Most Delaware SGCN depend, to some extent, on lands facing habitat loss and fragmentation from residential and commercial development. Delaware’s human population is predicted to increase by about 100,000 people between 2025 and 2050, resulting in increases in land development statewide (Delaware OSPC 2025). 

Land Development in the Northeast Region 

With population growth comes a need for residential development and accompanying commercial and industrial development. Recent commercial development trends tend toward spacious “big box” developments, superstores, shopping villages, and regional distribution facilities that consume large acreages of habitat. Rural increases in residential and commercial development account for much of the reported losses in wildlife habitat and other natural resources. Transportation infrastructure that accompanies development compounds impacts by further fragmenting habitats and interrupting wildlife travel corridors to breeding, spawning, and wintering habitats. 

Historically, 26% of the region’s natural land has been converted to development or agriculture, while 19% has been conserved for nature or multiple uses. This equals 1.4 acres converted for every acre conserved. Over the last decade, this trend has reversed in the Northeast with 6.7 acres conserved for every one acre converted since 2012 (Anderson et al. 2023). High density development of natural habitats can change local hydrology, increase recreation pressure, introduce invasive species either by design or by accident with the introduction of vehicles, and bring significant disturbance to the area. Urbanization and forest fragmentation are inextricably linked to the effects of climate change, because the dispersal and migration of forest plants and animals are disrupted by development and roads. 

Future Development in Delaware 

From 2018 through 2023, local governments in Delaware approved a total of 35,578 and 29,340,233 square feet of non-residential development for future development. More than half of this development was approved in New Castle County (69%). The remainder was split between Kent and Sussex Counties (12% and 19%, respectively) (Delaware OSPC 2023). For more in-depth analysis of land use please visit the Delaware Strategies for State Policies and Spending at strategies.stateplanning.delaware.gov.

Development and Fragmentation of Forest Habitat

The Delaware Forest Service (DFS) (2010) reported that between 2002 and 2009, nearly 16,000 acres of Delaware’s remaining 217,000 acres of unprotected forest (privately owned without a permanent conservation easement) were included within areas approved for development. If current trends continue, Delaware is estimated to lose 10,000 or more acres of forest to development in the next housing expansion (DFS 2020). 

Fragmentation subdivides large contiguous areas of natural land into smaller patches, resulting in each patch having more edge habitat and less interior. Thus, fragmentation can lead to an overall deterioration of ecological quality and integrity, and a shift in associated species from interior specialists to edge generalists. Some wildlife species require larger blocks of habitat than others and can be negatively impacted by activities that fragment habitat. 

Buildings and Structures 

Bird populations are declining rapidly and dramatically (Rosenberg et al. 2019). Collisions with buildings are the third largest cause of avian mortality (Loss et al. 2014), and mortality has been estimated as high as 1 billion birds annually (Loss et al. 2014, Kornreich et al. 2024). Collisions with powerlines, communication towers, and wind turbines contribute to over 60 million additional bird deaths each year (Loss et al. 2014). Many building collision victims are passerines (Rebolo-Ifran et al. 2019, Colling et al. 2022) and migratory species are especially susceptible (Sabo et al. 2016), including some SGCNs (Loss et al. 2014, Marler 2024), and game birds such as waterfowl and woodcock. 

Birds collide with buildings for three primary reasons. Reflective surfaces, including glass, that reflect sky or vegetation are perceived as sky or vegetation by birds. Transparent glass is not perceived at all (Klem Jr. 1990). Thus, birds collide with reflective or transparent parts of building facades. Larger and more reflective and transparent surfaces increase the hazard to birds (Gelb and Delacretaz 2009, Hager et al. 2013, Cusa et al. 2015, Riding et al. 2020, Basilio et al. 2020). Artificial light at night can attract or disorient birds, causing collisions or birds to circle the light source until collapsing from exhaustion (Parkins et al. 2015, Winger et al. 2019, Loss et al. 2019, Lao et al. 2020, Elmore et al. 2021, Van Doren et al. 2021). Buildings with many large windows have the potential to emit more artificial light at night than those with fewer, smaller windows. Residential buildings account for almost half of bird-building collision mortality (Loss et al. 2014). 

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