Female chestnut-headed oropendolas weaving together a new nest. When completed it will hang under the branch like a stuffed Christmas stocking. Watercolor over pencil, sketched through field scope. Barro Colorado Island, Panama. 10″ x 11″ (across two pages), Stillman & Birn Alpha Series sketchbook.
A flock of chestnut headed oropendolas, oriole relatives common to the Canal Zone of Panama, are establishing a colony in a bare-branched tree near our cabina on the hill. There are seven of them and they’ve just gotten started as of yesterday. The males posture and blurp while the girls do the hard work: gathering fibers to weave long-necked tree-top cradles in which they’ll rock their babies to sleep.
Male chestnut-headed oropendolas raise thready crests at the crescendo of their courtship display. Watercolor over pencil, drawn through scope across two pages of S&B Alpha Series sketchbook. About 11″ x 11″.
Every so often a
male will interfere with the weaving session. He and a rival female (update as of this morning: I’m still in research phase on this, but stay tuned) will interfere with a mating session- the two females will holler and joust, hook their feet together and spiral dramatically to earth.
Male chestnut-headed oropendolas looking seductive. Watercolor over pencil, S & B Alpha Series 8 1/2″ x 11″, drawn through scope.
A beat before hitting ground they’ll fly apart to rest, panting through open beaks, dwelling on thoughts of mortality. (Update: it seems to be a case of female/female competition- a second ‘helper’ female hovering nearby may be no more than a nest thief. The helicopter ride down, seen in this light, would be a hardcore game of chicken. Female fitness in a harem no doubt brings out some killer competition, and in this case, a five or six female-to-one male ratio might make things a tad competitive) And reproduction. And for her, a lot more weaving.
Here’s what happened: two females, one weaving, one waiting nearby. A male hops up, flashes his blue eyes and gurgles, whereupon the weaver takes a break and turns upside down, soliciting the male for sex. The second female takes advantage of the lag by hopping on the nest. The male sizes up the situation and decides he has a headache, leaving the unfortunate first female hanging, literally. She folds her wings, musters up her dignity, and rights herself, to see ‘her’ nest taken over by the ‘helper’. Other interactions between the females are more aggressive- the ‘helper’ lands on the poor, upside-down female, they tangle and squawk and spiral downward through the air like a maple samara. Drawn through scope, pencil on Robert Bateman 81/2″ x 11″ sketchbook, spiral-bound.