  Merriam (1898) assigned to Tamaulipas four Life-zones. There were: Transitional on the highest elevations of the Sierra Madre; Dice (1943) outlined Biotic Provinces on a map of North America and in the northern part of Tamaulipas showed two Biotic Provinces, Tamaulipan and Potosian. He did not show the southeastern limits of the Chihuahuan Biotic Province nor any of the limits of the Veracruzian Biotic Province and in text mentioned nothing about the limits of these two provinces with reference to Tamaulipas. Later, Goldman and Moore (1946) divided Tamaulipas in three Biotic Provinces: Tamaulipas, Sierra Madre, and Veracruz. Still later (1949), Smith published a map of Mexican Biotic Provinces based on the herpetofauna of the Republic. He divided Tamaulipas among four Provinces. Two were Nearctic (Austro-oriental and Tamaulipan) and the other two were Neotropical (Veracruzian and Cordoban). Leopold (1950 and 1959) recognized five principal vegetational types in Tamaulipas as follows: Mesquite-grassland; Pine-oak Forest; Thorn Forest; Tropical Deciduous Forest; and Desert. For dealing with the mammals of Tamaulipas in the following accounts the four Biotic Provinces (Tamaulipan, Potosian, Veracruzian, and Chihuahuan) of Dice are the most useful. For dealing with types of vegetation in the accounts that follow, Leopold's (1950) system is employed although reference is made to other associations and formations that have been reported in Tamaulipas. Tamaulipan Biotic ProvinceThis Province is recognized by most authors who have written about the zoogeography of MÉxico. It is the most extensive in the state and includes the northern part of the Coastal Plain (see Fig. 2). The vegetation of the Tamaulipan Biotic Province is in general Mesquite-grassland but in the Sierra San Carlos and Sierra de Tamaulipas other types of vegetation are found. Two formations occur in the Mesquite-grassland. The first is the Mesquite Scrub, in which the dominant plant is the mesquite (Prosopis juliflora), associated with Cordia boissieri, several species of Acacia, and in some areas with Opuntia and Yucca treculeana. The dominant grasses are of the genera Bouteloua and Andropogon. The second formation is the Gulf Bluestem Prairie, where species of Andropogon are the dominants on the well-drained sites. Sloughs and depressions are occupied by cordgrass, Spartina spartinae. Many areas have been invaded by mesquite and other shrubs. Around the Sierra de Tamaulipas and in the area between it and the Sierra San Carlos the vegetation is Thorn Forest (Tropical Thorn Forest of Martin et al., 1954), in which the dominant plants are Acacia, Ichthyomethia, Ipomea, Prosopis, and Cassia. Another type of vegetation in the Sierra de Tamaulipas is the Tropical Deciduous Forest at 300 to 700 meters elevation, the trees of which are 20 meters high with a canopy averaging eight meters high (Martin et al., op. cit.). The common species of trees belong to the genera Tabebuia, Ipomea, Bombax, and Conzattia. Species of Bursera, Acacia, and Cassia are less abundant. In the low canyons Bursera, Ceiba, and Psidium, draped with lianas and various epiphytes, can be found. The Pine-oak Formation grows above an elevation of 800 meters in the Sierra de Tamaulipas and is characterized by Pinus cembroides, P. nelsonii, P. teocote, and Quercus arizonica. Martin et al. (op. cit.) recorded Montane Scrub from the dry areas, between elevations of 600 and 900 meters. That scrub is formed by huisaches (Acacia farnesiana) along with a few oaks and some trees of the Tropical Deciduous Forest. The vegetation of the Sierra San Carlos was studied by Dice (1937) and divided into three life belts, each with several associations. For more information about the plants of each association and their related mammals see the publication of the mentioned author. Endemic mammals of the Tamaulipan Biotic Province, in the part of it that is in Tamaulipas, are the following: Scalopus inflatus; Lepus californicus curti; Spermophilus spilosoma oricolus; Cratogeomys castanops tamaulipensis; Dipodomys ordii parvabullatus; and Sigmodon hispidus solus. Other characteristic mammals of this Province in the state of Tamaulipas are: Sylvilagus floridanus connectens; S. audubonii parvulus; Lepus californicus merriami; Perognathus merriami merriami; Dipodomys ordii compactus; Orzomys melanotis carrorum; Reithrodontomys fulvescens intermedius; Peromyscus boylii ambiguus; Canis latrans texensis; C. l. microdon; C. lupus monstrabilis; Taxidea taxus berlandieri; Mephitis mephitis varians; Felis pardalis albescens; Trichechus manatus latirostris; and Odocoileus virginianus texanus. Many other kinds of mammals occur mainly in the Tamaulipan Province but are not listed above because they occur also in one or more of the other provinces. The Sierra de Tamaulipas is placed in the Tamaulipan Biotic Province because the fauna, especially of non-flying mammals, is closely related to that of the rest of the Province. Nevertheless, many mammals found in this Sierra are tropical in relationship. This is especially true of the bats. Therefore, most of the tropical bats that occur in Tamaulipas occur in the Veracruzian Biotic Province and in the Sierra de Tamaulipas. Potosian Biotic ProvinceThis Province occupies all of the Sierra Madre Oriental and, therefore, the southwestern part of the state. The vegetation in general is Pine-oak Forest, in which the most common trees are Abies religiosa, Pinus flexilis, P. patula, P. montezumae, In his study of plants of the GÓmez FarÍas area, Martin (1958) recorded several different types of vegetation, which in part can be placed in the Potosian Biotic Province, especially those types that occur to the northwest of the Cloud Forest. In addition to the Cloud Forest, Martin recognized Humid Pine-oak Forest, Dry Oak-pine Forest, Chaparral, Thorn Forest and Scrub, and Thorn Desert. The only mammal endemic to the Potosian Province in Tamaulipas is Cryptotis pergracilis pueblensis. Other mammals that occur mainly in this Province are: Sorex saussurei; Notiosorex crawfordi; Glaucomys volans herreranus; Cratogeomys castanops planifrons; Perognathus nelsoni; Liomys irroratus alleni; Reithrodontomys fulvescens griseoflavus; Microtus mexicanus subsimus; Ursus americanus eremicus; Conepatus leuconotus texensis; and Odocoileus hemionus. The fauna of this Province is a mixture of elements with tropical affinities on the east side of the Sierra Madre and with those of the Mexican Plateau on the west side. Chihuahuan Biotic ProvinceThis Province occurs in Tamaulipas only in a small portion of the Central Plateau physiographic region and occupies the southwesternmost part of the state. The vegetation is of two types: Desert or Mesquite-grassland. The last is like that described for the Tamaulipan Biotic Province. In the Desert type the dominant plants are the cactus, Opuntia leptocaulis, and yuccas, Yucca filifera and Y. potosina. Subdominants are mariola, guayule, Agave lechugilla, A. stricta or Larrea divaricata. Along stream banks mesquite, Prosopis juliflora, can be found. No endemic mammals of the Chihuahuan Province are known in Tamaulipas. Mammals that occur principally in this Province are: Dipodomys merriami atronasus; D. ordii durranti; Peromyscus melanophrys consobrinus; P. difficilis petricola; Onychomys torridus subrufus; and Neotoma albigula subsolana. Veracruzian Biotic ProvinceThis Province includes the southern part of the Coastal Plain physiographic region, south of the Sierra de Tamaulipas and Soto la Marina. But the exact line between this Province and the Tamaulipan Province to the north is difficult to draw. The northern boundary of the Veracruzian Province is the line between the Nearctic and Neotropical regions in eastern MÉxico. Vegetation of most of the Veracruzian Biotic Province is Tropical Deciduous Forest. This Forest is made up of Tabebuia, Ipomea, Bombax, and Conzattia, along with some Ceiba, Bursera, and Psidium. The mammalia fauna of the Veracruzian Biotic Province is tropical in nature. This is especially true of the bats. Representatives of the tropical genera Micronycteris, Sturnira, Artibeus, Enchistenes, Desmodus, Diphylla, and Molossus have their northern distributional limits in this Province. The non-flying mammals characteristic of the Province in Tamaulipas are: Philander opossum pallidus; Marmosa mexicana; Ateles geoffroyi velerosus; Geomys tropicalis; Oryzomys melanotis rostratus; O. alfaroi huastecae; O. fulvescens engracie (endemic to this Province in Tamaulipas); O. f. fulvescens; Reithrodontomys mexicanus; Peromyscus orchraventer (endemic); Neotoma micropus angustapalata; Eira barbara senex; Felis wiedii oaxacensis; and Mazama americana temama. |
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