Colony Skurup
Photographs and text by Jan Holmgren
Skurup is situated about 10 km from the south coast of Sweden.
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I opened the colony, with 16 holes in the gable, on 24 June 1990. It is in the centre of the area where I have studied Common Swifts roosting in the foliage of trees since 1982.
Newly fledged Common Swifts migrate southwards (towards Africa) on their own, mostly without the company of adult birds. In August, some of them choose to roost during the night in the foliage of trees, or on high masts, like the one in the left picture. Now, I have seen 63 swifts roost in trees, and 63 swifts roost on the mast. Those roosting on the mast are easiest to observe, since they often have to make numerous fly-ins towards the mast before they succeed to perch. Perhaps, some of them may have travelled far, from Finland, or even from Russia.
The 16 nest boxes can be inspected from the inside. In 1999, Common Swifts nested in the boxes B12, B14, and B16. One pair got established in B13, but too late to lay eggs. When Common Swifts are established as nesting birds, they normally return to the same nest as long as they live.
The first swift entered box 4 on 28 July 1990. In 1991 two swifts were close to get established in B14 or B15. However, one of them managed to get into the attic, and I had to catch and release it. After that, both swifts disappeared. In 1992 one pair had 2 eggs in B12, but the eggs did not hatch. Since then, young have been raised as follows; 1993: 2 young in B12, 1994: 2 eggs in B12 never hatched, 1995 2 young in B12, 1996: 2 young in B12, 1997: 3 young in B12, 1998: 1 young in B12, 1999: 2 young in B12, 2 young in B14, 2 young in B16, 2000:2 young in B12, 2 young in B13, 2 young in B14, 2 young in B16.
Two young Common Swifts, about 30 days old, in B14 1999.
One adult and one young Common Swift in B16.
Phenological and breeding dates of Common Swifts at a colony in Skurup (55,4°N 13,5°E) Sweden 12.02.2006 © Jan Holmgren
Dates in parentheses have not been verified
|
Year |
Box nr |
Arrival of 1st bird in Skurup |
Arrival of 1st adult on nest |
First egg |
Start of incubation |
Hatching |
Departure of 1st chick |
Departure of last adult |
Actual duration of adults’ stay on nest |
Actual duration of brooding until 1st chick hatched (hatch day not counted) |
Actual duration of 1st chick stay in nest (departure day counted) |
Remarks (within parentheses: time from start of brooding to departure of first chick, departure day counted) |
|
1992 |
B12 |
14.05 |
28.05 |
17.06 |
19.06 |
failed |
|
(05.08) |
(70) |
|
|
|
|
1993 |
B12 |
08.05 |
11.05 |
(10.06) |
12.06 |
(02.07) |
(12.08) |
16.08 |
98 |
(21) |
(41) |
(62) |
|
1994 |
B12 |
08.05 |
15.05 |
(01.06) |
03.06 |
failed |
|
(01.08) |
(79) |
|
|
|
|
1995 |
B12 |
04.05 |
18.05 |
03.06 |
05.06 |
(23.06) |
01.08 |
09.08 |
84 |
(19) |
(39) |
(58) |
|
1996 |
B12 |
18.05 |
18.05 |
07.06 |
(11.06) |
|
08.08 |
18.08 |
93 |
|
|
(59) |
|
1997 |
B12 |
14.05 |
25.05 |
(09.06) |
(13.06) |
|
08.08 |
15.08 |
83 |
|
|
(57) |
|
1998 |
B12 |
17.05 |
28.05 |
09.06 |
(11.06) |
|
11.08 |
21.08 |
86 |
|
|
(62) |
|
1999 |
B12 |
13.05 |
24.05 |
|
|
|
01.08 |
14.08 |
83 |
|
|
|
|
B14 |
01.06 |
|
|
|
26.08 |
28.08 |
89 |
|
|
|
||
|
B16 |
29.05 |
|
|
|
10.08 |
15.08 |
79 |
|
|
|
||
|
2000 |
B12 |
16.05 |
19.05 |
|
|
|
01.08 |
17.08 |
91 |
|
|
|
|
B13 |
|
13.06 |
(15.06) |
|
13.08 |
|
|
|
|
(60) |
||
|
B14 |
|
13.06 |
(15.06) |
|
15.08 |
19.08 |
|
|
|
(62) |
||
|
B16 |
|
|
|
|
13.08 |
|
|
|
|
|
||
|
2001 |
B12 |
12.05 |
18.05 |
(30.05) |
(03.06) |
|
|
|
|
|
|
|
|
B13 |
15.05 |
(28.05) |
01.06 |
|
|
|
|
|
|
|
||
|
B14 |
22.05 |
17.06 |
(19.06) |
|
19.08 |
20.08 |
91 |
|
|
(62) |
||
|
B16 |
28.05 |
13.06 |
(15.06) |
|
|
|
|
|
|
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|
2002 |
B3 |
13.05 |
11.06 |
25.06 |
27.06 |
|
28.08 |
|
|
|
|
(63) |
|
B12 |
17.05 |
27.05 |
31.05 |
|
28.07 |
(04.08) |
(80) |
|
|
(59); parents deserted after ringing |
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|
B13 |
13.05 |
23.05 |
27.05 |
|
25.07 |
(30.07) |
(79) |
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(60); parents deserted after ringing |
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B14 |
23.05 |