W. H. Martin's 2006 Timber Rattlesnake Report
Fall Ingress 2006 and Year’s Summary
Ingress
Ingress occurred within the normal range of dates but dragged on well past the usual time with a few snakes sporadically on the surface into early January. On 18 September on the High Allegheny Plateau of West Virginia, 3500 ft elevation, 11 snakes were seen. One subadult in a hibernating crevice, the patriarch (light male about 52 inches), two postpartum females, one gravid female, and four litters, one litter of which was fresh-born. Range of birthing dates at this site was estimated at 10-20 September. Returning to the site on 3 October, 26 rattlesnakes were seen plus a black rat of about 6 ft 1 found by Lance. Sixteen of the rattlesnakes were at or in the dens. The breakdown included 18 adult, and 7 young-of-year (3 post-shed), only one juvenile—a 20 incher. (The 16-28 inch juveniles typically form the first wave into the dens and most of them were apparently already under.)
On 4 October at two Virginia Blue Ridge (SNP) dens, 2550 and 2460 ft, four and five snakes—a mix of size-classes that included two post-shed young-of-year. Apparently the bulk of the population was still out in the woods. Todd Ivey arrived for a visit and late afternoon of 8 October at a northern Maryland den, we saw five—a mix. On 9 October checking four northern Maryland dens we saw 32 snakes of which 14 were post-shed young-of-year, 9 adults, 9 juveniles—a typical mix and apparently it was peak ingress.
On 10 October in the Virginia Blue Ridge (SNP) three denning areas of 1300-1700 ft elevation. Ten snakes, one juvenile, one young-of-year. Most were at dens. A young-of-year was seen coiled with a sub-adult in the woods 100 meters from a den.
We probably missed the last good day of the year on 18 October. It did not clear until mid-afternoon and with a favorable forecast for the following day I decided to wait until then. Unfortunately 19 October was clouded over with a high of 64 F. Jim McGibney, Jay Rubinoff and I saw three at a large den complex in the northern Blue Ridge near the Virginia/West Virginia line.
Late fall-type weather persisted well past the usual dates and sporadic reports continued to come in through the first week of January before severe winter cold arrived. Jim McGibney saw two TR (postpartum female and a 1-yr-old juvenile on 1 November and one, a juvenile on 10 November in northern Maryland. On 25 November Lance Benedict saw a postpartum female also in northern Maryland. On 4 January Rick Koval saw a young-of-year in eastern Pennsylvania. Randy Stechert saw a Black Rat on 6 January in New York (low Poconos) and Chris Comacho saw a young-of-year Timber in the Hudson Highlands. Randy also reports that on 7 January, two members of a party he lead into a southeast New York ice cave heard a snake rattling in a horizontal crevice in a chasm about 50-60 ft below the surface.
Emergence
Emergence occurred earlier than usual. First reports were for two adults seen by Rich DeMartino and Rick Sanderson in south-central Pennsylvania on 11 March. My first good day and possibly the third day on the surface for some of the snakes, was on 15 April when we saw 19 at one low-elevation (1200 ft) Blue Ridge den and 16 at another 1200-1600 ft den complex. Emergence may have peaked at the low- to middle elevations around 20-24 April and about 4 May at the higher elevations of 3000-3500 ft. My best day of the year was on 30 April when 72 snakes were seen, 45 (23 adult) at a westerly facing den complex 1200-1600 ft and then 27 (24) adult at a den located at the top of a west-northwest-facing scree slope at 1400 ft.
VHS Field Trip
I managed to make two Virginia Herp Soc field trips. In late May David Garst and I attended the trip to Fairystone State Park in the upper Piedmont of southern Virginia. We found potential denning habitat off a road where a lot of rattlesnakes have been seen. I believe that had it been a month earlier we might have found some. I also made the final day of the VHS field trip to Warm Springs Mountain in early July. The crew had already found one rattlesnake at near 4200 feet the previous day. Accompanied by Larry Mendoza, Rebecca Rivera, John Agee, and Michael Ribsby, we found a dark phase gravid female at the first place we checked on the summit of the mountain at about 3300 feet. We also saw a pre-shed light phase subadult on a utility line before it got too hot.
Timing of Reproduction
Births occurred a little earlier than usual, especially to the north. Births in the central Appalachians as well as north-central Pennsylvania apparently started around 16-18 August, peaked at the end of August and finished by 20 September. I saw first postpartum female on 23 August and litters on 25 August (Virginia Blue Ridge 1300-1700 ft) but Jim McGibney had seen a postpartum with a litter in northern Maryland on 19 August and Curt Brennan had seen first litters in north-central Pennsylvania on 18 August. The earliest report for 2006 was passed on by John Jose and came from a homeowner who observed a female giving birth in the Low Poconos of northeast Pennsylvania on 8 August.
Reproductive Effort
Reproduction was quite high across northern and southwestern Pennsylvania. Elsewhere and apparently including the Upper Mississippi Blufflands reproduction was spotty. Matt Heeter reports seven females with litters at one birthing site in Wisconsin (the previous high at that site was four females) but Brian Bielema had only one female reproduce at a northwest Illinois site where the previous high was six females. For my part, of 10 long-term sites checked in ’06 only one showed high reproduction. At that Virginia location, which consists of numerous gestating sites and three dens spread out over about a mile, 11 reproductive females were found under unfavorably hot and sunny conditions. The previous one-day high at this location was 19 females in September ’03.
Summary
Two new overwintering dens were confirmed and summer snakes were found at nine new sites. In addition I was shown new sites by David Garst in southwest Virginia, Chuck Waggy in eastern West Virginia, and Curt Brennan and Bill Munroe in north-central Pennsylvania. Total rattlesnakes seen was 461. Snakes were seen at 41 sites (18 in Virginia, 15 in Maryland, 7 in West Virginia, and one in Pennsylvania. Included in the count were 20 young-of-year (mostly post-shed) seen in October. An additional 25 litters (approximately 60 newborn counted) and about 50 newborn from eight litters shown me at one rock by Curt Brennan and Bill Munroe are not included in the count.
I was in the field with the following people last year. Jim McGibney, Karen Brown, Todd Ivey, Rich Legere, Zach Orr, David Garst, Renata and Lance Benedict, Michael Kieffer, Andrew Gizinski, Randy Stechert, Nelson Lewis, Larry Mendoza, Curt Brennan, Bill Munroe, Jay Rubinoff, Dennis Waggy, Chuck Waggy (plus wife Paula and daughter), Bob Dean, Mark Latta, Bob Pickett, Paul and Eric Kazyak, Steve and Gerrit Speiker, Jason McCauley, Justin Collins, Mike Jewel, Brandon Zimmerman, Rebecca Rivera, John Agee, and Michael Ribsby.
Minimum Potential Reproductive Interval
In 2005, two captive females of ’96 cohort both gave birth about the beginning of August. They had fed during pregnancy and about 5 days after giving birth they were actively courting—gliding around the cage with heads up and soon joined by a male. They both looked and acted pregnant through fall ’05 and summer ’06 but did not give birth. A false pregnancy? What is going on? Are they carrying slugs or just yolked up to breed this upcoming summer? Zach Orr tells me that he has several times had captive Canebrakes give birth in consecutive years. (Zach’s snakes are on an 8-mo active, 4-mo hibernation schedule as opposed to mine which are on a 6 and 6 schedule.) In each case the second birthing occurred in October, well past the normal time and the young were small. It may be that a minimum of 9 month active time is required between litters. Perhaps where the active season is 9 months (southeast Texas to northeast Florida) they might be capable of occasional consecutive-year births but it is doubtful that the feeding rate would normally support such an effort in nature.
Forecast
We are now (mid-March) in the final stages of winter. Snakes are out in the southeastern Coastal Plain. Todd Ivey reports two Eastern Diamondbacks and three Canebrakes on 11 March in southern South Carolina. The weather forecast does not suggest anything unusual. Lower elevations of the southern Appalachians and southern Piedmont should see some snakes on the surface in mid-March. Expect a few snakes out in the central Appalachians during the last week of March with a general emergence to begin in mid-April as usual. (I expect to get out around 15 April or a few days earlier if we should get an early warm-up.) After 3 years of below average precipitation and above average temperatures we are due for a wet spring and summer. A wet spring usually means an extended emergence and a wet summer delays birth of the young. The areas that had high reproduction in ’06 should see a low or moderate reproduction this year. It will be interesting to see if our anticipated high ’06 reproduction in the central Appalachians has simply been delayed until 2007. If so, it could be a highly productive year.
W. H. Martin
133 Flat Earth Lane
1227 Engle Molers Rd.
Harpers Ferry, WV 25425
(304) 876-3219
whmartin@crotalus.org whmartin@frontiernet.net