Saturday, September 10, 2011

When your stalker has feathers...


The parched colours of the dry season.
Photo by Kim Reijs.


When I venture into the field these days it's like I've somehow slipped into a Disney animated classic.

All I need is a ballooning skirt and a tripping walk to make the illusion complete.

Why am I suffering these weird fantasies?

Well, the moment I set foot in the bush, I'm surrounded by clouds of little blue birds, all atwitter with excitement. And then the little animals come creeping out of the undergrowth to gather at my feet.
Magic?  Charisma?  Sadly no.
You see it's the height of the dry season here. With the bush seared, dusty and leafless, everyone could use a drink.

In an effort to curry favour with my study subjects (essential if I'm to ever find the little brutes), I reward them with a small bowl of water whenever I join a group. And of course it doesn't take long for the other locals to catch on too.

The mongooses crowd around the bowl, some delicately lapping with pink tongues while others dip in their paws and lick the moisture from their toes. Meanwhile a menagerie congregates around us.
Four-footed or two, feathered, scaled or furred, no one can resist the lure of free drink.


Tamarind (HF047) enjoying a tipple.


The tree squirrels (Paraxerus cepapi) aren't backward in coming forward.


Rough-scaled plated lizards (Gerrhosaurus major) disdain rules of etiquette.


Rainbow skinks (Mabuya quinquetaeniata) tentatively seeking that elusive pot of gold water.


"... and then I told that great brute of a mongoose to just clear off..."


The blue waxbills (Uraeginthus angolensis; pictured above) are the most persistent (and impatient). They accompany me as I search for the mongooses, flitting through the bare twiggy undergrowth, peeping vociferously. We collect more and more followers as we go, with everyone complaining loudly about having to wait to wet their whistle. I find this entourage a bit irritating because it drowns out the subtle, tell-tale peeps of my mongooses.

But if the waxbills are annoying, there's one avian devotee that drives me insane. Dressed in humdrum colours, it flutters from branch to branch above my head, ruffling its wings, wriggling its white-edged tail and bobbing about like a creature possessed. It also feels compelled to squawk non-stop. One of my bird books likens its raucous call to the sound of a shaken box of matches, which is pretty accurate if you pump up the volume about 100-fold.

This irksome devotee will dog my steps for hours (OK, for the purposes of scientific accuracy, I'll admit that this is a slight exaggeration). It certainly doesn't retire once I find the mongooses (and they dislike it as much as I do). You see it's not after a mere sip of water. It wants wax.

Yep, you read right: the greater honeyguide is one of only a handful of critters who's able to dine on, and digest, wax (thanks to special microbes in its gut).

But before you start imagining some ghastly Hitchcockian scene, let me make it clear that it isn't after earwax.
This feathered stalker hungers for beeswax.

Its fervent taunting is designed to persuade me to follow it to a likely bee hive. Once there, it expects me to smoke out the bees and heroically retrieve the honeycomb so it can gorge itself on bee larvae and wax (it doesn't eat honey). I've never felt tempted to accept this offer (opening a jar of jam seems safer), but if I'm unwise enough to move or speak in the bird's presence, it gets super excited and zooms off, in a sweeping, undulating flight, toward the nearest hive.


Although greater honeyguides (Indicator indicator) are only about 20 cm (8 in) long, they vex the inhabitants of woodlands and savannahs throughout sub-Saharan Africa. When not guzzling wax or terrorising baby bees, they make do with flying insects.
Photo by Carol Foil.

Now as a zoologist who studies partnerships between species (see an example here), I know I should revere this bird. Collaboration between beasts of feather and fur is rare, and the greater honeyguide is the poster child for such complicity.
But God it's annoying!
And the creature's not easily deterred; honeyguides will invade villages and gardens in search of someone with a sweet tooth, and they even pursue cars and boats.

You see the honeyguide has had the dubious pleasure of sharing its habitat with humans for millions of years, and that's plenty of time to notice a mutual fondness for bee by-products. But what's really impressive about the alliance that's evolved, is how well human and bird communicate.

For example, when the Boran people of northern Kenya decide to do a spot of honey pilfering they inform the birds by whistling piercingly through clasped fists (this doubles their chances of bumping into a honeyguide, who then reduces the time they spend searching for a hive by two-thirds). Of course the bird has reason to come running flying: only 6% of the hives (of Apis mellifira) in its territory are accessible to beak and claw alone.

Upon arrival, the honeyguide gives its annoying come-hither call, zips off for a moment (presumably to identify landmarks along its proposed route) and then leads the honey gathers in a beeline for the closest hive. (A three-year study found that the birds monitored all the hives in their area, routinely stopping by for a minute or so to check they were active).
Intentionally or otherwise, the honeyguide also informs its followers how far they'll have to walk. The further away the hive, the longer the bird is gone on its initial reconnaissance mission, and the nearer the allies gets to the booty, the shorter the bird's perch-to-perch flights become. When the team finally rocks up at the hive, the bird gives a special 'here it is' call, perches close to the nest and then keeps mum.

If you haven't already seen footage of a greater honeyguide doing its thing, you can view one (and David Attenborough imperilled by bees) here (courtesy of the BBC's Trials of Life).

The weirdness of greater honeyguides is not limited to their dietary habits. These birds are territorial and each male has a special 'song post' where he sits from dawn 'til dusk throughout the breeding season vociferously boasting of his macho charms. Interested lady honeyguides simply drop by for a bit of fun every now and again.
But once knocked up, female honeyguides appear to go to pieces, abandoning the fruit of their passion at the earliest opportunity. They cunningly slip their egg into the nest of unsuspecting hole-nesting birds (such as barbets and woodpeckers). When their little darling hatches, it dispatches its nest mates with a wicked billhook designed for the purpose.
Serendipitously, you can see wonderful photos of this villainous behaviour here.


The adoptive parent (a meves starling) of a greater honeyguide chick bringing home the bacon frogs legs.
Photo by Johann du Preev.

But all is not well in the land of honey procurement.
When I first started working on the dwarf mongooses six years ago, I was constantly beset by these irritating birds; now it's a rarity. I hadn't really given this much thought: sure, the resident birds had learnt I was a no-show and had given up on me (sigh of relief). But after researching this post I began to realise how bad this is.

You see in many places greater honeyguides don't indulge in guiding at all. It's believed that this is the result of humans, at some time in the past, welshing on the deal. And increasingly local people are abandoning traditional food gathering techniques (hey, sugar's dirt cheap at the supermarket), leaving the birds high and dry.
Similarly, human activities such as honey gathering are banned in national parks and other protected areas, exacerbating the problem.

So this amazing alliance between bird and mammal - rightly lauded as the world's most impressive example of interspecies mutualism - is rapidly disappearing.

And I'm hastening its loss!



Honeyguides and Honey Gatherers: Interspecific Communication in a Symbiotic Relationship. H. A. Isack & H. U. Reyer. 1989. Science, 243: 1343-1346.

The Fallacy, Fact, and Fate of Guiding Behavior in the Greater Honeyguide. W. R. J. Dean, W. Roy Siegfried & I. A. W. MacDonald. 1990. Conservation Biology, 4: 99-101.

3 comments:

  1. Another great post. I find the honey guide interesting and did an essay on them for my course last year. The link between the ratel and honeyguide has interested me for a while especially as I really wish to see a honey badger.
    Keep up the interesting posts

    ReplyDelete
  2. Hey long time no speak!!
    How are you?
    I just want to say that your blog is amazing, I dont know how you do it!!
    I also wanted to ask how you got so many followers? I am trying so hard and I just cant geyt anyone to follow me blog! I only have 9 followers!! Hope to hear from you again!! Bye

    ReplyDelete
  3. Matt,
    It looks as if there's not much evidence to support the (very widespread) idea that honeyguides guide honey badgers. No one has actually seen it happen, from start to finish, although the bird certainly cashes in when a honey badger breaks open a hive. I'd have thought that baboons would be an ideal species for the honeyguides to target, but it looks as if they really need/prefer someone who subdues the bees.

    Kirsten,
    Great to hear from you. The photos on your blog are fantastic (I'm envious).
    I don't know what to suggest with regard to followers (I know you're supposed to promote your blog on Facebook and Twitter, but I don't). Try commenting on other people's blogs (mention how old you are and that you live in a wildlife reserve) as that will attract people to come and have a look. Also some bloggers will follow your blog if you follow theirs.

    ReplyDelete

Related Posts Plugin for WordPress, Blogger...