Talk:Desert Tortoise

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[edit] Capitalization

so I made everything lowercase as that's my personal preference. --Xanzzibar 19:51, 26 February 2006 (UTC)

[edit] Most important information is so far lacking on this page

Conservation status of the desert tortoise is both enormously controversial and also economically critical. Mohave populations of the desert tortoise were listed as Threatened by the US Fish and Wildlife Service in 1990 based on population estimates showing great declines. At the time of this listing, with hundreds of thousands alive, it was the most numerous land animal ever proposed for this status by an order of magnitude. Only the delta smelt (a California fish species) was listed with higher numbers.

It is clear that desert tortoises in many areas have declined. it is also clear that ravens (attracted by human trash and preying on small tortoises), land conversion and subdivisions, military activities, off-road driving, and disease (possibly worsened by human transport) all cause harm to tortoises. It is also clear that large, similar (to humans) appearing desert areas may have strikingly different numbers of tortoises and that some areas have much higher populations than others. Although it is easy to propose "death by a thousand cuts" and the added negative effects of climate change... The ultimate question of what is causing tortoises to decline is unanswered. In particular, the question of whether wholly protected areas (such as National Parks) are immune to these declines has not been adequately studied. The latter point could help discern whether declines were due to direct human actions or activities that don't stop at boundaries.

One of the reasons great controversy has always surrounded the desert tortoise status is because there are still no currently existing, reliable methods for estimating their numbers. Because these animals are cryptic (living in deep burrows they excavate in the soil) and because most areas contain very sparse populations (i.e., the natural density is low) the normal methods used in mark/recapture studies may be ineffective and low numbers of captures may cause failure of the mathematical models normally used for population estimation. Various "recovery plans" for the desert tortoise have been published each proposing some different population sampling method. So far, all such proposed methods have mathematical or logistical failings rendering their results unreliable or actually wrong.

There are relatively few published, peer-reviewed, scientific papers on how to count desert tortoises and to arrive at reasonable estimates. These papers need to be summarized herein or at least referenced in some way. At the very least, existence of this subject needs inclusion on the desert tortoise page.24.113.26.115 07:22, 15 July 2007 (UTC)