Acceptability of residential development in a regional landscape: Potential effects on wildlife occupancy patterns

Landscape and Urban Planning

Hawley

et al. 2017

Housing development is often intermixed within natural land cover, creating coupled humannatural systems that benefit some species, while eliminating critical habitat for others. As carnivore populations recover and expand in North America, understanding how populations may recolonize human-dominated landscapes is an important goal for conservation. We empirically test whether a population of American black bear (Ursus americanus) recolonizing a developed landscape is responding to land cover, housing density, or the amount of intermixture between forest and housing as quantified by the Wildland Urban Interface. Housing density was the most supported spatially explicit mark-recapture model and indicated that bear density was highest among exurban housing densities. Mean estimated bear density in exurban areas (6-49 houses/km 2) was 0.18 individuals/km 2 compared to 0.12 individuals/km 2 in rural areas (< 6 houses/km 2). Bear densities also declined to zero as development approached 50 houses/km 2. We also tested for differences in sex ratio between more and less intensely developed areas, using hybrid mixture models. Sex ratios were significantly more male-biased in areas of higher housing density. Elevated bear densities provide evidence that exurban land-use can facilitate recolonization of black bears, yet high housing density may also limit the recovery of bear populations. Explicit relationships between land-use and bear density will allow managers to anticipate future population distribution, and areas where bears and people may come into frequent contact.

Section: Discussionmentioning

confidence: 77%

Black bear recolonization patterns in a human-dominated landscape vary based on housing: New insights from spatially explicit density models

Evans

Landscape and Urban Planning

Hawley

et al. 2017

“…Such circumstances may appear to indicate beneficial coexistence, yet intermixed development can induce changes with negative consequences for wildlife population demographics and human–wildlife dynamics. The volatility of land‐use patterns and anthropogenic mortality sources will also determine long‐term outcomes for such populations (Bettigole, Donovan, Manning, Austin, & Long, ; Clark et al., ). The altered dispersal behavior and sex ratios exhibited by a high‐density population of black bears living within development indicate shifted ecological dynamics that may constitute an ecological trap.…”

Section: Discussionmentioning

confidence: 99%

Spatial genetic patterns indicate mechanism and consequences of large carnivore cohabitation within development

Evans

Hawley

et al. 2018

Ecology and Evolution

Patterns of human development are shifting from concentrated housing toward sprawled housing intermixed with natural land cover, and wildlife species increasingly persist in close proximity to housing, roads, and other anthropogenic features. These associations can alter population dynamics and evolutionary trajectories. Large carnivores increasingly occupy urban peripheries, yet the ecological consequences for populations established entirely within urban and exurban landscapes are largely unknown. We applied a spatial and landscape genetics approach, using noninvasively collected genetic data, to identify differences in black bear spatial genetic patterns across a rural‐to‐urban gradient and quantify how development affects spatial genetic processes. We quantified differences in black bear dispersal, spatial genetic structure, and migration between differing levels of development within a population primarily occupying areas with >6 houses/km2 in western Connecticut. Increased development disrupted spatial genetic structure, and we found an association between increased housing densities and longer dispersal. We also found evidence that roads limited gene flow among bears in more rural areas, yet had no effect among bears in more developed ones. These results suggest dispersal behavior is condition‐dependent and indicate the potential for landscapes intermixing development and natural land cover to facilitate shifts toward increased dispersal. These changes can affect patterns of range expansion and the phenotypic and genetic composition of surrounding populations. We found evidence that subpopulations occupying more developed landscapes may be sustained by male‐biased immigration, creating potentially detrimental demographic shifts.

“…Economic optimization approaches could be expanded to identify not only where protection is most cost effective, but also where it is most cost effective relative to other objectives such as Manage or Restore (Wilson et al 2007). There are also opportunities to incorporate social information (Butler et al 2007), human health data (Knight et al 2008), development tolerance (Bettigole et al 2014), and policy scenarios (Beaudry et al 2013) in identification of COAs that would enhance their relevance to conservation planning within social-ecological systems.…”

Section: Discussionmentioning

confidence: 99%

Beyond protection: Expanding “conservation opportunity” to redefine conservation planning in the 21st century

Liberati

Journal of Environmental Management

Vokoun

2016

The protected lands estate increased dramatically during the 20th century and forms the backbone of current fisheries and wildlife conservation in North America. However, there is increasing evidence that modern conservation goals cannot be achieved by only focusing on adding new acreage, particularly with opportunistic protection. In the 21st century, flexibility and adaptability of conservation options can be accomplished by expanding the vocabulary of conservation planning beyond protection. We suggest a conceptual framework that considers suites of objectives to translate the broad goal of "conservation" into multiple implementation-specific objectives. These objectives form the "PCRM-PI" approach: protect, connect, restore, manage, partner, and inform. We use a case study to illustrate the limitations of protection-centric planning and how expanding the definition of conservation opportunity can help planners do more on the landscape. We suggest that the PCRM-PI approach with implementation-specific objectives is an effective way to bridge planning-implementation gaps and translate broad, landscape-level conservation goals into implementable actions.