Coastal Plain Of Chiapas Research Articles

La tángara azul gris (Thraupis episcopus) en el estado de Guerrero, México

Registramos a la tángara azul gris (Thraupis episcopus) en la planicie costera del sureste del estado de Guerrero, México, en áreas urbanas con cobertura de árboles dispersos de especies nativas e introducidas. El área de distribución actual conocida para el taxón comprende tierras bajas del este de México, desde el centro-sur de Nuevo León hasta la península de Yucatán, incluido el este de Oaxaca y en la vertiente del Pacífico en la planicie costera de Chiapas. Sin embargo, no existen registros pre­vios publicados de la especie en Guerrero. Posiblemente T. episcopus es una especie que ha expandido su área de distribución en episodios de dispersión activa.

CLASSIC-PERIOD RITUAL CERAMICS FROM THE COAST OF CHIAPAS, MEXICO

AbstractIn 1947 Philip Drucker excavated an unusually dense concentration of artifacts from the plaza of a small Late Classic site on the inner coastal plain of Chiapas, Mexico that he proposed was a possible end-of-cycle ceremonial dump. Although the deposit contained both utilitarian and ritual items, only some of the latter have survived for present day investigation. Here we describe Drucker's excavations and the surviving ritual items, neither of which had ever been published in detail. We also examine archaeological expectations for end-of-cycle dumps based upon ethnohistoric descriptions of this Mesoamerican ritual practice and we explore the iconography of effigy censers, which constitute an important set of the items that Drucker collected. We conclude that this singular deposit most likely represents the material remains an end-of-cycle ritual as Drucker had originally proposed.

Socioeconomic factors, attitudes and practices associated with malaria prevention in the coastal plain of Chiapas, Mexico.

BackgroundMexico is in the malaria pre-elimination phase; therefore, continuous assessment and understanding of the social and behavioural risk factors related to exposure to malaria are necessary to achieve the overall goal. The aim of this research was to investigate socio-economic backgrounds, attitudes and practices related with malaria in rural locations from the coastal plain of Chiapas.MethodsIn January 2012, 542 interviews were conducted to householders from 20 villages across the coastal plain of Chiapas. Questions were about housing conditions, protection from mosquito bites and general information of householders. Chi2 analyses were performed to see whether there was a dependence of those reported having malaria with their house conditions and their malaria preventive practices. Results were discussed and also compared statistically against those obtained 17 years ago from the same area.ResultsMost households had 2–5 people (73.6%), 91.6% of houses had 1–3 bedrooms. The physical structure of the houses consisted of walls mainly made of block or brick 72.3%, the floor made of cement 90.0%, while the roof made of zinc sheet 43.9%, and straw or palm 42.2%. A 23.1% of the interviewed completed elementary school and 16.6% was illiterate. A 9.9% of the residents reported at least one family member having had malaria. A 98.1% of families used some method to prevent mosquito bites; those using bed nets were 94.3%. Almost 72% of families bought products for mosquito protection. A total of 537 out of 542 families agreed with the indoor residual spraying (IRS) of insecticide and a frequency of application as often as every two months was preferred.ConclusionHousing conditions and malaria preventive practices have improved in these rural areas in 17 years, which could be in favor of malaria elimination in this area. Information generated by this study could help in the decision making about whether to use insecticide as indoor residual spraying or to implement massive distribution of long-lasting impregnated bed nets, considering the number of bedrooms and the structure of houses in the region, which may lead to a more efficient vector control for the coastal plain of Chiapas.

Knowledge and beliefs about malaria transmission and practices for vector control in southern Mexico.

To investigate the knowledge and beliefs about malaria transmission and practices for vector control in eight villages on the coastal plain of Chiapas, Mexico. A cross-sectional survey was conducted during May and June 1995 in Chiapas, Mexico. A questionnaire to investigate family structure, knowledge on malaria transmission, preventive measures and attitudes towards seeking treatment was applied to both family heads of a sample of households. Associations were analyzed by estimating odds ratios with confidence intervals and p values, using bivariate and multivariate logistic regression methods. Malaria knowledge was poor and only 48% associated malaria with mosquito bites. The perceived benefit of indoor residual spraying was associated to a reduction of mosquitoes, a reduction in the numbers of cockroaches and rats, but only 3% associated it directly with the prevention of malaria transmission. Most villagers (97.6%) agreed with the indoor residual spraying of insecticides. Ninety nine percent of villagers had mosquito bednets, 75.7% used them all year round. Other measures used by villagers to prevent mosquito bites were smoke and mosquito coils. Above 40% of villagers self-medicated when any member of the family had a fever episode, but 51% attended proper health services (community dispensary, private physician, health worker). About 61% used pesticides for agricultural or livestock purposes and 55% applied themselves. Women had a greater participation as family health promoters, with 70% of the housewives being in charge of the application of self-protection preventive measures. Educational programs aimed at increasing awareness on the participation of mosquitoes on malaria transmission could promote community participation in malaria control in the region. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

Isolated Pasture Trees and the Vegetation under their Canopies in the Chiapas Coastal Plain, Mexico1

ABSTRACTThe Coastal Plain of Chiapas (southern Mexico) was formerly covered by large tracts of subhumid tropical forests but is heavily deforested at present. In this region, 15 pastures were selected to characterize species composition of isolated trees, as well as to describe species composition, growth form patterns, and patterns of dispersal units in the vegetation growing under their canopies. The 65 recorded pasture trees belonged to 20 species and 11 families, of which Fabaceae and Moraceae were the most species‐rich. Coccoloba barbadensis (Polygonaceae) and Enterolobium cyclocarpum (Fabaceae) were the most abundant and frequent trees in the studied pastures. More than half (55%) of isolated tree species were fleshy‐fruited. In the vegetation sampled under pasture trees, 134 species and 45 families were found. Fabaceae and Poaceae had the largest numbers of species. Herbs were the predominant growth form (46.3%), followed by shrubs (23.9%), trees (23.1%), and lianas (2.2%); 6 species could nor be placed in any growth form category. Most species of this flora were fleshy‐fruited (43.3%), followed by heavy, gravity‐dispersed fruits (17.9%). The analysis of dispersal units by growth form category confirmed the prevalence of fleshy fruits, although their predominance was not so obvious among herb species. Almost half (49.2%) of the flora under pasture trees was typical of secondary vegetation; this pattern was true for herbs but not for most woody species, which were typical of primary vegetation. A numeric classification of the vegetation samples taken under pasture trees produced eight floristic groups, all of which were independent of the specific identity of pasture trees. No significant effect of dispersal unit type of pasture tree on the characteristics of the vegetation growing under them was found. Future attempts to re‐create the original forest cover using isolated trees in pastures as regeneration foci should pay more attention to the maintenance of a large specific diversity independently of the dispersal types among these components of tropical landscapes.

Buried Sites on the Soconusco Coastal Plain, Chiapas, Mexico

AbstractA systematic survey was conducted of all river systems along a 100 km segment of the coastal plain of Chiapas, Mexico, in order to find buried archaeological sites. The survey was undertaken because the only known sites of the Late Archaic Period were highly obtrusive shell heaps situated in the littoral wetlands, but they seemed to have been formed by itinerant people; no coeval sites, presumed to have been left by the same group, had been found farther inland on the coastal plain. It is surmised that the “missing sites” had become buried by alluvium but that some of these might be visible in river cuts. Twenty-two such buried sites in river cuts were found and examined during this survey, including one site that possibly dates to the Archaic Period.In addition, a greater understanding was gained of the fluvial processes in the region and their roles as transformers of the archaeological record. This information will be crucial for developing predictive models to locate buried early sites.

Aquatic Vegetation as a Basis for Classification of Anopheles albimanus Weideman (Diptera: Culicidae) Larval Habitats

Larvae of Anopheles albimanus were collected on the Pacific coastal plain of Chiapas, Mexico, from 131 sampling sites representing different larval habitats. For each habitat the total percentage of emergent vegetation, floating vegetation, or both, percentage of cover of individual plant species, amount of phytoplankton, water conductivity, and the number of mosquito larvae collected in 30 dips were recorded. Individual habitats were classified into higher units, or habitat-types, by cluster analysis based on 37 environmental variables. Sixteen clusters, or habitat-types, were distinguished and defined by dominant plant species. Habitat-types were ranked by larval density and categorized as either low, medium, or high producers of A. albimanus .

Hybridization of Rufous-Naped Wrens in Chiapas, México

TEN years ago I had an opportunity to study hybridization between two strongly differentiated subspecies of the Rufous-naped Wren (Campylorhynchus rufinucha) on the Pacific coastal plain of Chiapas, Mexico, near the town of Tonala and the Laguna de la Joya. My investigations in 1954 (Selander, Univ. California Pubis. Zool., 74: 77-116, 1964) showed that C. r. humilis, which occupies xeric habitats in western Mexico, extends southeast from the Isthmus of Tehuantepec to within a few miles of Tonal'a, while the form C. r. nigricaudatus, which is found in relatively mesic habitats on the coastal plain of southwestern Guatemala and southeastern Chiapas, ranges northwest to the southeastern edge of the Laguna de la Joya (Figure 1). Although the Laguna de la Joya forms a partial barrier between populations of these two wrens, they are in contact through the narrow Ocuilapa Valley, which lies inland from the laguna near the base of the Sierra Madre de Chiapas. Field work in the Ocuilapa Valley in 1954 revealed the existence of a linearly distributed series of partially isolated, variable, hybrid populations connecting the two parental forms (see Figure 2, below). On the basis of this finding, it is apparent that the two wrens are conspecific, notwithstanding their considerable morphological differences (Table 1). In March, 1963, nine years after my first study, I revisited the Tonala region while enroute to and from Nicaragua and was able to obtain additional information on the zone of hybridization. The chief purpose of my study in 1963 was to resample certain populations in the central part of the Ocuilapa Valley and, by comparing the samples with those collected at the same localities in 1954, to determine if any change in the character of the zone of hybridization had occurred. Additionally, I sought to determine the extent of introgression of genes of C. r. humilis into the population of C. r. nigricaudatus on the coastal plain southeast of the Laguna de la Joya. Finally, I was able to determine more precisely the distances between collecting stations in the Ocuilapa Valley. For a discussion of the physiographical and ecological setting of the zone of hybridization and an analysis of characters in the hybrids, the reader should consult the detailed account in my earlier paper (Selander, op. cit., pp. 80-105). This research was supported by the National Science Foundation (Grants 20873 and GB 1624).