Conservation Objectives for Wintering and Breeding Waterbirds in California's Central Valley

Shuford, W. David; Dybala, Kristen E.

doi:10.15447/sfews.2017v15iss1art4

Cited by 10 publications

(24 citation statements)

References 25 publications

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“…To enable development of a conceptual framework for setting population or habitat objectives for at-risk species in the Central Valley, we first reviewed the methods being used to set such objectives for the various bird groups in the update of the CVJV implementation plan (DiGaudio et al 2017;Dybala et al 2017aDybala et al , 2017bShuford and Dybala 2017;Strum et al 2017, all this volume; 2016 email from G. Yarris, CVJV, to D. Shuford, unreferenced, see "Notes") and to what degree, if at all, these methods addressed at-risk species. We then developed a tiered approach for how population and habitat objectives for at-risk species not currently addressed might be set in the future.…”

Section: Framework For Setting Population or Habitat Objectivesmentioning

confidence: 99%

“…An update of the implementation plan currently underway will include chapters on the various bird groups included in the prior plan plus one on breeding grassland-oak savannah landbirds and another on at-risk birds that cuts across taxonomic groups and habitats. Other papers in the current volume provide detailed documentation of how population objectives were set for the various bird groups, except non-breeding and breeding waterfowl, covered by the CVJV's updated implementation plan (DiGaudio et al 2017;Dybala et al 2017aDybala et al , 2017bShuford and Dybala 2017;Strum et al 2017; all this volume). The technical papers and implementation plan chapters, however, vary substantially in whether they address at-risk taxa and, if so, to what degree and in what manner.…”

Section: Introductionmentioning

confidence: 99%

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Bird Species at Risk in California’s Central Valley: A Framework for Setting Conservation Objectives

Shuford¹,

Hertel²

2017

SFEWS

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Populations of many species of birds are declining worldwide from habitat loss and degradation and the effects of contamination, disease, and alien species. Effects have been great in California's Central Valley from the loss of over 90% of its historical wetland and riparian habitats. Conservation initiatives at various geographic scales have ranged from protecting and restoring habitats or ecosystems for broad suites of species to ones identifying individual declining and vulnerable taxa and spurring actions to halt or reverse their population declines. In taking the first approach, the Central Valley Joint Venture initially focused on restoring habitats and populations of wintering and breeding waterfowl but currently promotes the conservation of all birds. This joint venture is setting population and habitat objectives for seven taxonomic or habitat bird groups, but to date little attention has been paid to at-risk species of particular conservation concern. We identified 38 at-risk species, subspecies, or distinct populations of birds that warrant heightened conservation efforts in the Central Valley. At-risk birds are unevenly distributed among subregions and habitat types in this valley, but most face the primary threat of habitat loss and degradation. The treatment of at-risk species varies greatly among the seven bird groups considered by the joint venture, and, overall, conservation objectives are not addressed specifically for 50% of the region's at-risk taxa, though some surely benefit from objectives set for other groups. To adequately treat at-risk species, we recommend a framework for setting conservation objectives that evaluates assumptions about limiting factors, considers objectives already set for threatened and endangered species, assesses whether objectives set for other groups or focal species meet the needs of at-risk species lacking such objectives, establishes objectives for at-risk species for habitats or seasons not currently considered, and highlights information gaps to be filled to effectively set new or refined objectives.

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Section: Framework For Setting Population or Habitat Objectivesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Bird Species at Risk in California’s Central Valley: A Framework for Setting Conservation Objectives

Shuford¹,

Hertel²

2017

SFEWS

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Section: Study Areamentioning

confidence: 99%

“…We considered the xentral Valley Joint Venture planning region (Dybala et al 2017) to be the focal area for this study. We further divided up the region for some analyses according to Shuford & Dybala (2017) (Hanak & Lund 2012). xonsequently, there is less flooded agriculture in the south and higher year to year variability in flooding compared to in the north (Reiter et al 2015).…”

Section: Study Areamentioning

confidence: 99%

“…The xentral Valley of xalifornia is a region of hemispheric importance for waterbirds (Gilmer et al 1996;Shuford, Page & Kjelmyr 1998;xVJV 2006). With 90% of the historically occurring natural wetlands in the xentral Valley gone (Frayer, Peters & Pywell 1989), agricultural crops that are flooded post-harvest and hydrologically-managed wetlands are essential resources for migratory waterbirds (Elphick & Oring 1998;Dybala et al 2017;Shuford & Dybala 2017).…”

Section: Introductionmentioning

confidence: 99%

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Supplemental Information 6: Data Used to Assess Open Water in Managed Wetlands in the Central Valley

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Between 2013 and 2015 a large part of the western United States, including the Central Valley of California, sustained an extreme drought. The Central Valley is recognized as a region of hemispheric importance for waterbirds which use flooded agriculture and wetlands as habitat. Thus, the impact of drought on the distribution of surface water needed to be assessed to understand the effects on waterbird habitat availability. We used satellites to quantify the impact the recent extreme drought on the timing and extent of available waterbird habitat during the non-breeding season (July -May) by examining flooding in agriculture (rice, corn, and other crops) and managed wetlands across the Central Valley. We assessed the influence of habitat incentive programs, particularly The Nature Conservancy's BirdReturns and the Natural Resources Conservation Service's Waterbird Habitat Enhancement Program (WHEP), at offsetting waterbird habitat loss related to drought. Overall, we found significant declines in open water in post-harvest agriculture (20 -80% declines) and in managed wetlands (47 -59% declines) during the 2013 -2015 drought compared to non-drought years 2000 -2011. Crops associated with the San Joaquin Valley, specifically corn, as well as wetlands in that part of the Central Valley exhibited larger reductions in open water than rice and wetlands in the Sacramento Valley. However, seasonal wetlands on protected lands had a marginally significant (P<0.10) higher amount of open water in the drought years than those on non-protected lands. A large fraction of the daily open water in rice during certain times of the year,particularly in the fall for BirdReturns (64%) and the winter for WHEP (100%), may have been provided through incentive programs underscoring the contribution of these programs. However, further assessment is needed to know how much the incentive programs directly offset the impact of drought in post-harvest rice or simply supplemented funding for activities that might have been done regardless. Our, first of its kind, landscape analysis documents the significant impacts of the drought on freshwater wetland habitats PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.26483v1 | CC BY 4.0 Open Access | rec:

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Quantifying drought’s influence on moist soil seed vegetation in California’s Central Valley through remote sensing

Byrd¹,

Lorenz²,

Anderson

et al. 2020

Ecological Applications

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California's Central Valley, USA is a critical component of the Pacific Flyway despite loss of more than 90% of its wetlands. Moist soil seed (MSS) wetland plants are now produced by mimicking seasonal flooding in managed wetlands to provide an essential food resource for waterfowl. Managers need MSS plant area and productivity estimates to support waterfowl conservation, yet this remains unknown at the landscape scale. Also the effects of recent drought on MSS plants have not been quantified. We generated Landsat-derived estimates of extents and productivity (seed yield or its proxy, the green chlorophyll index) of major MSS plants including watergrass (Echinochloa crusgalli) and smartweed (Polygonum spp.) (WGSW), and swamp timothy (Crypsis schoenoides) (ST) in all Central Valley managed wetlands from 2007 to 2017. We tested the effects of water year, land ownership and region on plant area and productivity with a multifactor nested analysis of variance. For the San Joaquin Valley, we explored the association between water year and water supply, and we developed metrics to support management decisions. MSS plant area maps were based on a support vector machine classification of Landsat phenology metrics (2017 map overall accuracy: 89%). ST productivity maps were created with a linear regression model of seed yield (n = 68, R 2 = 0.53, normalized RMSE = 10.5%). The Central Valley-wide estimated area for ST in 2017 was 32,369 ha (29,845-34,893 ha 95% CI), and 13,012 ha (11,628-14,396 ha) for WGSW. Mean ST seed yield ranged from 577 kg/ha in the Delta Basin to 365 kg/ha in the San Joaquin Basin. WGSW area and ST seed yield decreased while ST area increased in critical drought years compared to normal water years (Scheffe's test, P < 0.05). Greatest ST area increases occurred in the Sacramento Valley (~75%). Voluntary water deliveries increased in normal water years, and ST seed yield increased with water supply. Z scores of ST seed yield can be used to evaluate wetland performance and aid resource allocation decisions. Updated maps will support habitat monitoring, conservation planning and water management in future years, which are likely to face greater uncertainty in water availability with climate change.

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Conservation Objectives for Wintering and Breeding Waterbirds in California's Central Valley

Cited by 10 publications

References 25 publications

Bird Species at Risk in California’s Central Valley: A Framework for Setting Conservation Objectives

Bird Species at Risk in California’s Central Valley: A Framework for Setting Conservation Objectives

Untitled

Quantifying drought’s influence on moist soil seed vegetation in California’s Central Valley through remote sensing

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