Cause and Effect of Felling City Trees

June 4, 2010 -- While we realize there are many ways for trees to die such as lightning strikes, wind, disease and insect infestation; the cutting down of healthy trees can have tragic consequences to the natural ecology as well as the environment as a whole. Large city blocks with small to average sized apartment buildings surrounding large courtyards in the middle of such a blocks, are becoming rare in San Francisco.

These Poplar trees were among the last remaining trees in such a large inner courtyard on Nob Hill in San Francisco. Birds such as Robins and House Finches were fond of these trees because the courtyard was safe and the trees were tall — offering security to birds non-trusting of humans.

Further, the trees offered a taste of nature to many dozens of apartments facing the courtyard. They offered beauty and reduced the volume of unending city noise. Most importantly, the Poplars, like all large trees, cleaned a great deal of carbon from the air.

In a city, with so many vehicles on the streets and businesses such as auto repair services polluting the air, big trees are important to the health of both people and birds alike. But, like it or not, trees as with all living things, need attention. And therein lies the rub. It means building owners must spend money on the trees. Considering that perhaps the great majority of building owners don’t live in San Francisco, the decision to plant or maintain trees on their far away properties has everything to do with the bottom line.

During one cold January 2010 day, House Finches are seen relaxing on the branches of Poplar trees. They are safe here even though there are small hawks in the area. Because Poplar trees are thick with small branches, small birds such as these colorful House Finches can quite easily evade capture by a hawk or falcon by escaping to the inner branches the hawks and falcons can’t penetrate.

Notice that the House Finches congregate together as an additional safety measure. In the event they can’t reach the safety of thick tree branches when threatened by birds of prey, they fly off in various directions, cheeping loudly while flying in a lilting manner designed to help avoid capture.

Such maneuvering in flight, combined with loud cheeping confuses the enemy and most of the time works to the advantage of the finches.

As the Poplar trees begin to bud these House Finches seen on a particularly beautiful March 16, 2010 day are, along with Robins, busy preparing nests in which to lay eggs which would soon be arriving by already pregnant females.

Almost daily we are shown tragedies from around the world of homes being blown away by wind or burned to the ground along with the grieving people who are the victims of such events.

Usually little or no attention is given to the fate of birds when natural or human events destroy their neighborhoods. These House Finches, enjoying the day as they foraged for nest building materials, hadn’t a clue as to the fate which was to befall them the very next day.

Alas, with the human caused disaster in the Gulf of Mexico killing all manner of birds and other species of life; perhaps people are becoming aware of the wanton death of living beings and destruction of habitat caused by human greed.

The morning of March 17th the people living around the center courtyard and the birds preparing nests in the Poplar trees would awaken to the sound of saws cutting down every tree.

People were seen silently looking at the unfolding tragedy from their windows and rooftops while the Robins and House Finches were seen frantically flying over and around the trees being dismembered. There was enough anguish to go around for both the people and the birds.

The out-of-town property owner could not be convinced to save just one of the Poplars for the people of the courtyard to enjoy and the birds to nest in. The days of a wide variety of birds visiting the courtyard and nesting in the trees had in a day come to a complete end.

A few days after the Poplar trees were sawed to the ground a female House Finch appeared at our birdbath and dropped an egg. Although we had hoped stress had caused an accident, we knew from years of observation that the female had aborted the egg.

Yes, like humans, House Finches practice abortion. However, usually the female will only drop an egg (usually from a tree branch) at the end of the breeding season.

Once the female finch has had enough of being pregnant and is tired she will practice abortion. But the stress of losing the trees right at the beginning of breeding was too much for her.  We carefully placed the egg in a safe, sunny area hoping against hope that she would return and accept the egg.

To our amazement the female House Finch returned not long after dropping the egg. We had great hope she was ready to accept and incubate the egg.

To our great sadness, the female finch went to the egg and smashed it with her beak. She seemed to be making it clear to us that she was having nothing to do with the egg.

A logistical nightmare had been created. Without the trees in which to both nest and incubate eggs, she would have to move on. Without the safety of the thick Poplar branches to protect her young, it was no time to be a mother.

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