US-Mexico border security wall may threaten wildlife species
Washington, July 8 (ANI): Biologists have determined that a 700-mile security wall under construction along the United States' border with Mexico could significantly alter the movement and "connectivity" of wildlife, with the animals' potential isolation a threat to populations of some species.
However, technology and alterations to the design could dramatically improve the potential for animals to move more freely between the two countries, the scientists added.
"The biggest concern is that this barrier will break small populations of animals into even smaller pieces that will result in fewer animals interacting," said Clinton Epps, a wildlife biologist at Oregon State University and co-author on the study.
"A major barrier such as this could lead to significant degradation of connectivity for many different species, ultimately threatening their populations," he added.
In their study, the authors looked at the potential effects of the security wall on two species - the pygmy owl and bighorn sheep.
They found that the low-flying pygmy owl made three-fourths of its flights below the height of the security wall, which is approximately four meters high, and that juvenile owls had lower colonization in areas of disturbance or areas with less vegetation.
"Some of the potential damage to pygmy owls could be mitigated with a few tweaks to the system," Epps added.
"Putting in poles near the fence could allow the owls to swoop down from a perch, and planting brush to provide better cover could help them avoid predation by larger avian species and improve their chances for colonization," he added.
"Movement of pygmy owls from Mexico to Arizona may be necessary for the persistence of the Arizona population," Flesch pointed out.
The security wall could have a bigger impact on the movement of bighorn sheep, which range widely among the hilly terrain.
The scientists' study estimated that at least nine populations of sheep in northwestern Sonora, Mexico, are linked genetically with animals in neighboring Arizona and an interruption of that connectivity could threaten populations on both sides of the fence.
An impermeable barrier would isolate sheep populations and potentially reduce their genetic diversity, but the scientists said that slight adaptations in the design of the fence could improve the animals' potential for connectivity while maintaining the desired security goals along the border.
"The key is to have gaps in the fence that are sufficient to allow passage of animals, while at the same time meeting security needs," Epps said.
"A 'virtual' fence could be an alternative to a solid wall in some places, especially in steep terrain that is ideally suited for bighorn sheep," he added. (ANI)