A couple of weeks ago my colleague Fabio Akashi Hernandes* from the Universidade Estadual Paulista sent me the file for a poster that I immediately printed on high-gloss paper and proudly affixed to the door of my office. The poster depicts some of the feather mites that Fabio has found on birds from Brazil and a few other tropical countries. Eye candy for acarologists! They are all scaled to the mm mark at bottom right, where you can see the gigantic Laminalloptes phaetontis (Fabricius) from tropicbirds. Among the selected mites are the hoatzin-dwelling Opisthocomacarus umbellifer (Trouessart) (mite #40) in which both sexes are adorned with feather-like setae of unknown function. Typically, though, male feather mites are more elaborate than females. The poster includes species whose males have vicious-looking hind legs (e.g., 1, 28), or are asymmetrical (e.g., 31, 32, 58), or are very well-endowed (20).
Fabio is doing some marvelous work on taxonomy and ecology of these mites, including the very recent discovery of a host-switch from wild cuckoos to domestic poultry. But even though he and his colleague Michel Valim have been working hard to describe new species, at least 80% of bird species in Brazil have yet to be investigated for their acarofauna. Many more wonders await.
Click on the poster image then mouse over and click to magnify.
My freezers at work are getting rather full, so I’ve been washing birds and sending the clean bodies to the Royal Alberta Museum. Last week I washed a batch of white-throated sparrows (Zonotrichia albicollis) that had met a sad communal death by flying into a window in Edmonton. They were very mite-rich, providing dozens of specimens of Proctophyllodes (Proctophyllodidae), Mesalgoides (Psoroptoididae), and Analges (Analgidae). All of these taxa belong to the feather mite superfamily Analgoidea. Analges means “without pain”, and the genus was called thusly by Nitzsch in 1818 because it seemed that even heavily laden birds showed no signs of distress. Almost two hundred years later, a huge comparative study by Ismael Galván and colleagues in 2012 compared feather mite load and host condition of 83 species of birds and found no evidence of a negative relationship. Feather mites in general appear to be harmless commensals of their hosts.
Analges species are interesting because of their striking male polymorphism. All males differ from females in having enlarged third legs with spear-like tarsal claws, but legs of some individuals are much more grotesquely hypertrophied than others. Such males are also larger overall.
Analges sp. mites from white-throated sparrows from Edmonton, Alberta. From left to right: female, homeomorphic male, heteromorphic male (all to the same scale).
Male polymorphism is very common in feather mites and many other Astigmata. The less elaborated male forms are typically called ‘homeomorphs’ and the extravagant ones ‘heteromorphs’ (the reason for the terms being that the former are more similar to females than the latter).
But what are the modified third legs used for? Holding females? Stabbing rival males? I’m not sure that anyone knows.
Legs of homeomorphic (left) and heteromorphic (right) male Analges. The pointy tarsal claws look nasty.
This afternoon one of my colleagues passed on the good news that he had just put a roadkilled charadriiform in the Museum of Zoology’s freezer. I don’t have a lot of mites from Albertan charadriiforms, so I was eager to see get the bird and wash it. The body turned out to be that of a Wilson’s Snipe, currently Gallinago delicata Ord in most taxonomies, though not all feel that it deserved having been raised from its previous subspecies status (G. gallinago delicata).
It was a lovely specimen and I took it to show to people in the main office. “It’s pretty rare to come back from a snipe hunt with an actual snipe!” I said, attempting to be amusing. Two people laughed, and two just stared. “You know what a ‘snipe hunt‘ is, right?” I asked the latter. Nope. When I explained, they got the concept immediately, and came up with other examples (e.g., an apprentice carpenter being sent for a ‘board stretcher’). I wonder if there is an unrecognized linguistic divide in Canada, with snipe-hunting being common in only some regions.
A snipe in the hand. I washed it after taking the photo and was rewarded with a small number of feather mites and lice.
Many Canadians go to Mexico to watch birds. In the vicinity of the UNAM field station at Chamela there is a huge diversity of forest-dwelling, estuarine and marine species. I won’t bore you with my list of twitched birds, but my trip here has allowed me to observe members of several families I’d never previously seen outside of a zoo or a museum (e.g., Cracidae, Fregatidae, Sulidae).
West Mexican Chachalacas (Cracidae) and Magnificent Frigatebird (Fregatidae)
But unlike most avian enthusiasts, as well as watching birds, I also wash them. Washing the body of a recently deceased host is one of the best ways to get feather mites (Acari: Astigmata: Pterolichoidea and Analgoidea). While at the station I have ruffled through the feathers of stuffed specimens from their ornithological collection, and was also lucky enough to get to wash a freshly road-killed Buteo magnirostris (Roadside Hawk). The washing yielded feather mites, feather lice, and one hippoboscid fly. The last has been added to the UNAM Chamela entomological collection, and the others get to come back to Edmonton with me.
The hawk about to be washed.