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We compared the vulnerability of a Nearctic-Neotropical migrant (Swainson’s Thrush, Catharus ustulatus) for three geographically-defined breeding populations in California by linking breeding and wintering regions, estimating migration distances, and quantifying relative forest loss. Using data from light-level geolocator and GPS tags, we found that breeding birds from the relatively robust coastal population in the San Francisco Bay area wintered predominantly in western Mexico (n = 18), whereas the far rarer breeding birds from two inland populations that occur near one another in the Sierra Nevada and southern Cascades mountain ranges migrated to farther wintering destinations, with birds from the Lassen region (n = 5) predominantly going to Central America and birds from the Tahoe region (n = 7) predominantly to South America. Landscape-level relative forest loss was greater in the breeding and wintering regions of the two Cascade-Sierra populations than those of coastal birds. Longer migration distances and greater exposure to recent forest loss suggest greater current vulnerability of Cascade-Sierra birds. Our results demonstrate that for some species, quantifying migration distances and destinations across relatively small distances among breeding populations (in this case, 140–250 km apart) can identify dramatically different vulnerabilities that need to be considered in conservation planning.

Many bird populations have experienced population declines across North America over the past several decades. The establishment of protected areas has been used as a conservation action to maintain or help in the recovery of these populations; however, the effectiveness of protected areas in safeguarding bird populations within their borders from negative impacts to populations in surrounding unprotected areas has rarely been evaluated. Our study aimed to evaluate the effectiveness of protected areas in the San Francisco Bay Area of California for landbirds. We conducted point count surveys along riparian corridors in coastal Marin County in protected areas, predominately national parks, and estimated the population growth rates for 14 species over 23 years. We compared these growth rates to North American Breeding Bird Survey growth rate estimates from the Coastal California and the Northern Pacific Rainforest Bird Conservation Regions, which comprise larger, regional populations. A safeguarding effect was detected for 9 of the 14 species. We expected an effect on species strongly associated with riparian vegetation, which has incurred significant loss and degradation in the region; however, we instead observed benefits to general riparian users that were at least as great as the benefits to strong riparian specialists. We also expected that populations of resident species might benefit more than migrants; however, we found strong support for a safeguarding effect for both groups. Species with increasing growth rates in coastal Marin County protected areas in comparison to regionally stable or decreasing populations demonstrate the potential for protected areas to not only maintain populations despite declines outside their boundaries but also to help them recover from current and previous losses. Continuing long-term monitoring and associated full life cycle research will help identify if and when other drivers (e.g., climate change) may weaken these safeguarding effects, or when additional conservation and management is warranted. LAY SUMMARY Designating protected areas has long been assumed to be an effective conservation tool and benefit bird populations within their borders, with very few studies evaluating this assumption. We tested the assumption by determining population trends for landbird species in protected areas in central coastal California using point count surveys and comparing our results to regional trends. Nine out of 14 species benefited from being inside protected areas with their population trends being more positive than the regional trends. Our study provides support for the effectiveness of designating protected areas as a conservation tool. We call for expanded long-term monitoring as well as exploration of reasons why the safeguarding effect was not universal and what actions are needed.

A new term, Multiple‐Benefit Conservation, has emerged in the conservation community, but has not been defined. We define Multiple‐Benefit Conservation as conservation efforts designed to simultaneously benefit local communities of people, enhance ecological function, and improve habitat quality for fish and wildlife. Its key features are setting ecological and societal goals at the outset and defining success as achieving these goals simultaneously. This is in contrast to efforts aimed at one goal that may also produce co‐benefits; it is inclusive of ecosystem services but not limited by a focus solely on human benefit. Strengths of this approach include that it is constructive, inclusive of multiple worldviews, easily communicated, solutions‐oriented, and compelling. Multiple‐Benefit Conservation as we define and describe it here appears to provide a pathway useful for designing conservation efforts that are more likely to be inclusive, that will quantify trade‐offs among goals, and can embrace pluralistic conservation leadership.

Author(s): Dybala, Kristen; Gardali, Thomas; Melcer, Jr., Ron | Abstract: The Sacramento–San Joaquin Delta is an important region for bird conservation in California, particularly as part of a large, productive estuary on the Pacific Flyway. The Delta currently provides habitat to an abundant, diverse community of birds, but it is likely only a small fraction of what the Delta’s bird community once was. Meeting the goal of restoring a healthy Delta ecosystem is legislatively required to include providing habitat for birds among the conservation goals and strategies in the Delta Plan, yet birds and their habitat needs are often not addressed in science syntheses, conservation planning, and large-scale restoration initiatives in the Delta. In this essay, we provide an avian perspective on the Delta, synthesizing recent scientific work to describe factors that contribute to the Delta’s current importance for birds, and the conservation needs of the diverse array of bird species that call the Delta home. We also evaluate the potential for the Delta to become even more important for birds in the future, incorporating climate change effects, species range shifts, and changes to the composition and configuration of the Delta’s landscape. Finally, recognizing the uncertainties about the Delta’s future landscape and the complexity of this social-ecological system, we provide recommendations—aimed at a higher- level policy and planning audience—for integrating bird conservation with other goals in the Delta. To improve ecosystem integrity, conserve biodiversity, and provide benefits to local communities of people, we urge a focus on creating a more resilient Delta and employing a diversified portfolio of conservation strategies, both old and new.

Restoration of deforested and degraded landscapes is a globally recognized strategy to sequester carbon, improve ecological integrity, conserve biodiversity, and provide additional benefits to human health and well-being. Investment in riparian forest restoration has received relatively little attention, in part due to their relatively small spatial extent. Yet, riparian forest restoration may be a particularly valuable strategy because riparian forests have the potential for rapid carbon sequestration, are hotspots of biodiversity, and provide numerous valuable ecosystem services. To inform this strategy, we conducted a global synthesis and meta-analysis to identify general patterns of carbon stock accumulation in riparian forests. We compiled riparian biomass and soil carbon stock data from 117 publications, reports, and unpublished data sets. We then modeled the change in carbon stock as a function of vegetation age, considering effects of climate and whether or not the riparian forest had been actively planted. On average, our models predicted that the establishment of riparian forest will more than triple the baseline, unforested soil carbon stock, and that riparian forests hold on average 68-158 Mg C/ha in biomass at maturity, with the highest values in relatively warm and wet climates. We also found that actively planting riparian forest substantially jump-starts the biomass carbon accumulation, with initial growth rates more than double those of naturally regenerating riparian forest. Our results demonstrate that carbon sequestration should be considered a strong co-benefit of riparian restoration, and that increasing the pace and scale of riparian forest restoration may be a valuable investment providing both immediate carbon sequestration value and long-term ecosystem service returns.

Climate change and biodiversity loss are two global challenges that can be addressed simultaneously through reforestation of previously cleared land. However, carbon markets can encourage reforestations that focus on maximizing carbon storage, potentially at the expense of biodiversity conservation. To identify opportunities to optimize reforestation design and management to meet both goals, we examined the forest stand features associated with carbon stocks in biomass and soil, as well as bird abundance and diversity, in remnant and restored riparian forest stands in central California, U.S.A. Within three decades of reforestation, both planted and naturally regenerating riparian forest stands provided significantly greater carbon storage and avian biodiversity benefits compared to baseline conditions. They were also similar to a remnant riparian forest stand. We identified a synergy between carbon storage and biodiversity benefits in their positive associations with understorey cover, but we also identified a trade‐off in their relationships to forest stand density. Biomass carbon stocks were strongly positively related to stand density, while bird density and diversity suffered at the highest stand densities. The variability in understorey cover across forest stands indicates an opportunity for further enhancement of carbon and biodiversity benefits in areas where understorey cover is low, while the variability in stand density suggests an opportunity to re‐examine reforestation goals and consider thinning to achieve those goals. Synthesis and applications. We identified synergies and trade‐offs between carbon storage and biodiversity in their relationships to forest stand features, indicating opportunities to optimize reforestation design and management to achieve multiple goals. Our approach can be adapted to other reforestation efforts intended to simultaneously address the global challenges of climate change and biodiversity loss.

Changes in climate, vegetation, and land use are recognized as important drivers of changes in the distribution and abundance of wildlife. However, the behavioral and demographic mechanisms through which these changes affect populations have received less attention. Identifying these mechanisms is an important component of predicting the impacts of increasing environmental change. We used 30 yr of nest monitoring data at a study site where White-crowned Sparrow (Zonotrichia leucophrys) breeding density declined 85% to evaluate factors influencing habitat selection and reproductive success. Rapid secondary plant succession occurred at our study site, but the rate of change was faster in some areas than others. White-crowned Sparrows exhibited strong patterns of nest site selection, preferring open shrub vegetation and avoiding forest. As a result, many parts of the study area that were used for nesting early in the study period were no longer occupied by the end of the study period. Over the cours...

Water infiltration is commonly recommended as an indicator of soil dynamic properties and water cycling on rangelands. We investigated the utility of a two-trial single-ring infiltration test by evaluating the relationship between the first and second trial, the spatial variation in infiltration rates within and between sampling locations, and the relationship between water infiltration and bulk density and soil organic carbon (SOC) in the context of texture and water content. We measured water infiltration rates at 156 sites in 14 counties in California. We found a strong correlation between first and second infiltration trials. In pairwise correlations, both first and second trials were significantly correlated with SOC and bulk density. However, we did not find a significant relationship between water infiltration and either initial water content or soil texture. Model comparison revealed that in the context of soil texture, infiltration can serve as an indicator of bulk density and SOC; shorter water infiltration time (i.e., faster rate) is associated with decreased bulk density and increased SOC. Our results suggest that a single-ring infiltration test can be a useful, but imprecise, indicator of soil dynamic properties such as SOC and bulk density.

Knowledge of migratory connectivity is critical to understanding the consequences of habitat loss and climate change on migratory species. We used light-level geolocators to determine breeding locations and migratory routes of wintering Golden-crowned Sparrows (Zonotrichia atricapilla) in two regions of California, USA. Eight out of 9 birds tagged at coastal-wintering sites in Marin County went to breeding sites along the Gulf Coast of Alaska, while 7 out of 8 inland-wintering birds in Placer County migrated to interior sites in the Yukon, Northwest Territories, and British Columbia, Canada. Our estimate of the strength of migratory connectivity was relatively high (rm = 0.66). Coastal-wintering birds followed a coastal migration route while inland-wintering birds migrated inland. Coastalwintering birds migrated significantly farther than inland birds (3,624 km versus 2,442 km). Coastal birds traveled at a greater rate during spring migration (179 km/d) than did inland birds (118 km/d), but there was no statistical difference in the rate of fall migration (167 km/d and 111 km/d, respectively). Dates of arrival and departure, and duration of spring and fall migration, did not differ between groups, nor did return rates. Rates of return also did not differ between tagged and control birds. The distinct migration routes and breeding areas suggests that there may be more structuring in the migratory geography of the Golden-crowned Sparrow than in a simple panmictic population.

Rangelands are an economically and ecologically important land type that make up more than 40% of California's land area. Protecting and, where appropriate, increasing soil organic carbon (SOC) stocks across these rangelands can help to promote on-site and public ecosystem services including forage production and climate change mitigation. A necessary step toward appropriately and effectively stewarding SOC is understanding baseline variability in SOC stocks and identifying how that variability relates to factors such as climate, soil texture, and topography. While these relationships have been examined at broader spatial scales and in other contexts, analysis for California's rangelands remains lacking. We leveraged a voluntary ecological monitoring program consisting of 45 working ranches to explore how SOC varies with geographic distance, climate, vegetation, soil type, and topography within and across three regions of California. We found that there was large variability in soil C stocks across the state, with the Central Coast region storing more SOC than the San Joaquin and Sacramento Valleys. Network-wide, SOC stocks ranged from 4.83 to 63.54 Mg ha−1 for 0–10 cm depth and 12.15–205.37 Mg ha−1 for 0–40 cm depth. As hypothesized, climate was the strongest predictor of SOC stocks across the entire network, and in general other predictor groups became more important at the regional level. Within each region, we found on average a sixfold difference in SOC stocks, with much of the variation unexplained by the predictor variables included. While some differences in SOC likely result from unaccounted variables such as soil mineralogy, conceivably some of the variation is also due to differences in past and current land use—indicating that there is potential to rebuild SOC through management.

To address the loss of wetlands and riparian forests in California, private lands habitat programs are available through U.S. federal and state government agencies to help growers, ranchers and other private landowners create and enhance wildlife habitat. The programs provide financial and technical assistance for implementing conservation practices. To evaluate the benefits of these programs for wildlife, we examined bird use of private wetlands, postharvest flooded croplands and riparian forests enrolled in habitat programs in the Central Valley and North Coast regions of California. We found that private Central Valley wetlands supported 181 bird species during the breeding season. During fall migration, postharvest flooded croplands supported wetland-dependent species and a higher density of shorebirds than did semipermanent wetlands. At the riparian sites, bird species richness increased after restoration. These results demonstrated that the programs provided habitat for the species they were designed to protect; a variety of resident and migratory bird species used the habitats, and many special status species were recorded at the sites.

Experimenting with new and unconventional restoration methods and designs is critical to advancing the field of ecological restoration. Conventional methods cannot be considered reliable in a future with climate change-induced shifts in weather conditions, species distributions, and ecosystem processes. It is crucial that researchers and practitioners collaborate to identify the most effective restoration methods, yet there remains a disturbing lack of restoration experiments at the spatial or temporal scales relevant for evaluating wildlife responses. We suspect that willingness to attempt such experiments is hampered by the perceived difficulty of conducting these experiments combined with a fear of failure. However, we argue that failure to experiment with new methods guarantees learning nothing new. Here, we address many of the major challenges of designing an experiment to evaluate wildlife responses to restoration, including (1) distinguishing between the goals and objectives of the restoration project and the key uncertainties the experiment will address, (2) designing the experiment itself, including optimizing plot size and replication, and (3) determining how and when the results will be evaluated. We then illustrate how we designed an experiment to evaluate riparian bird responses to restoration along the lower Cosumnes River in the Central Valley of California, USA. Researchers and practitioners working together from the start of the objectives-setting process, through experimental design, implementation, and evaluation can proactively address the challenges of conducting a restoration experiment and maximize the chances of successfully identifying effective restoration methods, adding to the practitioners’ toolbox, and accelerating the rate of successful habitat restoration.

To evaluate the effects of climate change on landbirds in western North America, we reviewed the published literature on changes in avian phenology, geographic distribution, morphology, physiology, and population size that have been linked to climate change in the region. Despite a large literature on the projected effects of climate change, we found surprisingly few published papers that evaluated effects already observed on western North American landbirds. The topic that has received the most attention is the phenology of migration and reproduction. However, researchers have demonstrated consistent patterns of phenological change in fewer than 10 of the region’s species. Similarly, shifts in the elevational distribution of birds have not been consistent with the expectation that climate change will cause species to shift upward in elevation. Demonstrable effects of climate change, or in some cases lack thereof, will improve future projections of its effects and efforts toward conservation. Some data from which changes can be evaluated are already available. Our review demonstrates that there is still a very real need to understand how climate change is already affecting landbirds in western North America.

Author(s): Dybala, Kristen E.; Clipperton, Neil; Gardali, Thomas; Golet, Gregory H.; Kelsey, Rodd; Lorenzato, Stefan; Melcer, Jr., Ron; Seavy, Nathaniel E.; Silveira, Joseph G.; Yarris, Gregory S. | Abstract: Riparian ecosystems provide important ecosystem services and recreational opportunities for people, and habitat for wildlife. In California’s Central Valley, government agencies and private organizations are working together to protect and restore riparian ecosystems, and the Central Valley Joint Venture provides leadership in the formulation of goals and objectives for avian conservation in riparian ecosystems. We defined a long-term conservation goal as the establishment of riparian ecosystems that provide sufficient habitat to support genetically robust, self-sustaining, and resilient bird populations. To achieve this goal, we selected a suite of 12 breeding riparian landbird focal species as indicators of the state of riparian ecosystems in each of four major Central Valley planning regions. Using recent bird survey data, we estimated that over half of the regional focal species populations are currently small (l 10,000) and may be vulnerable to extirpation, and two species have steeply declining population trends. For each focal species in each region, we defined long-term (100-year) population objectives that are intended to be conservation endpoints that we expect to meet the goal of genetically robust, self-sustaining, and resilient populations. We then estimated the long-term species density and riparian restoration objectives required to achieve the long-term population objectives. To track progress toward the long-term objectives, we propose short-term (10- year) objectives, including the addition of 12,919 ha (31,923 ac) of riparian vegetation in the Central Valley (by planning region: 3,390 ha in Sacramento, 2,390 ha in Yolo–Delta, 3,386 ha in San Joaquin, and 3,753 ha in Tulare). We expect that reaching these population, density, and habitat objectives through threat abatement, habitat restoration, and habitat enhancement will result in improvements to riparian ecosystem function and resilience that will benefit other wildlife populations and the people of the Central Valley and beyond.

https://doi.org/10.15447/sfews.2017v15iss1art8Quantitative population objectives are necessary to successfully achieve conservation goals of secure or robust wildlife populations. However, existing methods for setting quantitative population objectives commonly require extensive species-specific population viability data, which are often unavailable or are based on estimates of historical population sizes, which may no longer represent feasible objectives. Conservation practitioners require an alternative, science-based method for setting long-term quantitative population objectives. We reviewed conservation biology literature to develop a general conceptual framework that represents conservation biology principles and identifies key milestones a population would be expected to pass in the process of becoming a recovered or robust population. We then synthesized recent research to propose general hypotheses for the orders of magnitude at which most populations would be expected to reach each milestone. The framework is structured as a hierarchy of four population sizes, ranging from very small populations at increased risk of inbreeding depression and extirpation (< 1,000 adults) to large populations with minimized risk of extirpation (> 50,000 adults), along with additional modifiers describing steeply declining and resilient populations. We also discuss the temporal and geographic scales at which this framework should be applied. To illustrate the application of this framework to conservation planning, we outline our use of the framework to set long-term population objectives for a multi-species regional conservation plan, and discuss additional considerations in applying this framework to other systems. This general framework provides a transparent, science-based method by which conservation practitioners and stakeholders can agree on long-term population objectives of an appropriate magnitude, particularly when the alternative approaches are not feasible. With initial population objectives determined, long-term conservation planning and implementation can get underway, while further refinement of the objectives still remains possible as the population’s response to conservation effort is monitored and new data become available.

A growing concern among restoration ecologists is inadvertently creating ecological traps, yet identifying ecological traps is difficult, particularly over a large region and for an entire suite of species. Here we use an example to show that restoration ecologists can evaluate the risk of creating ecological traps. We reviewed the literature and synthesized data to evaluate the risk that restored riparian forests create ecological traps for riparian birds by attracting dense populations of the brood parasite, Brown-headed Cowbird ( Molothrus ater ; hereafter cowbird) in the Central Valley of California, U.S. We found that most riparian bird populations are not highly vulnerable to cowbird parasitism, that there were no differences in cowbird density or parasitism rates between restored and remnant riparian forests, and that the riparian bird community responded positively to restoration. We concluded that riparian restoration in California’s Central Valley has a low risk of creating ecological traps through cowbird parasitism. We recommend that restoration ecologists consider the potential for creating an ecological trap early and throughout the restoration design and implementation process, and include plans to monitor species responses to restoration, both in restored areas and in source populations nearby, as well as any specific conditions associated with a potential trap.

Conservation-reliant species require continuing management to ensure their long-term persistence. We qualitatively assessed the extent of conservation reliance for 92 California bird taxa listed under federal or California endangered species acts or recognized as California bird species of special concern. Habitat loss and fragmentation are the major threats for over 90% of these taxa, whereas interactions with predators or brood parasites threaten less than half, and human actions imperil roughly 40%. Some form of habitat enhancement is proposed to reduce the threats for most taxa, reinforcing the value of habitat-conservation strategies. Protecting habitat for wetland taxa and restoring habitat for island taxa appear to be particularly costly actions. Importantly, the species of special concern are every bit as conservation reliant as are taxa listed as endangered or threatened; management of these yet-unlisted taxa may be especially effective in preventing them from slipping into a more preca...

Few studies have quantitatively projected changes in demography in response to climate change, yet doing so can provide important insights into the processes that may lead to population declines and changes in species distributions. Using a long-term mark-recapture data set, we examined the influence of multiple direct and indirect effects of weather on adult and juvenile survival for a population of Song Sparrows (Melospiza melodia) in California. We found evidence for a positive, direct effect of winter temperature on adult survival, and a positive, indirect effect of prior rainy season precipitation on juvenile survival, which was consistent with an effect of precipitation on food availability during the breeding season. We used these relationships, and climate projections of significantly warmer and slightly drier winter weather by the year 2100, to project a significant increase in mean adult survival (12-17%) and a slight decrease in mean juvenile survival (4-6%) under the B1 and A2 climate change scenarios. Together with results from previous studies on seasonal fecundity and postfledging survival in this population, we integrated these results in a population model and projected increases in the population growth rate under both climate change scenarios. Our results underscore the importance of considering multiple, direct, and indirect effects of weather throughout the annual cycle, as well as differences in the responses of each life stage to climate change. Projecting demographic responses to climate change can identify not only how populations will be affected by climate change but also indicate the demographic process(es) and specific mechanisms that may be responsible. This information can, in turn, inform climate change adaptation plans, help prioritize future research, and identify where limited conservation resources will be most effectively and efficiently spent.

Measuring site quality for birds at migration stopover grounds and identifying critical stopover habitats are both important components of gauging the full life cycle conservation of migratory birds. We evaluated riparian stopover habitat quality on the San Joaquin and Mokelumne rivers in California's Central Valley for migrant Willow Flycatchers (Empidonax traillii), Orange-crowned Warblers (Oreothlypis celata), Yellow Warblers (Setophaga petechia), and Wilson's Warblers (Cardellina pusilla). For each species, we used 3 approaches to assess habitat quality: (1) we examined change in mass of individuals that were recaptured at least once; (2) we tracked body condition over the time of day and over the course of the migratory season; and (3) we compared the rates of hourly mass change for Wilson's Warbler to similar studies in Canada and the United States. On average, individuals of all species recaptured at stopover sites increased mass from initial capture to final capture (0.49 g to 0.88 g). ...

We used light-level geolocators to describe the migratory geography of Swainson's Thrushes (Catharus ustulatus) from a breeding population in central coastal California. Between 11 June and 20 July 2010, we attached geolocator tags to 35 Swainson's Thrushes at three sites in Marin County, California, and recovered 12 in the following two breeding seasons. All 12 birds spent the winter in Mexico, north of the Isthmus of Tehuantepec. Eleven of the birds went to the Jalisco region in western Mexico, but two of those birds (18% of total) moved east in midwinter to either the Sierra Madre Oriental or Sierra Madre del Sur; the 12th bird went directly to one of the latter regions. The return rate over the next 2 years for tagged birds (34%) was not statistically lower than that for control birds (45%). We combined our results with the results of an earlier study that used geolocators on Swainson's Thrushes from British Columbia to quantify the strength of migratory connectivity using Mantel's correlati...

We evaluated the contribution of interspecific interactions, intraspecific processes, and environmental forcing to variation in speciessa' abundance in a habitat undergoing rapid successional change. We applied a Bayesian hierarchical approach to a 29‐yr time series of territory density of seven landbird species at a site in coastal California where secondary plant succession has occurred. We found that interspecific interactions were the least important driver in our system, explaining between 0% and 5% of variation. The combined effects of vegetation and rainfall variation explained 6% to 30% of variation in species trends. Intraspecific processes explained between 0% and 39% of variation. Between 27% and 90% of variation was attributed to unexplained variation. Our results demonstrate that in the system studied, interspecific interactions among landbirds are relatively unimportant. These results suggest that in some cases it may be valid to model projections of individual populations to predict community responses to future conditions; however, this conclusion should be interpreted with caution because interspecific interactions in our community did not include novel interactions that could result from distributional shifts in species ranges.

Although the effects of climate change on species distributions have received considerable attention, land-use change continues to threaten wildlife by contributing to habitat loss and degradation. We compared projected spatial impacts of climate change and housing development across a range of housing densities on California’s birds to evaluate the relative potential impacts of each. We used species-distribution models in concert with current and future climate projections and spatially explicit housing-development density projections in California. We compared their potential influence on the distributions of 64 focal bird species representing six major vegetation communities. Averaged across GCMs, species responding positively to climate change were projected to gain 253,890 km2 and species responding negatively were projected to lose 335,640 km2. Development accounted for 32 % of the overall reductions in projected species distributions. In terms of land area, suburban and exurban development accounted for the largest portion of land-use impacts on species’ distributions. Areas in which climatic suitability and housing density were both projected to increase were concentrated along the foothills of the Sierra Nevada and areas of the north coast. Areas of decreasing climatic suitability and increasing housing density were largely concentrated within the Central Valley. Our analyses suggest that the cumulative effects of future housing development and climate change will be large for many bird species, and that some species projected to expand their distributions with climate change may actually lose ground to development. This suggests that a key climate change adaptation strategy will be to minimize the impacts of housing development. To do this effectively, comprehensive policies to guide land use decisions are needed at the broader scales of climate change.

Restoration and conservation may be enhanced by using ecologically-based methods for prioritizing actions. Efforts are currently underway to restore river flows to the San Joaquin River in California's Central Valley. Although fish are the primary restoration target for restored flows, complementary efforts are being designed to protect, enhance, and restore riparian and floodplain habitats to benefit the larger ecological community. We describe our efforts to use bird habitat distribution models to inform and prioritize conservation activities along the San Joaquin River. We demonstrate the integration of habitat distribution models into an established conservation planning process that illustrates the synergies and tradeoffs of protecting high quality habitat for multiple species-groups and other restoration opportunities on the San Joaquin River. We used quantitative models to develop habitat quality indices for marsh birds, early-successional riparian birds, and mid/late-successional riparia...

Long-term monitoring is essential to understand the effect of environmental change on bird populations. Ornithological field stations that have recorded detailed demographic data on bird populations over decades are well positioned to make important contributions to emerging research questions. On the basis of our experience at PRBO Conservation Science's Palomarin Field Station and a review of the literature, we assess the ability of field stations to use their long-term data to address current and future issues in conservation and management. We identify barriers to the application of data from field stations as well as some of the unique contributions made by these stations, and we present recommendations regarding the development, maintenance, and enhanced application of long-term data.

There has been a growing interest in whether established ecogeographical patterns, such as Bergmann’s rule, explain changes in animal morphology related to climate change. Bergmann’s rule has often been used to predict that body size will decrease as the climate warms, but the predictions about how body size will change are critically dependent on the mechanistic explanation behind the rule. To investigate change in avian body size in western North America, we used two long-term banding data sets from central California, USA; the data spanned 40 years (1971–2010) at one site and 27 years (1983–2009) at the other. We found that wing length of birds captured at both sites has been steadily increasing at a rate of 0.024–0.084% per year. Although changes in body mass were not always significant, when they were, the trend was positive and the magnitudes of significant trends were similar to those for wing length (0.040– 0.112% per year). There was no clear difference between the rates of change of long-distance vs. short-distance migrants or between birds that bred locally compared to those that bred to the north of the sites. Previous studies from other regions of the world have documented decreases in avian body size and have used Bergmann’s rule and increases in mean temperature to explain these shifts. Because our results do not support this pattern, we propose that rather than responding to increasing mean temperatures, avian body size in central California may be influenced by changing climatic variability or changes in primary productivity. More information on regional variation in the rates of avian body size change will be needed to test these hypotheses.

In some passerines, the extent of preformative molt varies among individuals. Wrentits (Chamaea fasciata) undergo either a complete preformative molt or an eccentric (i.e., incomplete) preformative molt where some juvenile remiges are retained through the first cycle. Factors that influence the incidence and extent of molt are largely unknown. Using a 10-yr data set from the Palomarin Field Station in central coastal California, we quantified the incidence of eccentric molt and the degree to which variation in the incidence was associated with fledging date and weather. From 1999 to 2009, 159 Wrentits were banded as nestlings and subsequently recaptured. Of these, 21% of first-year Wrentits underwent eccentric molt. We used logistic regression and an information theoretic approach to compare models with fledging date, weather (annual precipitation and breeding-season temperature), and a random effect of year as predictors of the incidence of eccentric molt. Our top model included a random intercept term for year and a fixed effect for the effect of fledging date; birds that fledged later in the season were more likely to undergo eccentric molt. Although the proportion of individuals that underwent eccentric molt varied among years, models with breeding-season temperature and annual rainfall showed little to no support. Our results suggest that the incidence of eccentric molt is more strongly associated with fledging date than with annual variation in weather. The absence of a correlation with weather suggests that weather does not impose an energetic constraint on molt or, if it does, that birds are constrained in their ability to respond to changes in weather by adjusting the extent of their preformative molt. Other factors, such as nestling condition, may provide alternative explanations for year-to-year variability in the incidence of eccentric molt. RESUMEN En algunos paserinos, la cantidad de muda despues de la etapa juvenil varia entre individuos. C. fasciata sufre una muda despues de la etapa juvenil completa o una muda excentrica (i.e., incompleta) en donde las rectrices de algunos juveniles son retenidas a lo largo del primer ciclo. Los factores que influyen y extienden la muda son en su mayoria desconocidos. Usando una base de datos de 10 anos de la estacion de campo Palolmarin en la costa central de California, cuantificamos la incidencia de la muda excentrica y el grado en el cual la variacion en la incidencia estaba asociada con el dia de abandono del nido y el clima. Desde 1999 hasta 2009, 159 polluelos de C. fasciata fueron anillados y subsecuentemente recapturados. De estos, el 21% de las recapturas de C. fasciata del primer ano sufrieron una muda excentrica. Usamos una regresion logistica y una aproximacion con informacion teorica para comparar modelos con fechas de abandono del nido, clima (precipitacion anual y temperatura durante la temporada reproductiva), y ano como efecto aleatorio para vaticinar la incidencia de la muda excentrica. Nuestro modelo incluyo un termino de intercepto aleatorio para ano y un efecto fijo para el efecto de la fecha de abandono del nido; las aves que abandonaron el nido tarde en la temporada aumentaron la probabilidad de experimentar muda excentrica. Aunque la proporcion de individuos que experimentaron muda excentrica vario entre anos, modelos con temperatura durante la temporada reproductiva y precipitacion anual mostraron poco o ningun soporte. Nuestros resultados sugieren que la incidencia de la muda excentrica esta mas fuertemente asociada con la fecha de abandono del nido que con la variacion climatica anual. La falta de correlacion con el clima sugiere que el clima no impone una restriccion energetica en la muda o, si lo hace, estas aves estan limitadas en sus habilidades de responder a cambios en el clima a traves del ajuste en la extension de su muda despues de la etapa juvenil. Otros factores, como la condicion de los polluelos, pueden brindar explicacion alternativas para la variacion ano tras ano en la incidencia de la muda excentrica.

Between 1979 and 2006, we captured 452 Sharp-shinned Hawks (Accipiter striatus) at the Palomarin Field Station in the Point Reyes National Seashore, Marin County, central coastal California. Of all captures, the majority, 83%, were young males. We recaptured 46 individuals; 42 were originally banded at our site, and four were originally banded at a site 24 km southeast of our banding site, suggesting that our site may be a point on migration or a wintering destination for some Sharp-shinned Hawks. We captured Sharp-shinned Hawks during every month of the year, with peak captures occurring in the fall from late September to mid-November. Capture rate significantly increased over the course of our study, consistent with results from some other monitoring programs.

Evaluating the success of restoration projects requires well-designed studies. Among the decisions that need to be made are what taxonomic groups to study and when to conduct the monitoring. To explore how these decisions can influence assessments of restoration success, we examined species richness and composition data collected over several years on different terrestrial fauna (landbirds, rodents, bees, and beetles) at Sacramento River restoration and remnant riparian sites. Our selection of study organisms enabled us to ask whether variability in species richness among restoration sites is less for vagile taxa than for sedentary taxa, and if invertebrates display greater variability among sites than vertebrates. Our results demonstrate that responses to restoration can vary depending upon the season when it is assessed, and the taxa that are studied. For all taxa except bees, there was considerable variability in the relative performance of taxa at restoration sites from one sampling date to the next, such that the relative ranking of the sites often changed dramatically. Comparisons of β -diversity (variability in species richness across sites) revealed that certain taxonomic groups were more spatially variable in their response to restoration than others. Among vertebrates, sedentary taxa (rodents) had significantly higher variability in species richness across sites than highly vagile taxa (birds); however, no such pattern was observed for invertebrates. Overall, vertebrates had lower variability than invertebrates, suggesting that evaluations of restoration success based on a few better-known taxonomic groups (e.g., birds, rodents) may be inadequate to represent the biodiversity response of other groups (e.g., insects).

While burning effects did not persist through time, reinstituting burning at appropriate intervals would be feasible given the abundance of grassy fuel present and positive response of native grasses to burning (Packard and Mutel 1997). If additional knapweed suppression was desired, residual knapweed densities on restored plots remained low enough where hand pulling would be an effective and practical treatment (MacDonald et al. 2013). Our results are most applicable to the restoration of native warm-season grasses on degraded, knapweed-infested sites in the upper Midwest, and demonstrate that these native grasses can effectively suppress knapweed for extended time periods even in the absence of fire. Where the restoration of more diverse native plant communities is an important goal, the inclusion of these native grasses in a broad seed mix may similarly facilitate the gradual suppression of spotted knapweed.

The Least Bell's Vireo (Vireo bellii pusillus) was listed as state endangered in 1980 and federally endan- gered in 1986 in response to a sharp population decline and range reduction. This vireo commonly bred in riparian forests throughout the Central Valley of California, but prior to 2005, no nesting pairs had been confirmed in the region in over 50 years. On 29 June 2005, a Least Bell's Vireo nest was located in a 3-year-old riparian restoration site at the San Joaquin River National Wildlife Refuge in Stanislaus County, California. In 2006, a Least Bell's Vireo pair returned to the refuge to successfully breed, followed by an unsuccessful attempt in 2007 by an unpaired female. These records are approximately 350 km from the nearest known breeding population and appear to be part of a growing number of sightings outside of the species' current southern California breeding range. These nesting attempts lend credence to the idea that extirpated species can recolonize restored habitat by long-distance dispersal.

Mist netting is widely used to monitor the reproductive success of passerines, yet little is known about its effects on bird ecology. Using a 25-year data set from central California, we evaluated the effects of constant-effort mist netting on the reproductive performance of the Wrentit (Chamaea fasciata) and Song Sparrow (Melospiza melodia). We compared nest survival, number of young fledged, and an index of nestling condition (mass corrected for body size) at nests where at least one parent was captured while the nest was active to these variables at nests where neither parent was captured. We also compared these characteristics for nests at varying distances from nets run at different frequencies. Wrentit nestlings from nests closer to less frequently run nets were in poorer condition than those from nests close to more frequently run nets and than those far away from any nets. For the Song Sparrow, daily nest survival was higher where at least one parent was captured while the nest was activ...

Identifying nest predators is critical to understanding predation pressures that birds face, and using surveillance cameras appears to be the most reliable method of nest predator identification. However, presence and methods of using camera equipment may introduce bias in predation rates. To summarize potential effects of cameras on nest success we reviewed published and unpublished studies that estimated daily nest predation for bird nests with and without surveillance cameras. We used meta-analyses to quantitatively synthesize the direction and magnitude of these effects from independent studies. We found evidence that, on average, use of camera equipment may reduce nest predation rates, although these differences were not always significant and varied relative to geographic regions, vegetation types, and study duration. Researchers using camera surveillance to monitor nests must be aware that the equipment may be affecting rates of predation and possibly biasing data collected on predator identity. Based on our review and analysis, we provide recommendations for researchers seeking to minimize or control for potential bias when using surveillance cameras to monitor nest predation.

The ranges and abundances of species that depend on freshwater habitats are declining worldwide. Efforts to counteract those trends are often hampered by a lack of information about species distribution and conservation status and are often strongly biased toward a few well-studied groups. We identified the 3,906 vascular plants, macroinvertebrates, and vertebrates native to California, USA, that depend on fresh water for at least one stage of their life history. We evaluated the conservation status for these taxa using existing government and non-governmental organization assessments (e.g., endangered species act, NatureServe), created a spatial database of locality observations or distribution information from ~400 data sources, and mapped patterns of richness, endemism, and vulnerability. Although nearly half of all taxa with conservation status (n = 1,939) are vulnerable to extinction, only 114 (6%) of those vulnerable taxa have a legal mandate for protection in the form of formal inclusion on a state or federal endangered species list. Endemic taxa are at greater risk than non-endemics, with 90% of the 927 endemic taxa vulnerable to extinction. Records with spatial data were available for a total of 2,276 species (61%). The patterns of species richness differ depending on the taxonomic group analyzed, but are similar across taxonomic level. No particular taxonomic group represents an umbrella for all species, but hotspots of high richness for listed species cover 40% of the hotspots for all other species and 58% of the hotspots for vulnerable freshwater species. By mapping freshwater species hotspots we show locations that represent the top priority for conservation action in the state. This study identifies opportunities to fill gaps in the evaluation of conservation status for freshwater taxa in California, to address the lack of occurrence information for nearly 40% of freshwater taxa and nearly 40% of watersheds in the state, and to implement adequate protections for freshwater taxa where they are currently lacking.

Riparian vegetation along the Sacramento River— California’s largest river—has been almost entirely lost, and several wildlife species have been extirpated or have declined as a result. Large-scale restoration efforts are focusing on revegetating the land with native plants. To evaluate restoration success, we conducted surveys of landbirds on revegetated and remnant riparian plots from 1993 to 2003. Our objectives were to estimate population trends of landbirds, compare abundance patterns over time between revegetated and remnant riparian forests, and evaluate abundance in relation to restoration age. Of the 20 species examined, 11 were increasing, 1 was decreasing (Lazuli Bunting [Passerina amoena]), and 8 showed no trend. The negative trend for Lazuli Bunting is consistent with information on poor reproductive success and with Breeding Bird Survey results. There was no apparent guild association common to species with increasing trends. Nine species were increasing on revegetated and remnant plots, four were increasing on revegetated plots only, three were increasing on remnant plots only, the Lazuli Bunting was decreasing on both, and three species were stable on both. Although many species were increasing at a faster rate on revegetated plots, their abundance did not reach that of the remnant plots. For revegetated plots, ‘‘year since planting’’ was a strong predictor of abundance trends for 13 species: positive for 12, negative for 1. Our study shows that restoration activities along the Sacramento River are successfully providing habitat for a diverse community of landbirds and that results from bird monitoring provide a meaningful way to evaluate restoration success.

We estimated apparent annual survival and recapture probabilities for adult Black-headed Grosbeaks (Pheucticus melanocephalus) and Spotted Towhees (Pipilo maculatus) at four sites along the Sacramento River, California. To calculate our estimates, we used capture-recapture mist-net data collected over two time periods at four study sites: from 1993 to 1995 at Flynn, Ohm, and Sul Norte, and from 1995 to 2000 at Ohm and Phelan Island. Our primary objective was to determine whether there were site-specific differences in adult survival and recapture probabilities for each species. Such differences are rarely investigated, yet, if present, suggest site-specific differences in habitat quality, with important implications for source/sink dynamics. We found site-specific variation in Black-headed Grosbeak survival within both the 1993–1995 dataset (Flynn = 0.797 ± 0.496, Ohm = 0.158 ± 0.191, Sul Norte = 0.773 ± 0.131) and the 1995–2000 dataset (Ohm = 0.088 ± 0.090, Phelan Island = 0.664 ± 0.111). For Sp...