A long black tube-like bird came fluttering across the grasses. It seemed to be flying barely, flopping through the air, like a balance beam gymnast having trouble. “Can we stop?” I shouted to our driver. The slender shape was not quite vertical to the ground. I was standing in the back of a Landcruiser with my head out the roof, and there was no way I could hold binoculars still enough to train them on this creature.
It appeared all black, skinny, and extremely long, but I could get no details in the gray light. Body size seemed like our North American Red-winged Blackbird, but the tail was three, maybe four times the length of a blackbird’s tail. Males of African widowbirds are supposed to have extremely long tails that they use to attract females. So long, that its length can inhibit their ability to fly or so it seems.
“Yes, Red-collared, a male,” he had his binoculars up and was watching it come closer and closer.
I held my breath, hoping it might land nearby. Evolutionary, widowbirds are fascinating. The eight recognized species are all polygynous. Males vigorously defend a territory from all others, and they do a flight display to entice a female into their space. This individual was performing right now.
If a female shows interest, a male Red-collared Widowbird will use a partially built nest as a prop when he courts her. If she likes the nest structure and his performance, she might stay, accept the nest, and mate with him. But he doesn’t help the female finish the nest, incubate the eggs, or feed the young. So, by pairing with the male, the female gets the use of his territory and his sperm, nothing else.
Presumably, she can evaluate the territory when moving through it, and in some respects, this will reflect the quality of the male, too. Good males will usually hold the best patches. She needs a safe place for her nest, one that will tend to protect it from predators, and an excellent area to find food for her young. But how else can she judge the “genetic” quality of the male?
Experiments done by ornithologists showed that she focuses on the length of his tail. Males with longer tails tend to mate with more females than those with shorter ones. This drives selection on males for even longer ones, and they now have a tail during the breeding season that it is so long that it appears to hinder their ability to fly. Presumably, being able to survive with such an extravagant tail indicates their superiority. But what do males key on when they compete among themselves?
The male widowbird flew onto a bare branch not far from our vehicle, and his long tail blew back and forth in the wind. A bright crimson collar surrounded a black face and bill. Even in the subdued light, it radiated an intensity of red that surprised me. Of any birds, these males have the highest levels of carotenoids in those feathers. The concentrations of lutein and zeaxanthin help give that intense red color.
Converting nutrients into this red pigment is a costly process, requiring extra energy and a specialized metabolic pathway. But it is this red collar that tells other males an individual’s status. Scientists have manipulated the size and intensity of these collars and found that males with smaller or less bright ones had a harder time securing a territory or holding one. The researchers concluded that the “redness” of the collar and, to a lesser extent, its size indicated the dominance status of a male.
I jerked my hand down; it had been rubbing my beard for the last few minutes. I’d just turned 68 the previous week and had been wearing hair on my face for only five months. This widowbird was making me wonder why I kept it. Last summer, I had let it grow on a week-long camping trip and discovered that some hair follicles on my cheeks and chin had stopped making melanin. The beard was a mixture of gray and brown, different from the solid brown on my head.
After the camping trip, I let it continue to thicken because I wanted to see the mosaic of grays and browns when the beard was fuller. I had three weeks before a trip back east to see my sisters and planned to have it cut by then. The weekend before my flight, I went hiking with my nephew, and he talked me out of shaving it. To my surprise, my sisters liked it. They said something like, “It gives you a distinguished look.” Later a friend said she thought it gave me a “professorial bearing.”
The male widowbird shifted his stance in the bush, and his red collar seemed to shimmer in the mid-day light. Perhaps, he was a dominant male, possessing a high-quality collar that intimidated other males, and his long black tail might be irresistible to females. He then flicked that tail and flew out over the grassland, waving it back and forth as he fluttered a few feet above the vegetation.
“You ready,” Robinson asked as the car started to drift forward.
“Yes,” came out as I rubbed my facial hair, wondering its significance for a single man at my age.