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First arrivals
Most birdwatchers eagerly await their first Swallow or first Cuckoo of
the year and hope that they will beat their previous early record.
Birdwatchers are fascinated by extremes; their earliest Willow Warbler
date and latest Turtle Dove date have a special place in notebooks.
Most of us just jot down dates in notebooks which never see the
light of day again, whist others are more meticulous. Bird Observatories
are a good example of meticulous note keeping, daily logs are kept
which record not only the first arrival dates in the spring and
late departure dates in the autumn but counts for every day of the
month. These log books are an incredible resource.
| By
looking in detail at these bird observatories log books we can
glean some interesting information. Dick Loxton and Tim Sparks
ploughed through vast amounts of paper to extract arrival dates
at four observatories; Portland, Skokholm, Bardsey and Calf
of Man. The table below shows the average arrival date at each
observatory. For some species there was not enough information
to produce a meaningful average arrival date. |
 |
 |
| Skokholm
Bird Observatory |
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Table:
Average arrival dates of 24 spring migrants at four bird observatories
| Species |
Portland |
Skokholm |
Bardsey
|
Calf
of Man |
| Wheatear |
11
March |
- |
- |
21
March |
| Chiffchaff |
12
Mar |
- |
- |
22
Mar |
| Sand
Martin |
25
March |
1
April |
3
April |
6
April |
| Sandwich
Tern |
27
March |
- |
12
April |
- |
| Ring
Ouzel |
28
March |
31
March |
3
April |
4
April |
| Swallow |
29
March |
5
April |
3
April |
9
April |
| Willow
Warbler |
31
March |
3
April |
2
April |
4
April |
| Blackcap |
31
March |
18
April |
10
April |
21
April |
| Redstart |
5
April |
17
April |
19
April |
19
April |
| Tree
Pipit |
6
April |
25
April |
18
April |
21
April |
| Yellow
Wagtail |
7
April |
25
April |
25
April |
- |
| House
Martin |
8
April |
16
April |
12
April |
22
April |
| Grasshopper
Warbler |
13
April |
21
April |
17
April |
21
April |
| Common
Sandpiper |
15
April |
20
April |
15
April |
27
April |
| Whitethroat |
15
April |
24
April |
24
April |
27
April |
| Sedge
Warbler |
16
April |
24
April |
20
April |
24
April |
| Whinchat |
16
April |
26
April |
26
April |
28
April |
| Cuckoo |
19
April |
3
May |
26
April |
30
April |
| Pied
Flycatcher |
19
April |
- |
28
April |
- |
| Garden
Warbler |
20
April |
5
May |
1
May |
10
May |
| Turtle
Dove |
20
April |
3
May |
4
May |
16
May |
| Lesser
Whitethroat |
23
April |
- |
- |
- |
| Swift |
23
April |
29
April |
29
April |
3
May |
| Spotted
Flycatcher |
28
April |
5
May |
2
May |
7
May |
For some species
the average arrival dates at all four observatories are very similar
eg Willow Warbler, Ring Ouzel which suggests that these species
move quite fast northwards. Other species such as Turtle Dove seem
to move more slowly northwards in the spring, with 20 days between
the average arrival dates at Portland and Bardsey. Further
reading
We hope that
Migration Watch will tell us much more about how fast birds
move through the country.
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