The Cuatro Cienegas basin is an hourglass-shaped intermontane basin of about 50 km long and 8 to 24 km wide (about 600 sq. km), its floor being at 720 m altitude. Much of the central part of the basin is marshy, with dry sandy slopes leading up the rocky valley slopes. A number of deep (up to several metres) ponds occur within the marshy area, and retain crystal-clear water throughout the year. About half the bottom is covered by dense submerged aquatic vegetation (mainly Chara), the other half is bare sediment. Waterlilies grow in the shallow parts, and thick stands of cattails (Typha) and Eleocharis fringe the ponds. Water temp is about 27 to 29 degrees C. Ponds may be separated from dry nesting areas on the slopes by substantial distances (several 100 m) of flat marshy grassland. (Webb and Legler 1960).

Within this basin, T. taylori has only been encountered in the river and clear deep pools, but not in the marshy areas (Legler 1960).

T. taylori appears to be predominantly vegetarian (Legler 1960).
Apparently no information is available on reproduction.

T. taylori intertgrades or hybridizes with T. scripta elegans in the Rio Chiquito/Rio Nadadores from it flows out of the Cuatro Cienegas basin, to the degree that the entire population inhabiting the river for over 30 miles outside the basin is intermediate in characteristics (Legler 1960, 1963).

Red List Category

Red List Criteria

Version

2007

van Dijk, P.P. & Flores-Villela, O.

Buskirk, J.R., Iverson, J.B., Rhodin, A.G.J. & Vogt, R.C. (Tortoise & Freshwater Turtle Red List Authority)

The species is listed as Endangered because it is restricted to a single basin of about 600 sq. km, and it does not occupy the entire basin since the species is restricted to aquatic areas. Within this restricted range it is subject to progressive human-induced habitat loss through desiccation resulting from water extraction, and human utilization of the land for agriculture and general development.
The species is potentially subject to hybridization by an invading relative Morphological evidence suggests that hybridization is happening, but the molecular studies have not been done.

In 1960 this was the commonest turtle in the Cuatro Cienegas basin, outnumbering Apalone about five to one (Legler 1960, Webb and Legler 1960).

Decreasing

T. taylori intergrades or hybridizes with T. scripta elegans in the Rio Chiquito/Rio Nadadores from where it flows out of the Cuatro Cienegas basin, to the degree that the entire population inhabiting the river for over 30 miles outside the basin is intermediate in characteristics (Legler 1960, 1963). The advance of this hybridization zone into the Cuatro Cienegas basin could lead to the genetic pollution, dilution and eventual loss of the taylori genotype and taxon. The date of initial contact between the taxa and thus start of hybridization is uncertain, but was probably facilitated by human alteration of the basin’s hydrology before 1920 (Smith and Smith 1979).

The survival of T. taylori is dependent on the ecological and hydrological integrity of the Cuatro Cienegas ecosystem. The Cuatro Cienegas basin has been extensively altered in its hydrology by digging canals and groundwater pumping for local and regional agricultural irrigation, and for drinking water (Howeth in litt 24 Jan 2007, Flores-Villela in litt. 25 Jan 2007, Hendrickson in litt. 27 Feb 2007). The western side of the basin is experiencing particularly rapid aquatic habitat loss; Laguna Grande was completely dry in 2006 for the first time in at least 50 years (Howeth in litt 24 Jan 2007).

Roads, railroads, pipelines and other infrastructure for industrial, tourism and recreational purposes have impacted the ecosystem, and farming expansion continues at the expense of natural habitat (Reuters 2007), Roads have created direct-mortality impacts (Groombridge 1982 and references therein).

Turtles in general are protected from exploitation under Mexican wildlife and natural resource legislation.

The entire range of the species falls within the 843 sq. km Cuatro Cienegas Flora and Fauna Protection Area (IUCN Category VI), established in 1994. Provided no further major engineering works impact the ecological integrity of the Cuatro Cienegas basin, and the protected area regulations are adhered to, the species and its habitat should be relatively secure; however, recent and ongoing developments as well as plans for further development involve broad-scale ecological processes (water extraction, agriculture, infrastructure development) that will continue to impact the habitat in the foreseeable future. Such development must be managed and their impacts minimized as much as possible.

More information on the population status, natural history, of the species, and the general conservation situation of the Cuatro Cienegas basin, are urgently needed.
A study of the effects of intergradation/hybrisdization of taylori with scripta elegans is needed, and insurance colonies of taylori may be contemplated.