Moving Targets: a tale of survival

An urban wildlife tale: predation in the city

The drama took only a few seconds to unfold.

And here’s how it happened.

About 15 feral pigeons (Columba livia domestica) are feeding tamely beside the road.

Photo credit: commons.wikimedia.org

Suddenly, a Yellow-billed Kite (Milvus migrans) glides out of nowhere, into sight, in all its broad-winged, fork-tailed majesty.

Photo credit: Wilkinsonsworld.com

The pigeons know the kite hasn’t come to show off its beautiful feathers or flying skills. Without losing any time, they take off to safety in as many different directions as there are pigeons.

The kite, unfazed, promptly fixes on one of the pigeons in hot pursuit.

It just happened that I was standing on the opposite side of the road from the action, with a companion, on that hot Sunday afternoon, watching the story play out (it was like Nat Geo Wild, live!)

As I stood there, watching one of my favourite topics in behavioural ecology (predation avoidance) play out before me, and thoroughly enjoying myself, I was asked by my companion, “but why did the kite focus on that single bird?”

Good question.

The answer: to increase its chances of securing a meal.

Animals which are targeted as prey develop behaviours by which they avoid being another animal’s ‘breakfast’. We call this, in animal ecology, predation-avoidance behaviour. One such behaviour is seen in the formation of groups, to enable individuals take advantage of the safety in numbers.

In addition to group-forming, birds (and some other animals eg. fish) also evade predators with what is called the “confusion effect”. When a predator shows up, all the birds in the group take off at the same time, giving the predator several moving targets. This leads to confusion, and reduces the chances of the predator catching any one individual.

Photo credit: PxHere.com

Clever, isn’t it?

However, if the predator is smart enough to know to single out a target (like the kite in my story); it increases its chances of successfully making a kill, and thus securing ‘dinner’.

Unfortunately (for the prey), the greater the difficulties involved in obtaining food (which is so essential for survival), the wiser predators become. And in turn, the wiser (and faster) the prey have to be because their lives are at stake.

Anyhow, at the end of the chase in the story I just related, the kite lost a meal, and the pigeon gained its life for a few more minutes. Or perhaps hours, days, or even years….you never know.

Thanks to the companion whose question inspired this article, and to the friend who gave me, on the same plate, a deadline to put up a blog post, and the threat of a bad name, namely: reneger (okay, I exaggerate).