Nonnative Plants: Ecological Traps

[Cirsium]

Nonnative Plants: Ecological Traps

Offering alluring habitat for songbirds, exotic plants may actually decrease the animals' long-term survival and fitness

National Wildlife Federation
01-14-2013 // John Carey

ASIAN HONEYSUCKLES ARE BEAUTIFUL AND SHOWY BUSHES. Their white and pink flowers can fill the air with fragrance. Songbirds, including northern cardinals, American robins and gray catbirds, flock to nest in the plants’ dense leaves and gorge on their smorgasbord of red and yellow berries.

But these lush plants have a darker side. ...

Scientists are taking a closer look at the plants’ impact on birds, for example. While it’s true that abundant honeysuckle berries (right) attracted large numbers of fruit-eating songbirds in Pennsylvania, concluding that “honeysuckle is good for birds is like going to a highway rest stop, seeing starlings at a dumpster and saying that rest stops are good for birds,” says University of Delaware entomologist Doug Tallamy.

Rodewald’s latest research suggests that even generalists like cardinals may be harmed. ...

But this pattern changes when honeysuckle invades a forest. Because honeysuckle leafs out sooner in spring than most plants, the fittest cardinals rush to mate and nest in the shrubs’ dense foliage. But instead of a gain in reproductive success, these birds pay a price. The early nesters in honeysuckle rear 20 percent fewer young than those that nest in native plants.

Nonnative Plants: Ecological Traps - National Wildlife Federation

[recurve]

I like it! Thanks Cirsium I'm going to use this article as a resource in a paper I'm writing about managing backyard habitats.

[Cirsium]

Here's another thread that has some interesting information about birds and alien honeysuckles:
http://www.wildlifegardeners.org/for...our-birds.html

[dapjwy]

Nice find, Cirsium.

I have removed a lot of Asian honeysuckle from our property...always being aware of the structure that they provided (since they prevented natives to fill that niche)...but it wasn't until this year that I found a nest (left over from last year) in one--on the edge of our property. Over four years, I've only seen this one nest, but still felt concern that I was removing habitat (degraded as it was)...this year, I'm removing the rest of them--although the ones on the edge of a drop off I've just cut off at the base--I'm sure they will resprout, but I need their root systems intact for now to hold the bank against erosion. In their place, I've added a choke cherry or two...some pagoda dogwood (Cornus alternifolia), wild blueberry bushes, and others.

I feel better knowing that, ultimately, my restored habitat will benefit more species than I can imagine.

[KC Clark]

Source-sink systems and ecological traps are very VERY complicated subjects. I started looking into them a few years ago when I heard that backyard gardens had been shown to be a problem. Would seem that whether a backyard garden is bad depends on on the species. I recently read a paper that found that monarch butterflies seemed to benefit from butterfly gardens, so that is good. But, I've seen other papers that show other butterfly species are adversely affected. I'm not going into any details. I'm just going to suggest you look into what research is out there if you are interested in finding out what has been observed.

Google Scholar is one of the searches I use for finding research articles on the subject.