July 28, 2022
I received an update yesterday from my Audubon Bird site touting the recent advances in determining what birds eat. Until recently determining what different species were eating has been cumbersome and required close observation of the berries or fish included in the diet. Now biologists are turning to genetic tools to eliminate the guesswork of figuring out avian diets. This builds on methods scientists have used for the past decade to solve other ecological questions, like which animals use a specific environment by looking for samples of DNA. The process used for birds works like a barcode scanner in a grocery store. Scientists match chunks of DNA found in avian poop to a species identification database to pinpoint the plants or animals the bird consumed. Those snapshots are providing a fuller picture of the health needs of species from the tropics to the poles. I was amused as the site designer had set the page so wherever you clicked on the page it would produce a splat of bird poop.
Delving deeper, I found another article on baby bird poop. While the ground beneath the nests may be littered, the nests often contain little evidence of poop. Diaper duty is one of the most unique and understudied behaviors among birds. A nestling turns its rear toward the parent and ejects a floppy white bag of poop encased in mucous (a fecal sac). The parent then either flies away to dispose of, or at times eats it. Fecal sacs are only produced by the nestlings and are common among passerines and other “altricial” birds (requiring 24-hour parental care at birth). Videos of fecal sacs abound but scientists know relatively little about them and only a handful of studies have been done on the sacs. Evidence suggests the fecal sacs have several uses. A fecal sac is essentially a diaper that allows the parents to pick up feces and remove it from the nest keeping the birds healthy by isolating them from any potential harm from the feces. Occasionally birds eat the sacs, allegedly because the nestlings cannot completely digest the food they eat and there are still nutrients available in the sacs. The third idea is that poop free nests might be less noticeable by predators that are drawn to the sight or smell. As said, there needs to be more research (scientist for, “I do not know.”).
The last poop article declared that in the hierarchy of animal droppings, bird poop stands supreme. Where most poop is buried under grass, bird poop lands all over the place, including on our freshly washed cars. Bird poop begins in the cloaca where instead of urine, nitrogenous wastes are excreted in the form of whitish acid and are expelled along with the feces. The volume of droppings depends on the size of the bird, but the varying shapes of splat are all physics. “Most bird poop has the classic smatter, that heavy drop with a slight sperm-like tail. Other familiar shapes include the double-execution shot, the spiral galaxy, Philip Baker Hall eyes, the crater, the radish rose, the melted Dali clock, the wax postage seal, the two-dollar taco, and the halfhearted runny egg. As a collective, the drops take on a feeling of abstract expressionism, channeling the drip paintings of Jackson Pollock.” While the designs may be interesting, the uric acid can corrode the paint on your car. Personally, I have never thought of the bird poop found after parking under a tree to be an expressionist work of art.
Thoughts: When I was in Jr. High our driveway was lined with a row of trees and it was not uncommon to come out in the morning and find one or two splats of poop deposited as the birds took flight in the morning. One morning we found the entire car covered by dozens of fresh droppings. While there must have been a large flock of birds roosting in the trees above our car, we deemed this the work of Eddy Eagle. This has continued to be remembered as part of our family lore to this day and is invoked when one of us encounters a large splatter of poop. Childhood memories shape us all. Whether they are good or bad (or just odd), they affect our thoughts and impressions as adults. That is why it is so important to nurture each child with a positive upbringing. Act for all. Change is coming and it starts with you.