Data from: Using ricelands to provide temporary shorebird habitat during migration

To help mitigate large wetland losses in California, The Nature
Conservancy launched a dynamic conservation incentive program to create
temporary wetland habitats in harvested and fallow rice fields for
shorebirds migrating along the Pacific Flyway. Farmers were invited to
participate in a reverse auction bidding process and winning bids were
selected based on their cost and potential to provide high quality
shorebird habitat. This was done in 2014 and 2015, for separate enrollment
periods that overlapped with spring and fall migration, both before and
after the traditional post-harvest flooding period. To assess the success
of the program we monitored shorebird use of fields that were enrolled
(treatments), and others that were subject to typical rice farm management
(controls). To put these observations in context, we used satellites to
simultaneously monitor the extent of shallow-water habitat across the
~215,000 hectares of ricelands in the area. Results showed that providing
habitat during migration, when it is typically unavailable in rice fields,
yielded the largest average shorebird densities ever reported for
agriculture in the region. Treatment fields had significantly greater
shorebird density, richness and diversity than control fields in both
spring and fall (especially September – early October, and late March –
early April), but in fall the difference was greater. Shorebird responses
to habitat provisioning, and regional habitat conditions, were variable
from year to year, and highly dynamic within a given season. Overall,
shorebirds densities were found to be negatively related to the total
amount of flooded habitat in the rice landscape. Factors that affected
habitat availability included allocation schedules of water deliveries
from reservoirs, and rainfall patterns, both of which were influenced by
drought. Collectively, these results suggest that appropriately managed
agricultural lands have great potential to provide high value habitat for
shorebirds during times of habitat deficit, including migration, and that
fall may be a particularly impactful time to create additional habitat.
Migratory species face great challenges due to the climate change,
conversion of historical stopover sites, and other factors, but dynamic
conservation programs offer promise that, at least in certain instances,
their needs can still be met.