From Oregon State University in the USA:
July 7th, 2009
A 700-mile security wall under construction along the United States’ border with Mexico could significantly alter the movement and “connectivity” of wildlife, biologists say, and the animals’ potential isolation is a threat to populations of some species. …
Results of their study are being published in the journal Conservation Biology.
“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.”
In their study, the authors looked at the potential effects of the security wall on two species – the pygmy owl and bighorn sheep – primarily because they already had studied those animals in that region. 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. …
“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. …
Though their study focused on pygmy owls and bighorn sheep, the scientists also recognized other animals that could be affected by the security wall. Flesch said black bears, jaguars, pronghorn antelope [see also here and here], desert tortoises and ground-dwelling birds including wild turkeys and quail could be affected by restricted movement.
Bush Exaggerated Fire Risk in Owl Habitat to Favor Logging: here.
New glass could reduce one billion annual bird deaths from U.S. window collisions: here.
UPDATE January 2010: In Reversal, Jaguar Habitat Will Be Protected: here. Sounds like the new Obama administration’s small changes away from the disastrous Bush policies (while unfortunately not changing away from those policies on other issues). Will Bush’s wall go as well now, the main problem for jaguars weanting to go to the USA?
If you’ve never heard of the San Patricios, you’re not alone. The story of Irish immigrants joining Uncle Sam’s army during the Mexican-American war might be the kind of thing Bill O’Reilly would celebrate — that is, if they hadn’t defected en masse to defend Mexico from the invading forces: here.