Population variation in the Sonoyta mud turtle at Quitobaquito

Authors: Peter Holm, Tyler Coleman

Year: 2017 (xlix)

Abstract

Quitobaquito is a rare perennial oasis in the Sonoran Desert that was historically connected to the Rio Sonoyta Endemic to this system are the Sonoyta mud turtle, Quitobaquito or Sonoyta pupfish, and an undescribed form of long-fin dace Intensive sampling of the Sonoyta mud turtle began at Quitobaquito in 1982 and over 2200 observations have been record until now Population estimates (excluding young of the year) from 1984 to 2007 ranged from 39 to 134 (average 911, n=14) and from 2010 to 2016 ranged from 123 to 189 (average 1558, N=7) Mud turtles at Quitobaquito are generally smaller than in the Rio Sonoyta Two animals found dead were examined and found to be emaciated and growth rates following removal increased, suggesting that food may be limited There are wide variation s in growth between individuals and between years We don’t fully understand the roles of climate, water quantity and quality, and species interactions Due to declining spring flow and extremely low pond levels, 79 turtles removed in 2007-2009 and 24 repatriated in 2011 Sixteen of the repatriated turtles have been recaptured Although Quitobaquito is a protected area, the future of its aquatic habitat cannot be guaranteed Recovery efforts for the mud turtle should focus on increasing the number of population units rather than increasing the capacity for Quitobaquito to support more individuals