Metro Manila, green spaces, birds and our survival

My grandparents and granduncles remembered the Manila of their youth in the late 1920s and 1930s as a “garden city” with wide-shaded sidewalks. They attended university at the Padre Faura campus of the University of the Philippines and at the wide greens of the then newly built University of Santo Tomas campus on España Street. Manila then had wide avenues shaded by Ponciana and Acacia trees; this was true especially of the UP campus in Ermita. They recall the numerous birds that feasted on green caterpillars when the academic year began in June. They also recall that they never had classes suspended due to floods.

Today, that part of Manila is heavily urbanized — with the trees largely gone. An afternoon downpour can result in classes suspended for the day. The Padre Faura campus, now UP Manila, is almost completely built up. The UST campus, while still having some green space, now has more buildings. This cannot be avoided as student populations are increasing and there is a need for more classrooms and laboratories. Thus, the only significant green space in the metropolis is the UP campus in Diliman.

Our research team of ornithologists, geographers, wildlife scientists and environmental scientists recently concluded the first phase of a three-year, metro-wide study on bird biodiversity, green spaces and people in the city. We used species-area analysis, spatial analysis of buildings and their proximity to green areas and biodiversity predictive models. Our results have been published this year in Landscape and Urban Planning*. Our results suggest that Metro Manila, despite a deteriorating environment, still has a significant bird biodiversity of 56 species, comparable to greener cities in the region such as Singapore and Kuala Lumpur. However, what contrasts Metro Manila with these cities is that the birds (some species of which are endangered) are able to live in Metro Manila even if there is only minimum greenery left. Based on our estimation of green spaces and parks in Metro Manila, the city has 13 percent green cover left and the overwhelming majority of that is in the Diliman and La Mesa districts of Quezon City. Quezon City remains as the greenest city with 25 percent green space. Manila is the least green with less than five percent green space. Much of this is in the Baywalk and Luneta parks.

The number of built-up areas and whether green spaces are nearby or not are major predictors of bird abundances. In more built-up areas, urban-tolerant species and exploiters such as the Eurasian tree sparrow Passer montanus exist in high densities. Consequently, bird biodiversity is lowest in these areas. However, in urban parks with greenery, there are more species to be observed. While all of them are urban-tolerant, some like the melodious fantail, lowland white eyes and the yellow vented bulbul require the presence of trees. However, only four species that are extremely urban-tolerant contribute 48 percent to the total estimated abundance of birds in Metro Manila. The other 52 bird species are uncommon to rare. Fifty percent of the species observed are residents, while 19 percent are migrants. The migrants require an urban environment with parks, watercourses and gardens. We also observed that in the city, Philippine endemic species survive at low numbers in the greenest parts of the city.

This would mean that Metro Manila residents have to value their trees and to plant urban-adaptable trees in their city. Aside from the cooling properties of trees, they provide the habitat complexity that birds and other animals require. Our research also suggests that we have to restore the waterways and wetlands of the city to support bird biodiversity because these geographical features ensure the survival of uncommon species. The waterways need to be kept green with riparian (riverside) vegetation preserved or restored.

With the damage and loss of life and property caused by tropical storm Ondoy’s (Ketsana) floods last September, Metro Manila citizens have been rudely awakened to the need to restore these waterways, keep them clear of obstructions and let their water naturally flow. It is apparent that purely engineering approaches fail to mitigate the effects of flooding. It is now clear that to restore these rivers, we have to restore the vegetation along their banks and minimize flooding.

Renowned landscape architects and urban planners, such as Architect Felino Palafox and Paulo Alcazaren, brought out land use plans for Manila — some dating back more than 70 years ago. In the plans, rivers and creeks were planned to have greenbelts along them to mitigate flooding. These plans were never followed. However, there is a positive development. Real estate developers have realized that maintaining the green raises property values. Even Metro Manila’s shopping malls have included greenery in their redevelopment. This must be the reason why I have recently observed egrets flying and roosting in the Makati Central Business District. The birds themselves can be tourist attractions. In the University of the Philippines, several foreign bird watching societies have expressed interest in bird tourism. It is estimated that each tourist would bring in at least $100 a day to the local economy.

So in our post-Ondoy world, the birds themselves provide us with an age-old indicator of survival as it did in the Bible’s story of the Great Flood. If we see that they live in our green spaces, it is likely that we can survive the effects brought upon us by a changing climate. That is as long we keep these green spaces green.

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*Vallejo BM Jr., Aloy AB and Ong P (2009) Distribution, abundance and diversity of birds in Manila’s last green spaces. Landscape and Urban Planning 89:75-85

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Benjamin Vallejo Jr. is an assistant professor at the Institute of Environmental Science and Meteorology, College of Science, University of the Philippines, Diliman, Quezon City. He is a biogeographer whose interests range from urban to marine environments and how these respond to environment change. E-mail him at [email protected].