Locally hyperabundant deer are not a trivial nuisance. They have profound, long-lasting impacts on entire ecosystems. These deer impacts affect every other plant, animal, and bird out there. It’s an important, vastly under-reported story, one that’s unfolding right under our noses in America’s sprawling suburbs and exurbs.
In DEERLAND you met a few of the botanists, ecologists, and foresters who helped me trace these connections, and at times I’ve told a simpler version of the story here at my blog. I’ve shown you forests with browse lines and a missing understory, and exclosures that tell a simple “deer on the right, no deer on the left” story. I’ve explained how overabundant deer reduce songbird numbers and diversity in the forest canopy, and why all these effects are incredibly persistent. Even when deer are weakened and starving, their numbers can remain high enough so their habitat never fully recovers.
But let’s not forget the deer themselves. In their weakened state, they’re more vulnerable to disease—and also more likely to spread disease. They tend to carry a much higher parasite load, which only weakens them further. They host protozoan parasites that include toxoplasmosis, babesiosis, and theileriosis, and they’re often infested with some combination of liver flukes, lungworms, stomach worms, meningeal worms, arterial worms, abdominal worms, and tapeworms. And then there are external parasites, like the ticks tormenting the deer in these two photos.
(The rather scrawny, tick-bitten doe was spotted in the suburbs of Connecticut, and the fawn in the photo below was found out on Long Island near Calverton, N.Y. For earlier posts on Long Island deer, see here and here. And here’s an op-ed on Long Island deer that I wrote for the Wall Street Journal.)
The moral of the story? When deer populations skyrocket, standing by to “let nature take its course” is not always our best option—or our most humane.
© 2014 Al Cambronne. Photos courtesy Tom Rawinski and Clifford Dayton. For more of Cliff’s photos, visit his website.