264 NATURAL HISTORY NOTES
At ~1500 h on 14 February 2014 we captured an adult female V. panoptes in savannah woodland about 150 m from the Margaret River in Western Australia. The animal had hidden in grass thickets upon our approach, but was spotted and captured by hand for a study of the species’ spatial ecology. Immediately upon capture the lizard regurgitated an adult V. scalaris and five large caterpillars (Sphingidae). The regurgitated lizard was covered in saliva but was not degraded, indicating recent consumption. Protruding from the mouth of the V. scalaris was one of the five caterpillars; the other four caterpillars were lying near the V. scalaris. All prey items were dead. The V. panoptes was taken to the field laboratory and the V. scalaris and caterpillars were preserved in 80% ethanol. The V. scalaris weighed 94 g, which was 7.3% of the body mass of the V. panoptes (1285 g). In our judgment the V. panoptes had consumed the V. scalaris within a few minutes or hours of capture, based on the immaculate condition of the latter. Although we cannot eliminate the possibility that the regurgitated lizard was scavenged, predation is more likely due to the condition of the prey. Moreover, V. panoptes consumes other species of monitor lizards (Shine 1986. Herpetologica 42:346–360; Christian 1995. Herpetol. Rev. 26:146; Rhind and Doody 2011. Herpetofuna 41:64–65; Doody et al. 2012. Herpetol. Rev. 43:491–492). The caterpillar in the mouth of the V. scalaris probably reflected foraging by that lizard; however, the other four caterpillars, which were also in very good condition, may have been eaten and regurgitated by either the V. scalaris or the V. panoptes. The caterpillars were conspicuously abundant on ground level vegetation during the time of our observation. Regardless, our observation spans three trophic levels, providing insights into the community ecology in the riparian zone of the tropical savannah woodland. It also suggests that V. panoptes may regulate V. scalaris. When the invasive Cane Toad (Rhinella marina) invaded other parts of northern Australia, the ~90% reduction in V. panoptes (due to lethal toxic ingestion of toads) caused increases in some of its prey (Doody et al. 2006. Wildl. Res. 33:349–354; Doody et al. 2009. Anim. Conserv. 12:46–53; Doody et al. 2013. Biol. Inv. 15:559–568). It is possible that the same mesopredator release will occur with V. scalaris when toads arrive at our site within the next few years. However, V. scalaris can also suffer lethal toxic ingestion of cane toads (S. Doody, S. Clulow, and C. McHenry, unpubl. data). Thus, the complex effects of Cane Toads may make predictions of their impacts difficult in this system. J. SEAN DOODY, Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, Tennessee 37996-1610, USA (e-mail: jseandoody@gmail.com); COLIN MCHENRY, Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3800, Australia (e-mail: colin.mchenry@monash.edu); STEPHEN MAHONY, School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia (e-mail: stephen. mahony93@gmal.com); SALLY TAYLOR, Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria 3800, Australia (e-mail: sally.taylor@monash.edu; SIMON CLULOW, School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia (e-mail: simon.clulow@newcastle.edu.au).
SQUAMATA — SNAKES AGKISTRODON PISCIVORUS (Cottonmouth). PREDATION. Geococcyx californianus (Greater Roadrunner) is a generalist predator well known for its occasional habit of preying on venomous reptiles. However, to our knowledge Agkistrodon piscivorus
fig. 1. Geococcyx californianus (Greater Roadrunner) preying on a juvenile Agkistrodon piscivorus in the Hagerman National Wildlife Refuge, Sherman, Texas, USA.
has yet to be documented as a prey item for this species (Ernst and Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, DC. 680 pp.). On 19 September 2014, one of us (TN) observed a G. californianus kill and consume a juvenile A. piscivorus in the Hagerman National Wildlife Refuge, Sherman, Texas (Fig. 1) on a caliche road approximately 130 m from the nearest body of water. Over the course of 5–6 min, the G. californianus pecked at and flung the A. piscivorus around until it was unresponsive. At this point, the G. californianus swallowed the snake. TREY NEAL, 1600 North Saint Charles Ave, Pilot Point, Texas 76258, USA (e-mail: trey@natureswildscapes.com); DAVID A. STEEN, Alabama Natural Heritage Program, 1090 South Donahue Drive, Auburn, Alabama 36832, USA.
AHAETULLA PRASINA (Asian Vinesnake). DIET AND FEEDING BEHAVIOR. At 0830 h on the morning of 2 October 2013 on the grounds of Ubud View Bungalows hotel in Ubud, Bali, (8.5167242°S, 115.2647486°E, datum WGS84; elev. 20 m), we observed a juvenile Ahaetulla prasina (total length ca. 60 cm) falling to the ground with a gecko (Hemidactylus platyurus; total length ca. 10 cm) seized in its jaws by the nape (Fig. 1). The snake and gecko both fell from a height of ca. 3 m from the overhead canopy of a palm tree on to a stone pavement, where they struggled before the snake began retreating backwards dragging its prey away from the exposed area. First it moved ca. 1.5 m across the pavement, then up a small wall ca. 0.5 m high and continued ca. 1 m across a flower bed. During this time, the gecko appeared to have lost most function in its forward and hind limbs. The snake held on to the gecko and continued chewing movements, likely increasing venom delivery (Whitaker and Captain 2008. Snakes of India, the Field Guide. Draco Books, Chengalpattu, India. 385 pp.). After ca. 40 min, the gecko appeared to be completely immobilized and the snake proceeded to swallow it headfirst while continuing to move in a backwards motion up the base of the tree. After reaching ca. 0.5 m up the base of the tree, the snake stopped swallowing and released the gecko having only achieved swallowing the head. The gecko was large in proportion to the snake, but another possibility is that the snake abandoned its prey in response to disturbance from us. Although vine snakes are typically arboreal they have been observed consuming large prey on the ground, possibly falling after striking prey (Miranda et al. 2013. Herpetol. Notes 6:187– 188). Falling from the tree would likely have placed the snake in a situation where it was at an increased risk of predation. Despite
Herpetological Review 46(2), 2015