Transcript from podcast ‘Strange Bedfellows’, episode 242 ‘Mole Birds and Beetle Babysitters’. Hosts Ariadne Royce (AR) and Lex Charlton (LC).
LC: Hello and welcome to Strange Bedfellows – a dive into the bizarre world of symbiotic organisms. I’m Lex Charlton, and I’m joined by my co-dependent symbiote and low-key parasite: Ariadne Royce.
AR: I’d be offended, but I still owe you for last week’s takeaway so…
LC: Ariadne it is your turn to pick our symbionts of the week. What do we have? Where are we going? Why… are we here?
AR: In reverse order: we’re here because you love me and weird animals, we’re heading to the Papagaios Islands-
LC: Everyone’s favourite mid-Atlantic archipelago.
AR: -and we are looking at…drumroll please… a bird.
LC: A bird.
AR: A bird.
LC: Is it a special bird?
AR: I think so. It is called Cego and it’s unique among birds in that it is entirely fossorial.
LC: Fossorial is a nice word. Although I know other birds who dig like kiwis, puffins, burrowing owls -
AR: Burrowing owls, friend of the show.
LC: -so in what way is this bird entirely fossorial that the others aren’t?
AR: Most birds that dig do so to have a place to lay their eggs and that’s it. Some are a little more complex and sleep underground year-round, but they still spend a good chunk of time above ground hunting, foraging, finding mates, defending territory and so on.
LC: And this Cego doesn’t?
AR: It does not. Quick etymology aside, because that will make everything later make sense. Cego, for those at home it’s pronounced ‘say-go’ but its spelled C-E-G-O-
LC: One of those sneaky Cs that sound like Ss.
AR: ‘Cego’ is Portuguese for ‘blind.’ An old Portuguese folk name for moles is ‘ratos-cegos’ or ‘blind-mice’ and so when they discovered these birds that live entirely underground like moles they called them ‘pássaros-cegos’: blind-birds. Eventually the ‘bird’ part was lost in other languages.
LC: That leads to an obvious question then. Are these birds blind?
AR: More or less. They do have eyes but they are very small and only really see light and shadow. They do most of their sensing through really long, thin, sensitive feathers all over their head that have developed into whiskers.
LC: Okay so these birds are blind and have a load of whiskers. Let’s step back. What kind of birds are they, what are their closest relatives?
AR: They’re a type of cavador, the stocky ground birds of Papagaios. Most of those birds dig a bit, even if it’s a single chamber for their eggs but the cego has taken this behaviour to an extreme.
They are the smallest cavador at about 12cm long. They are dark grey in colour and their feathers are massively simplified, more like fur or the plumage of a chick than proper feathers. They have large heads with big wedge-shaped beaks for digging and also massive feet to kick back all the dirt. Their nearest relatives have spiny, porcupine-style feathers near the tail and the cego’s tail is a little bristly, but nowhere near as extreme. Their rear is also padded with fat, partly as defence and partly to counter-balance their big head.
