Recent Efforts to Monitor and Manage the Argentine Tegu in Central

Recent Efforts to Monitor and
Manage the Argentine Tegu in
Central Florida
Tessie Offner
Florida Fish and Wildlife Commission : Nonnative Wildlife Biologist
Email: [email protected]
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
(Salvator merianae)
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
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
April – May
Brumation
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
Ivegot1 Hotline Calls from West Central Florida
100
90
80
70
60
50
40
30
20
10
0
350
300
250
200
150
100
50
0
2008
2009
2010
2011
2012
2013
2014
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
33%
Amphibians
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?
[email protected]
Hotline: 1-888-Ive-Got1
(1-888-483-4681)
Office/Cell: (813) 293-7159
MyFWC.com/nonnatives