Saturday, April 1, 2017

Learning to get along....

In a recent post (Pelican and dolphin - Playing together or vying for food?) I pondered the possible symbiotic relationship between two animals in search of fish - a bottlenose dolphin and a brown pelican.

The two critters I wrote about were interacting with each in a small cove off Indian River Lagoon in Bethune Beach.  It was the second time I'd observed the same behavior between a dolphin and a pelican in that location.

Below is a video I took the first time I saw it happen.

In the above video, I'm not sure if the dolphin was trying to catch a fish that the pelican stole away or whether it happened the other way around with the dolphin being the winner in the hunt for dinner. Either way, some sort of symbiotic relationship was taking place, which got me thinking about another encounter involving pelicans that I noticed last November when Ralph and I were biking along the shoreline in New Smyrna Beach.

On that occasion, a seagull was using the pelican to gain an easy meal by stealing fish right out of the bigger bird's mouth.

This type of behavior by seagulls is not unusual.  Pelicans hunt by collecting several fish at once in the large pouch attached to their beak. When their expandable sac is full, they need to shift their catch around before swallowing, a process that usually involves tossing a fish slightly into the air.

Seagulls flying overhead are on the lookout for just such action. When gulls notices a brown pelican about to eat its catch, they swoop down in an attempt to steal the fish away from the larger bird's pouch just as the pelican is about to maneuver it into position for swallowing. Sometimes a gull will even land on the pelican's head - like it did in the above video - in order to get as close as possible to a potential meal.

Although I doubt if pelicans enjoy being harassed by a colony of gulls, especially when one lands on its head, they seems to accept the behavior as an inevitable part of the process.

There are three kinds of symbiotic relationships in nature: mutualism, commensalism, or parasitism. In mutualism, both animals benefit from the relationship. In commensalism, one member benefits and the other is unaffected, whereas in parasitism, one species generally gets hurt, such as when fleas infest a dog's coat and feed on its blood.

The relationship between cattle egrets and bovines is an example
 of commensalism symbiosis because the egret benefits by eating insects
that bother cattle while bovines are unaffected by the piggybacking birds.

I'm not sure what type of symbiotic relationship happens between a dolphin and pelican or between pelicans and seagulls.  In both cases, no animal is hurt although it could be argued that by having food stolen away, one animal suffers.  More likely, both are examples of commensalism symbiosis.

All I know for sure is that the interconnectivity between organisms is an essential part of life for all creatures on our shared planet. Like the cow that tolerates the cattle egret standing on its back or the pelican enduring the squawks, jabs and thievery of seagulls, we all have to learn how to tolerate stress.  In order to live successful, fulfilling lives, people as well as animals need to get along with each other, even in those cases where interdependence is difficult or detrimental to our individual health.

If a hungry pelican can tolerate a gathering of annoying seagulls trying to steal away its catch, it seems like we humans should be able to endure the slings and arrows of our own adversaries.

Of course, even a pelican has its limit. When it has taken all the abuse it can take, a pelican will spread its wings and fly off to fish elsewhere.

Yet another lesson from our feathered friends. Breath in...breath out...move on.

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