Wednesday, January 28, 2015

Food scraps and road kill bring a raptor back from the brink of extinction!

The Red Kite (Milvus milvus) is a scavenging species that once thrived in the UK but numbers plummeted, ironically, when the UK cleaned up. Unfortunately, as conditions became more sanitary, there were fewer food sources for these birds. Combine that with fewer trees in expanding urban areas - the population crashed to near extinction.

Red kite standing in snow

Now the species is making a rebound. How so? Trees are maturing and become nesting sites and people are feeding them. These aren't bird feeders like you and I might have. A great paper by Orros and Fellowes in Ibis describe a great study where they surveyed people about feeding them and did surveys of roadkill. 

There's about 16 g roadkill/km/day. Sounds like a lot but that's a mouse or two. Garden feeding was much greater at 23 g meat+ nonmeat scraps/km/day. They discuss competition with foxes and rats but not increasing the population with those two organisms, which might have negative consequences for other birds (through nest predation) and human health. 

I wonder if this is a synanthropic species - adapted to humans - but at an earlier time when we flung our crap out the windows. 

There are a number of videos of Red Kites out there but I like how this shows the high densities you can get as well as their agility. They don't stop to eat!

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