Birds in the city: Mysteries, risks and our role in urban wildlife

Birds in the city: Mysteries, risks and our role in urban wildlife

The presence of birds in the city raises critical questions about the complex interplay between wildlife and urban environments. As the downtown noise of Cebu begins to ebb around 6 p.m., commuters linger at jeepney stops, while students gather in clusters. Some carry umbrellas, their eyes drawn upwards to the spectacle unfolding above: hundreds of birds facing a uniform direction perching on the high wires of A. Borromeo and Colon streets.

For some observers, it’s akin to an alien invasion looming; for others, a foreboding sign of things to come. Among the questions that arise, one wonders why these birds, in their synchronized gathering, aren’t electrocuted. Additionally, concerns about potential disease transmission linger.

Behavior

In a Facebook post by Cebu City - South District Councilor Jose Abellanosa, the Department of Environment and Natural Resources (DENR) suggests that the presence of birds downtown indicates the availability of food. This could be attributed to termites in old buildings or a sign that an abundance of garbage is attracting insects.

Offering further insight into this phenomenon, Birdfact, a page specializing in bird behavior, explains that birds often utilize urban areas as preparation during migration. The elevation provided by power lines offers safety from ground predators, making them ideal spots for resting, roosting and hunting.

Moreover, the wires provide a convenient resting spot for birds, particularly in areas devoid of tall trees or vegetation. Surprisingly, in some regions, the presence of power lines has facilitated the expansion of certain bird species into desert and prairie environments where suitable perches are scarce.

Although it might seem strange at first, thinking about things like safety, convenience and habitat availability helps us understand why this happens.

Swiftlets

The birds perched on power lines in these areas are identified by the DENR as swiftlets. According to BirdForum, an online birding community, the Philippine Swiftlet (Aerodramus amelis) has two recognized subspecies: A. a. amelis found in various regions including Luzon, Mindoro, Cebu, Bohol and Mindanao, and A. a. palawanensis primarily found in Palawan.

These subspecies were previously classified under the Uniform Swiftlet or treated as a monotypic species called Aerodramus palawanensis, also known as the Palawan Swiftlet.

In Palawan, locals refer to them as “Balinsasayaw,” nesting in caves and foraging in surrounding forests. The Balinsasayaw Festival in El Nido celebrates their environmental and economic significance. In Cebu, they are called “sayaw.”

Swiftlets inhabit various habitats, from forests to coastlines and islands, thriving in both lowland and highland regions. They feed by capturing insects mid-flight, often forming large flocks and mingling with other swift species in low-altitude landscapes throughout the day. These birds create edible nests from a gelatinous secretion, highly valued for their culinary and medicinal uses.

Risk

Many wonder whether the hanging wires in downtown Cebu streets pose an electrocution risk to birds. Interestingly, birds are not good conductors of electricity. Their bodies do not provide a path for electricity to flow through.

Birds can perch on power lines without getting shocked because their bodies and the wire have the same electrical potential. However, if a bird were to touch both a wire and the ground or a utility pole connected to the ground simultaneously, electrons in the wire could pass through the bird, potentially leading to electrocution.

While this danger is uncommon for smaller bird species, larger birds may occasionally encounter this risk.

Harm

In an interview with microbiologist Christian Calumpang, the transmission of diseases may occur more rapidly in urban areas due to higher bird densities and congregations.

“The presence of Philippine Swiftlets may increase microbial diversity and abundance through their droppings,” Calumpang said.

Highlighting the diverse ecological roles of birds within ecosystems, Calumpang emphasized their functions as predators, pollinators, scavengers, seed dispersers, seed predators and ecosystem engineers.

“The gathering of birds in Colon may lead to fluctuations in microbial species, indicating both decreases and increases. Additionally, birds have a greater capacity than insects to disperse matter — whether biotic or abiotic — due to their ability to cover greater distances,” Calumpang said.

Research from Arizona State University suggests that urbanization has introduced challenges for birds, including increased stress from factors like noise and pollution, weakening their immune systems and making them more vulnerable to parasites.

However, cities also offer abundant food sources for birds, such as insects attracted to streetlights and bird feeders in yards, leading to large concentrations of birds in urban areas and facilitating parasite transmission.

Reminder

According to pest control experts at Champion Pest Control, birds transfer diseases through fecal matter, feathers and nests. Dry bird droppings can crumble into fine particles potentially containing pathogens, which may be inhaled, especially before storms. Birds can contaminate uncovered food with bacteria and viruses from droppings, and drinking contaminated water can also lead to infection. Handling dead birds without protection can transmit diseases, and insects that bite birds can carry diseases to humans.

While swiftlets, like many other birds, can potentially carry diseases, they are not typically associated with transmitting diseases to humans. The main species that carry the most diseases are sparrows, pigeons, gulls or egrets and starlings. However, they may harbor pathogens or parasites that could pose health risks to other birds or animals. It’s essential to handle all wildlife, including swiftlets, with caution and take appropriate hygiene measures to minimize the risk of disease transmission.

As we marvel at the beauty of birds in our cities, let us also embrace our responsibility to protect and preserve their habitats. By fostering environments that support biodiversity and minimize harm, the next generations can still enjoy watching birds flying around town.

Remember, it’s not just about looking at birds. It’s about knowing we’re all connected in nature and taking care of the world around us.

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