Pygmy hog in Endangered land: Louse Talk

The pygmy hog sucking louse is a parasite, or an organism that lives on or in another organism (called a host) and gets its nourishment from that host. The louse lives only on the pygmy hog, the smallest of all pig species. Because it lives on the hog’s body surface, the louse is known as an ectoparasite.

Biologists (people who study living organisms) have not yet been able to collect a male louse specimen. Female pygmy hog sucking louses measure about 0.15 inch (0.38 centimeter) in length. They are wingless and have flat, leathery bodies. Their legs are strong with powerful claws for clinging to the hairs on the pygmy hog’s body. These louses feed only on the hog’s blood, and their mouths are specially developed for piercing and sucking.

Biologists do not know exactly how the louses reproduce. Mating seems to take place between males and females on a host hog. Females attach their eggs to the hairs on the hog’s body, and the eggs hatch in about two weeks.

The pygmy hog sucking louse cannot survive apart from the pygmy hog. Therefore, it is found only where pygmy hogs are found. The primary habitat for these hogs is dense, tall grasslands. The greatest number of hogs is found mainly in Manas Wildlife Sanctuary and Barnadi Wildlife Sanctuary, both located in northwestern Assam (a state in far eastern India). Biologists estimate that less than 300 pygmy hogs currently exist.

The greatest threat to the pygmy hog sucking louse is the loss of its host, and the pygmy hog is one of the most endangered mammals in the world. Hunting has reduced the number of pygmy hogs, but destruction of the animal’s habitat is the main reason for its decline. The upland savannas of northern India are fertile, and farmers routinely set fires to these grassland areas to clear them to create farms. The extensive fires often kill many pygmy hogs because they cannot escape in time. Those that do escape are forced onto very small grassland areas where they are sometimes killed by unexpected fires or by hunters.

In 1985, the International Union for Conservation of Nature and Natural Resources (IUCN) placed the pygmy hog on its first list of the 12 most threatened species in the world. The following year, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) designated the Manas Wildlife Sanctuary as a World Heritage Site. In India, the pygmy hog has been granted the maximum legal protection

allowed.

Despite these protective measures, pygmy hog habitat continues to be destroyed. If nothing is done to stem this destruction, the pygmy hog—and with it the pygmy hog sucking louse—will disappear.

(Ref:Endangered species / Sonia Benson & Rob Nagel).

Annual Research Seminar 2008 (Wildlife Institute of India)

A critical issue in conservation biology is the establishment of a strong relationship between species richness and a surrogate index. Such a relationship could provide the basis for the establishment of cost effective and easy to monitor methods for measuring biodiversity, providing an alternative for the prioritization of sites for conservation. Both family and genus richness are tested in their ability to predict the number of spider (Araneae) species independently of sampling detection, spatial autocorrelation, area, geographical location and type of habitat. Data from two protected areas of TCA was used as a test case. Genus richness is considered a good surrogate of species richness, despite some caution being needed regarding the comparison of sites with considerably different sampling effort. Only genus alone is found to be reliable either for ranking sites according to taxa richness or for determining near-minimum sets of sites for conservation. The study recommends surrogacy at this higher taxonomic level as a promising approach for the prediction of spider species richness or evaluation and ranking of areas according to their conservation importance.

Annual Research Seminar 2007 (Wildlife Institute of India)

The habitat heterogeneity hypothesis states that the more complex the habitat, the higher the species diversity and structure. The present study analyses the effect of local habitat factors on regional spider richness and diversity. The objective is to untangle the relative importance of habitat structure and other environmental variables. Richness and diversity values of the spider species and family were modeled using multiple regression and a set of independent variables extracted from NMS ordination of vegetation, microclimate and disturbance variables. Vegetation structure, especially height variation in shrubs, plant species richness, tree and shrub densities were found to be important predictors for richness and diversity. The species and family composition is highly influenced by vegetation cover, litter cover and management intensity. Here I also examine the efficacy of spider assemblages as ecological indicators of habitat condition. Using correspondence analysis and weighted averaging, I identified potential indicator species (13 species out of 65 species analyzed) and showed gradients in response to reflect overall habitat condition.

Annual Research Seminar 2006 (Wildlife Institute of India)

This study deals with the comparison of spider diversity and composition in a complex landscape of the TCA characterized by alluvial floodplains of tall grassland interspersed with woodland, swamps, and riparian patches. High water table, annual flooding, and annual grassland fire maintain its dynamic complexity. Spiders were sampled from March 2005 to August 2006 by using pitfall traps and other semi-quantitative collection methods along transects. A total of 3666 adult spiders representing 22 families, 60 genera, and 160 species were recorded. Using the abundance-based estimator, Chao1, the predicted richness for the total area sampled is 173 ± 8.32 (SD) species. This indicates that the inventory was almost complete at the regional scale (92%). With similar proportions of captured species, rarefied richness value showed that species richness was highest in riparian swamp forest. Comparison of different sites revealed that species composition was much more similar within the same vegetation type than among different vegetation types. Assemblage composition differed most between riparian swamp forest and plantation. Family composition varied considerably in relation to the structural quality of vegetation. On a coarse scale, this study revealed the relative importance of diverse habitat types on diversity and composition of spider assemblages in TCA.

Annual Research Seminar 2005 (Wildlife Institute of India)

Spiders currently comprise 109 families, about 3,733 genera, and nearly 40,700 species. Strong evidence supports spider monophyly: cheliceral venom glands, male pedipalpi modified for sperm transfer, abdominal spinnerets and silk glands, and lack of the trochanter-femur depressor muscle. The study began with defining the systematic position of the spiders and reviewing the available taxonomic knowledge of the taxon. It also addresses the past studies in India, the region and the continent. This study provides a baseline inventory of the diversity of spiders including description of anatomical features of spider in general, their relation to classification, and genera of spiders sampled from the TCA.

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