Ticul Alvarez

“ The time is excellent for the establishment of the wildlife refuges [Pg 384] in Tamaulipas because large areas are still in Federal ownership and because a considerable number of animals remain. Other favorable factors are that roads are not yet good in the areas proposed for refuges, the human population is low, and agriculture consequently is not practiced. But, with the rapid increase in population in México, these favorable conditions will change in a few years and it will be almost impossible to establish the refuges then. ”

“ Examination of more material and taking into consideration the relation between the interorbital constriction and the greatest length of skull, cause me here to refer those specimens to peragrus.
Hooper (1953:8) reported three young specimens from Rancho Pano Ayuctle as of the subspecies aquaticus, but study of two adults from the same locality reveals that this locality should be included within the geographic range of peragrus. ”

“ Considering that México has no professional trappers and that commerce in skins of wild animals is illegal, it is felt that the number of skins found in the tanner's shop indicated a relative large population of game mammals.
The number of species of small game also is large. Some species are killed by natives for food, but most are killed in order to protect the cultivated crops, which are injured mainly by rabbits and squirrels. ”

“ Comparison of 10 specimens of B. a. flavus from Coahuila and Texas with two of B. a. astutus (Distrito Federal, 1; Las Vigas, Veracruz, 1) from central México reveals that the skulls do not differ qualitatively and that the skull of flavus tends to be smaller and relatively wider, but that there is overlap in size. In all flavus that I measured and in the two adults of astutus the tail is shorter than the head and body. The only real difference is the color; ringtails from Texas are deep fulvous instead of grayish as is [Pg 457] astutus from the Distrito Federal and Veracruz. ”

“ It is understandable, therefore, that the natives kill the animals. In this way they protect their cultivated fields, obtain food and sometimes money for the skins. Many natives, however, destroy the wildlife only for pleasure or to obtain money for skins and meat, which sometimes is sold to restaurants.
Probably the best solution for the problem of conservation of wild animals is the establishment of wildlife refuges. In Tamaulipas, at least three refuges are needed in order to preserve the mammalian wildlife. ”

“ The Río Grande, as was pointed out by R. H. Baker (1956:146) , has low banks, is relatively shallow, and does not form an effective barrier for most mammals. For only two species, insofar as I know, has the Río Grande constituted a barrier. Cratogeomys castanops has not entered southeastern Texas from México, and Spermophilus spilosoma has not entered México from southeastern Texas except on the coastal barrier beach. Alvarez (1962:124) postulated that the beach was the route by which S. spilosoma arrived at La Pesca where the barrier beach meets the mainland. ”

“ When one deer in a night can destroy part of the corn, and in some areas not only one deer but several invade a field, and when one considers that besides deer there are rabbits, squirrels, raccoons, and coati, to name only some animals that feed on the corn, we find that the small cornfield at the end of the season may not contain any corn to harvest. ”

“ ACCOUNTS OF SPECIES AND SUBSPECIES Didelphis marsupialis
Opossum
The opossum occurs throughout Tamaulipas but is commonest in the south, especially in the areas of tropical forest and along water courses. Most of the specimens examined were caught in steel traps baited with remains of small animals (mostly mammals and birds, but one trap was baited with the head of a black bass) . At Villa Mainero five individuals were caught in one night in five of seven traps scented with spilogale musk. ”

“ One specimen from nine miles southwest of Tula was caught in an outcrop of rocks and two others were taken among bushes on the desert. A female on October 10 carried 4 embryos 2 mm. in crown-rump length.
Specimens of P. melanophrys here listed are the first to be reported from Tamaulipas. They are assigned to the subspecies consobrinus on the basis of dark color and because their size closely corresponds to that of the holotype. The specimen from the vicinity of Palmillas and one from Miquihuana (56408) are larger than the others and grayish. ”

“ From Tamaulipas, the northeasternmost state in the Mexican Republic, 146 kinds of mammals, belonging to 72 genera, are here reported. Mammals that are strictly marine in habit are not included. The state is crossed in its middle by the Tropic of Cancer. Elevations vary from sea level on the Golfo de México to more than 2700 meters in the Sierra Madre Oriental; most of the state is below 300 meters in elevation. Its area is 79,602 square kilometers (30,732 square miles) . ”

“ With the establishment of these three refuges and with good management the fauna of Tamaulipas could be saved from extinction, would provide some recreation for sportsmen, and especially for the people in general who wish to study, photograph, or merely observe the native animal life. ”

“ Nycticeius humeralis has the same distributional pattern in Tamaulipas as has Lasiurus borealis in that both are represented there by two subspecies, one known only from Matamoros and the other occurring in the rest of the state. Bats of this species (N. h. mexicanus) from Ciudad Victoria and some from the Sierra de Tamaulipas were shot in flight in evening; others from the last-mentioned locality were taken in mist nets. Lactating females (22 specimens) were collected in June and July. ”

“ The Montane route was used by mammals of boreal affinities (Microtus and Neotoma) , that moved into Tamaulipas from the north; also in this category are bats of the family Vespertilionidae. For movement from south to north, the route was used by several species native to México, for example, Cratogeomys castanops. The [Pg 378] seaward slope of the montane area has enabled some tropical mammals to move farther north than they have done at higher and lower elevations. Philander opossum seems to be an example. ”

“ 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.
[Pg 376]
The mammalia fauna of the Veracruzian Biotic Province is tropical in nature. ”

“ Several came from the Great Plains, and a few came from the eastern part of the United States. Also, a few mammals that may have originated in the Tamaulipan Province moved northwards. Some of these, according to Dice (1937:267) were Liomys irroratus texensis, Peromyscus leucopus texensis, and Lepus californicus merriami. Other mammals thought to have moved north by this route are Didelphis marsupialis, Dasypus novemcinctus, Oryzomys palustris, Nasua narica, and Tayassu tajacu. Some mammals that passed through Tamaulipas into Texas have extended their geographic ranges far north of Texas. ”

“ Considering the 48 genera of non-flying land mammals of Tamaulipas, 24 genera occur in habitats from the North American part through habitats of northern México into the Brazilian Subregion. Of the remaining 24 genera, 16 occur in the North American part of the Nearctic Subregion or in it and the part of northern México north of the Brazilian boundary, whereas eight occur in the Brazilian Subregion or in it and the northern part of México. None occurs only in Tamaulipas or only in northern México. ”

“ Of 53 specimens examined, 17 are black and one from 70 kilometers south of Ciudad Victoria is clearly more whitish than the others. Specimens from the northeastern part of the range of the species (= southeastern Tamaulipas) average darker than those from the south and west. In individuals that are not black, the ventral reddish color covers the shoulders and in some it extends between the shoulders to the median dorsal area. ”

“ Careful comparisons of the specimens from one mile south of Altamira with topotypes of G. personatus personatus (and specimens of other subspecies) indicate that tropicalis differs from personatus in a number of important characters, some of which tropicalis shares with Geomys arenarius of the Rio Grande Valley and adjacent areas in Texas, New Mexico, and Chihuahua (see Table 2) . ”

“ Greatest length of skull is a case in point. The difference in size is reflected in the weights. Average weights of nine males and nine females from southern localities are, respectively, 14.7 (12-16.5) and 13.8 (12-15.5) instead of 18.5 (17-20) and 17.0 (15-18) grams for four males and six females from the northern localities. In general, Tamaulipan specimens average somewhat smaller than those from other localities in eastern México (see measurements given by Baker, 1956:238, Dalquest, 1953:107, and Osgood, 1900:53) . ”

“ In this official program some lectures in conservation are needed with reference to the animal life. I know that some education now is given to people with respect to conservation of the water, soil, and forest, but gather that there is little that covers also conservation of animals. ”

“ 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 ”

“ Distribution in Tamaulipas.—Tropical forest in southern part of state, north to Rancho Santa Rosa and Padilla.
In Tamaulipas this squirrel is called "ardilla chica" or "ardilla barcina," and is abundant in areas where tall trees and dense brush prevail. This species evidently does not have restricted periods of activity, as does S. aureogaster, but is active throughout the day. At El Carrizo a nest, nine to 10 inches in diameter and constructed of leaves and small sticks, was in a thick tangle of branches 25 feet above the ground. A male having testes 11 mm. ”

“ Distribution in Tamaulipas.—Known only from the barrier beach in northeastern part of state.
The specimens examined are referred, tentatively, to Geomys personatus personatus on geographic grounds. They average smaller in all measurements than personatus (but are larger than G. p. megapotamus) , do not have the sagittal crest that usually is present in personatus, and the shape of the pterygoid bones is distinctive. In personatus and megapotamus the ventral border of the pterygoids (in lateral view) is convex instead of nearly straight as in specimens from the barrier beach. ”

“ Tamaulipan specimens do not differ significantly in external or cranial measurements in comparison with the specimens from Veracruz reported by Dalquest and Hall (1949:154) , but do differ in color. Most are in the gray phase and are Avellaneus (grayish with yellowish hairs mixed) instead of Clay Color as are specimens from Veracruz; those few in the red phase are between Clay Color and Tawny-Olive instead of between Burnt Sienna and Chestnut. By consequence, bats from Tamaulipas resemble in color the smaller N. s. mexicanus of western México to a greater degree than they resemble N. s. ”

“ 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 ”

“ Considering the distinctive combination of characters possessed by tropicalis, and its isolated, restricted geographic range (the nearest known record of Geomys is approximately 165 miles to the north) , tropicalis is here regarded as a full species. A skull alone examined from 10 miles northwest of Tampico does not differ from those of other specimens studied.
The average weight of five non-pregnant July-taken females was 189.4 (180-200) grams. Weights of three males were 280, 270, and 255 grams. Females are in all measurements smaller than males. ”

“ 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 ”

“ At Cueva La Esperanza, 300 feet deep and on the east side of the Sierra Madre Oriental, four different congregations of vampires were found along with about 400 Natalus. A male Desmodus obtained in a cave 13 miles west and six and a half miles north of Jiménez also was associated with Natalus.
Females with embryos or in lactation were collected as follows: [Pg 406] Rancho Pano Ayuctle, March 10, one pregnant female (embryo 40 mm. in crown-rump length) ; Río Sabinas, May 23, two pregnant females (embryos 36 and 43 mm.) ”

“ People need to eat fresh meat and for some it is almost impossible to obtain meat in any other way than by killing wild animals. Some natives cannot afford to purchase meat in the markets or they live too far from any village or city to do so. ”

“ Eight of the 11 Mexican species that are considered as Big Game are recorded from the state. Until this century Tamaulipas was not densely populated by man either in the pre-colonial period or thereafter. Therefore many species of game are still relatively abundant. ”