The weather may be cold and grey these days in the Pacific Northwest but the wildlife knows what time of year it is. For one thing, I’m seeing a few gulls gathering at the nesting island offshore that’s been bare since last summer. Over the winter my local beaches are frequented by gulls since the hunting is good — plentiful crabs and clams in this eelgrass bed — before departing to nest on islands safely isolated from people and other land mammals. And for another, this is also where I see them revving up interactions in early spring. When I saw these two gulls recently on the beach clearly interacting with each other I suspected they might be a pair re-establishing their monogamous link in preparation for nesting season.
Scientific study of gull behavior began with Nikolaas Tinbergen, a Dutch biologist (1907 - 1988) who enjoyed spending time out in nature as a child watching seabirds, pond creatures and other wildlife on the coast.
Throughout my life, Fortune has smiled on me. Holland's then unparalleled natural riches - its vast sandy shores, its magnificent coastal dunes, the abundant wildlife in its ubiquitous inland waters, all within an hour's walk of our urban home - delighted me, and I was greatly privileged in having access to the numerous stimulating writings of the two quite exceptional Dutch naturalists, E. Heimans and Jac P. Thijsse - still household names in the Netherlands. — N. Tinbergen
He continued his observations professionally, and focused on gulls in the 1940s and ‘50s to learn about bird social behavior and structure. Tinbergen was a pioneer in the study of animal behavior and received the 1973 Nobel prize in Physiology/Medicine, sharing it that year with two other biologists who also broke new ground in understanding why animals behave as they do, Karl von Frisch (honeybee waggle dance) and his friend Konrad Lorenz (imprinting). Tinbergen’s field work took a novel approach: observation of natural behavior in a wild setting combined with testing hypotheses, to determine whether behaviors were instinctual or learned, or a combination. He published articles and books describing his findings, an important one being what he called fixed action patterns (FAP), a sequence of instinctual behaviors triggered by a specific stimulus. You may be familiar with a gull chick pecking at the red dot on a parent’s bill to trigger regurgitation and feeding. He also did a number of experiments with gull eggs to determine why and when gulls remove eggshells from the nest.
Tinbergen watched gulls’ courtship displays and described the behaviors. I’ve seen gulls acting that way. Some actions are: walking (or swimming) side by side, calling out loudly with a stretched neck (the “Long Call”), bowing together or alternately, chuckling together, and picking up seaweed. It’s an intense but peaceful encounter.
I watched these two with interest.
Up until then, I had every reason to think I was watching a male and female gull meeting and catching up after a winter, perhaps chatting about the upcoming nesting season.
Then this happened. The darker-necked gull lunged at the lighter-necked gull and grabbed it by the wing. A flurry of fighting ensued, mostly with the darker-headed one holding the other by the head.
As flying creatures, a fight between gulls is three-dimensional.
At the time, it looked like a somersaulting and flurry of wings. Looking at my still pictures later I am amazed somebody didn’t get hurt, considering how sharply their necks and wings were bent.
Eventually they tumbled into the water and broke apart, but continued to call at each other.
Obviously the initial behaviors I observed were not about courtship, since fighting is never included in a description of that, to the best of my knowledge. What does Tinbergen have to say about this ambiguity? Evidently, some behaviors can have more than one meaning. The seaweed-carrying can mean practice nest-building, but it’s also called “grass-pulling”, and means “I’m going to do this to you”. Gulls call loudly as an aggressive threat to others (including other birds, even eagles) and also in greeting a prospective mate. There are certainly other meanings that we as humans are not skilled to differentiate.
Tinbergen describes a behavior only seen between mates: “head-flagging”, when the two gulls look a way from each other. The opposite of aggression. I did not see that at all with these two gulls. They were watching each other throughout.
The two flew down the beach a ways, which was a relief to me — they both looked just fine. After a few minutes I heard calling again in that direction, and they were at it once more. This time though, the lighter-headed gull had the darker-headed one in its grip. There were a few minutes of knock-down drag-out, until they ended up in the water again.
I’d been wondering about the strange oval markings on their cheeks, which they had from the very beginning. Clearly these two had been fighting for a while before I saw them. They split up and both flew off around the corner of the headland.
What I watched was likely a territorial dispute between two gulls, genders unknown. Usually such disputes occur at the nesting colony site but sometimes they will defend winter feeding territory too.
But was it really? How do I know what they were thinking or what their behavior signified? Thinking about these gulls and animal behavior in general, I realize (once again) that there’s a lot going on among animals we humans are clueless about. They communicate, they observe, they think, they interact physically, they have lives filled with complexity. Our attempts to translate their visible behavior are necessarily shallow and ambiguous, filtered through our own subjective experience and feelings. In fact there are many things we can never know about the world of wild animals. We humans know a lot less about the world than we’d like to think we do.