The Nest Big Thing: Bird Habitat in Urban Environments

              In today’s modern and rapidly globalizing world, society is quickly seeing the decline in natural habitat and the expansion of urban regions. Prairies are giving way to pavement and population centers, and forests are giving way to far expanses of concrete jungle. As the green in the world turns into grey, much of the world’s habitat is being replaced with expansive and towering cities. These new regions of sprawl are providing a new kind of habitat – one that is frequently seen as not forgiving for species of plants and animals that rely on them. One organism affected by this spread is countless bird species across the world. In an effort to research conservation methods as the unstoppable spread of urbanization conquers their natural world, ecologists look to comparable habitats to provide study points for these concrete jungles. One such habitat is that of islands – regions of natural habitat often isolated in nature (Fernandez-Juricic and Jokimaki 2001). By using methods carried out in analysis of island habitat in similar literature, scientists can extrapolate analyses onto the isolated environments presented in the sparse environment, whether presented through parks or pathways, that urban environments provide. The authors aimed to extrapolate conclusions from habitat island theories to environments provided in urban landscapes in order to further the framework for urban bird conservation, education, and management (Fernandez-Juricic and Jokimaki 2001).

              The authors were able to draw several conclusions based on this cross analysis of sources. One primary driver for bird species richness within urban settings is the area that urban parks provide (Fernandez-Juricic and Jokimaki 2001). This is important to understand, as the isolated patches of urban parks, similar to that of island biomes, are often far and few between within cities and urban sprawls, meaning that each appearance of it would be especially important for bird species as they adjust to changing environments around them. A second important driver in species diversity is both the age and complexity of urban parks (Fernandez-Juricic and Jokimaki 2001). While somewhat connected, as the age of a park typically allows for greater diversity in vegetation and age of growth, the complexity of a park provides greater diversity of habitat for bird species, something that can be concentrated down in often limited spaces provided in urban areas for parklands. A third conclusion drawn is that bird species richness is negatively correlated with the amount of paved ground within parks (Fernandez-Juricic and Jokimaki 2001). This highlights the important dichotomy between two park types – those that are more natural and greener so to speak, and those that are paved open areas with a lower density of trees. This conclusion shows that birds in urban areas will prefer areas with less pavement and more green area (figure 1, taken from Fernandez-Juricic and Jokimaki 2001).

              This research is helpful to my groups ongoing project on Grinnell College’s campus. We are examining the suitability of prairie habitat patches on the northern reaches of Grinnell College’s land by the soccer fields for birds. By understanding the ways that island habitats interact with birds outlined in the literature, the isolated island-like patches of prairie habitat planted on campus can be assessed comparatively for their ability to provide harbor for bird species. Having these types of habitats on our campus is important, as the city of Grinnell is an urbanizing area compared to generations ago, in that over the years there has been notable habitat loss both on campus and in the town. Through the reintroduction of properly planted and managed habitat, the campus can be a natural habitat substitute for the habitat that has been taken from birds. This is both beneficial for native sedentary birds and migratory birds alike, hopefully assisting in the bird’s recovery against rapidly declining numbers (Rosenburg et al. 2019). It would be appropriate to hypothesize that the lack of paved ground in the soccer field prairie habitats at Grinnell College would be beneficial in encouraging more birds to visit the habitats. Furthermore, prairie habitats on campus that are more diverse in vegetation and possibly containing older growth are more likely to be better habitat for birds.

References

Fernandez-Juricic, Esteban, and Jukka Jokimäki. "A habitat island approach to conserving birds in urban landscapes: case studies from southern and northern Europe." Biodiversity & Conservation 10.12 (2001): 2023-2043.

Rosenberg, Kenneth V., et al. "Decline of the North American avifauna." Science 366.6461 (2019): 120-124.