Using ricelands to provide temporary shorebird habitat during migration

Abstract

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 ha 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.

Integrating citizen science data with expert surveys increases accuracy and spatial extent of species distribution models

“…Each site was surveyed for at least two minutes and lasted as long as necessary to count all birds present (for more detail on count methods see Golet et al 2018). Effort for each point count consisted of date, time started and ended, and name of observer.…”

Quantifying shorebird habitat in managed wetlands by modeling shallow water depth dynamics

“…Recently the highest shorebird densities recorded for agricultural land in the Sacramento Valley were documented in temporary shallow water habitat provided in rice fields through the Bird Returns payment for services program (Golet et al. ). Such dynamic conservation strategies (Reynolds et al.…”

“…For example, Bird Returns fall migration contracts were limited to two week periods due to weed management and mosquito control concerns (Golet et al. ). Transferability of such programs to other wetland regions would depend on local conditions, including the availability and cost of water, agricultural practices and the availability of funds to incentivize private landowner participation.…”

The history and importance of private lands for North American waterfowl conservation

“…Several partnership‐based programs and initiatives have been developed to deliver waterfowl habitat conservation on working ricelands. A few of the more notable of these include the Rice Stewardship Partnership (RSP) administered by Ducks Unlimited, Inc. (DU) and USA Rice with significant funding from the NRCS RCPP, The Nature Conservancy's Bird Returns program (Golet et al ), and more recently the California Winter Rice Habitat Incentive Program (CWRHIP) in the California Department of Fish and Wildlife (CDFW). Herein we highlight accomplishments of CWRHIP and the RSP.…”