| Willow Warbler |
| Two clear patterns in
migration counts are shown in the graph below, with most
Spring birds arrivning in April and continuing to arrive
well into late May most years. Return passage migrants
occur from quite early in July, with a pronounced peak in
August. Birds in September are relatively scarce. |
| ... |
| Combined monthly
migration totals per year |
 |
| ... |
| Annual/monthly
migration totals (numerical) |
| ... |
| Year |
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Total |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 1998 |
|
|
|
37 |
9 |
|
23 |
58 |
2 |
|
|
|
|
129 |
| 1999 |
|
|
|
27 |
10 |
|
6 |
82 |
3 |
|
|
|
|
128 |
| 2000 |
|
|
|
39 |
5 |
|
|
57 |
2 |
|
|
|
|
103 |
| 2001 |
|
|
|
38 |
12 |
|
23 |
30 |
3 |
|
|
|
|
106 |
| 2002 |
|
|
|
36 |
3 |
1 |
75 |
70 |
3 |
|
|
|
|
188 |
| 2003 |
|
|
|
30 |
19 |
|
21 |
62 |
4 |
|
|
|
|
136 |
| 2004 |
|
|
|
15 |
8 |
1 |
5 |
40 |
7 |
|
|
|
|
76 |
| 2005 |
|
|
|
27 |
1 |
|
31 |
48 |
3 |
|
|
|
|
110 |
| 2006 |
|
|
|
22 |
2 |
1 |
19 |
30 |
1 |
|
|
|
|
75 |
| 2007 |
|
|
|
20 |
2 |
|
16 |
43 |
6 |
|
|
|
|
87 |
| 2008 |
|
|
|
19 |
1 |
|
18 |
62 |
6 |
|
|
|
|
106 |
| 2009 |
|
|
|
19 |
|
|
32 |
42 |
1 |
|
|
|
|
94 |
| 2010 |
|
|
|
10 |
2 |
|
26 |
44 |
|
|
|
|
|
82 |
|
