Nesting Biology and Conservation of a Northern Population of Spiny Softshell Turtles ( Apalone spinifera )

摘要

The Lake Champlain population of Spiny Softshell Turtle (Apalone spinifera) is isolated at thenortheastern end of the range of the species in North America. Due to a lack of suitable habitat, nesting is confinedto a limited number of sites, including one along a Canadian tributary river: Rivière aux Brochets, Québec. Highegg mortality is a conservation concern for this population; however, little is known about its nesting ecology. Weobserved nesting behavior from 2003–2016 and recorded environmental variables from 2009–2016 at this site.We monitored hatching success of 75 clutches, in situ and ex situ, and measured morphology of 836 laboratoryincubatedhatchlings. Nesting activity occurred mostly in June between 1100–2000. We observed a second clutchwithin a season four times, laid by two females. Egg laying was more likely on days when the difference betweenair and water temperatures was smaller. Air temperature, water temperature, cloud cover, and precipitationwere not correlated with the probability of egg laying, while high river discharge inhibited egg-laying activities.Nesting behavior and clutch and hatchling characteristics were similar to what has been reported by previousstudies. Artificial incubation more than doubled hatching success. Based on our results, we believe that ex situegg incubation is a useful conservation tool for freshwater turtles in critical situations, in locations where hatchingsuccess is naturally low, and threats cannot be easily and rapidly mitigated.