The Large Falcons of Tsavo
Tsavo is home to 9 resident falcons and is a very important stop-over for six others on migration. Add that up and it has more falcon species than those found in either the USA, Europe and Australia. Not that it means that much, for numerically the most common are the migrant Eurasian falcons by a factor, sometimes, of thousands to one. While we need to be careful of misleading statistics, Tsavo is a very special place.
The large resident falcons include the African Peregrine, Lanner, Barbary and Taita Falcon. The Taita Falcon (Falco fasciinucha), named after the hills and people that oversee most of the park, is tiny. But now genetics has firmly placed it in the Peregrine clade, and because it behaves as though it is four times its size, it is given the red-carpet “large falcon” status.
Left: A paler than usual Taita Falcon warming up ready for take-off near Mazima Springs Tsavo West. Right: Same Taita Falcon showing large head, feet, chest and short wings.
Some may argue that the Barbary Falcon (Falco peregrinus pelegrinoides or Falco pelegrinoides), now also tucked in tightly with the Peregrine clade, is not deserving of species status, but neither would be the Taita Falcon if one applied the same split-hair logic. Here in Kenya, the Barbary Falcon is the smallest most evolved of all… akin to the Yemen, Oman, Horn of Africa, Somali group. Placed next to a Barbary from Morocco and it’s a very different animal. Place it next to a Peregrine from Haida Gwaii (formerly Queen Charlotte Islands) and it will be eaten, not that it would because that lumbering giant would stand no hope in catching up to it. The Barbary’s flying style, energetics, behavioural biology, habitat and prey preferences and finally but importantly its temperament in captivity, all collude to separate it from the main stock Peregrine. It has been separated for thousands of years, Horus the Egyptian Sun God is a Barbary Falcon perfectly depicted and very different to either a Peregrine or a Lanner (though those not in the know continue to misidentify Horus).
Juvenile Barbary Falcon in Tsavo West. NB thin streaks on a dusty greyish background, thinner malar stripe than Peregrine. Unseen are the pale nuchal patches on the back of the head (sometimes present in juvenile Peregrines too).
While DNA studies have revealed a great deal it has oversimplified things to a point whereby a former genus name, which had a number of closely related species within it…now has to make room for others that clearly belong to their own defined sub-groups. Thankfully falcons themselves have been mostly spared this lumping but other raptors such as many eagles have been thrown into the same pot with no indication of their former sub-genus affiliations. This is beginning to sound geeky so lets leave Linnaeus spinning in his grave and get back to listing the large falcon species found in Tsavo.
The Russian Peregrine (Falco peregrinus calidus) is a long lanky, small toed, pale, big peregrine twice the size of our native F. peregrinus minor and it does visit Tsavo and the Galana especially on its northward migration. In the early 1980s its ratio of encounter with our African Peregrine was some 20 to 1…but now it’s about 1 to 1. Our African Peregrine population has plummeted sufficient for us to up-list it to Endangered even as far back as the late 1980s. Meanwhile the recovery of northern Peregrines occurred, explaining perhaps this ratio change.
Here lies a case-study in conservation bureaucracy, for the down-listing of all Peregrines, thanks to active human intervention in the western world, means that here in Africa (where active intervention is unlikely ever to occur) it is difficult to call international attention to our local situation. Yes we have local regional listings but these cannot hope to address species (and races) that only a few specialists have any insight in. And even if we succeeded in up-listing it, what use is it? Neil Baker, the most informed bird man in Tanzania once dryly noted: “You may as well put it on the stock exchange for that’s about as useful”. Peregrines and peregrine politics and mania remain a controversial and an iconic case-study in raptor conservation. If it keeps us on our toes then well and good.
Left: Kanderi Swamp…Female adult Peregrine waiting for doves and sandgrouse July 2021. She was joined by her mate. This pair nest above KWS HQ Voi. Right: Juvenile Peregrine hunting doves in Tsavo East, July 2021.
The now much rarer Saker Falcon (Falco cherrug) I have not personally seen in Tsavo but it is sure to occur for it has been recorded on the Sabaki. I used to see one every two years or so in Kenya, but over the last fifteen years I have seen one, maybe two. There was one very pale male adult with a cream coloured head that sat on a pylon just set back from lake Elementeita on Soysambu Conservancy in 2016…and again in the following winter. He, and a female Russian Peregrine, would patrol the lake shore creating havoc (a Scandinavian word for “hawk”) among the shore birds. But since then I have not seen him. These falcons are being fried wholesale on powerlines across their Mongolian steppe range by precisely the same lethal powerline configurations we are installing across East Africa. The difference is that they are doing something about stopping it in Mongolia.
The Lanner Falcon (Falco biarmicus), the stalwart of our large falcons in Africa isn’t so persistent as it once was either. In Kenya it occurs in two races: biarmicius and abyssinicus, the former almost spotless on the chest, the later dotted heavily. In practice we have both races and their intergrades. Its population has declined also. Once common and sometimes on absurdly small and accessible Grade C cliffs it has now mostly vanished from these and retreated to massive unreachable Grade A cliffs. Its tree and pylon/transmission mast nesting habit (in corvid nests) was setting a new meme but seems to be cut short with much fewer records today. Grading cliffs is a good way to qualify a gut feeling of what is a good, ok and a poor nesting site. There is no question that increasing numbers of baboons in semi, and fully protected areas have been a major reason for their decline in C graded cliffs. Other “synanthropic” (human tolerate) animals include the Pied Crow, Egyptian Goose and Verreaux’s Eagle Owls…all of whom now vie for the same nesting sites and kill the young of falcons at a rate far higher than ever previously.
An adult female Lanner Falcon…angry! This one I photographed on Soysambu recently, but a pair of adults were at Aruba Dam throughout my stay in July 2021, hunting as predicted, the birds that flight into the waterholes.
Tsavo West is better supplied with kopjes and cliffs of a nature suited to large cliff nesting falcons, while Tsavo East has only a few sites, near Voi and along the Yatta Plateau. The Yatta cliffs are poor quality (C and B cliffs) and do not host many falcons. Kanderi Swamp was and remains a great place to watch hunting falcons as are the other waterholes and boreholes. Here birds fly into the water and the falcons and other raptors line up to hunt them. It is just like watching lions around a water hole waiting for zebra coming to drink. It is guaranteed action.
While I was dimly aware of some order in this procession it was my friend Rob Davies who best described it. He noted at waterholes in the Auob and Nassop riverbeds of the Kalahari Gemsbok National Park that birds of different species would arrive at specific times of the day to drink. Doves for example, would arrive as a contingent of Collared doves or Namaqua doves. Small seed eating birds would arrive all in one go earlier in the day. Sandgrouse would move in when the others left. Each species taking their turn. Down would come the Shikra, Gabar and Red necked falcons for the seed eaters, then in would move the Lanners and Peregrines for the doves and sandgrouse. I have forgotten the sequence in southern Africa but I did see it for myself with Rob and Laila Bahaa el din, who took incredible photographs. It was an unforgettable performance, a three ringed circus that kept us on the edge of our seats for days. Hunt after hunt took place throughout the morning till noon when the heat drove everyone to shade. As there are no other hunts on earth as fast as these and it was repeated 20-50 times in a morning it is sensational by anyone’s standards. Much the same pattern of events occur each day at the Tsavo waterholes. We pity the tourists who only come to watch elephants and lions.
When I arrived at Satao on the 22 July 2021 I saw a tiny falcon clipping its way ceaseless around a large arc and flattening out for a shallow stoop at Namaqua doves. I knew immediate that it was a Taita Falcon, though it was less rusty red than usual. Its speed was incredible. It would dive down in a long flat curve from 2km distance and whip around the waterhole, past elephants and kongoni to climb back up to where it had started. It seemed to gain momentum as would a spaceship slingshot round a planet. After three such circuits it hit a Namaqua dove and flew rapidly to a tree carrying it. I was unable to approach it as it was a long way from the road. I was so excited I had forgotten to reach for my camera. So the evidence for what just happened was over in a micro-second.
An unfinished painting by Simon Thomsett of a pair of Taita Falcons warning an intruder. Maybe a bit too red. NB., the shortish middle toe unexpectedly strong foot with thick tarsus possibly over-emphasised but a feature nevertheless.
The next day we paused for breakfast with David Gulden at a borehole and here we saw a slim falcon plough against a strong wind hunting doves and sandgrouse. I used to have a Barbary Falcon and have seen quite a few wild ones and there is a gut feeling so strong that defines it as opposed to the thicker winged more business-like Peregrine. Barbaries have thin wings, smaller tails, big heads and broad deep chests and they flicker through the sky, whereas our African Peregrine pumps its wings and the Lanner sails buoyantly on flat wings with turned up tips. Perhaps slow motion photography would capture that wing beat but for now I went on gut feeling. It flew like a Barbary. I took some distant photos and on inspection back at Satao Camp it turned into an oddly streaked juvenile Peregrine. Yet the upper tail, shortish tail, thin wing and fairly thin moustache and patchy mottles on the back of the head still hinted at the Barbary Falcon. The photo doesn’t capture the gut feeling though.
The questionable Barbary….no… Peregrine juvenile?
When large falcons were so much more common I used to focus much of my attention on them. Funny thing is that now that they are so much rarer we can’t obsess about something we don’t see. My worry is that today resources and justifications to conserve are being focused only on those species that offer measurable human benefit. Vultures hit the lime light because of this, yet what of those other raptors that are rarer and facing a bleaker future? Has the vulture focus pulled concern away from other species? Are large falcons a luxury that we can do away with in Africa?
Another moral to this story is that no matter how familiar you are with raptors there will always remain individuals that you just can’t identify with absolute certainty. I enjoy mystery and I welcome it as it opens up all sorts of inquiry that include intergrades (hybrids between races), isolated sub-population groups, etc. In the end I’m probably wrong, but it’s the thought theory behind it that makes raptor watching so much more interesting.
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