Tweets:

In the "News and Views" department of the 3 February issue of Nature
Peter D. Moore discusses a recent article on the effect on the
nesting success of songbirds of choosing to nest in an introduced
honeysuckle shrub (Lonicera maackii) that has invaded eastern North
America. American Robins in particular are attracted to these
shrubs, to the point that over the six-year course of the study
nesting in Lonicera increased from 5% to 30% of the robin population.
This honeysuckle leafs out early in spring, which may offer a false
sense of security. Unfortunately the structure of these shrubs is
such that birds utilizing them place their nests relatively closer to
the ground than they do in native vegetation and thus suffer a higher
rate of mammalian predation (particularly from larger mammals such as
raccoons). The declining Wood Thrush also likes to nest in Lonicera,
with similar consequences, but Wood Thrushes are being outcompeted by
robins for nest sites in this inviting but perilous situation, so the
utilization rate by the thrushes is not increasing. "In this
respect," the author says, "[robins] may be doing the Wood Thrushes a
big favor."

Here is yet another bit of evidence of the drastic consequences of
the introduction of plant species rippling through the ecosystem and
altering relationships. The original article, by K.A. Schmidt and
C.J. Whelan, appeared in Journal of Conservation Biology 13 (1999).

Hal Opperman
Medina, Washington
mailto:halop at accessone.com