Recent Efforts to Monitor and Manage the Argentine Tegu in Central Florida Tessie Offner Florida Fish and Wildlife Commission : Nonnative Wildlife Biologist Email: Tessie.Offner@myfwc.com Thank you to:
Argentine black and white tegu (Salvator merianae) Found in Hillsborough County, 2005 Confirmed breeding, most sightings around private properties adjacent to natural areas We are assessing this animal as we remove them but our feeling is that they are established
Argentine black and white tegu Bioprofile: Origin: Argentina, Uruguay, Paraguay, Brazil Color: Black body with white dorsal bands or dashes Size: up to 8kg (17.6lbs) and 145cm (57in) total length Diet: omnivore Fecundity: 20-54 eggs Can become dormant in winter (Salvator merianae) Information from: Enge, Kevin M. FWC Bioprofile for the Argentine Black and White Tegu (Tupinambis marianae). FWC 2006
Seasonal Cycle for tegus in Florida February Males emerge Late October Brumation April May Mating season Summer Eggs hatch
Tegu populations impact Florida Resource exploitation on managed lands Alligator nest raids (Mazzotti et al. 2014) Gopher tortoise burrow visitation Damage to private property Digging under structures Chicken coup raids
A broad approach was employed by FWC to enhance tegu monitoring in west central Florida Three major strategies: Public engagement Site-specific surveys Live-capture trapping
Public Engagement Creating opportunities for citizen science HOA presentations Flyer distribution Posters in public areas Media events
Increased public awareness led to increased reporting on our Ivegot1 hotline and website. EDDMapS database Ivegot1 hotline database 350 300 250 200 150 100 50 0 2008 2009 2010 2011 2012 2013 2014 Ivegot1 Hotline Calls from West Central Florida 100 90 80 70 60 50 40 30 20 10 0 2011 2012 2013 2014
*data current to july 2014 Study Area: eastern Hillsborough County
Site Specific Surveys Natural area monitoring Opportunistic surveys Track plots Wildlife cameras Burrow scoping
Formal track plot surveys were conducted on Balm Boyette Scrub Preserve Conducted spring and summer of 2014 Two sessions with a break for trapping Plots cleared daily Volunteers provided support Track Plot Results 2014 Tegu Tracks Session 1 (April) 30 Session 2 (June/July) 39 Total 69
Wildlife cameras and burrow scoping captured tegu interactions with gopher tortoises Gopher tortoise
Gopher tortoise
Tegu presence in 2013-14
Live-capture Trapping Box style traps used successfully Traps were deployed in natural areas and loaned to homeowners Baited with eggs or fruit Number of tegus trapped: 2013 2014 Private 8 30 Public 0 5 Total 8 35
Necropsy and diet analysis Volunteers assisted with dissections and analysis Tegus weighed and measured Stomachs and reproductive organs saved for analysis Stomach contents washed and dried
Results of gut content analysis Frequency of Occurance in 39 Tegus Plants 62% Mammals 46% Birds 10% Reptiles Amphibians 33% 38% Molluscs 17% Arthropods 94% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Oak toad (Anaxyrus quercicus), blueberries (Vaccinium sp.), paper wasp nest (Polistes sp.) Swamp eel (Monopterus albus) Black racer (Coluber constrictor), egg Tegus can access a variety of novel food sources
Insects most common prey item Arthropoda (37; 94%) Coleoptera (21; 53%) Orthoptera (19; 48%) Lubber grasshopper, Romalea guttata Hymenoptera (6; 15%) Wasps and their nests
Tegu Gut Contents Analysis Vertebrates (27; 69%) Mammalia (18; 46%) Amphibia (15; 38%) Frogs and toads Repitilia (13; 33%) Snakes, lizards, eggs
Tegu Gut Contents Analysis Plantae (24; 62%) Native berries Shiny blueberry (Vaccinium myrsinites) Saw palmetto (Serenoa repens) Black cherry (Prunus serotina) Blackberry (Rubus trivialis) Wild grape (Vitaceae spp.) Cultivated plants Blueberries Citrus Ornamental palms
Future research needs Several questions remain unanswered Nest site selection Impacts to gopher tortoises and commensal species Location of winter shelters Telemetry study planned for 2015
Questions? Tessie.Offner@myFWC.com Hotline: 1-888-Ive-Got1 (1-888-483-4681) Office/Cell: (813) 293-7159 MyFWC.com/nonnatives