Window Watcher

A Southern Yellow-billed Hornbill pauses at the window at KwaMbili, Thornybush - close enough for every movement of that bright yellow eye to register through the glass.

Tok. Tok. Tok.

The sound was coming from behind the drawn curtain.

I was back in my room at KwaMbili in Thornybush, getting ready for dinner in the boma. The late-afternoon warmth was still hanging in the air, but the winter light had begun to fade. At that time of year in the Lowveld the change can be quick. One moment there is still warmth coming off the bush; not long afterwards, a cool edge slips into the evening and the temperature begins to fall.

Then I heard it again.

Tok. Tok. Tok.

It wasn't loud, but it was deliberate. I stopped what I was doing and listened. In the Greater Kruger, an unexplained sound immediately outside your room usually deserves a little attention.

I crossed the room and pulled back the curtain.

A huge yellow eye stared straight at me.

For a second or two I simply stood there. A Southern Yellow-billed Hornbill was perched on the narrow ledge outside the window, separated from me by little more than a sheet of glass. At that distance its head seemed almost exaggerated: fine grey feathers, bare reddish skin around the eye, and that magnificent curved yellow bill reaching forward in a sweep that appeared almost too large for the bird carrying it.

The surprise seemed entirely one-sided.

The hornbill didn't fly. It hardly seemed bothered by me at all. Instead, it watched.

I moved slightly across the room and that bright eye shifted with me. When I moved back towards the window, it followed again. Its attention wasn't fixed entirely on me - another bird somewhere nearby occasionally drew its gaze - but there was a wonderfully calm, deliberate quality to the way it observed everything happening on my side of the glass.

I was amused, and rather pleased to see it.

Southern Yellow-billed Hornbills have always been among my favourite birds. There is something almost caricatured about their proportions: the oversized bill, the bright enquiring eye and the purposeful way they carry themselves. Disney-like is perhaps the best description I can give it. They somehow manage to look both serious and faintly comical at the same time.

I had photographed them before, but never like this.

On game drives I usually find hornbills considerably less accommodating. You see one perched beautifully ahead of the vehicle, begin working out the photograph, and quite often it decides that this is precisely the moment to leave. On foot they normally keep their own comfortable distance as well.

And although I have stayed at quite a number of camps across the Greater Kruger, I couldn't remember ever finding a Yellow-billed Hornbill sitting outside my room, never mind one knocking on the window.

My camera was still packed in its bag beside the glass. I reached down for it, half expecting that movement to end the encounter. The hornbill remained where it was, calmly following some of my movements while I took the camera out.

I raised it and began to focus on the eye.

The hornbill gave one enormous blink.

For a fraction of a second that brilliant yellow eye disappeared. Then it opened again, bright and watchful. It was such a tiny movement, but from little more than arm's length away it seemed huge. I remember smiling behind the camera.

Then I began photographing.

The remaining light was soft and low. Most of the natural evening light was disappearing behind the bird, while a gentler glow from the patio caught the side of its face and bill. The glass wasn't helping. Reflections creep in, contrast softens and fine detail can disappear when you photograph through a window, particularly as the light inside and outside begins to differ.

But I wasn't about to disturb the bird simply to make the photograph easier.

So I worked through the glass.

What interested me most was the eye. The scene was already subdued and I allowed the darker parts of the frame to fall away, leaving the face, the yellow sweep of the bill and that intensely alert eye to carry the photograph.

For the next few minutes the hornbill remained almost ridiculously comfortable on its ledge.

Its attention kept shifting. It looked towards the other bird, back towards me, and occasionally towards the window itself. Then came the tapping again.

Tok. Tok.

At first I wondered whether the glass itself might explain what I was watching. Birds sometimes react to their reflections in windows, interpreting the reflected bird as another individual. Perhaps the tapping had something to do with that.

But there was no obvious aggression. The hornbill seemed more enquiring than confrontational, and something I learnt later that evening offered another possibility.

Eventually it flew off, only to return a little later. On one of those visits another hornbill arrived with it. The difference between the two birds was immediately noticeable. The newcomer saw me and became wary, lingering only briefly before deciding it wanted nothing more to do with the man behind the window.

My original visitor was far more composed.

It stayed a little longer, gave one or two short calls and then disappeared again into the gathering evening.

I closed the curtain and finished getting ready for dinner.

Before going through to the boma, I stopped at KwaMbili's little wooden bar. It is an intimate, old colonial-style space, with small stools, photographs and books tucked around it. Neil, our guide, was sitting there, and I told him about the strange visitor to my room.

He wasn't particularly surprised.

Neil explained that some of the Yellow-billed Hornbills around camp had become accustomed to people. More interestingly, he said that the window-tapping behaviour had been seen before. On another occasion, when guides had been staying at KwaMbili for training, a hornbill had apparently appeared at the same room and behaved in much the same way.

The guides suspected that somebody, at some stage, had rewarded the birds with food.

A tap on the window. A person appears. Occasionally, perhaps, something edible follows.

Neil's advice was equally uncomplicated: don't feed them.

I hadn't, and wouldn't.

The natural history of the species makes the possibility of opportunism quite believable. The IUCN Hornbill Specialist Group describes Southern Yellow-billed Hornbills as largely ground-foraging birds, feeding heavily on ants and termites during the dry season but also taking beetles, grasshoppers, caterpillars, centipedes, scorpions and, when available, fruit and seeds. They are generally resident, often occurring in pairs or small family groups, and in many areas remain within the same home range throughout the year.

That made the appearance of the second bird, and the return visits, a little less mysterious. It didn't explain the knocking.

There is another distinction worth making here.

An animal can become accustomed to people without being fed by them. Repeated exposure to humans who pose no obvious threat can reduce its normal wariness. Interestingly, this has even appeared in research on this species. Tanja van de Ven, whose doctoral work focused on Southern Yellow-billed Hornbills, described males in her Kalahari study population as semi-habituated — sufficiently comfortable with the researchers for close behavioural observations to be made. She and Andrew McKechnie are among the Southern Yellow-billed Hornbill researchers associated with the IUCN Hornbill Specialist Group.

That does not mean those research birds were being fed, nor does it prove what was happening at my window. Quite the opposite: it helps separate two things that can easily become confused.

A wild bird can learn that people are harmless.

It can also learn that people are useful.

Food conditioning goes a step beyond simple tolerance. An animal begins associating people, particular places or even particular actions with the possibility of food. From my few minutes with this hornbill I couldn't prove that had happened, but Neil's account made it increasingly difficult to ignore.

There was another small piece of evidence the following morning.

The hornbills came back.

This time there was no window between us. I found them around the patio, sitting only a few metres away, and again they seemed unusually interested in me. A third bird appeared briefly as well. I spent some time photographing them and watching them move around before they eventually disappeared.

After that I didn't see them again.

Perhaps the original bird had also been intrigued by its reflection. Perhaps familiarity with people explained part of its confidence. But after hearing that similar window-tapping had been observed before, and then finding the birds close to me again the following morning, I thought food was the more likely explanation.

I still wouldn't call the bird tame.

There was too much alertness in it for that. It noticed my movements, kept track of the other hornbill and could leave whenever it chose. The second bird's immediate caution was a useful reminder of the response I was more accustomed to seeing.

But something in the usual distance between us appeared to have changed.

The wider research around this familiar species gives that idea of change an interesting context. Southern Yellow-billed Hornbills are currently assessed as Least Concern, although BirdLife records their population trend as decreasing. And researchers studying a Kalahari population between 2008 and 2019 have shown how dramatically changing environmental conditions can affect them. In research, such as that recently done by Frontiers, comparing the first three seasons of the study with the final three, occupancy of available nest boxes fell from 52 per cent to 12 per cent, while the proportion of breeding attempts successfully fledging at least one chick dropped from 58 per cent to 17 per cent. High temperatures and drought were strongly associated with that collapse in breeding performance.

That research concerns heat and breeding, not hornbills tapping on safari-lodge windows, and I don't think the two should be confused. What it does show is that a bird we often regard as common, familiar and adaptable is still responding continuously to the conditions around it.

Some of those conditions are natural. Increasingly, some are created by us.

Which brought me back to the bird outside my room.

The question was no longer simply why a hornbill had knocked on my window. It was what changes when animals living around camps learn that people can be a source of food.

At first the exchange can seem wonderfully harmless. A bird comes closer. Someone gets an extraordinary view. A guest offers a small piece of food and, for a moment, the normal barrier between human and wild animal seems to disappear.

But the animal is learning from the exchange as well.

SANParks prohibits the feeding of wildlife for precisely that reason. Its current regulations warn that feeding can cause animals to become dependent on people and, in some species, increasingly aggressive or dangerous. SANParks has separately cautioned that feeding itself can contribute to habituation. A hornbill is obviously not a baboon, hyena or leopard, and the consequences should not be exaggerated, but the underlying principle is difficult to dismiss: repeated human behaviour can begin shaping wildlife behaviour in return.

What made that slightly uncomfortable thought interesting was how much I had enjoyed the encounter.

I loved having the hornbill there. I loved its confidence, the absurdly oversized bill, the way the eye shifted as I moved around the room, and that wonderful, exaggerated blink just as the camera found focus. For a photographer it was a gift — unexpected, intimate and over within minutes.

It also said something about where photographs come from.

Wildlife photography is often associated with the search. We leave before sunrise, follow tracks, scan distant branches, sit beside waterholes and drive slowly through the bush looking for the slightest movement. There is skill and patience in all of that, and many of my photographs have come from exactly those circumstances.

But the bush doesn't stop because the game drive has ended.

Animals move through camps. Birds land on roofs and railings. Something rustles beyond a walkway while you're heading to dinner. A strange sound comes from behind a closed curtain.

Sometimes the camera is zipped away and you're halfway through getting ready for the evening when something begins tapping against the glass.

That afternoon I hadn't gone looking for a Yellow-billed Hornbill.

It had appeared at my window.

And the following morning, when I found those same bright eyes watching again from only a few metres away, there was no glass between us at all.