Evaluating Habitat-Association Models for the Saltmarsh Sparrow

Meiman

Rubega

2015

Restoration Ecology

Self Cite

Tidal marshes are among the most threatened habitats on Earth because of their limited natural extent, a long history of human drainage and modification, and anticipated future sea‐level rise. Tidal marshes also provide services to humans and support species of high conservation interest. Consequently, millions of dollars have been spent on tidal marsh restoration throughout North America. Southern New England has a long history of tidal marsh restorations, often focused on removal of the invasive plant Phragmites australis. Working in 18 Connecticut marshes, we examined the bird community in 21 plots in restoration sites and 19 plots in reference sites. Restoration plots were divided into those in marshes where management involved restoring tidal flow and those where direct Phragmites control (e.g. cutting, herbicide) was used. Saltmarsh sparrows Ammodramus caudacutus, which are considered globally vulnerable to extinction, were less common where tidal flow had been restored than at reference sites and nested in only one of 14 tidal‐flow restoration plots. No abundance differences were found for large wading birds, willets Tringa semipalmata, or seaside sparrows Ammodramus maritimus. Vegetation at sites where tidal flow had been restored showed characteristics typical of lower‐elevation marsh, which is unsuitable for nesting saltmarsh sparrows. We conclude that, although tidal‐flow restorations in Connecticut control Phragmites and restore native saltmarsh vegetation, they produce conditions that are largely unsuitable for one of the highest conservation priority species found in eastern U.S. salt marshes.

Section: Introductionmentioning

confidence: 99%

Tidal‐flow restoration provides little nesting habitat for a globally vulnerable saltmarsh bird

Meiman

Rubega

2015

Restoration Ecology

Self Cite

“…While not a variable in the top models, high marsh habitat was among the genetic diversity models receiving moderate support and with a non-zero beta coefficient, suggesting a role for this habitat in supporting robust populations. Although Saltmarsh Sparrows may be present and feed in areas of low marsh, high marsh that is not inundated from daily tides is required for successful nesting and is the best proxy for the vegetation structure features important for high-quality nesting habitat (Gjerdrum et al 2008, Meiman et al 2012, Meiman and Elphick 2012). High marsh is indicative of high-quality nesting sites and female sparrows may seek out better quality nesting habitat following failed nesting attempts (DiQuinzio et al 2001, Benvenuti et al 2018, Kocek 2022).…”

Section: Discussionmentioning

confidence: 99%

Surrounding landscape, habitat and hybridization dynamics drive population structure and genetic diversity in the Saltmarsh Sparrow

Walsh

Fenderson

Ornithological Applications

et al. 2023

Determining factors that shape a species’ population genetic structure is beneficial for identifying effective conservation practices. We assessed population structure and genetic diversity for Saltmarsh Sparrow (Ammospiza caudacuta), an imperiled tidal marsh specialist, using 13 microsatellite markers and 964 individuals sampled from 24 marshes across the breeding range. We show that Saltmarsh Sparrow populations are structured regionally by isolation-by-distance, with gene flow occurring among marshes within ~110–135 km of one another. Isolation-by-resistance and isolation-by-environment also shape genetic variation; several habitat and landscape features are associated with genetic diversity and genetic divergence among populations. Human development in the surrounding landscape isolates breeding marshes, reducing genetic diversity and increasing population genetic divergence, while surrounding marshland and patch habitat quality (proportion high marsh and sea-level-rise trend) have the opposite effect. The distance of the breeding marsh to the Atlantic Ocean also influences genetic variation, with marshes farther inland being more divergent than coastal marshes. In northern marshes, hybridization with Nelson’s Sparrow (A. nelsoni) strongly influences Saltmarsh Sparrow genetic variation, by increasing genetic diversity in the population; this has a concomitant effect of increasing genetic differentiation of marshes with high levels of introgression. From a conservation perspective, we found that the majority of population clusters have low effective population sizes, suggesting a lack of resiliency. To conserve the representative breadth of genetic and ecological diversity and to ensure redundancy of populations, it will be important to protect a diversity of marsh types across the latitudinal gradient of the species range, including multiple inland, coastal and urban populations, which we have shown to exhibit signals of genetic differentiation. It will also require maintaining connectivity at a regional level, by promoting high marsh habitat at the scale of gene flow (~130 km), while also ensuring “stepping stone” populations across the range.

“…We defined costs according to the conservation action that is the focus of our planning (see Carwardine et al 2008), which is the cost of purchasing land in the coastal zone. We measured conservation value in relation to two targets: the projected extent of tidal marsh in 2100 assuming no additional barriers to marsh migration are constructed (Hoover 2009), and the current extent of saltmarsh sparrow nesting occurrence (Meiman and Elphick 2012). We also considered two lesser effort data sources that are potential proxies for saltmarsh sparrow nesting: saltmarsh sparrow abundance, estimated from count surveys (Wiest et al 2016), and the current extent of tidal marsh, estimated from remote sensing (Hoover 2009).…”

Section: Methodsmentioning

confidence: 99%

Quantifying the return on investment of social and ecological data for conservation planning

Field

2019

Environ. Res. Lett.

The interdisciplinary nature of conservation problems is increasingly being incorporated into research, raising fundamental questions about the relative importance of the different types of knowledge and data. Although there has been extensive research on the development of methods and tools for conservation planning, especially spatial planning, comparatively little is known about the relative importance of ecological versus non-ecological data for prioritization, or the likely return on investment of incorporating better data. We demonstrate a simple approach for (1) quantifying the sensitivity of spatial planning results to different ecological and non-ecological data layers, and (2) estimating the potential gains in efficiency from incorporating additional data. Our case study involves spatial planning for coastal squeeze, a process by which development blocks coastal ecosystems from moving landward in response to sea-level rise. We show that incorporating spatial data on landowners' likelihood of selling had little effect on identifying relative priorities but drastically changed the outlook for whether conservation goals could be achieved. Better data on the costs of conservation actions had the greatest potential to improve the efficiency of spatial planning, in some cases generating more than an order of magnitude greater cost savings compared to ecological data. Our framework could be applied to other systems to guide the development of spatial planning and to identify general rules of thumb for the importance of alternative data sources for conservation problems in different socio-ecological contexts.