Global Change Center at Virginia Tech

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.”

Dr. Mark Stanback is a biology professor at Davidson College and a long-time mentor to David. He was one of the main reasons David got into birding: his enthusiasm and passion is contagious.

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.

Instead, we find a much more pleasing site: hornbills. 

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.

The sky is bright blue and a cool breeze blows across the savannah as we load into the field rover for a morning’s fieldwork session. Last night’s electric rain shower brought a renewed sense of prosperity to the land, and the air is thrumming with joy and thumb-sized African beetles. Like tiny helicopters, they attempt to land on our shoulders and heads, attracted to the bright colored ties we wear in our hair.

They’re harmless enough, but our guide warns that the insect’s nickname, ‘blister beetle’ is well earned for the welt it can deliver.

“Just duck, it’s cool—it’s like Jedi training,” says David Millican, our guide and researcher extraordinaire.

We’ve followed him to what could be considered the middle of nowhere—just outside of Otjiwarongo, Namibia. But the truth is, despite the low human population it’s quite definitely a somewhere: a beautiful rocky and sandy landscape brimming with biodiversity. Some of the world’s most rare and unique animals—cheetahs, giraffes, jackals, aardwolves, leopards, hornbills, and much, much more— call this harsh climate home.

Today, we’re accompanying David on a trip to check for cavities—and not the painful trip-to-the-dentist kind. We’re looking for bird homes: holes and rips in tree trunks and branches that are used by bird species within the local cavity guild. While the guild consists of bird, mammals, and reptile species, we’re most interested in the feathered ones.

As a bird biologist, David has a nagging question: which types of tree cavities are the birds using? By recording the species of birds that reside in different types of cavities, we can also determine who may be in competition. Finding the answer to these questions will help him answer larger ones about the structure and dynamics of the guild community.

David has established 20 sites across four adjacent farms that he believes could harbor a significant amount of tree cavities. During this season’s fieldwork he will repeatedly visit the sites, which are 16 hectares, to monitor cavities he’s discovered and search for new ones.

Acacia trees—which are abundant in these parts—are a favorite nesting spot. Some of the cavities we will visit were created by lightning, broken limbs, and insects or fungal decay. But others—known as excavated cavities—are pecked and created by the birds themselves. The birds that create the holes are known as primary excavators and the birds that live in the holes another bird created are known as secondary nesters, according to David.

“Some cavities can take a while to excavate, especially in live trees,” says David.

David’s tools today are a ladder, a peeping camera, a handheld GPS system, and a notebook for recording our findings.

He uses the GPS to navigate through his seventh site— a scrubby grassland of fallen brush and thorny plants, littered with a few antelope skulls.

Using the ladder to climb up to the first cavity resting high in the tree, David sticks the long cord of the peeping camera into the hole and is able to see on his monitor what awaits inside. This time, it’s nothing.

However, a few cavities later, we see signs of a former nest: feathers and grass. David’s hopes are lifted.

On the way to the next cavity, a cacophony of peeps arises from a tree ahead.

“Those are alarm calls,” says David, pointing in that direction. “That means there is likely a predator is nearby—could be a black mamba, boomslang, or mongoose. It’s best for us to go around that area.”

Working our way around the commotion, we come to a beautiful old camel thorn tree with a long slivered cavity in the trunk, about eye level . David inspects the hole with delight. Part of it is caked over with a thick mud: the telltale signs of a hornbill nest.

When female hornbills are ready to nest, they will enter a cavity and caulk themselves in, closing up the hole with mud, millipede shells, grass, and other vegetation. This is to prevent predators from entering and disturbing the nest when both babies and mom are vulnerable: moms lose their wing and tail feathers when incubating eggs and cannot fly.

Carefully and quietly, David sticks his cord into the small opening that remains and watches his monitor. Three timid faces stare back at him. Nestlings! And not very old at all, judging by their pink, featherless alien bodies.

David points the cord upwards into the hole and sees a fluff of feathers that he determines to be the mother, a yellow-billed hornbill. Often the mother will move to an area with more space above the cavity floor, allowing her to climb above the cavity entrance if a predator tries to break in.

David quickly retracts the cord. We will leave this nest alone for now, tiptoeing away quietly to avoid upsetting the sweet family.

Written by Lindsay Key/Photos by Jelena Djakovic.