Geology topics

Daniel Haro

Publications and source records attributed to Daniel Haro.

3 recordsLinked to original sources

USGS2026

Bait baskets reduce trap disturbance and rebaiting for invasive Argentine black and white tegus (Salvator merianae) in the Greater Everglades Ecosystem, USA

Effective invasive species management can be informed by strategies that maximize removal while minimizing costs. In the southeastern United States, metal-mesh bait baskets are routinely used to protect chicken egg lures in traps targeting invasive Argentine black and white tegu lizards ( Salvator merianae ). These bait baskets are designed to reduce bait loss and nontarget species captures, potentially lowering rebaiting frequency and associated labor. Using data from a multi-year trapping effort and from a crossover experiment on the periphery of Everglades National Park, Florida, we evaluated the influence of bait baskets on tegu and nontarget capture rates, trap disturbance, and rebaiting needs. We found no evidence that bait baskets affected tegu or nontarget capture in either the multi-year or crossover experiment datasets, but they did reduce trap disturbance and rebaiting frequency in the multiyear dataset following their implementation in 2016. In the crossover experiment, rebaiting frequency declined only in the first trial. Overall, bait baskets may enhance trap efficiency by extending functional trap time and reducing maintenance costs.

Florida↗

USGS2023

Capsaicin-treated bait is ineffective in deterring non-target mammals from trap disturbance during invasive lizard control

Excluding non-target species from invasive species control efforts can be challenging due to non-target attraction to trap structure, baits, and lures. Various methods have been used to deter non-target species from entering or disturbing traps including altered features (e.g., mesh size, trip mechanism, or entrances), staking traps, and chemical deterrents. Invasive populations of Argentine Black and White Tegu lizards ( Salvator merianae ) occur in several locations across Florida and Georgia, and there are ongoing trapping efforts to control them. At sites in Georgia, non-target mammals disturb most of the lizard traps (>80%), consume egg bait/lures, and thus reduce trap efficacy. In contrast, our Florida site has fewer problems with non-target mammals. Our goal was to quantify the efficacy of capsaicin-coated eggs, a known distasteful irritant to mammals, as a non-target bait deterrent in live traps set for tegus in both Georgia and Florida. We conducted feeding assays on three tegus and found that individuals readily consumed food coated in capsaicin. We then conducted a three-part, live trapping experiment to test 1) if trap disturbance by mammals habituated to eggs without capsaicin decreased when capsaicin-coated eggs were deployed in Georgia, 2) if mammals not habituated to eggs as bait (treated or untreated) disturbed live traps at the same rate as those habituated to eggs in Georgia, and 3) if tegu capture rates were different when capsaicin treated eggs were deployed in Florida. In Georgia, we found that trap disturbance by non-target mammals did not decrease when capsaicin was applied to eggs in an area previously habituated to trapping with this bait nor when applied in a novel area. In Florida, we found no significant difference in tegu captures using capsaicin-treated vs. untreated bait. Tegus were tolerant of capsaicin, but capsaicin treated eggs did not reduce non-target mammal disturbance to traps. Therefore, removal of invasive populations could be problematic if methods to reduce trap disturbance by non-targets are not identified and deployed.

NeoBiota↗

USGS2020

Evidence for an established population of tegu lizards Salvator merianae in southeastern Georgia, USA

Documenting emergence of invasive species in new areas is vital to understanding spatiotemporal patterns of invasions, propagule pressure, and the risk of establishment. Salvator merianae (Argentine Giant Tegu) has established multiple unconnected populations in southern and Central Florida, and additional sightings have been reported elsewhere in the state. In 2018, land managers in Georgia received >20 reports of this species in the wild. To evaluate the probability of establishment, we assembled verified records of the non-native Argentine Giant Tegu in Georgia over the past nine years. We report on 47 tegu observations throughout Georgia, with a concentration of sightings (n = 38) in Toombs and Tattnall counties. In 2019, we used modified Havahart traps and captured adult male and female tegus at one of our three locations during 3085 corrected trap nights. While we did not find evidence of a well-established population (i.e., varied size structure of tegus captured) with our limited trapping effort, we suspect tegus are breeding in Toombs and Tattnall counties due to the concentration of captures and reports of adult males and females, the consistent reports of adults across years, the confirmed presence of tegus in 2018, 2019 and 2020, and the reproductive capacity (i.e., turgid testes and secondary follicles) of tegus captured. Ongoing tegu introductions from captivity are likely to maintain high propagule pressure in the southeastern United States. Effective early detection, funded rapid response networks, and public outreach to solicit reports of tegu sightings are critical to prevent establishment and associated ecological impacts of this invasive species elsewhere in the southeastern US.

Southeastern Naturalist↗