Davidson College: Scientific Serendipity

This article first appeared through Davidson College.

Of all the birds he's seen and studied, Professor Mark Stanback counts the hornbill as his favorite.

"They're big, pretty, weird and have such a strange breeding biology," Stanback explained.

When a female hornbill is ready to breed, she and her mate find a cavity in a tree. The female squeezes into the cavity and cements herself inside -- except for one very small space through which the male can stick its beak to feed his ensconced mate. The female remains in the cavity for over two months -- the entire egg-laying, incubation and chick-rearing period.

Photo: Photo Credit: Mark Stanback

Since Stanback began teaching at Davidson in 1995, he has conducted research with more than 100 students. Projects focus on local species, such as eastern bluebirds, Carolina chickadees, house wrens, purple martins and eastern screech-owls. But you won't find hornbills anywhere near North Carolina.

TRAVELS TO AFRICA

Stanback has become increasingly fascinated with species found in Africa -- hornbills and others with exotic names like the lilac-breasted roller, the green woodhoopoe, the pearl-spotted owlet and cape glossy starling.

He is currently involved in two projects in Namibia and South Africa concerning cavity nesting birds. Unlike woodpeckers and barbets, secondary cavity nesters cannot excavate their own tree hole homes; rather, they must inhabit those created by tree rot or left behind by other species.

"We don't fully understand the competitive relationships within African secondary cavity-nesting birds," Stanback said. "That understanding would provide conservation biologists with a tool for determining which members of this large and taxonomically diverse group are most susceptible to the loss of large trees, which local residents cut down to make charcoal."

He has devised an innovative approach to gather data about the threat that deforestation poses and is testing his approach in Namibian and South African game parks. By installing individual and groups of nest boxes within close proximity to each other, Stanback is creating competitive situations that lead species to sort themselves spatially, allowing him to decipher their relative competitiveness and determine which are most and least vulnerable to the loss of trees with nest cavities.

Because large trees are much more likely to contain cavities that many species of birds require for roosting and nesting, the loss of the larger trees is especially devastating, Stanback explained.

BIRDS AND BEES

Davidson alumnus David Millican '11, a doctoral candidate at Virginia Tech, is Stanback's collaborator in this study. While Stanback's research focuses on artificial nest boxes, Millican is doing parallel work to examine competition at natural tree cavities.

A Monteiro's hornbill photographed in its nest.

Stanback's studies of dominance and deforestation have also led him in an unexpected direction.

"I'm discovering that honey bees are big players in the ecology here," he said.

At some of his Namibian sites, up to half of the nest boxes have been occupied by honey bees. Cavity nesting birds avoid the bees, so the cavity is unusable to them. Even when the bees swarm and leave the nest boxes, the honeycomb they leave behind blocks the nest and potentially makes it unavailable to birds.

Enter the lesser honeyguide. Like all honeyguides, this bird can digest wax and seeks out abandoned hives to feast on.

"I've found that one project leads to another," he said. "I had no intention of studying honeyguides, but as we noticed the disappearance of old comb, I realized that honeyguides play an unappreciated role in maintaining cavity availability."

Stanback plans to return to Africa during sabbatical semesters in spring term 2017 and 2018. He will continue to look at competition among various cavity nesting birds, the extent to which honey bees shape that competition and the role that Honeyguides play in ameliorating it. Moreover, he is starting a new collaborative project that focuses on the endangered cape parrot in South Africa, another cavity nester facing stiff competition from honey bees.

He hopes to translate his findings into recommendations for African government ministries and NGO's tasked with balancing resource protection and development, and believes the results of his work will interest ornithologists, community ecologists and conservation biologists.

STATESIDE STUDIES

Stanback grew up in Salisbury, North Carolina. While he enjoyed watching birds at the feeder and on family vacations, he doesn't recall a particular moment of discovery that led him to pursue his current passion. Though, as a high school student he built and monitored bluebird nest boxes -- perhaps an indicator of things to come.

Stanback and Pat McGovern '11 checking bird houses at the college’s Lake Campus, where Stanback has installed more than 80 nest boxes.

He attended Davidson, graduating with a biology major, then earned his doctorate at the University of California-Berkeley. Stanback first visited Africa in 1991, after finishing his doctorate. He then went on to a post doctorate fellowship in Seattle, focusing his studies on woodpeckers. He returned to Africa for eight months in 1994-1995 as a Fulbright postdoctoral fellow.

Thereafter, teaching and family responsibilities kept him stateside until an opportunity to visit South Africa arose in 2008. That visit rekindled his interest in African ornithology and lead to more recent visits, including a month-long trip over the 2015-2016 winter break.

During his tenure at Davidson Stanback has studied blue birds, erecting scores of nest boxes on college property, private homes and public spaces. About 80 boxes on 6-foot poles are located in a broad meadow at the college Lake Campus.

The nest boxes have been the basis for many of Stanback's studies. He is currently collaborating with ornithologists at Cornell University to determine how climate change is expanding the breeding grounds of tree swallows.

Stanback also is a long-time friend of Audubon North Carolina. His observations of the brown-headed nuthatch's nesting habits helped inspire an Audubon project that established 10,000 new nuthatch nest boxes across North Carolina.

His studies have been funded by organizations including National Geographic, as well as several zoos interested in strategies for managing declining species.