LINKED PAPER | OPEN ACCESS
Widespread supplementary feeding in domestic gardens explains the return of reintroduced Red Kites Milvus milvus to an urban area.
Melanie E. Orros & Mark D.E. Fellowes.
IBIS. DOI: 10.1111/ibi.12237
Red Kites were once such urbanites that London was ‘the city of kites and crows’ (Shakespeare’s Coriolanus). Lacking modern sanitation, the streets provided rich pickings for an unfussy scavenger. Yet, although kites have now been reintroduced across the UK, our far cleaner towns and cities weren’t expected to appeal. So why are hundreds now visiting Reading?
I wasn’t supposed to be working on Red Kites. My PhD was on the effects of feeding more ‘typical’ UK garden birds but a passing comment by my supervisor, Mark Fellowes, turned into two chapters of my thesis. Mark had noticed that he saw far more Red Kites once he got into the urban parts of Reading than on the rest of his morning commute through the southern English countryside. This seemed strange – although not too far from the site of the highly successful Chilterns reintroduction of 25 years ago, Reading is a large, built-up town whose wider urban sprawl covers some 100 km2. It has no substantial kite roosts and just a handful of nest sites (Bucknell et al. 2013; Balmer et al. 2013), and, given that kites are predominantly scavengers, at first sight relatively few sources of food.
We got to chatting about the kites’ behaviour in the town – drive along some of the roads close to the main university campus and you’ll see them circling low over gardens as if searching for their next meal, occasionally swooping out of sight behind a fence. Kites are not fussy eaters and we assumed that they had spotted a likely food item, perhaps put out deliberately. We knew that villagers close to the Chilterns reintroduction had fed kites since the early days of the release but could not find any information for urban areas. Did many people really do the same in such a built-up environment as Reading?
Our interest piqued, we decided to find out. After all, it wouldn’t take long and I could add the number of kite feeders into a study I was doing about local garden bird-feeding habits. A team of students diligently stood outside local supermarkets and asked 500 people questions about kites, including whether or not they fed them (see the paper for full protocol and measures against bias). We were taken aback that so many (4.5%) said yes – to the extent that we repeated the questionnaire 6 months later (so much for a quick result). We found the same again. Kites were being offered food in well over 4,000 gardens across Reading and the surrounding suburban area. A further ‘sense-check’ in a Chilterns village closer to the reintroduction site found an even higher percentage of kite feeders, 13% (unpublished data).
I had the data for my study but we could not leave it there. Could this high number of households actually be the main reason behind Mark’s commuting observations? My thesis changed course and we launched a series of projects to try and answer our outstanding questions. Were kites actually spending more time around gardens than elsewhere? Was it food deliberately put out by people or other urban meals that were the main draw? After all, their Medieval predecessors used to feed in huge numbers on the waste on city streets – road-kill or discarded food might have similar importance to today’s urban kites.
The answer to the first question was yes – driving set routes across Reading, we saw more kites in residential areas than anywhere else. To answer the second, we needed to know not only what other potential foods were out there but also how the amounts compared with what was on offer in gardens.
Surveys of Reading’s streets recording every item that a kite might eat revealed only enough to feed up to 29 kites a day and that was assuming that no other scavenger or street cleaner found it first, that the same amount of potential foods turned up every day and that everything seen could indeed be eaten by kites. Somewhere in the low hundreds of kites are thought to visit Reading each day – it seemed that street food was not what they were coming for.
This brought us back to garden feeding. However, although we knew by now that lots of people fed kites, we had no idea of how much food they gave. Time for another questionnaire. Intending to target only kite feeders, we went online and spread the word as much as we could. The results not only gave us lots of useful information about how and why kites are fed, but allowed us to estimate how much food was actually being taken by kites each day (see Orros & Fellowes, 2014, for more details). At the level of individual gardens, this turned out not to be a huge amount – on average a kite would need to visit between 4 and 9 gardens offering food each day in order to get a full day’s meal (differences due to different estimates of kites’ daily energy needs). Further, we estimated that on any given day only just over 1 in 4 of those who feed kites actually put food out for them. However, so many people feed kites in Reading that this means somewhere between around 140 and 320 kites could get all of the food they need each day – in fact, as no-one has yet shown 100% dependency of any bird species on supplementary food, it is likely that an even higher number of kites get some support in this way.
Over two years after Mark first made his early-morning musings, we had an explanation. Of course, as tends to be the way, there are now far more questions to answer. I hope that some of you reading our work will be up for the challenges ahead.
References and further reading
Balmer, D., Gillings, S., Caffrey, B., Swann, B., Downie, I., & Fuller, R. 2013. Bird Atlas 2007-11: The Breeding and Wintering Birds of Britain and Ireland. BTO, Thetford, UK. More details.
Bucknell, N., Clews, B., Righelato, R., & Robinson, C. (2013). The Birds of Berkshire Atlas and Avifauna. Reading, UK. The Birds of Berkshire Atlas Group. More details.
Carter, I. 2007. The Red Kite. 2nd ed. Arlequin Press, Shrewsbury, UK.
Orros, M.E. 2013. Characterisation and ecological effects of garden bird feeding. PhD thesis. University of Reading, UK. View abstract
Orros, M.E, & Fellowes, M.D.E. 2014. Supplementary feeding of the reintroduced Red Kite Milvus milvus in UK gardens. Bird Study 61: 260−263. View.