Poems and Thoughts    by Frank Maurer

[Return to Poems and Thoughts index page]

"White Streets?!?" Have you ever noticed on a winter's evening at dusk, large numbers of crows flying into your city (including Davis) to roost in the city streets' trees to poop on the parked cars and pavement? Ever wondered why? Did you know there is an approximate winter 10 F degrees difference of the ambient temperature between that of the city and that of the surrounding fields? Well, the crows know and have been exploiting for decades the heatsink of a city in the winter! Trained falcons nor artificial gun noises will ever change their minds--and those and more have been attempted. The warmth of the city is too alluring. But, do these crows continue this practice during the warmer months of the year? No. The fields and arboral areas around the city are generally 10 F degrees cooler than the heat sink of the city! What to do? Not only are the crows affected by the city's heat sink, but so are humans: heat stroke; uncomfortable, hot pavement to traverse; higher AC electric bills; more watering of lawns, etc. Is there a solution to this local problem, mingled with the huge--harder to solve--worldly climate change? One solution is to lighten to a light gray, the darker areas of our cities: roofs, parking lots, and, indeed, our myriad of city streets. I have measured, in January, the difference between the temperatures of white streets (measured on a new neighborhood white cement bridge) and black asphalt within 20 feet of the lighter cement pavement where the difference was 10 F degrees with an ambient temperature of 56 F degrees. Just four months later, in April, with an ambient temperature of 88 F degrees, the two temperatures differed by 21 F degrees! In July the difference was 25 F degrees. Los Angeles during hot summers, have recorded more than 25 F degrees difference. Why do we humans wait to do something? One helpful solution is now clear and easy to solve. Davis, CA proposed to experiment on a city parking lot and indeed, did so in May 2022 (see Cool Pavement Project--Davis, CA). In conclusion, as a biologist, watching our planet slowly dessicate from the Arctic ice shelves to the wonderful Kalahari (through which I have wandered), I am in agony. As long ago as 30 years, I was struggling with my overheating house and lethal temperatures in my free range chicken barns, where they would crowd together from the heat (that is a chicken's reaction to heat!) and die of suffocation. My house roof was then foamed and painted white, as well as the chicken barn, and the problem was greatly reduced by as much as 15 F degrees. If an old farmer can partially solve this problem, locally, why can't our cities do the same with thousands of human beings (some with chickens!)? One other point I have contemplated. In the winter, if a street where crows roost is lightened in color, would the temperature differential be enough to actually discourage crows from roosting there and go to a warmer street that is not treated? This could help further solve the winter roosting problem question and would empirically demonstrate that the white streets have an effect on roosting crows. Of course there are still pros and cons concerning this procedure, but there are enough cities starting this that it is heartening to see we are willing to try. The question is, are we doing it in time? Frank Maurer 2021.