Giosa E, Mammides C, Zotos S (2018) The importance of artificial wetlands for birds: A case study from Cyprus. PLoS ONE 13(5): e0197286. https://doi.org/10.1371/journal.pone.0197286
Fueled by development, the loss of wetland habitats and its impacts on the many species of birds that depend on this habitat has been concerning conservationists for many years. Artificial wetlands, by-products of human development, may actually help combat some of the detrimental impacts of wetland habitat loss on birds. But the potential benefits of artificial wetlands remain a largely understudied topic. Efthymia Giosa et al. (2018) address this knowledge gap by evaluating the importance of artificial wetlands for birds, and comparing them to natural wetlands, using several natural and artificial wetlands in Cyprus as case studies.
Cyprus might be on someone’s shortlist for our vacation, but it actually also plays an important role in the migration route for many bird species. Over 400 species have been recorded on the island (~30% of these are resident species)! This large diversity of species is heavily reliant on the country’s network of wetlands for sustenance and nesting. For this study, the authors used data from nineteen wetlands, consisting of both natural and artificial wetlands, and used survey data to estimate the bird diversity at each site.
Wetlands, how different are they?
So what exactly are artificial wetlands? They come in many shapes and sizes, but are generally made up of agricultural ponds, rice paddy fields, reservoirs, and/or waste water treatment plants. Basically, this includes any artificially constructed body of standing water. As the quantity and quality of natural wetland habitats continue to dwindle, artificial wetlands may have an increasingly important role to play in filling the habitat requirements of migratory bird species like the Greater Flamingo (Phoenicopterus roseus, Fig 1).
But you cannot simply sub out an artificial wetland for a natural one, and expect the same result. Since they were likely not constructed to support birds, the usefulness of the artificial wetland will largely depend on two key characteristics; its size and depth. Larger wetlands provide more breeding and foraging habitat for birds because of habitat heterogeneity and shallower wetlands can support a more diverse array of species (not just diving water birds). Additionally, development centered factors like the density of road networks adjacent to the wetland can play a crucial role. Oftentimes, when artificial wetlands are constructed the natural landscape is altered, and the location of the artificial wetland is not always ideal because of habitat fragmentation and other impacts of development such as direct mortality due to collisions with vehicles as result of road development.
How do artificial wetlands matchup against natural wetlands?
The study’s results identified no significant differences between the numbers of bird species found in the two types of wetlands. However, generally, fewer individuals of most species were found in artificial wetlands compared to natural ones. Similar to previous studies, this study identified wetland depth as the most important factor determining how many species were found, regardless of wetland-type. Shallower wetlands supported more species than just diving birds. As expected, wetlands surrounded by a higher density of road networks supported a lower diversity of birds due to impacts of habitat fragmentation.
The results from this study highlight the importance of wetlands in Cyprus for numerous bird species and echo what other researchers and conservationists have found in previous research as to the importance of wetlands as critical nesting and foraging habitats for migratory (and resident) birds. Additionally, this study helps address some key knowledge gaps regarding artificial wetlands. While it may be tempting to simply replace natural wetlands with artificial ones and call it a day, the results from this study suggest a more cautious approach is in order. While artificial wetlands are certainly capable of supporting a diverse array of bird species, overall, natural wetlands support more species because ultimately, artificial wetlands aren’t always constructed for the primary purpose of supporting birds. Therefore, the role of artificial wetlands appears to be one that is complimentary to natural wetlands, rather than a direct replacement. Artificial wetlands can be used to support or expand the function of natural wetlands, but all attempts to safeguard the few remaining natural wetlands in Cyprus (and elsewhere) while minimizing development adjacent to these sites, must continue full-steam ahead.