During my earlier days, I watched individuals make adobes along the floodplain of the Rio Grande. They mixed clay soils with water, sand, and straw and placed the mixture into rectangular molds. The bricks made were used as building blocks for dwellings. I asked the workers, "Why the straw?" Their answer was, "Cause that's just the way we do it."
Questions unanswered, I did not search further until a few years later when I was watching a pair of barn swallows build a nest. They used a mixture of mud and grass stems, which served the same purpose as straw. Both bind the ingredients of the mud to one another, allow even drying, and prevent the nest from cracking.
Who thought of that marvelous idea? Humans used adobe bricks for construction as early as the 8th Century B.C. Barn swallows, however, were on planet Earth long before that, and I would assume swallows used their mud/straw nests from their beginning.
During those early times, barn swallows built their nests in caves and under rocky ledges. Later human structures provided nest sites.
Barns were probably the swallow's first choice, hence the name, barn swallow.
Broken windows, open windows, and doorways of old barns were especially favorable for entrance of the birds to nesting sites. Urban dwellings were also used for nests. When the swallows return from their winter grounds in Mexico and South America in the spring, it is common to watch them conduct aerial maneuvers in and around buildings catching insects and searching for nest sites.
So what are the human interactions regarding the spring arrival of barn swallows? Most individuals look forward to their return and enjoy their activities during the summer.
Here is an example of "swallow love." Our Portales friends, the Schroeders, dealt with a damaged nest by using a wash cloth folded in the form of a triangle. They lined the longest edge of the cloth parallel with the rim of the nest and used screws to attach the three corners of the cloth to the wood the nest was attached to. Four chicks in the damaged nest simply ducked down during construction. The swallows fledged those four, and we can assume some or all four returned to the Schroeder's residence the following spring.
On the other hand, some individuals do whatever they can to prevent the nesting of swallows primarily because they dislike the messiness of their poop.
Methods I have witnessed include — plastic wrap on a potential nest site, spraying the site with insect spray or Lysol, and attaching tin foil or rubber snakes to the site. When I asked one individual her method, she told me to mind my own business.
Another problem is vandals have easy access to the swallow nests. Fortunately, the swallow is protected by state and federal laws. It is not unlawful to prevent them from selecting a nest site, but once the nest in being built, it is unlawful to destroy it or remove the eggs.
Perhaps those who have not had an opportunity to share a summer with barn swallows may be fortunate in the future. Then, those individuals can experience "nest tenacity" which is the ability of the swallows to rebuild a nest at the same site every spring, sometimes in spite of methods to repel them.
And, no one can prevent smiling and continuously gazing at the little chicks as they expose their heads above the rim of the nest while waiting for their caretaker to come home with an insect or two.
Desert Biologist Tony Gennaro of Portales writes a monthly column on creatures of the Southwest. Contact him at: firstname.lastname@example.org