7.2 LOUISIANA PINE SNAKE (PITUOPHIS RUTHVEN!) TRAPPING EFFORTS ON FORT POLK AND PEAS ON RIDGE MILITARY RESERVATION Author: Christopher A. Melder

ABSTRACT efforts from 1999-2013 on Fort Polk and the Vernon Unit IUA. The 2013 LPS The Louisiana pine snake (Pituophis ruthveni; trapping season on Fort Polk produced no LPS) is a species of special concern, LPS in 2833 trap days. LPS trapping has associated with mature pine forests, occurring occurred on the Peason Ridge military in the gulf coast plain of west-central reservation since 2006, producing five LPS Louisiana and east Texas (Rudolph and captures. The 2013 trapping season Burgdorf 1997). LPS trapping efforts have produced one LPS in 1671 trap days. occurred since 1999 .on Fort Polk and the Vernon Unit IUA of the KNF in four different The driver of this project is the revised trapping efforts. Twenty-four individual LPS 2013 INRMP and Fort Polk's voluntary have been captured in total for all trapping involvement in the USFS's CCA for the Louisiana pine snake.

INTRODUCTION managers, as one of the last contiguous tracts · of remaining LPS habitat. LPS The LPS (Pituophis ruthveni) is recognized as trapping efforts have occurred since 1999 one of the rarest snakes in all of North on Fort Polk and the USFS IUA of the America, and one of the rarest vertebrates in Vernon Unit in four different trapping the United States (Young and Vandeventer efforts. Overall, 24 individual LPS have 1988, Himes et a!. 2006). The LPS is a species been captured in all snake trapping efforts associated with mature pine forests, occurring from 1999-2013 on Fort Polk/Vernon Unit in the gulf coast plain of western Louisiana (Figure 7.2. 1). With the moderate trapping and east Texas (Rudolph and Burgdorf 1997). success, large occurrence records and a It is listed as a candidate species by the significant amount of potentially suitable USFWS, but receives no federal protection. habitat under active management, the LPS The state of Texas does list the snake as population of the Fort Polk/Vernon Unit is threatened, and protects it from unauthorized considered stable, in accordance to the U.S. collection. In 2013, the state of Louisiana-­ Fish and Wildlife Service (USFWS, 2013). placed protective measures from unauthorized A Habitat Management Unit (HMU) for the capture, harassment or killing of the LPS. In LPS was established on Fort Polk, which 2003, a CCA for the LPS was developed, to consists of29,037 acres. assess management and habitat needs for the species. This cooperative involved federal and The Peason Ridge military reservation's state agencies of Lduisiana and Texas, LPS population, by comparison to the Fort multiple private landholders and Fort Polk. A Polk/Vernon Unit LPS population, has revised version of the CCA was completed in produced much fewer snakes historically. 2013. The driver of this project is the 2013 The LPS HMU established for Peason INRMP, and Fort Polk's voluntary Ridge consists of 11 ,265 acres, which has involvement in the USFWS revised CCA for significantly less potentially preferable the LPS. habitat than previously estimated. The USFWS describes the status of the LPS The Fort Polk military installation and population on Peason Ridge as uncertain adjacent Vernon Unit of the KNF lands to the (USFWS, 2013). south, are recognized by biologists and land

114 LPS trapping efforts have produced five Conservation Branch personnel monitored individual LPS since trapping began in 2006. these traps once a week, if training access permitted. In 2008, 25 traps were monitored appear to be most active from March LPS (five full linear arrays), adding four more through May and from September through traps on Army-owned property to the effort. They are least active in December November. Again, personnel monitored these traps February, as well as in August (Himes through once a week, if access permitted. Only one 1998). Baird's pocket gophers ( Geomys LPS was captured during the 2007 and are the primary prey of the LPS. breviceps) 2008 trapping seasons. The LPS capture Additionally, this semi-fossorial species shows rate was one LPS per trap 8,587 days for close associations with Baird's pocket gopher 2007 to 2008. burrow complexes, and uses their burrows as nocturnal refugia and hibernacula (Rudolph et In 2009, trapping efforts began following a al. 1998, Ealy et al. 2004). new protocol. Conservation Branch biologists installed new traps in locations METHODOLOGY most likely to encounter LPS, in The first LPS trapping event was a small-scale-- ­ accordance to the Landscape Resources effort initiated in 1999 on Fort Polk and the Selection Function (LRSF) Model (Wagner IUA. Fort Polk Conservation Branch et al. 2009) for P. ruthveni. This model uses personnel and USFWS personnel checked four the LPS' preferred habitat probability to eight traps, once every two weeks for a model (Figures 7.2.1 and 7.2.2). year. Three LPS were captured during this Additionally, traps were placed above trapping effort from 1999 to 200 1. The LPS active Baird's pocket gopher mound capture rate was approximately one LPS per complexes (Figure 7.2.3). The biologists .. 1,300 trap days, for those trapping seasons. monitored 14 traditional traps weekly, throughout the eastern portion of Fort Polk. second, much larger effort, led by the The Four modified traps were also placed on the Research Station (SRS) began in Southern northern end of the Geronimo Drop Zone 2002. The primary focus of the project June (GDZ), in response to an expansion of the to document the distribution and habitat was drop zone area. In 2009, the traditional of the LPS on Fort Polk and the IUA. selection traps captured two LPS and the modified additional project goal was to assess the An traps captured one LPS, for a total of three that roadways have on overall snake effect LPS captures in 2009. populations. This project used 15 linear arrays running perpendicular to roads. Each array The 2010-2012 LPS trapping effort consisted of five box traps, spaced 200 m continued the protocol established in 2009, apart. SRS personnel checked these 75 traps with the exception of running the modified on a weekly basis, if training access permitted. traps at the north end of the GDZ. These This trapping effort officially ended after the traps were removed, to facilitate the 2006 trapping season, with a total of 12 LPS expansion of the GDZ area. New traps were captures from 2002 to 2006. The LPS capture installed in Compartments 26, 34, 37, and rate was approximat~ly one LPS per 11,000 60. The 2010-2012 LPS trapping efforts trap days for the 2002 to 2006 trapping produced four new LPS and three seasons. recaptured LPS. Capture rates for LPS individuals between 2009 and 2012 were third effort, which was a scaled-down The one new LPS per 1,605 trap days and of the SRS' s effort, began in 2007 by version recaptures included, one LPS per 1167 trap Polk Conservation Branch personnel. Fort days. The 21 traps used for this scaled-down effort were mostly on Army-owned property, with LPS trapping efforts on Peason Ridge the exception of two traps on the USFS IUA. began in 2006. Conservation Branch 115 Figure 7.2.1: Vernon-Fort Polk 1999-2013 LPS Trap Capture Locations on LRSF Probability Model Map.

*Note: Fort Polk compartments are numbered.

116 Trap Capture Figure 7.2.2: Peason Ridge 2006-2013 LPS Locations on LRSF Model Map.

. *Note: Peason Ridge compartments are numbered western side (Compartments 39, 42 and 43) personnel installed 19 traditional snake traps of Peason Ridge, above Baird's pocket throughout the military reservation, typically gopher mound complexes. Only one LPS within Red-cockaded woodpecker (Picoides was captured during the 2010-2011 borealis; RCW) cluster sites, so as to add seasons. However, much less effort was additional protection for the traps. The number to required. The capture rate of the 2010- of traps was reduced from 19, in 2006, 2012 seasons was one LPS per 3,275 trap seven active traps, on the western side of the of days. reserve in 2009. Reduction in the number traps was due to personnel shortages, and All trapping efforts on Fort Polk, the IDA, increased access restrictions to these training and Peason Ridge have utilized the same lands. Additionally, it has become more traditional snake trap design. A 4-foot by 4- apparent in review of the trapping data, and foot by 2-foot plywood frame covered with of the LRSF model guidance, that the focus Y-t-inch hardwire cloth are the materials the the trapping efforts should be on used to build the snake traps. Four funnels northwestern side of Peason Ridge. Only one are built into the four sides of each trap to on LPS was captured in the trapping effort provide an entrance. Fifty-foot lengths by 2 a Peason Ridge from 2006 to 2009. This was feet wide hardwire cloth fence runs from capture rate of one LPS per 11,864 trap days. each of these four funnels (Figure 7.2.3). These fences guide the snakes toward the In the 2010-2012 trapping season, the protocol traps, where they go up the incline of the established on Fort Polk was also used on funnel and fall into the trap. Peason Ridge. New traps were installed in the 117 Figure 7.2.3: Snake Trap Located above a Baird's Pocket Gopher Burrow Complex on Fort Polk.

Captured snakes were provided water in each The 2013 trap effort produced 128 total trap, through the use of plastic domestic snake captures (Table 7.2.1) represented by chicken watering cans. These cans were refilled nine identifiable species, all of which are each time the trap was checked. Snakes were expected to occur on the installation and removed from traps with the use of snake habitat sampled. By far, the most abundant tongs, then released beyond the 50 foot fence, snake species encountered in 2013 was the to discourage immediate recapture. Venomous coachwhip (Masticophis flagellum), snake species were given a length estimate comprising slightly more than 63% of all before being released. Non-venomous snake snake captures. The coachwhip was followed species were measured (centimeters) for total by Slowinski's com snake (Panthrophis length, snout to vent length, and then inspectecf slowinsldi) at 12.5%. The target species, for injuries or malformations before being Pituophis ruthveni, was not encountered released. during the 2013 trapping effort. The thirteen traps were closed on 23 October 2013. The RESULTS total oftrap days for 2013 was 2833. The 2013 Fort Polk trapping season began 18 The Peason Ridge 20 13 trapping season March 2013, by opening up eight newly began 26 March 2013, by opening five newly installed LPS traps in Compartments 22 and 33. installed traps in Compartment 39, and two Four previously run LPS traps (Compartments previously run traps in Compartment 42. On 34 and 37) were opened on 19 March 2013. 4 April 2013, an additional LPS trap was Additionally, a newly installed trap in opened in Compartment 43, for a total of Compartment 28 was opened on 28 March eight actively running traps. Methodology for 2013. Methodology for the installation of these the installation of these traps followed the traps followed the same protocol as used in the same protocol as used in the 2009-2012 2009-2012 trapping seasons. trapping seasons.

118 Table 7.2.1: 2013 Fort Polk Captures (Not Represented by Individuals) from 13 Snake Traps.

SCIENTIFIC NAME COMMON NAME CAPTURES % Agkistrodon contortrix contortrix Southern copperhead 7 5.47 Agkistrodon piscivorus leucostoma Western cottonmouth 3 2.34 Coluber constrictor Racer 4 3.13 Pantherophis slowinskii Slowinski's com snake 16 12.5 Pantherophis obsoletus Western rat snake 10 7.81 Lampropeltis holbrooki Speckled king snake 2 1.56 Lampropeltis calligaster calligaster Prairie king snake " 3 2.34 MasticophisflaJ?ellumfla}?ellum Eastern coachwhip 81 63.28 Nerodia e!Ythrogasterflavi}?aster Yellow-bellied water snake 1 0.83 Pituophis ruthveni Louisiana pine snake 0 0.0 unidentifiable species 1 0.83

TOTAL - 0 ' 128 100.00%

The Peason Ridge trapping effort produced 83 snake captures) during the 2013 trapping total snake captures represented by thirteen effort (Figure 7.2.4).This capture was in a identifiable species (Table 7.2.2). Over 55 previously run trap which captured an percent of all snake captures on Peason Ridge additional LPS in 2012, the year this trap was consisted of the coachwhip, followed by installed. All eight traps were closed on 22 western rat snake (Panthrophis obsoletus) at October 2013, for a total of 1671 trap days . • 15.7 %. The target species, Pituophis ruthveni, The 2013 capture rate for LPS on Peas on was encountered on one occasion (1.2% of all Ridge was one LPS per 1671 trap days.

Table 7.2.2: 2013 Peason Ridge Captures (not represented by individuals) from Eight Snake Traps.

SCIENTIFIC NAME COMMON NAME CAPTURES o;o Agkistrodon contortrix contortrix Southern copperhead 1 1.20 Agkistrodon piscivorus leucostoma Western cottonmouth 1 1.20 Cemophora coccinea copei Northern scarlet snake 2 2.41 Coluber constrictor Racer 6 7.23 Pantherophis slowinskii Slowinski's com snake 5 6:02 Pantherophis obsoletus Western rat snake 13 15.66 Lampropeltis holbrooki Speckled king snake 1 1.20 Lampropeltis calligaster calligaster Prairie king snake 1 1.20 Masticophis flagellum flagellum Eastern coachwhip 46 55.42 Yellow-bellied water 2 2.41 Nerodia erythro}?asterflave}?aster snake Opheodrys aestivus aestivus Rough green snake 1 1.20 Pituophis ruthveni Louisiana pine snake 1 1.20 Thamnophis proximus proximus Western ribbon snake 2 2.41 unidentifiable species 1 1.20 TOTAL 83 100.00%

• 119 Figure 7.2.4: LPS in Trap Captured on Peason Ridge (Compartment 42).

D ISCUSSION documented. However, trapping efforts vary from year to year depending on These trapping efforts have provided a solid the number of traps set (13 to 18 traps per baseline for snake species occurrence in the year) and training access restrictions. longleaf pine ecosystems, found throughout .. Fort Polk and Peason Ridge. Additionally, new The 2013 trapping season on Fort Polk species to the installation have been produced no LPS captures. However, many encountered, to include by-catch amphibian of the new traps installed (Compartment 22, species, such as the Pickerel frog (Lithobates 28 and 33) are on the edge of the palustris) on Peason Ridge and Hurter's installation's HMU for the LPS. Overall on spadefooted toad (Scaphiopus hurterii) on Fort Fort Polk, Pituophis ruthveni has been Polk. Eighteen snake species have been encountered in relatively low numbers, and encountered on Fort Polk, and seventeen snake typically captures are in the first year or two species were observed on Peason Ridge since of a new trap being installed, with few 2009. Snake captures from 2009 to 2013 recaptures. The Fort Polk capture rate over (Tables 7.2.3 and 7.2.4 - Charts 7.2.1 and 7.2.2) the last five years (2009-2013) stands at one consistently produce a high number of LPS per 1959 days of effort (Table 7.2.3). It coachwhips annually, followed by Slowinski's is anticipated that 15 LPS traps will be set on com snakes, Western· rat snakes and Racers Fort Polk for the 2014 season. These will be Coluber constrictor). Trapping efforts of this comprised of previously run traps kind typically see diminishing trap success of (Compartments 22 and 33) and newly the target species, Pituophis ruthveni, over installed traps in Compartments 35 and 16. multiple years of trapping in the same locations. The first trapping effort (2006-2009) Thus, Fort Polk implemented moving trap on Peason Ridge produced only one LPS, locations in two to three year intervals, as a for a capture rate of one LPS for protocol in the 2009-2013 snake trapping every 11,864 days effort. This one individual was captured seasons. As a( result, more captures of the target in the northwestern portion (Compartment species, with less trap effort, have been 42) ofPeason Ridge, the first year the traps

120 (2009-2013), Peason Were installed in this area. The trapping In the last five years a capture rate of one effort put forth in 2010 of placing five new Ridge has carried 2111.5 days of effort. No traps in the northwestern portion of Peason LPS for every have occurred on Peason Ridge (Compartment 40 and 42) appeared to LPS recaptures For the 2014 LPS have very good results, with the first LPS Ridge (Table 7.2.4). previously established capture in five years. The 2011 trapping trapping season, six in the northwestern effort produced no LPS. However, the 2012 traps will be set Ridge. Additionally, trapping effort was the most productive LPS portion of Peason be established on the trapping season to date on Peason Ridge and four new traps will lands to the south of produced two LPS captures. recently purchased Peason Ridge.

Table 7.2.3: Louisiana Pine Snake Trapping Efforts on Fort Polk. TOTAL NEW NO. NEWLPS LPS TRAP LPSperTRAP YEAR TRAPS CAPTURES RECAPTURES RUN DAYS DAYS 1092.3 2009 18 3277 3 0 3294.0 2010 15 3294 1 0 1586.5 2011 14 3173 2 3 1547.5 2012 14 3095 2 0 NA 2013 13 2833 0 0 1959 TOTAL 15672 8 3

Ridge. Table 7.2.4: Louisiana Pine Snake Trapping Efforts on Peason NEW NO. NEW LPS TOTAL TRAP LPS per YEAR TRAPS LPS RECAPTURE DAYS TRAP DAYS RUN CAPTURES s NA 2009 7 1238 0 0 1449 2010 7 1449 1 0 NA 2011 8 1826 0 0 1131 2012 10 2262 2 0 1671 2013 8 1671 1 0 2111.5 TOTAL 8446 4 0

121 Chart 7.2.1: Fort Polk 2009-2013 Captures (Not Represented by Individuals) of All Snake Species.

~ Unidentifiable snake species I

Eastern garter snake J Western ribbon

Louisiana pine snake ~ rough green snake ~ Diamond-back water snake J

Broad banded water snake ll

Yellow bellied water snake ~ J Texas coral snake 11 2013 ~ 02012 Coachwhip 02011 Prairie king snake 'I'"' . 2010 !::J Speckled king snake 02009 ~ Eastern hognose

Western rat snake

Slowinski's corn snake Racer ~ Scarlet snake ~ Cottonmouth r Copperhead

0 20 40 60 80 100 120

122 Chart 7.2.2: Peason Ridge 2009-2013 Captures (Not Represented by Individuals) of All Snake Species .

Unidentifiable snake species • = Western ribbon snake Diamondback water snake Broad banded water snake Yellow bellied water snake Rough green snake • Louisiana pine snake • 2013 Texas coral snake Coachwhip 2012 Prairie king snake 0 2011 Speckled king snake • 2010 Eastern hognose 02009 Western rat snake _ Slowinski's corn snake Racer

Scarlet snake = Cottonmouth

Copperhead ~

0 10 20 30 40 50

REFERENCES 1. Ealy, M.J., R.R. Fleet, and D.C. Rudolph. 2004. Diel Activity Patterns of the Louisiana Pine Snake (Pituophis ruthveni) in Eastern Texas. Texas Journal ofScience 56: 383-394. 2. Himes, J.G. 1998. Activity Patterns, Habitat Selection, Excavation Behavior, Growth Rates, and Conservation of the Louisiana Pine Snake (Pituophis melanoleucus ruthveni). Master's thesis, Louisiana State University, Shreveport, LA. 58 pp. 3. Himes, J.G., L.H. Hardy, D.C. Rudolph, and S.J. Burgdorf. 2006. Movement Patterns and Habitat Selection by Native and Repatriated Louisiana Pine Snakes (Pituophis ruthveni): Implications for Conservation. Herpetological Natural History 9: 103-116. 4. Rudolph, D.C., and S.J. Burgdorf. 1997. Timber Rattlesnakes and Louisiana Pine Snakes of the West Gulf Coastal Plain: Hypotheses of Decline. Texas Journal ofScience 49:111-122. 5. Wagner, R.O., D. Hightower, J. Pierce, D.C. Rudolph, and R. Schaefer. 2009. Landscape-Scaled Resource Selection Functions of Potential Louisiana Pine Snake (Pituophis ruthveni) Habitat. Unpublished Report submitted to the U.S. Fish and Wildlife Service, Lafayette, LA. 19 pp. 6. Young, R.A., and T.L. Vandeventer. 1988. Recent Observations of the Louisiana Pine Snake, Pituophis melanoleucus ruthveni Stull. Bulletin of the Chicago Herpetological Society 23(12): 203-207.

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