Raptors in the City!

The term Raptor describes several species of birds, also known by the term Birds of Prey, that hunt on prey that are vertebrates and generally feed upon prey that is relatively large for their size. This includes Kites, Eagles, Hawks, and Owls among others. The word Raptor comes from the Latin word Rapere, meaning "to seize" or take by force, which is instantly evocative of the way they hunt: picture an eagle diving mid-flight to swiftly seize up a rat and then taking off into the sky with its prey.

Over time Raptors have come to possess certain adaptations through evolution that enable them to hunt better. They are equipped with a sharp and long-distance vision to spot prey from large distances as well as while in flight. In fact, Eagles are known to be able to see clearly eight times as far as humans can. Raptors are also equipped with powerful talons to grasp their prey, and a strong curved beak adapted to tearing flesh. While the Birds of Prey are specially adapted to hunting on medium-sized living vertebrate prey, many species of raptors will consume insects as well as deceased carcasses of other animals, known as carrion. Most Raptors tend to be on the larger side compared to other birds, and tend to have broader and more muscular wings in order to fly higher and for longer. This is because Many Raptors like Black Kites, spend large amounts of time soaring in flight, trying to spot prey.

The Black Kite, one of the most populous raptors around the world, can be commonly spotted across the city of Bengaluru. They are opportunistic hunters, which means they can adapt to a variety of food sources and can switch to scavenging as well. While they once more commonly hunted on rodents and other small prey, due to rapid urbanization, these birds have actually benefited with regards to securing a food source. This, coupled with the fact that they are well-adapted to living in proximity with humans, has resulted in an exponential increase in their populations in Indian urban centers in recent years. They are more commonly spotted circling in the sky above, near heaps of garbage or meat markets, seeking bits of scrap meat to feed on, or trying to spot rodents that are attracted to the garbage. Their loud and echoing shriek is easily identifiable. They can be commonly seen soaring high in the sky gliding on thermals, or upward currents of warm air. Many high-flying birds benefit from riding these columns of warm air currents as they allow them to ascend to greater heights without expending much energy, as well as increase the duration of their flight time while hunting for prey and simultaneously conserve energy. This is why several high-flying birds can be seen flying in spirals, as this allows them to ride the thermal currents. The Brahminy Kite, though less populous than the Black Kite, is also easily spotted due to its distinctive plumage, a deep ochre across its wings and white around its head and neck.

 

A Black Kite

Most Birds of Prey, much like several other bird species, display sexual dimorphism: Males and Females of the same species exhibit distinctive characteristics from one another, beyond differences in their reproductive systems. However, unlike what is common among non-predatory birds, in Raptors, Males tend to be smaller than Females and less aggressive. It is believed that male raptors gain an advantage by possessing a more aerodynamic body that helps conserve energy and thus requires less food, and provides them with greater agility while hunting and defending the territory around the nest. Females, contrarily, are able to incubate a larger number of offspring and defend them from within the nest because of their larger and more intimidating bodies.

Raptors are known for their legendary vision, greatly adapted to spot prey across massive distances. The number of receptors gives them greater visual acuity, while the placement of their eyes gives them good binocular vision, allowing them to accurately judge distances. Nocturnal Birds of Prey have further specialized adaptations that enable them to see better in low-light conditions. Raptors such as Owls have a greater number of rod cells which increases their light sensitivity and possess a reflective layer in their eye known as Tapetum Lucidum that increases the amount of light that their photoreceptors receive.

The Spotted Owlet is the most commonly sighted Owl around human habitation. It is small in size and hunts mostly at night, and feeds on insects, reptiles and smaller rodents. The Indian Eagle Owl, less commonly spotted in areas densely populated by humans, is one of the largest species of owls and may feed on larger rodents and even other birds, including smaller raptors as well. The Barn Owl is the most widely distributed species of Owl in the world, and like the Spotted Owlet, is quite common within the city and well adapted to living alongside humans. It is medium-sized and hunts primarily on small rodents such as squirrels. Owls, especially the Indian Eagle Owl within India, have had many superstitions develop surrounding them that claim they are omens of death and can be used in black magic rituals. This is most likely due to their striking glare, predatory nocturnal behaviour, and deep resonant hooting call.

Although raptors have earned a reputation of being fierce and are generally feared, they are vital components of our ecosystem. Most species of raptors are capable of switching to scavenging, and some species such as Vultures are specifically adapted to and mostly feed on carrion. This aids in restoring balance in the natural energy cycle, by cleaning up the environment of dead organic remains and paving the way for new life to flourish. They also help keep the populations of several pests in check. However, the exponential growth in their population, specifically near cities, signals an increase in the amount of waste being generated, which is a result of overpopulation and signifies an imbalance in the urban ecosystem. Much like their piercing calls, their increasing numbers should serve as a dire warning to us that our current way of living is throwing the ecosystem out of balance.