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An Eleonora’s Falcon saga

The Eleonora’s Falcon is the largest of the hobby group (a sub-genus formerly called Hypotriorchis) nesting in loose colonies on cliffs overlooking the Mediterranean Sea with scattered groups on the Canary Islands and Western Moroccan sea cliffs. Like its close, but smaller and faster relative the Sooty Falcon, the Eleonora's times its breeding and migrations to coincide with the passage of exhausted small migrant birds. As soon as those migrants pass through the falcon young must trail their parents, presumably following the migrant birds into Africa. Somewhere south of the Sahara insects, such as flying termite alates, scarab beetles, mole crickets, grasshoppers and dragonflies, and small seed-eating birds that all emerge from seemingly nowhere at the onset of the rains, become their staple. They fly into Tanzania through Kenya and then make the ocean crossing to Madagascar along with the Sooty Falcons.

Illustration by Simon Thomsett of two adults feeding a chick overlooking the Mediterranean and two adults flying in the distance. Some Eleonora’s are black, others dark morphs and others very Hobby-like. The outside toe is unique in being as long as the middle toe and has two large round protuberances. While the cere, eye ring, lip and feet of an adult male turn from bluish to yellow, adult females retain a bluish cere, eye ring and lip though their feet are yellow.


Eleonara's are lithe, long winged falcons with exceptional ability to fly long and gracefully for hundreds of kilometres a day. They often fly during thunderstorms with other small migrant falcons, all eating that sudden and brief excess of easily caught food. Then they are gone. I have seen them hunting bats, unsuccessfully chasing swallows and seen them along with Sooty falcons at dusk catching Red-billed Quelea as they roost or nest in their millions. They eat locusts too, and note that both Quelea and locusts get poisoned in their millions and the impact on raptors must be significant if persistently overlooked. I’ve been lucky enough to see them with Sooty Falcons (and once with a Bat Hawk, both chasing bats) in Madagascar. Curiously I have also seen them hunting bats, with Bat Hawks in Langata near Nairobi many years ago.


On the 9th of December 2022 we got a call from Alfred Koech of the Peregrine Fund who had in turn received a number of messages from people in Tinderet (north western highland Kenya) about a falcon with huge rings on it. We got images, shocking images of it being man-handled in a very bad way and looking near death. I will quote Alfred’s message so as to make clear the harmful curiosity that rings and marked birds receive from so many people and the fact that a number of people intervened and saved its life. It became almost viral being posted on all sorts of social media, and this doesn’t do the bird much favour and many conflicting opinions can combine to make rescue of ringed birds difficult.

Right: the falcon being pulled about and in a state of shock that can rapidly proceed to death. Left: notice how big the rings are and how much curiosity they got.


Message from Alfred Koech:

The bird fought with a Black Sparrowhawk, it was tired and exhausted and seeked refuge in Daniel Ruto’s compound. Children got excited with the bird which had rings and called the father. The father upon reaching home found many people who wanted to kill it as they saw the bird as demonic. Others wanted to chop its legs off to go with the rings since they thought it to be gold. It took the courage of Daniel Ruto to call the area chief to chip in and contain the situation…hundreds of people flocked into his compound with different motives, that’s when the chief contacted KWS warden and Kapsabet and the warden called me.

It turned out that the falcon was ringed as a nestling off the Spanish coast in Sept 2022.


Nick Trent and I flew up the moment we got KWS permission and landed in a tea estate among precipitous valleys still cloaked in indigenous, though obviously much degraded, forest. After some delay at the airfield being surrounded by hundreds of overly curious people we met Gilbert Yego who handed us the bird in a box and we returned home to give the exhausted falcon fluids, food and a check up. It had puncture wounds under the arm and drying blood, was thin and had a few crushed feathers but was otherwise OK. OK except for its ragged feathers that looked weather beaten and frayed, offering only some 60% of its “sail” area - the usable cm2 of surface area needed to fly. This falcon stood no chance and will have to moult before release. The question was why was it so obviously stressed and in poor condition? Those rings, the ones that had created all the excitement and the wish of some to chop off its legs, could easily be a contributing factor. We don’t exclude the possibility that the Sahara/Sahel crossing is more hostile today than previously recorded. Desert temperatures are at an all time high. Last year we had hundreds of records of dying European Rollers and many small falcons. But add large rings to an increasing environmental problem and you have higher risks.

Right: the falcon at Soysambu Raptor Centre, sitting happily on the hand, well fed and on its way to recovery. We took off the big rings and before release we will put on a single Kenya accepted size ring. Left: the wings show how moth eaten the feathers are and the emerging fresh feathers must all be moulted out before she can fly again. Her release depends upon the quality of these flight feathers and she will be vigorously exercised to the lure before we attempt it.


Weighing up scientific data vs life quality

Having assisted raptor biologists for many years, some of my colleagues and I have come to doubt that large colour rings, large permanent backpacks and wing tagging especially, have a positive contribution to conservation in our part of the world. We know a great deal already, sufficient to launch multiple conservation actions, without having to delay things because a fresh academic student or scientific institution wishes to redefine the quality of the data with new tracking technology. So far higher resolution of movement data = larger size burdens to carry. We are told that better knowledge of movements is supposed to translate to increased chances of survival for the species but this is not a proportional correlation. There is a compromise between getting crucial data and compromising the individuals’ lives, the quality of their lives, health, reproductive success, ability to defend territories, etc..


These tags are physical burdens whether one likes it or not, things that require carrying and when you are a high performance small bird taking on any extra burden has a life-change cost. Common sense dictates that it must do. The fact that the data received back from the study may not fully support these concerns may be a facet of an understandable protection of the project, conflict of interest, self-persuasive biases and even competition within the scientific circles resulting in an extra pressure to publish to get funding. Or more simply they may result in slight imperceptible changes that make broad studies incapable of detecting subtle behavioural compensation changes at individual level. Yet to others in other disciplines, specifically those who handle, rehab, veterinary treat, fly them or watch them very closely, it is all too obvious and a de facto consequence.


How to measure or quantify these risks individually or as an accumulative is an important question. Fresh foreign students when challenged to account for this risk inform us that “these tags are the necessary price the individuals have to pay in order to make strategic plans to save the species”. It’s the standard response, repeated from innumerable previous studies and yet it has a veiled confession.


We have to recognise that their stock summary may apply in their home countries, but it does not hold up in our region, where to date, no science has had any tangible effect on promotion of conservation actions for raptors, let alone any measurable result in a species’ revival. This is not the fault of the science so much as the follow up systems. Poorly placed developments, lethal infrastructures, poisoning, massive avian eradication projects go ahead despite what science and movement data has informed us. Perhaps if the science was able to be used to inform decisions and it was encouraged, facilitated and financially enabled to implement conservation actions we’d be more cooperative. If we could implement conservation actions commonly used by the public in the western world with less endangered species and (in some cases) with less supportive data, our attitude to the preliminary science may change, but not before then. In Kenya, we have a very different ethos in which all wildlife has equal protection rights and this permeates into studies made upon them and ultimately what we can do to actively conserve them. We’re different that way, and as a result we have developed a few innovative less intrusive methods and it’s interesting to see some overseas biologists follow some of our ideas in their home countries.


A relatively new idea is to have colour coded rings and/or letters so big you can see them from a distance. Good citizens espying these numbers through expensive binoculars or prime lens cameras report these numbers, and so more records build up a larger database than previous rings that needed to be read in the hand. But these rings must be big and gaudy and carry a greater risk than small rings.


Rings are a tradition going back to King Solomon’s time when he ringed a Hoopoe (with which, despite being an ardent fellow with 1000 wives, he sent a message of love to the Queen of Sheba). It is invaluable and has formed the basis of what we know about bird movements and it is poignant to know that for the majority of ringed birds it is almost entirely done for free by very skilled ringers who police themselves. But there are good and bad rings and now clod hopping massive coloured rings on tiny birds with numbers that are supposed to be read at 100m or more. Those with a background stemming from rehab care and falconry would not allow anything close to these new rings. We are not alone in taking the moral high ground because there’s a common sense aspect that many agree upon, including many within the scientific community. Let me rephrase the criticism on the large coloured numbered rings, for it depends on the size of the bird you put them on. An eagle can carry a billboard compared to a sparrow that cannot. There’s a cut off size in which big rings (or backpacks and wing tags) really do start to harm the bird. There’s a difference in lifestyles, hunting strategies, territory size (migration across half the planet) that also must be factored into a decision on what is an acceptable burden. Again we are not alone in this. E.G. Dixon et al 2016., in reference to Vandenabeele et a., regarding maximum weights raptors can carry on backpacks gave the following observation:

“When determining the potential impact of harness-mounted tags, many researchers rely on an arbitrary ‘maximum mass’ that can be deployed, usually expressed as percentage of body weight, for example, 2–3% (Fuller et al. 2005) or 5% (Cochran 1980). This simple assessment fails to take into account differences in the life history of the study species (such as the time birds spend airborne), the age of the individuals tagged, the size/shape of transmitters, the effect on drag or the method of attachment.

This is in reference to backpacks and not to rings, but the discrepancy between what is acceptable and unacceptable between individual researchers remains the same. Not mentioned is the very real danger of mortality due to human persecution, whether intended or not, of those birds retained by the public if they are found to be carrying a ring or tag.


Here’s where the debate starts and people can have strong differing opinions. During one torrid debate about tagging small migratory falcons some people suggested to put ankle collars and 15kg permanently attached back packs on their colleagues who did the same to birds and things got out of hand. So the issue is not confined to here, it’s a serious matter elsewhere.


One rationale used is that “there is insufficient evidence to say that these harm the birds” or “We have seen most of the birds return each year and breed”. One guess as to who says this? Is it the biologist keen on data, or those that care about the welfare of the bird itself? If you guessed right then there is something amiss. One errs to caution; the other does not.


A tiny leg, in the case of this Eleonora’s falcon exactly 4.9mm across at its centre, is just a bit bigger than a match stick head and it isn’t going to be able to carry a ring with a number that you can read from 5m. So forget about it. Hard headed opponents would argue that modern prime long lens cameras could read a number at 150m but in Africa, this equipment and those that aim them at raptors is as rare as dragon teeth outside the most popular of our national parks and reserves. And there comes a time when the slight increase in “returns” is outweighed by the extra stress on the bird. The attitude of those that wish to kill birds when they find them with rings, or keep them until some recompense is given, is not unusual in our region and it is a sad fact that death of birds with rings is a common sequel. That needs consideration by those who do put large rings on birds.

This photo came in around the same time. The outside tail feathers appeared to differ from the one we received and this bird was said to have died. It is being handled like a dead bird and the person who stated it was dead had reason to believe it was. The large PL yellow ring on the left leg would indicate it to be the same bird and it turned out to be so. The bird was very lucky to recover.


Pirates and predators

One of the worst problems isn’t the most obvious one; it is the presence of avian pirates. What biologists call kleptoparasitism (stealing food from others), plagues the daily life of raptors. If seen carrying food by another species they are flown down until they let it go. Because a hawk is compromised by the fact it is carrying something, they tire quicker and give up their prey. They would do anything to avoid a fight because injury can mean death. Occasionally when I was young I would see a wild hawk or falcon, or Tawny eagle especially, fly down one of my trained hawks who carried nothing. Nothing other than short jesses. I’d be on hand to save them of course and I changed to tiny anklets and got rid of bells and transmitters. A biologist would not be on hand to save their birds or change what they did. Remember this Eleonora’s Falcon was caught by a Black Sparrowhawk.


Large burdens compromise natural behaviours, energetics and survival rates so it results in dubious data in the end. Here is where you separate scientists from humans, for if this last argument makes them hesitate and desist it exposes them just as a mirror exposes a vampire.


As if to validate our concerns we were informed that an Eleonora’s Falcon had gone down in the Seychelles - and it had almost exactly the same rings. Tamara Dreyer from Project Paradise Seychelles sent pictures of the falcon being fed and we are trying to help advise them to ensure that the bird gets fit enough for release. Tamara noted that the Seychelles Bird Record Committee has had 53 records for the Eleonora’s which is interesting, but it suggests an off course vagrant visitation, probably accompanied by high mortality and a disorientated return.

Above are photos of the Eleonora’s Falcon at their centre in the Seychelles. Note the rings. Tamara agreed the rings were too big and they will be removed and the falcon will be allowed to recover. There’s the concern that a release in the Seychelles may not actually be that effectual and in an ideal world it should be released with its consorts either in Madagascar, or in our region to follow the normal migration, or back in its nesting grounds off the Spanish coast.

 

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Kenya Bird of Prey Trust

Understand - Protect - Restore

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