Fig 1.
Wildlife crossing structures (WCS; n = 5), 11.9 km of fencing, and wildlife guards (WG; n = 18) constructed by the Texas Department of Transportation to address ocelots and other animals’ mortality along State Highway 100 in Cameron County, Texas, USA.
All structures were monitored using remote cameras. Data were collected at WCS from January 2017 to May 2019 and at WG from April 2017 to May 2019. Basemap provided by Esri. Esri reserves the right to grant permission for any other use of the Image.
Fig 2.
Four of the five wildlife crossing structures (WCS) constructed by the Texas Department of Transportation to address ocelot (Leopardus pardalis albescens) mortality along State Highway 100 in Cameron County, Texas.
(A) Box culvert, openness ratios: 04 and 0.36 (WCS2); (B) Bridge: below grade, openness ratio: 1.76 (WCS3); (C) Box culvert: below grade, openness ratio: 0.21 (WCS4); (D) Box culvert: above grade, openness ratio: 0.62 (WCS3A). Note: WCS1 is not pictured because it has the same configuration as WCS2. (E-H) Examples of pictures from the camera showing wildlife crossing WCS at night.
Fig 3.
Two wildlife guard (WG) types were constructed by the Texas Department of Transportation to address ocelot mortality along State Highway 100 in Cameron County, Texas; (A) pipe and (B) bridge grating. (C, D) Examples of pictures from the camera showing wildlife at WG at night.
Fig 4.
Cameras were placed at the opening of a wildlife crossing structures (WCS; A) and wildlife guards (WG; B) constructed by the Texas Department of Transportation to protect ocelots and other animals along State Highway 100 in Cameron County in Texas from January 2017 to May 2019. (C) Schematic diagram of an active infrared camera (b) and one video camera (c) facing toward the WCS opening (a) while one passive infrared camera (d) faces away. The external sensing system is represented by the black and white boxes connected with the dashed line (e). (D) Schematic diagram of an active infrared camera (a) facing toward the WG and road while one passive infrared camera (b) faces toward the habitat side. The external sensing system is represented by the dashed line (c).
Fig 5.
Water inundation at one wildlife crossing structure (bridge: Below grade), located on State Highway 100 in Cameron County, Texas, occurring between January 2018 and May 2019.
Water levels depicted: little to no water (A); intermediate pooling of water (B); full of water (C). Reprinted from [40] under a CC BY license, with permission from A. D. Rivera Roy, original copyright 2020.
Fig 6.
Schematic diagram of wildlife interactions with wildlife crossing structures (WCS) and wildlife guards (WG).
(A) WCS and (B) WG.
Fig 7.
Bar graph showing mean number of crossings and refusals per survey day ± standard error at each wildlife crossing structure (WCS) during construction (January 2017—May 2018) and post construction (May 2018—May 2019).
Crossings and refusals were significantly different between WCS1, WCS2, and WCS3A (crossings: P = 0.001; refusals: P = 0.001) and significantly higher during construction than post construction (crossings: P = 0.001; refusals: P = 0.001) along State Highway 100 in Cameron County, Texas.
Table 1.
Most abundant species crossing at each wildlife crossing structure (WCS), during and post construction periods, based on similarity percentage analysis of data collected from January 2017 to May 2019 in Cameron County, Texas.
Average number of individuals denotes average number of individuals crossing per month, and similarity percentage refers to the extent to which each species contributed to the similarities of communities observed crossing at each WCS and time period.
Table 2.
Number of wildlife interactions determined by photo evaluation and count of different species detected by cameras at three wildlife crossing structures (WCS) constructed by the Texas Department of Transportation to protect ocelots and other animals’ motility on State Highway 100 in Cameron County, Texas.
Interactions observed at these three WCS were compared during construction versus post construction. Other WCS were excluded from this as they were still being built during the construction period. Monitoring was broken into two-time periods; during construction (January 2017—May 2018) and post construction (May 2018—May 2019).
Fig 8.
Bootstrapped metric multidimensional scaling (MDS) plot showing differences in monthly crossing rates between communities observed at three wildlife crossing structures (P≤0.001) and between during construction (Jan 2017-May 2018) and post construction (May 2018-May 2019; P≤0.001) along State Highway 100 in Cameron County, Texas.
Differences are indicated by physical distance between bootstrapped averages surrounded by 95% confidence areas.
Fig 9.
Bar graph showing mean number of repels and crossings per survey day ± standard error at pipe and bridge grating wildlife guards during construction (Apr 2017-May 2018) and post construction (May 2018-May 2019) along State Highway 100 in Cameron County, Texas.
Repels and crossings per survey day were significantly different between pipe and bridge grating wildlife guards (P = 0.001) and significantly higher post construction (P = 0.002).
Table 3.
Number of wildlife interactions determined by photo evaluation and count of different species detected by cameras at two wildlife guard (WG) types constructed by the Texas Department of Transportation to protect ocelots and other animals’ motility on State Highway 100 in Cameron County, Texas.
Interactions observed at WG were compared during construction versus post construction. Monitoring was broken into two-time periods; during construction (April 2017—May 2018) and post construction (May 2018—May 2019).
Fig 10.
Bootstrapped metric multidimensional scaling (MDS) plot showing differences in monthly repel rates between communities observed at each wildlife guard type (P = 0.012) and between during construction (Apr 2017-May 2018) and post construction (May 2018-May 2019; P = 0.010) along State Highway 100 in Cameron County, Texas.
Differences are indicated by physical distance between bootstrapped averages surrounded by 95% confidence areas.
Table 4.
Most abundant species being repelled at pipe wildlife guards (PWG) and bridge grating wildlife guards (BGWG), during and post construction, as a result of similarity percentage analysis of data collected from April 2017 to May 2019 on State Highway 100 in Cameron County, Texas.
Average number of individuals denotes average number of individuals being repelled per month, and similarity percentage refers to the extent to which each species contributed to the similarities of communities observed crossing at each WCS and time period.
Table 5.
Results of global generalized linear model testing counts of all species crossings against structural characteristics and landscape variables in the post construction period (May 2018-May 2019) in Cameron County, Texas.
Table 6.
Results of best-fitting generalized linear models resulting from the dredge function in R, testing binomial counts of crossings of the five most frequently observed species against environmental factors, from data collected post construction (May 2018—May 2019) in Cameron County, Texas.
Fig 11.
Daily crossing rates (Σcrossings/Σtotal occurrences) of all wildlife compared to three assigned water levels at WCS3 for data collected from January 2018 to May 2019 in Cameron County, Texas.
Water levels indicate little to no water (0); intermediate pooling of water (1); full of water (2).