Thursday, July 28, 2011

July 2011 Alabama Indigo Snake Reintroduction Update

As many of you know, the 2011 tracking season is in full swing. On May 3, 2011 we re-released the 6 snakes that survived 2010. Of the 17 released in 2010, 6 snakes lived, 6 snakes died, and 5 snakes disappeared. Of the 6 that died, 2 were hit by vehicles, 2 were eaten by predators (one avian, one mammal), and 2 died of “natural causes”. During 2010, 7 snakes disappeared, 2 excreted their transmitters, 2 emigrated onto private land where we were unable to keep track of them, and 3 had battery failure before recapture. However, 2 of these snakes were captured in late February while basking in front of their hibernacula. One snake had excreted its transmitter and was thought dead, the other’s radio battery had died. Both of these snakes were found using the same gopher tortoise burrows as snakes with working radios. The 6 snakes recaptured in February were brought to Auburn where they were implanted with new radios with a longer 2 year battery life. They were then re-released at their point of capture.
Since their release, we have been consistently locating all 6, and to date they are all still alive and seem to be doing well. Some of these snakes seem to be at or over the 6 ft mark. A4 was seen eating another copperhead on Mother’s Day. Most of the snakes have been using the same areas that they occupied last year. They have, interestingly, been utilizing many of the same burrows and retreats that they used last summer.
On May 16, 2011, 31 more snakes were released onto the site. Of these, 21 were implanted with radios and 10 received only a PIT tag. Of these 21, 10 were female and 11 were male. Of the 21 radioed snakes, 10 were soft released into the pens and 11 were hard released outside the enclosures along a nearby fire break. Within the 6 enclosures, 4 received 2 snakes (2 with a male and a female, one with 2 males, and one with 2 females) and 2 received 1 snake (one with a male and one with a female). Snakes were distributed by clutch and size across the release methods. All of the snakes without radios were males and were hard released outside the enclosures in the area.
It was 11 days before the first snake escaped from the pens. After that, snakes trickled out of the pens. As observed last year, there were no noticeable breaches in the fences and it appears the snakes are finding their way out through underground passages. As of now, 4 snakes (3 females and 1 male) remain in the enclosures. While in the pens, the snakes utilized upturned tree rootballs, burned out stumpholes, and gopher tortoise burrows for refugia similarly to snakes outside the pens.
Several times, snakes from this year’s release located and used the same burrows as snakes from last year’s release. This occurred with both soft and hard released snakes and some of the locations were a considerable distance from the initial release site. These observations were surprising, particularly since the pens and most of the Forest Service compartment around the release site were prescribed burned this winter and spring to improve the habitat in the area.
Snakes have occasionally been encountered crossing roads and so far have made it safely across. Do Not Harm signs have been placed around the area and should encourage drivers to avoid running the snakes down. Last week, the Forest Service observed and photographed an unknown snake crossing a paved road. This snake has not yet been identified, but is known to be a snake without a radio, since all of the snakes with radios were accounted for in areas a considerable distance away from here. The unknown snake could be one of the snakes released last year that was last seen in this area or one of 10 males released this year without radios. We hope that with further examination, the photographs taken of this snake will distinguish between these two possibilities. We also hope to encounter this snake again soon and capture it to scan the pit tag so we can be sure of its true identity.
Blue Lake Methodist Camp across the Pond Creek drainage has been a popular spot for the snakes again this year. Four of the snakes have been observed on camp property on the same day. The camp director was re-contacted and again expressed support and enthusiasm for the project, welcoming us to track on the property whenever needed. According to her, encounters with venomous snakes are up on the camp this year and she hopes the indigo presence there will help control dangerous encounters.
A couple of snakes have also used habitats around the Blue Lake Recreation area this year, and a couple of snakes have recently moved further north. A number of the snakes have also been using neighboring private land.
Movement has increased over the past couple of weeks, and many of the snakes have moved into the nearby creek drainages. As observed last year, the males are moving further distances and with more frequency than females. The furthest distance recorded from the release site this year is 2.62 km by a male from this year’s release.
Snakes encountered on the surface are often slithering around flicking their tongues and prodding under logs and in holes in a foraging behavior. One snake was observed eating a corn snake yesterday. The tree climbing behavior observed in a few snakes last year has not been documented in the field this year. Many of the snakes have been observed rattling their tails, hissing and inflating their bodies in a threat pose when approached.
Habitat use has been diverse, with snakes utilizing all habitats available. The most surprising observation so far in terms of habitat has been the high incidence of snakes locating many of the same retreat sites that were used by snakes last year. The verdict on prescribed burning’s affect on habitat use is still out for now, but is expected to have more influence in winter habitat use when snakes rely more on gopher tortoise habitats for overwintering.
Feedback from the local community has remained positive. The new metal signs distributed around the area and placed at trailheads, the local country store and popular recreation areas should increase opportunities to bolster support of the project.
As of today, 26 of the 27 radioed snakes are alive and well. Only one snake from this year’s release has been found dead and this mortality appears to be a natural predation. As the snakes find their way around and achieve rapid growth, the likelihood of natural predation should decrease. Additionally, the sighting of an unknown snake by the Forest Service is encouraging, since it may indicate an increase in the survival of last year’s snakes.
The overall outlook for repatriated indigos establishing self-sufficient populations in the wilds of Alabama remains good. Although it will be years yet before the true success of the project can be measured, continuing research should reveal important information to increase the chances for success. For conservationists, the success of this project would represent more than just a step in the recovery of a federally threatened species; it would also indicate that years of management in the longleaf have restored this imperiled ecosystem enough to support the diverse array of species that once inhabited this wilderness. As important predators that help keep ecosystem health in balance, and as a part of the natural heritage we had thought forever lost in Alabama, the attempt to return indigo snakes to Alabama is an investment in the future and that is good news indeed.

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