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INTRODUCTION
Georgia’s historic conservation and management efforts have resulted in a range of ecosystems
rich in endemic and charismatic species. Georgia’s barrier islands are touted as the crown jewels of
Georgia’s coast due to their status as the least disturbed coast on the eastern seaboard
(http://www.georgiawildlife.com/node/1060). These dynamic, protected coastal ecosystems serve as
nurseries for a host of beloved and increasingly threatened species.
New challenges continue to emerge with a key issue being the introduction and assimilation of
aggressive ant species. Red imported fire ants, Solenopsis invicta, Black imported fire ants, S. richteri,
their hybrid, and the tropical fire ant Solenopsis geminata can be found throughout the state (Gardner
et al. 2008) (Wetterer 2011). Meanwhile big-headed ants, Pheidole megacephala, and little fire ants,
Wasmannia auropunctata are both present on the Florida coast (Wetterer 2012, Wetterer 2013) and
could easily move north into Georgia’s barrier islands in a similar fashion to the tawny crazy ant
Nylanderia fulva, which was first reported in Georgia in 2013 (Gochnour 2015).
The above species are known to negatively affect or outright depredate a plethora of species,
such as shrub nesting songbirds, small mammals, butterflies, shore birds and both marine and terrestrial
reptiles (Conner et al. 2010, Diffie et al. 2010, Wauters et al. 2014, Long et al. 2015, Dziadzio et al. 2016).
When species are not out-right depredated by ants, vertebrate behavior can be altered by the ants
presence (Langkilde 2009). Notably, on Georgia’s barrier islands nesting Loggerhead sea turtles, shore
birds, and endemic herpetofauna are at risk of negative impacts from aggressive, predatory ants.
Additionally, native ant species are likely to have evolved to take advantage of the resources historical
present among the barrier islands. While other issues may be larger threats to these species, every
successful nest protected from depredation increases the health of already fragile populations.
Similar to the species richness found in Georgia’s vertebrate fauna, Georgia has an abundant
and diverse ant assemblage (Ipser et al. 2004) yet the barrier islands are understudied in regards to ants.
Native ants are also negatively impacted by invasive ant species, with invasive species often
outcompeting or even extirpating local ant fauna. The difficulty of sampling for small cryptic animals on
sand as well as their relative scarcity has left open a natural history niche with a wide array of research
possibilities. While invasive ants have been shown to depredate sea turtle eggs and hatchlings (Allen et
al. 2001, Parris et al. 2002, Wetterer et al. 2007), very little is published regarding ant depredation of sea
turtles in Georgia, with the most recent article on the matter published nearly 20 years ago (Moulis
1997).
We propose a 2-year research project involving a large-scale survey of the ground-inhabiting ant
assemblage on Georgia’s barrier islands. This effort will involve collaborations with teams throughout
the Georgia coast who will be collecting ants observed in the process of depredating sea turtle nests and
hatchlings. These surveys will broaden our knowledge of ant diversity and abundance on Georgia’s
barrier islands while providing confirmation of which ant species are affecting beach-nesting vertebrates
and document the current situation. In addition the survey will also help monitor for the presence of
potential invasives such as W. auropunctata, P. megacephala, and, N. fulva.
MATERIALS AND METHODS
Collaborators throughout the state will be collecting ants encountered depredating sea turtle
nests and hatchlings. Ants will be collected in 120 mL (4oz) specimen cups, frozen, and stored. Samples
will be identified to species once in Athens.
The detailed survey entails traps constructed of PVC tubing encapsulating a bait (combination of
peanut butter, tuna fish, or hot dog) inside two nested tubes, which can be opened/closed by rotating
the outer sleeve. The traps have holes large enough for ants to enter but prevent larger animals from
gaining access. Importantly, the baits will be deployed for a 1-2 hour window then promptly collected,
minimizing the potential for recruitment of vertebrate pests.
Twist and seal bait trap design
A 1.27 cm (1/2“) long ring was cut of 3.175 cm
(1-1/4“) diameter PVC and affixed with Oatey heavy duty
clear PVC cement inside a 1-1/4“ slip cap. A 2.54 cm (1”)
diameter PVC pipe cut to 16.5cm (6.5”) in length was
then inserted into the same slip cap, guided by the ring,
and affixed to the slip cap with PVC cement. A 3.175 cm
(1- 1/4“) PVC pipe cut to 15.24 cm (6”) in length was
inserted into the dried slip cap. A series of three holes
spaced roughly 3.81 cm (1.5”) apart along the length of
the apparatus were drilled into both pipe lengths
simultaneously using a 3/16 drill bit. A parallel set of
three holes was then drilled, spaced roughly 5 cm (2”) in
circumference away from the first holes. Finally, a second
slip cap was attached to the apparatus, but not
cemented to provide an accessible opening.
Figure 1: Slip cap and ring
Figure 2: Both pipes can be manipulated
independently
Baits will be deployed for 2 hours, collected,
processed, and then redeployed in the same plot. Each
time portion of a sequential time-series, 8am-10am,
10am-12pm, etc., will be sampled until a 24 hour cycle is
completed in the plot to asses which ant species forage
along the dunes at which time of day.
Figure 3: One slip cap remains uncemented and
serves as the bait reservoir
A plot will be considered a replicate and entail 5 traps deployed every 10 meters along a
transect perpendicular to the tide line from the inland dune edge to the seaward primary dune front. 21
traps will also be deployed along the dune front parallel to the tide line until 200 meters of beach length
have been covered. 4 secondary transects will be placed every 50 meters. A rough plot design can be
seen below, consisting of 21 traps along the dune front and 12 within the primary dune for 33 total
traps.
Initial Transect
Dune Front
Inter-dune edge
Figure 2: Bait trap plot design. Each star represents a bait trap. This hypothetical design would be modified based on dune
topography and delicacy in each area. Pitfall traps would be placed at both ends of the five transects
Sampling will be intentionally biased towards the dune front because sea turtle nest
depredation is possibly correlated to nest proximity to the dune front and ants are known to nest in
dunes but not open sand of the upper or intertidal beach. As such, foraging ants of greatest interest to
this study are those which are active along the dune front. However, occasional samples throughout the
dune will ensure that we are performing due diligence in our sampling of scavenging ant species
present. Intermittently, covered pitfall traps will be deployed alongside the baited traps. Each replicate
would have 12 rounds of timed baits deployed to survey an entire 24 hour period to ensure both night
and day foragers are sampled for. Five plot replicates will be attempted during the course of the survey
season and dispersed throughout the island’s length. Each plot site will be selected based on historical
sea turtle nest depredation data and input from island naturalists. Extreme care will be taken to ensure
native organisms and ecosystems are not unduly disturbed. No baits or excess materials will be left on
the beach or near vulnerable sites to attract unwanted scavengers.
Ten pitfall traps will be placed alongside the bait traps on the perimeter of the plot. The pitfall
will be 7.62 cm (3”) diameter PVC pipe buried to a depth of 0.5 m; analogous to the depth of a
loggerhead nest. The tops of the pitfalls would be covered to prevent both accidental capture of
unwanted organisms and sand inundation. The length of the pitfall trap would be perforated with small
holes drilled with a 3/16 bit starting just beneath the cap, at 5 cm in depth, and spaced every 10 cm
thereafter so that subterranean foragers have access to the trap. The trap will have no bait and a cup at
the base containing a vertebrate safe collecting solution, propylene glycol. Pitfalls would be deployed at
the beginning of a survey and checked daily thereafter and removed at the end of each two week survey
period. The burial of the pitfall will have the added benefit of causing disturbance similar to turtle nest
deposition or hatchling emergence, another possible trigger for ant recruitment.
Plot placement of the traps would be selected based on historical ant depredation data
provided by Georgia Department of Natural Resources and the Georgia Sea Turtle Cooperative, as well
as input from management and research professionals on site. At least 2 sites will be sampled per
survey trip and trips will be undertaken until at least 5 plots have been sampled.
Precautions
Extreme caution will be undertaken to ensure no nesting birds, turtles, or other wildlife are
disturbed, and areas where such nesting is underway will be excluded from the survey plots. Care will
be taken during trap deposition and collection to ensure native organisms and ecosystems are not
unduly disturbed. No baits or excess materials will be left on the beach or near vulnerable sites to
attract unwanted scavengers. Additionally, the traps are small, white, and discreet. Baited traps will
only be ephemerally present on the beach as they are timed and then immediately collected. Pitfall
traps will be buried and mostly out of sight ensuring a minimum degree of both physical and visual
disturbance. The traps use propylene glycol, which is neither volatile nor sweet, and non-toxic to
vertebrates. This will prevent unwanted predator attraction while the covered design prevents all
organisms larger than a 3/16 drill bit from entering the trap.
Survey Project Goals
1. Document the current species composition and relative abundance of the ground nesting ant
community by collecting both predacious ants via baits and subterranean ants via pitfall traps.
2. Determine the foraging time and efficiency of scavenging ants by baiting through a 24 hour time
series.
3. Compare species observed in our survey to species collected by turtle monitoring field teams
throughout the state to identify which species of ants are interacting with beach nesting
vertebrates.
Future Research Goals
While it is not possible to guarantee at this time, once ant specimens have been collected, they
could be analyzed in the future for a suite of biocontrol pathogens. Parasitic flies, microsporidia, and
species specific viruses have all been identified as possible biocontrol agents for problematic ants and
leave distinct traces on parasitized ants. Already present in some ant communities in north Florida
(Valles et al. 2010) and Georgia (Gardner et al. 2013), the presence or absence of biocontrol agents
along the coast would inform future researchers as to their potential management utility.
These current and future project goals would coalesce to furthering our scientific understanding
of a unique system by better documenting the species assemblage and abundance of ground nesting
ants. Further, by determining their presence, foraging behavior, and associates, an optimal control
model can be generated to manage problematic species through a combination of biocontrol agents and
targeted bait treatments. Once such a plan has been made, local island agents would have a wellinformed ability to respond to ant issues appropriately and effectively with minimum impact to other
important species.
Works Cited
Allen, C. R., E. A. Forys, K. G. Rice, and D. P. Wojcik. 2001. Effects of fire ants (Hymenoptera :
Formicidae) on hatching turtles and prevalence of fire ants on sea turtle nesting beaches in
Florida. Fla. Entomol. 84: 250-253.
Conner, L. M., J. C. Rutledge, and L. L. Smith. 2010. Effects of Mesopredators on Nest Survival of ShrubNesting Songbirds. J. Wildl. Manage. 74: 73-80.
Diffie, S., J. Miller, and K. Murray. 2010. Laboratory Observations of Red Imported Fire Ant
(Hymenoptera: Formicidae) Predation on Reptilian and Avian Eggs. J. Herpetol. 44: 294-296.
Dziadzio, M. C., A. K. Long, L. L. Smith, R. B. Chandler, and S. B. Castleberry. 2016. Presence of the red
imported fire ant at gopher tortoise nests. Wildl. Soc. Bull. 40: 202-206.
Gardner, W. A., H. B. Peeler, and S. K. Diffie. 2013. Occurrence of Phorid Fly (Diptera: Phoridae)
Parasitoids of Imported Fire Ants (Hymenoptera: Formicidae) in Georgia. J. Entomol. Sci. 48:
243-250.
Gardner, W. A., S. Diffie, R. K. V. Meer, and M. A. Brinkman. 2008. Distribution of the fire ant
(Hymenoptera : Formicidae) hybrid in Georgia. J. Entomol. Sci. 43: 133-137.
Gochnour, B. M., Joe A.; Suiter, Daniel R. 2015. The Tawny Crazy Ant, Nylanderia fulva, in Georgia. In U.
o. Georgia [ed.]. UGA-CAES Extension.
Ipser, R. M., M. A. Brinkman, W. A. Gardner, and H. B. Peeler. 2004. A survey of ground-dwelling ants
(Hymenoptera : Formicidae) in Georgia. Fla. Entomol. 87: 253-260.
Langkilde, T. 2009. Invasive fire ants alter behavior and morphology of native lizards. Ecology 90: 208217.
Long, A. K., L. M. Conner, L. L. Smith, and R. A. McCleery. 2015. Effects of an invasive ant and native
predators on cotton rat recruitment and survival. J. Mammal. 96: 1135-1141.
Moulis, R. A. 1997. Predation by the imported fire ant (Solenopsis invicta) on loggerhead seat turtle
(Caretta caretta) nests on Wassaw National Wildlife Refuge, Georgia. Chelonian Conservation
and Biology 2: 433-436.
Parris, L. B., M. M. Lamont, and R. R. Carthy. 2002. Increased incidence of red imported fire ant
(Hymenoptera : Formicidae) presence inloggerhead sea turtle (Testudines : Cheloniidae) nests
and observations of hatchling mortality. Fla. Entomol. 85: 514-517.
Valles, S. M., D. H. Oi, and S. D. Porter. 2010. Seasonal variation and the co-occurrence of four
pathogens and a group of parasites among monogyne and polygyne fire ant colonies. Biol.
Control 54: 342-348.
Wauters, N., W. Dekoninck, H. W. Herrera, and D. Fournier. 2014. Distribution, behavioral dominance
and potential impacts on endemic fauna of tropical fire ant Solenopsis geminata (Fabricius,
1804) (Hymenoptera: Formicidae: Myrmicinae) in the Galapagos archipelago. Pan-Pacific
Entomol. 90: 205-220.
Wetterer, J. K. 2011. Worldwide spread of the tropical fire ant, Solenopsis geminata (Hymenoptera:
Formicidae). Myrmecol. News 14: 21-35.
Wetterer, J. K. 2012. Worldwide spread of the African big-headed ant, Pheidole megacephala
(Hymenoptera: Formicidae). Myrmecol. News 17: 51-62.
Wetterer, J. K. 2013. Worldwide spread of the little fire ant, Wasmannia auropunctata (Hymenoptera:
Formicidae). Terrestrial Arthropod Reviews 6: 173-184.
Wetterer, J. K., L. D. Wood, C. Johnson, H. Krahe, and S. Fitchett. 2007. Predaceous ants, beach
replenishment, and nest placement by sea turtles. Environ. Entomol. 36: 1084-1091.