Non-Trapping, Non-Invasive, Rapid Surveillance Sampling Using Tracking Tunnels, Trail Cameras, and eDNA to Determine Presence of Pest Predator Species

Abstract Accurate identification of predator species is a critical requirement to investigate their diet using faecal samples. We used non-invasive sampling and two methods of predator identification to investigate the diets of sympatric carnivores in a highly deforested region of the Brazilian Amazon. Of 108 scats, 81 could be identified at the species level using DNA sequencing and/or trichology. The former performed better than the latter (81.5% vs. 54.3% of the identified samples), and results were quite congruent (89.7% concordance in the 29 samples that could be assessed with both approaches). Nine species were identified, out of which four (crab-eating fox, ocelot, puma and jaguar) presented a sufficient number of samples to allow dietary analyses. The crab-eating fox was the most generalist (BA=0.92); ocelots focused on small- to medium-sized prey; pumas fed mostly on medium-sized items; and jaguars mostly targeted large-sized prey. A considerable overlap was observed between ocelots and pumas in all estimations (O=0.47–0.83). The presence of jaguars in the same region could be driving pumas to select medium- and small-sized prey. The results of this study highlight the importance of reliable predator identification and the need for in-depth ecological studies in areas where carnivore species are sympatric.

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Cues used by predators to detect freshwater turtle nests may persist late into incubation

The Canadian Field-Naturalist ◽

10.22621/cfn.v128i2.1583 ◽

2014 ◽

Vol 128 (2) ◽

pp. 179 ◽

Cited By ~ 10

Author(s):

Julia L. Riley ◽

Jacqueline D. Litzgus

Keyword(s):

Incubation Period ◽

Freshwater Turtle ◽

Predator Species ◽

Nest Sites ◽

Painted Turtles ◽

Turtle Conservation ◽

Nesting Sites ◽

Nest Depredation ◽

Trail Cameras ◽

The Relationship

Previous studies have found that turtle nest depredation is concentrated immediately post-oviposition, likely because cues alerting predators to nest presence are most obvious during this time. In Algonquin Provincial Park, Ontario, we examined the frequency of nest depredation during the incubation period for Snapping Turtles (Chelydra serpentina [Linnaeus, 1758]) and Midland Painted Turtles (Chrysemys picta marginata [Agassiz, 1857]). Contrary to most past findings, nest depredation occurred throughout the incubation period for both species. In fact, 83% and 86% of depredation interactions with Snapping and Painted Turtle nests, respectively, occurred more than a week after oviposition at our study site. Peaks in nest depredation (weeks with ≥10% nest depredation) occurred late in incubation and may have coincided with hatching. Trail cameras deployed at four nesting sites revealed six predator species interacting with nests. The presence of predators at nest sites increased late in the incubation period indicating a persistence or renewal (from hatching) of cues; additional research is necessary to determine the nature of these cues. These findings have implications for both research and turtle conservation. Further research should examine the relationship between temporal changes in predator species’ density and patterns of nest depredation. Additionally, in areas where protective nest caging is used as a species recovery action, it may be important to ensure that cages remain in place throughout the incubation period until emergence of hatchlings.

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Turtles and trail cameras: non-invasive monitoring using artificial platforms

Basic and Applied Herpetology ◽

10.11160/bah.169 ◽

2019 ◽

Author(s):

Shem David Unger ◽

Allison Santana

Keyword(s):

North Carolina ◽

Camera Traps ◽

Freshwater Turtle ◽

Freshwater Turtles ◽

Non Invasive ◽

Painted Turtles ◽

Trapping Methods ◽

Urban Pond ◽

Early Fall ◽

Trail Cameras

Freshwater turtles often utilize basking habitats, allowing researchers to obtain population estimates and relative abundances from visual observations via spotting scopes in addition to other traditional trapping methods. Emerging technologies, such as camera trapping with wildlife trail cameras have been extensively utilized in other taxa, primarily mammals and in reptiles such as terrestrial tortoises, but to a lesser extent for monitoring freshwater turtles. Given their ability to bask, combining readily available non-invasive camera traps with standardized platforms may aid researchers study freshwater turtle populations and basking behavior. We assessed this method by deploying a novel artificial basking platform design in tandem with camera traps for weekly monitoring of turtles at a small semi-urban pond in central North Carolina for six months (April to September 2018). Basking behavior was documented with 1098 observations, with the number of turtles utilizing platforms varying according to season, and overall peak use during late spring and early fall. We also noted shifts in artificial basking structure use by species, with Painted turtles, Chrysemys picta, replacing Yellow-bellied slider turtles, Trachemys scripta, as the dominant basking species over time. Conservation managers should consider using both platforms and trail cameras, for monitoring of freshwater basking turtle populations and as a metric for turtle presence or for detailed studies of behavior.

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X-ray microtomography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107058 ◽

1988 ◽

Vol 46 ◽

pp. 998-999

Author(s):

H.W. Deckman ◽

B.F. Flannery ◽

J.H. Dunsmuir ◽

K.D' Amico

Keyword(s):

Computed Tomography ◽

Internal Structure ◽

Imaging Technique ◽

Three Dimensional ◽

Tissue Structure ◽

Individual Element ◽

X Ray ◽

Non Invasive ◽

Panoramic Imaging ◽

Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

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