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The recovery of a dead bird

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One of the most important parts of this study is the end of the life of a kite. Survival and causes of mortality are some of the main focuses.  To find out if one of our tagged birds died, every third day we check all the loggers that we have flying around. The GPS positions send by SMS tell us if a bird is still moving or not. Additional information on temperature and activity make it a bit easier to assess if a bird is still alive.  On the 8th of January it was my turn to 'check the birds'. A very interesting thing to do because you really get an insight in the movement patterns of the kites, who's migrating and in which direction? Who’s all day long in its territory and who goes to a communal roost? and of course; are there any birds that died? Which was the case this time, an adult female with transmitter SWIK40. On the 4th of January it woke up at a communal roost, 9,5 km from it's territory where it usually spend the days. At 6 o-clock the transmitters tempera...

The first adult breeding bird that left the country

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Kiws39 is a female kite that was caught on the 20th of June last year at her nest. Two chicks fledged. One got predated by a goshawk around the 20th of August, the logger of the other chick stopped sending points on the 4th of August (Probably logger failure). This female is at the moment of writing the only bird (out of 45 tagged adult breeding birds) that is not in her territory in Switzerland anymore. On the 15th of October she started her migration and arrived on the 3rd of November in Southern Spain between Sevilla and Malaga. The route that Kiws 39 made to get to her overwintering ground. She left the 15th of October and arrived the 3rd of November at the place where she is stationary now.   Kiws 39 bringing a complete cheese to the nest. The straws that come together with it, reveals that the cheese comes from one of the typical dung heaps that most farmers have here. Next to cow dung, there are often food rests dumped on those heaps, making them popular spots...

Another youngster settled down, but still hangs out with friends during the nights..

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Swik38 is a male bird, born in 2015 that seemed to have settled a territory rather far from his natal home range, about 50 kilometers North East.  Today I went to look him up. I arrived around 15pm and immediately heard two birds calling, the tagged bird and another adult, both were sitting in a treetop. So it looks like Swik38 formed a pair already.  Swik38 on the right and its pressumed female on the left, both calling in each others intervals. The bird on the left still had a very dark, contrasting bill which probably makes it a younger bird, Swik38 already got a bit a greyish, less contrasting bill. digiscoped with the phone, 30-10-2017. Swik38 showing some curiosity towards this guy with the camera, standing in the meadow.. 30-10-2017. The upper parts of the third calendar year bird, S1,2 and 3 on the left look old as well as S2 on the right wing. 30-10-2017. I observed the situating for about 2   hours, both birds flew around a bit and ...

Where to settle a territory as a youngster

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How a young male adult (SWIK46), born, raised and tagged in 2015, settled a territory. Swik46 sitting on a fence post, while calling when black crows and other kites come close. This is the place with the most GPS points on the map. The couple of meadows around this fence must provide the kite with most of its food, probably voles and earthworms. Note the dark, contrasting bill which is typical for a younger bird. 29-10-2017, Switzerland FR. Of the 44 nestlings tagged in 2015, about 19 are still alive, of those, 5 birds settled a territory of which two (both females) build nests this year, of which one laid eggs but failed to breed successfully. Although our Red Kites are (partial) migrants, settling and defending territories is a process that seems to continue in autumn and winter. The male on the picture above, now in its third calendar year, settled his territory, which is obvious when looking at his movement pattern of the last month (October). The movement of Swik46 in...

Starting a blog about my work in Switzerland

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Two adult Red Kites photographed at a feeding site, Milken, 18-4-2017. Since January 2016 I’m working in a huge research project on Red Kites, Milvus milvus in central Switzerland. At the moment of writing, we've equipped about 340 birds with GSM-UHF gps tags, about 60 adults, the rest all as nestlings. We also do experiments as local supplementary feeding and several surveys, like a raptor density survey and a rodent survey. In the breeding seasons of 2016-’17 we followed about 90 kite nests with camera traps, resulting in more than 4.5 million pictures of red kites family life. Next to the academic studies that are done with this data, there are also a lot of very interesting ‘small’ things happening.   In this blog I will try to show some of these interesting observations I do in the field and behind the computer, while following this stunning bird of prey.