Friday, September 19, 2008
Return of the Blanding’s Turtles
On the weekend of Old Home Day, 2005, Nancy Weiss discovered a Blanding’s Turtle laying eggs in her yard (Mosquito online archive, July 1, 2005). They hatched on September 5 (Labor Day) and because the species is threatened, they were put into the state Natural Heritage and Endangered Species Program (NHESP) for raising until they were larger and less susceptible to predators. These Old Home Day turtles found themselves in a new home until September 3 of this year when they were returned to Carlisle.
Survival. Survival rate of Blanding’s hatchlings is low in the wild. The nests are very likely to be raided by raccoons, and if the nest is undetected, the young hatchlings may be eaten by skunks, raccoons, Great Blue Herons, and even by large bullfrogs.
Protective custody, however, is not a guarantee. Of the eight hatchlings “head-started” by NHESP, three succumbed. Even so, the survival rate of 62% is significantly higher than is normal in the wild. For larger turtles the risks from natural predators decrease greatly. The major threats at this point are man-made, mainly motor vehicles and loss of habitat. Blanding’s Turtles have been known to reach 77 years.
Hibernation. There are two schools of thought about hibernation for Blanding’s hatchlings in captivity. One approach is to keep feeding the turtles through the winter so they grow faster
and can be released safely at a younger age. The other is to get them acquainted with hibernation so it won’t be a shock when they spend their first winter in the wild. So far, herpetologists have insufficient experience with the two methods to know which is best.
Our turtles went through three hibernations in captivity. This meant they had a few months of down-time in terms of growing. It took three years before they were thought large enough to have good chances for survival in the wild. Five healthy turtles (two quite large, one medium, and two smaller ones) were released back into Carlisle on September 3 in time to celebrate their third birthday in a wild, if not crazy, way. They are omnivorous, and very opportunistically carnivorous. Their birthday party probably had aquatic insects, frogs, snails and slugs on the menu.
Tracking. The original plan back in 2005 was to tag the released turtles with radio transmitters and monitor their whereabouts. The funding for programs like this suffered the fate of many a Blanding’s nest – it was demolished. Each turtle, though, has notches in its carapace and will be recognizable if encountered again either by happenstance or as part of a future turtle-monitoring program.
Blanding’s Turtles reach breeding age at around 12 to 14 years. These three-year-olds were too young to tell the males from the females. All we know is that we now have five more members of a threatened species with a reasonable chance of reaching breeding age, in our conservation land.
Raising turtles. While these turtles were raised for three years in captivity, it is unlawful to do this on your own. You need to be approved by the state and working under the guidance of the NHESP.
Submissions. Please send in your ideas for topics for this column to firstname.lastname@example.org – or better still write the column. It should be about some species living in Carlisle and found in the wild.
© 2008 The Carlisle Mosquito