David Millican has a nickname around the community he lives in when he is in Namibia: Bird Man. He’s unique in that he is one of only a handful of people in the community studying birds; most are there to work with the cheetahs at the Cheetah Conservation Fund (CCF).
We arrived to CCF about a day ahead of David, who was held up in the capital city of Windhoek having repairs made to his vehicle.
“Oh you’re here to hang out with Bird Man,” said one CCF volunteer with a chuckle. “Although,” he added, “we’ve decided that maybe we should start calling him Bird Boy. Because Mark is the original Bird Man.”
Mark began conducting research in Namibia in the 1990s. Two years ago, after an extended time away from Africa, he returned to launch a new set of experiments with the help of CCF and invited David to help.
Two years ago, he and David set up nest boxes around Otjiwarongo and Windhoek in hopes of attracting as many cavity nesting birds as possible so that he could study multiple aspects of their lives including mating, nest site competition and feeding habits.
But when Mark came back to monitor the boxes, he did not find birds but a disturbing new resident: honeybees, also known as African killer bees! The bees were highly aggressive in taking over the bird holes and also messy tenants— they left tree holes chock full of wax in their wake and birds can’t nest in the used cavities.
“I was not happy– it was ruining my nest-site competition experiment,” explained Mark. “But eventually I decided to study them instead of fighting them. And it got me thinking about honeyguides.”
Honeyguides are the only kind of bird that eats beeswax for a living.
“My hypothesis is that the honeyguide can act as a keystone species, having a greater impact on the community than their numbers would indicate,” said Mark. “I’ve never seen one here, but I know that when I arrived a year ago, 25 boxes that had had bees in 2015 had been picked clean of wax. So I want to know how quickly they can find wax and how quickly they can eat it.”
Mark generously invited us to go out with him to inspect next boxes. We drive down a dirt road, and get out every kilometer to check the boxes, which he has expertly tied to trees. We soon find that the African bees can’t be bought—there are no hives in the boxes.
If you’re more familiar with Disney movies than exotic bird species like I am, it will help to picture Zazu from the Lion King to get a good idea of what a hornbill looks like. The birds are shockingly prehistoric-looking and beautiful, with black and white plumage and long curved beaks that are perfect for digging in the dirt and crushing lizards and millipedes.
In the first box we check, we find a mother and two half-grown nestlings. Mark predicts that they will fledge soon. The mom spends more than two months in the box, with most of that time spent incubating the eggs. When the biggest nestling is about two thirds grown, the mother breaks out, and the nestling then seals up the hole until it’s ready to leave. When the oldest leaves, the next chick will seal up the hole until it’s ready to leave, and so on.
About an hour later, we find another hornbill family (a mom, two babies, and un-hatched egg) in another box. The mother seems to glower at us as we observe and record our findings. But she does not move.
In another box, we find only remnants of a hornbill nest: grass, poop, and crushed millipedes. Another project Mark is working on involves trying to determine what purpose millipedes may serve in the hornbill home.
“People have known for a long time that hornbills smash millipedes and incorporate them into their nests and nest plugs,” said Mark. “And people have known for a long time that millipedes release cyanide. So people have kind of assumed that the hornbills are using the millipedes to cut down on pests in their nests. But no one has tested it.”
To test this, Mark will find multiple hornbill nests, and wait until the eggs start to hatch. Then he will replace all of the nests with new nest material, with half receiving smashed millipedes as well. After the nestlings fledge, he will monitor the parasite load in the control and experimental nests to determine any positive correlation between millipedes and number of parasites.
Mark will also collect data on egg size and egg production rate in one particular species: the Monteiro hornbill.
“I have a lot of projects going on right now,” says Mark with a chuckle. In addition to his own projects, he is on David’s thesis committee, serving as an adjunct professor at Virginia Tech.
Together, the two “Bird Men” have their work cut out for them over the next few months.
Written by Lindsay Key; Photos by Jelena Djakovic.