Narrator: Listen to part of a lecture in a wetlands ecology class. The professor is talking about sanderlings. Urbanization and coastal development has dramatic

Narrator: Listen to part of a lecture in a
wetlands ecology class. The professor is talking
about sanderlings.
Urbanization and coastal development has
dramatically reduced the beach habitat
available for foraging shorebirds worldwide.
This study tested the general hypo thesis that
recreational use of shorebird foraging areas
adversely affects the foraging behavior of
sanderlings Calidris alba. Observations
conducted on two central California beaches
from January through May and September
through December of 1999 showed that
number and activity of people significantly
reduced the amount of time sanderlings spent
foraging.
Although the sample size was low, the most
significant negative factor was the presence of
free running dogs on the beach. The
experimentally determined minimal approach
distance did not vary significantly with the type
of human activities tested.
Based on these results, policy recommendations
for minimizing the impact of human beach
activities on foraging shorebirds include: (1)
people maintain a minimum distance of 30 m
from areas where shorebirds concentrate and
(2) strict enforcement of leash laws A total of
492 focal birds were observed, of which a
sanderling was disturbed by passing humans on
an average of one every 15 min with 96% of
those sanderlings responding to humans at a
distance of 30 m or less (Fig. 1). Sanderlings
responded to human activity by either running
(42%) or flying (58%). Within the 1-min
sampling time, the disturbed sanderling
generally moved once (58%), with 42% moving
more than once due to human disturbance.