A Scatalogical Perspective on Avian Primacy

BB&B welcomes this guest post from Christian Schwarz, a celebrated west coast mushroom authority, birder and co-creator of the multi-taxon burrito from Santa Cruz, CA. Let us join in his wonder of the life forms that organize their physical structures and lifestyles around something...uric.

In Life's rich tapestry, there exist hierarchies.

Trophic, taxonomic, dimensional. This is 'que obvio' to all.

I study mushrooms. Mushrooms are close to the bottom of the hierarchy of valuation among USA-people. Birds are close to the top.

But there is a deeper affirmation of the primacy of birds, expressed as imitation by non-human organisms. I don't mean mimicry as we see in the Mullerian butterflies or the Batesian newts. Those would leave room for the familiar equation of imitation to flattery. No... I am referring to something groveling. Something wretched. Something... uric.

I speak of the shit-mimics. Yes, there are organisms lying on widely-set branches of the tree of Life On Earth that make their livings by imitating bird feces. These abject organisms live as shambling, breathing representations of bird excreta. Whether out of cowardice or admiration we may never know, but the fact remains that their DNA contains instructions to turn them into a neat facsimile of guano.

   

    

Credits clockwise from top right: Vijay Anand Ismavel, Geoff Calice, flickr User Kibuyu, Thomas Ziegler.

There are the spiders: Cyclosa ginnaga, a resident of East Asia, whose web patterning mimics bird poop. Then there is the Australian species Celaenia escavata; remarkable for being a double-imitator: it resembles bird poop by day and releases female moth pheromone-mimicking compounds by night (to attract prey). While we are on the topic of olfactory mimics, please note that some Phrynarche spp*. not only look like bird poop, they release volatile comounds that smell like bird poop.

The caterpillars of Papilio xuthus are Champion Scheisse-Imitators, and have been studied quite closely. Researchers found that the poop-imitating characters were inducible (by treating more advanced larva with hormones present at earlier stages).

And then there is a full-on vertebrate, the frog species Theloderma asperum, found in China and southeast Asia. These poor things are threatened due to habitat loss and collection for the pet trade, apparently.

Some may quibble about ingenuity, Lion and Fox approaches to power and so forth. These apologists aside, I think it's self-evident that you can count yourself pretty high on the fucking totem pole when multiple beings have evolved over the millenia such that their bodies look like ever-more-precise representations of your shit.

Refer to the images above Lest You Forget. The spiders, the frogs, the caterpillars have voted with their bodies: Birds Reign.

But nature always leaves room for complication. Many Bothans died to bring me the following fact: There are some birds that mimic insects.

The underwing pattern of Black-thighed Falconets has been hypothesized to be a Batesian imitation of a toxic butterfly with which they live (they are almost the same size!). And in a dramatic series of revelations this summer, I learned that the chicks of Elegant Mourners are covered in down feathers with extremely long, thin, hispid shafts.

An image by Eustace Barnes from Cotingas and Manakins of the World is here:

They look strikingly like the toxic urticating caterpillars that share their habitat. A related species, the Cinereous Mourner, employs a similar natal plumage, and the flattened, sinuous swaying of the chick deepens the charade - see this behavior at the 5 minute mark in this remarkable video by Dano Grayson. Incredible stuff.

I wish there were a species of bird in which the chicks mimicked guano-mimicking caterpillars. That would be the pinnacle of recursive evolution. Just imagine - a bird imitating its own shit. That would be so good.

** Here's how Henry Ogg Forbes (the discoverer of the Phrynarche decipiens) described his first encounter with the species: "The first specimen I got was in West Java, while hunting one day for Lepidoptera. I observed a specimen of one of the Hesperidae [Butterfly] sitting, as is often a custom of theirs, on the excreta of a bird on a leaf; I crept near it, intending to examine what they find in what one is inclined to consider incongruous food for a butterfly. I approached nearer and nearer, and at last caught it between my fingers, when I found that it had as I thought become glued by its feet to the mass; but on pulling gently the spider, to my amazement, disclosed itself by letting go its hold: only then did I discover that I was not looking on a veritable bird's excreta."