Mallards are the ducks most likely to be seen in park ponds. The male is readily identified by his green head and narrow white neck-band; the brown female, superficially similar to the females of several other duck species, shares the male’s distinctive wing pattern, with a metallic blue patch bordered by white lines. Watch these birds for a while, especially in the late winter and early spring, and you are likely to see behavior that might disturb you.

Many mallards associate in female-male pairs, and the male of a pair attempts to prevent other males from approaching his mate. When other males, individually or in groups, succeed in getting to a female, they often grab her and force copulation, sometimes holding the female underwater. Following such an event, the female’s attending mate often also forces copulation.

These behaviors have long been noted and are presumably what poet Michael Drayton (1563-1631) had in mind when he referred to a mallard seated on a satirical avian jury as “lecherous” and thus no more qualified to pass judgment on a defendant than are other bird jurors characterized as ridiculous, witless, ignorant and gluttonous.

Drayton’s reference to a mallard as subject to one of the “seven deadly sins” is clearly metaphorical and meant as criticism of human behavior. Some people, though, unfortunately including some biologists, have described the mallards as committing “rape” or “cuckoldry” and equated the duck behavior with human behaviors of the same names.

Duck behavior is not human behavior. Ducks might well be used to satirize human foibles in a 17th-century poem or to produce comic effects in a Disney or Merrie Melodies cartoon, but they are not people. Ducks do not, as far as is known, have the sense of personal integrity, ethical frameworks or legal proscriptions that help us to define “lechery,” “rape,” “cuckoldry,” and other actions often condemned in human societies.

The first word that comes to mind when a gull is seen taking a fish from another gull might be “stealing,” but no law is broken. “Infanticide” has been used to describe the behavior of male lions that kill the young of females when the male takes over a pride; females that lose offspring become sexually receptive, allowing the new male access to reproduction.

Again, there are no legal implications. The several red-winged blackbird females nesting on a male’s territory have been called a “harem” without legal or religious approval or condemnation.

What is natural for a duck, gull, lion or blackbird is not necessarily natural for any other species, including ours. Using words that carry strong emotional, and in some cases legal, impact to describe the behavior of other animals risks both misunderstanding of those species, and the justification of similar human behaviors, however antisocial or condemned in some cultures, as “natural” and therefore acceptable.

Would the behavior of closer relatives provide better evidence of what is “natural” for humans?

Our two closest living relatives, equally close to us, are the bonobo and the chimpanzee. The two closely related species are both social, but they behave rather differently. Bonobos often resolve conflict with sexual activity, including same-sex sexual interactions. Chimpanzee groups, on the other hand, sometimes have lethal fights with other groups of the same species.

You’ll notice I’ve attempted to use strictly descriptive words, rather than ones like “gay,” “lesbian,” or “war” to describe these behaviors; those words have complex cultural and, in some cases, legal meanings for human societies that do not apply even for our closest relatives (e.g., no Geneva Conventions for chimpanzee “warfare”!).

In 1907, naturalist Ernest Thompson Seton wrote “The Natural History of the Ten Commandments” attempting to show that “The Ten Commandments are not arbitrary laws given to man, but are fundamental laws of all highly developed animals.” The examples above show that other species, including our closest relatives (“highly developed” in Seton’s language), do not follow any particular human religious code.

Other animals are so diverse that we could find something similar to almost any human behavior among other species. Similarly, we could find other species without that behavior or that practice. Thus, the proponents and opponents of the “naturalness” or “unnaturalness” of any activity could make the same argument from nature, which makes the “natural” aspect of either case equally weak.

We can pick and choose, according to our own standards, positive or negative examples from the behavior of other species for inspiration or condemnation. Our behavioral choices, though, must be based on our own conceptions of human dignity.

The chimpanzee’s deadly fights might serve the more bellicose among us to justify the “naturalness” of human war, while bonobos could serve as inspiration for those who celebrate the diversity of human sexual interaction. The behavior of other species can engage our curiosity and imagination; perhaps suggest possibilities for our own actions, or serve as symbols for our own individual and societal choices, but those choices are not dictated by any analogy to other animals.

David Spector (he/him) is a retired biologist and former board president of the Hitchcock Center for the Environment. This column’s headline is from a song in the 1946 musical “Annie Get Your Gun,” written by Irving Berlin and sung by Ethel Merman.

Earth Matters has been a project of the Hitchcock Center for the Environment for 14 years. After more than three years of the COVID-19 pandemic, the center’s doors and trails are once again open at 845 West St. in Amherst. To learn more, visit hitchcockcenter.org.

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