We had been collecting in the El Triunfo cloud forest for an hour or two, following the Costa trail south, when we arrived at the crest of the trail, at 2100 metres elevation, before it descends toward the Pacific coast. Up to that point, we had been finding only a single species of Mexigonus, a brown and creamy-yellow one:
Brown and yellow Mexigonus from El Triunfo, nice but not too exciting
Then, at about the same moment, Łukasz and I both found dark brown Mexigonus females that looked unfamiliar. We wondered: what do the males look like?
Unfamiliar dark brown Mexigonus female.
Male and females of many spider species look quite different. Male jumping spiders often bear fancy plumes and colours they show during dances to the females. And, of course, their genitalia are different. Because we taxonomists find many useful characters to distinguish species in their genitalia, we want to find both male and female specimens of each species in order to get a complete characterization.
But, I have to admit, arachnologists tend to be biased toward the males for scientific reasons — the species are easier to distinguish by the males — and for aesthetic reasons — the males are sometimes spectacularly ornamented. Seeing those two dark females was like hearing the call of an unfamiliar bird but not seeing it. We knew there was a kind of male in this forest, perhaps right in front of us, that we had never seen before. Would the males have muted colours, or would they burst resplendently from the forest like a colourful quetzal?
Knowing there were more out there, including the unseen males, we tried to guess their precise habitat. The females had been on small trees with some mosses and suspended dead leaves, and so we tried shaking various such trees over our sheets, seeing what fell out. After about an hour, we had found some juveniles, but not adult males. We were discouraged.
And then, he appeared. He fell on the beating sheet, his two long and furry front legs instantly marking him as a male. On the sheet, from above, he appeared as a nondescript grey.
Male of the grey-brown Mexigonus is finally found!
Once he was in the vial, I turned my hand lens on him.
Male of Mexigonus “quetzal”.
His face was red. The “fur” on his front legs shone a brilliant metallic green and blue and orange. He was a miniature quetzal. I was over the moon.
One of his most noticeable features is the wide fringe on the sides of his first legs, like the bell-bottomed spiders from Oaxaca. These fringes make his first legs appear very wide from above, but very narrow from the side:
Mexigonus “quetzal” male
Notice the blue glow from his right legs! Under some lights, the face positively glows orange-red:
Mexigonus “quetzal” male
(I’m sorry. I can’t stop from adding more and more photos.) Generally he hides his colours, but Uriel and I put him in front of a female and this is the pose the male took:
Mexigonus “quetzal” courtship pose. Wow.
In fact, the true quetzal, the bird that is both real and mythological, that gives proof to the magical realism that is Mexico, lives as well at El Triunfo. Is it the emblem of the park. We were told that we might see one were we to wake up early enough. We didn’t. We were fully satisfied with our little eight-legged quetzals.
We hiked down from El Triunfo on Wednesday, thankful for our time in the pristine, verdant wilderness, and for the park staff’s professional help. Our visit was supported generously and capably by Janette, Arcenio, and the rest of the El Triunfo team.