry begins with the English name (the common, or vernacular, name) for the species adopted by the American Ornithologists'Union (AOU). In a few cases, part of the name appears in parentheses, as in "(Lesser Yellow-headed) Savanna Vulture" or "Ruddy (Crake) Rail." The parentheses in the first example indicate that the AOU currently uses the specific common name "Lesser Yellow-headed" for this vulture, but I prefer the name "Savanna." In the second example, it is the group name that differs: the AOU places this species in the group crake, but I prefer to call it a rail. In all such cases both names appear in the index. If the difference is very slight, for example between my usage of the more grammatically correct and precise "Spotted-breasted Wren" and the AOU's "Spot-breasted Wren" (does the wren have one spot or more than one?), parentheses are not used, and the AOU version of the name is not shown in the Index.
- A number in brackets following the English name indicates that the species is illustrated on that plate. The color plates are numbered 1 through 48. The black-and-white plates, numbered I, II, III, and IV, follow the color plates.
- "Turco Real"
- This is the Spanish name for the species; in almost every case it is either the Spanish name I used in the second edition or the name used by Peterson and Chalif in their book Aves de Mexico.
- Momotus momota
- The scientific name of the species, in Latin form, corresponds to the name currently accepted by the AOU.
- In this category, the overall range of the bird in the Western Hemisphere, excluding the Antilles, is given first. "Mex-SAm" indicates that this particular motmot occurs in Mexico, in all the countries between Mexico and South America (i.e., Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama), and on into South America. There is no attempt to indicate the details of its distribution in South America. If the bird occurs from the contiguous United States to some country in South America but is absent from El Salvador, this part would be written "US-SAm, exc ElSal." If the species is to be found from Alaska to western Nicaragua, but not in Belize and Honduras, it would be written "AK-Mex, Guat, ElSal, Nic."
The bird's seasonal status and distribution within its overall range are given next. "Res Mex (sPac, c.nAtl-sAtl, Yuc), Blz, Guat (Pac, Atl), ElSal" means, first, that the species is resident (found year-round) in Mexico, Belize, Guatemala, and El Salvador. Other seasonal status abbreviations are "sum" (found in the summer), "tr" (transient, travels through seasonally, as in the spring and /or fall), "win" (found in the winter). Second, the parenthetic abbreviations indicate that it does not occur throughout Mexico but only in the southern Pacific subregion (sPac), all of the Atlantic Region except the northernmost part of the northern Atlantic subregion (c.nAtlsAtl, meaning central nAtl through the cAtl and sAtl subregions), and generally throughout the Yucatan Region (Yuc); and only in the Pac and Atl regions of Guatemala. (If the range included all the Pacific Region within Mexico, it would be abbreviated simply Pac. If it included only the central and southern Pacific subregions, it would be abbreviated csPac.) Third, the lack of parenthetic statements for Belize and El Salvador indicates that the bird is rather generally distributed throughout those countries in proper habitat. This statement doesn't attempt to provide any further details about the bird's occurrence in countries other than the four countries in our area of coverage. If the bird does not occur in a country, that country is not mentioned in this part of the species write-up.
Some range descriptions will end with a statement of relative abundance. To show how this works, let's compare the Blue-crowned Motmot's entry with the Keel-billed Motmot's ("Very rare, local"). The Blue-crowned Motmot write-up, by omitting any statement of relative abundance, indicates that the bird is likely to be seen often enough in the proper habitat and range that an average birder would not have to be told that someone else might think it is common, fairly common, or abundant. Expectations created by the use of such terms vary so widely from person to person that they are practically meaningless, especially when one word purports to cover the bird's status over its entire range in our area. The words "rare," "very rare," "local," or "irregular," on the other hand, are more likely to connote much the same status to each birder, regardless of the species being discussed or the background of the birder. Therefore, those terms are useful in describing the Keel-billed Motmot.
- This category describes the bird's preferred habitat, concentrating on water features, geological features, and characteristic vegetation. Some write-ups also mention where the bird is likely to be seen within that habitat. For example, the White-breasted Hawk's habitat is described as "cloud forest or other dense humid forest, or partial clearings," and the bird can be seen "flying rapidly among the trees or perched in middle branches."
- A description of the voice (song, call, or alarm note) has been included for most birds that are secretive or nocturnal and those that have simple distinctive songs or calls. The reader is urged to purchase some of the commercially available recordings of birds of our area.
- Field Marks
- This category begins with the length of the bird from tail tip to bill tip, in inches (in the Blue-crowned Motmot's case, 16 inches). The measurement is usually obtained from a museum specimen lying on its back; nevertheless, as an indicator of relative size, it can be very useful. For example, the smaller Keel-billed Motmot is listed at 13 inches, and the much smaller Tody Motmot is listed at 7 inches. When two measurements are listed in this space, the first refers to the size of the male and the second to the size of the female. Following the length is a brief physical description of the species, condensed from a much longer description in the first edition, retaining only the more important diagnostic features. In many species the male plumage differs from that of the female and of the immature birds, in which cases separate descriptions are included. Subheadings within the Field Marks category include M (male), F (female), adt (adult), imm (immature), sum (summer plumage), win (winter plumage), various morphs, and others. A few species have distinctive behavioral characteristics that may aid in field identification. In those cases the behavior is noted before the physical description.