In connection with the listing the Service published “Rufa
Red Knot Background Information and Threats Assessment,”
a thorough study of the species that is almost 400 pages
long and includes about 65 pages of resources. Before the
official listing the Service conducted over 130 days of public
comment periods, held three public hearings, and received
more than 17,400 comments.
In an important article featured in the journal, Science,
in May of 2016, researcher Jan A. van Gils from the Royal
Netherlands Institute for Sea Research and his colleagues
sought to explain a dramatic decline in the number of red
knots that spend the winter in West Africa. They presented
evidence that pressure on the birds from climate changes in
their breeding area may have caused the decline in numbers
of birds.
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Because food supplies in their Arctic breeding grounds are
dwindling, the physical size of the newer generation of birds
is smaller. They have shorter bills, and they are not able to
dig as far into the sand for the clams on which they usually
feed during the winter. They are about 15 percent smaller
than their counterparts from 30 years ago and must resort to
feeding on less nutritious rhizomes (grass roots).
Looking at the evidence gathered over three decades,
Dr. van Gils said, “I foresee some sort of crash.” The
migration path of the red knots these scientists studied is
from Mauritania to the Russian Arctic and back, but their
changes may bode ill for red knots on the Atlantic flyway.
Martin Wikelski, a scientist at the Max Planck Institute for
Ornithology, with another colleague, reviewed this latest
research with some reservations about the conclusions, but
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