USDA/Wildlife Services: tools and strategies t for Burmese python control Michael L. Avery 1, John S. Humphrey 1, Tony G. Duffiney 1, Tom Mathies 2, Rick E. Mauldin 2, Peter J. Savarie 2, and Richard M. Engeman 2 1 USDA/WS, Gainesville, FL 2 USDA/WS, Ft. Collins, CO
The National Wildlife Research Center is the federal institution devoted to resolving problems caused by the interaction of wild animals and society.
NWRC headquarters, Ft. Collins, CO
Florida Field Station, Gainesville Large outdoor test t pens
NWRC is solution-oriented Major research emphasis on invasive species - brown treesnake - coqui frog - Gambian giant pouched rat - feral monkeys - feral pigs - iguanas - sacred ibis - common myna - monk parakeet
NWRC Burmese Python studies: Toxicant development Bait preference Fencing and trap development Pheromones, attractants Cold weather effects
Acetaminophen trials All test subjects were juvenile animals Burmese pythons (n=7/level) Amount 19.0 mg 39.5 mg 77.1 mg Mean mg/kg g 166.7 mg/kg g 310.4 mg/kg g 545.7 mg/kg g % Mortality 14.3% 85.7% 100% Nile monitors (n=8/level) Amount 10.1 mg 19.0 mg 39.5 mg Mean mg/kg 199.4 mg/kg 405.6 mg/kg 934.33 mg/kg % Mortality 0% 50% 100%
Acetaminophen trials Extrapolation from lab trials (juveniles) to field situation (large snakes) Mean Burmese python body mass in ENP 10-11 11 kg Estimate field dose using allometric scaling of metabolism Estimated lethal dose for average python = 3.74 g acetaminophen Key questions remain: - How to deliver it to wild pythons? - How to prevent non-target exposure?
Evaluation of bait matrices All are commercially available Also used for screening tests on Nile monitors Beef-flavored dog treat Coturnix quail egg Zebra finch egg Coturnix quail chick (dead) Squid Tilapia Ground turkey Chicken livers Neonatal mouse (dead)
Evaluation of bait matrices Test 1: % acceptance using fresh baits (n = 4 juvenile snakes) Beef-flavored dog treat 0 Coturnix quail egg 0 Zebra finch egg 0 Coturnix quail chick (dead) 75 Squid 0 Tilapia 0 Ground turkey 0 Chicken livers 0 Neonatal mouse (dead) 75
Evaluation of bait matrices Test 2: % acceptance using baits aged 24 hours at 85 o F and 50% RH Beef-flavored dog treat 0 Coturnix quail egg 0 Zebra finch egg 0 Coturnix quail chick (dead) 50 Squid 0 Tilapia 0 Ground turkey 0 Chicken livers 0 Neonatal mouse (dead) 0
Evaluation of bait matrices Nile monitor % bait acceptance (n = 8 juveniles) Fresh Aged Beef-flavored dog treat 0 12.5 Coturnix quail egg 12.5 12.5 Zebra finch egg 62.5 75.0 Coturnix quail chick (dead) 75.0 62.5 Squid 25.0 37.5 Tilapia 87.5 87.5 Ground turkey 75.0 87.5 Chicken livers 62.5 87.5 Neonatal mouse (dead) 87.5 75.0
Tests in semi-natural setting
Drift fences as capture devices
Drift fences and traps
Drift fences and traps
Drift fences and traps
Drift fences and traps
Pheromones as attractants
Testing for airborne pheromones Male snakes were exposed to the air surrounding the female snake. No reaction was elicited, but the test condition was not optimal. So this is still an open question.
Testing baits and lures
Pen and python also used for BBC segment on snake detection with IR camera
Cold tolerance in pythons Opportunistic observations - January 2010 All had survived previous two winters outdoors All snakes were well-fed and professionally cared for going into winter All had insulated refuge with heat mat Observations on behavior, health, survival
Cold tolerance in Burmese pythons 30 28 Dec to 12 Jan Am bient Tem mperature ⁰C 20 10 0-10 Hourly temperature readings
Cold tolerance in Burmese pythons Inappropriate thermoregulatory behavior: Some snakes basked in cold air temperatures rather than seeking refuge and heat 3 of 9 snakes died outright 2 others had to be euthanized 2 others were brought inside and revived certain mortalities otherwise (respiratory) The largest snakes died, including all 3 females
Cold tolerance in Burmese pythons We conclude that, Burmese pythons from ENP have limited ability to respond behaviorally to cold Larger snakes seemed more at risk (e.g., breeding females) Climatic extremes, not averages, determine range limits Burmese pythons are unlikely to become long- term established in north-central Florida
Thanks to our Animal Care staff Kandy Keacher, Eddie Bruce, Kelin Maciejewski Support from Everglades National Park and USDA Thanks to Skip Snow for providing the pythons