Making it in the city: Public data reveal patterns and drivers of terrestrial mammal occurrence across urban Philippines
An analysis of 42,688 occurrence records reveals that while urbanization in the Philippines reshapes terrestrial mammal communities in a taxonomically uneven manner—with bats being notably overrepresented—it does not significantly reduce overall diversity, as species presence is primarily driven by forest cover, human density, and city size rather than true adaptation to urban life.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Cities are often imagined as concrete deserts where nature retreats, leaving only a few hardy survivors to scavenge in the margins. Yet, in the tropical archipelago of the Philippines, the reality is more complex. This region is a global hotspot for unique life, home to countless species found nowhere else on Earth, many of which are now squeezed into shrinking forests as human settlements expand. Scientists have long known that urbanization changes the rules of survival, favoring animals that can eat almost anything, hide in human structures, or move easily through crowded spaces. But in a country made of thousands of islands with such high levels of unique species, it remained unclear exactly which animals were managing to live alongside people, and whether their presence meant they were thriving or simply trapped. Understanding this distinction is vital: if a rare animal is found in a city, is it because the city has become a new home, or because its original forest home has vanished, leaving the city as the only place left to go?
A team of researchers set out to answer these questions by looking at the big picture across the entire nation. They did not spend years in the field setting traps or cameras in specific neighborhoods. Instead, they turned to a massive digital library of wildlife sightings, compiling over 42,000 records of where terrestrial mammals had been seen in the Philippines between 1950 and 2025. These records came from scientific studies, museum collections, and public observations, all mapped out to see which ones fell inside city boundaries and which fell outside. By comparing these two groups, the team could see patterns that a single field study might miss, revealing which types of mammals are making it into the urban landscape and what factors allow them to stay there.
The results painted a clear, if somewhat surprising, picture of who is living in Philippine cities. Out of the 200 mammal species they assessed, 129 were found within city limits. This included 16% of the species that are considered threatened with extinction. However, the mix of animals inside the cities was very different from the mix outside. Bats were the undisputed champions of urban life, with 85% of all bat species in the Philippines recorded inside cities. In contrast, only about half of the rodent species were found in urban areas, and many of the larger, more specialized mammals were absent. This suggests that the ability to live in a city is not random; it is deeply tied to an animal's family tree and its specific biological traits. Bats, with their ability to fly over buildings and find shelter in bridges or tree canopies, seem uniquely equipped to navigate the urban maze.
The researchers also looked at whether cities were simply reducing the total number of species or just changing who was there. They found that the overall diversity of mammals—how many different species were present and how evenly they were distributed—was not significantly different between urban and rural areas. This does not mean cities are perfect habitats, but rather that they are not emptying out completely. Instead, cities seem to act as a filter, keeping some species while pushing others out. The study found that the presence of mammals in a city was strongly linked to how much natural forest remained within the city limits and how few people lived there. Cities with more trees and lower human populations supported more species. Conversely, as a city grew larger and more crowded, the number of mammals dropped.
Perhaps the most critical finding was a warning about how we interpret these numbers. The presence of threatened or rare species in a city should not be celebrated as a sign of successful adaptation. The researchers argue that these animals are likely not thriving in the concrete jungle; rather, they are persisting there because their natural forests have been destroyed or fragmented elsewhere. The city becomes a last refuge, a place where they can survive but perhaps not truly flourish. For the 16% of threatened species found in cities, their presence is more a symptom of habitat loss than a victory for urban conservation. Similarly, the high number of endemic species—those found only in the Philippines—in cities suggests they are being compressed into the remaining pockets of green space, rather than actively colonizing the urban environment.
The study also highlighted the limitations of relying on public data. While the records showed a rich variety of life, they likely missed the most common urban pests, like rats, because scientists and citizen scientists rarely bother to report animals that are everywhere. This means the data might overrepresent the rare and interesting species while undercounting the everyday ones. Despite this gap, the analysis provides a crucial baseline for understanding the future of wildlife in the Philippines. It shows that urbanization is reshaping mammal communities in a specific, uneven way, favoring the adaptable and the mobile while squeezing out the specialized and the forest-dependent.
Ultimately, the research suggests that saving wildlife in Philippine cities requires a shift in perspective. Simply having trees in a city is not enough if the surrounding landscape is too hostile for animals to move between green patches. The findings point to the importance of maintaining large, connected areas of natural forest within and around cities, and keeping human density in check in those specific zones. If cities are to remain places where nature can endure, they must be designed not just as human spaces, but as landscapes that allow the remaining fragments of the wild to connect, ensuring that the animals found there are not just surviving in a trap, but living in a viable part of their world.
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