Artificial nests, real conservation results

Can you hear the thunder?

Ground hornbills are one of the most iconic bird species in South Africa, where they are known as ‘thunder birds’ due to their booming calls (which can sound almost like a lion roaring) and perhaps because when you see one flying, it looks like a black cloud coming towards you.

In one of our earlier blogs, we talked about some of the reasons that these remarkable birds are amazing. Here, we’re going to focus on their unusual breeding behaviour (which is also a factor in their scarcity).

Habitat loss

When ground hornbills breed, they look for a safe hole or cavity in a large tree, or sometimes in a rock face or earth bank. Habitat loss means that there are fewer large trees than there used to be, which means fewer nesting options.

Boxing clever

During October, researchers Kyle and Carrie from the Associate Private Nature Reserve (APNR) Ground Hornbill Project (a dedicated team based in the Greater Kruger area) chose a suitable location for a specially designed artificial nest.

This specially designed nesting box was paid for by The Royal Portfolio Foundation and installed in a large jackalberry tree at Royal Malewane – exactly the kind of towering tree that the birds might have chosen for themselves.

The location is a ground hornbill hotspot – that is, a place where they were frequently seen by our Guides and Trackers, but with no known nests nearby. It’s the latest in a series of artificial nests that have made a major contribution to the breeding success of ground hornbills in the Greater Kruger.

The APNR researchers are currently monitoring 26 nests in the Greater Kruger – of these, only 2 are natural, with the rest being artificial. That shows just how scarce potential sites are, and how important these nesting boxes have become. The fact that the ground hornbills have completely accepted them as part of their world is shown by the fact that 109 of the last 139 ground hornbill chicks that have been successfully fledged, have come from artificial nests.

It takes a flock

Ground hornbills breed at a very slow rate – another fact which helps explain how rare they have become. They do not mature until they are 10 years old, and then they form monogamous pairs for life. Also, they don’t breed every year – in the Greater Kruger, the average is only once every nine years for each pair.

By providing artificial nests in private reserves, the APNR project has seen ground hornbills in these areas breed every three years on average. That’s a dramatic improvement.

Ground hornbills practice what is called cooperative breeding – that is, the alpha male and female are typically assisted by one or two other ground hornbills with important tasks like finding food for the chicks.

These ‘helpers’ are usually immature birds from previous years – you can distinguish them from the adult by the colour of the skin on their throats and around their eyes. In the adults, it’s a vivid red; in youngsters, a sort of dirty yellow.

Get involved

Next time you’re on safari at Royal Malewane, keep an eye out for these very special birds, and ask your Guide to point out some of the artificial nests to you. You can also learn more about the APNR Ground Hornbill Project by spending a day in the field with the researchers, or by visiting our new Conservation and Research Centre.