Spring migration

For many birdwatchers, the spring migration period is the most exciting time of the year. It is a time of change, with the departure of winter visitors and arrival of summer migrants. Whether you live on the coast or inland, you will see birds moving. Birdwatchers regularly record the first arrival dates of migrants such as the first Swallow or Cuckoo of the year. These first dates are often ‘extremes’ and don’t give us much information about the main periods of migration. By contributing to BirdTrack you will help build up an annual picture of spring migration and we will be able to monitor the timing of arrival of spring migrants and departure of winter visitors.

There is a lot of excellent information collected annually by Bird Observatories. The wardens make complete counts of the birds in a defined area each day and record the results in daily logs. These log books are an incredible resource and have been used by Dick Loxton and Tim Sparks to look at arrival dates over time at four bird 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.

Table 1: 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 March
-
-
22 March
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
 

 

Turtle Dove by Mike Weston

 

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.

However, there are just 18 Bird Observatories dotted around the coastline of Britain and Ireland. With large numbers of birdwatchers spread over a broad geographical area we can find out much more information about the timing and pattern of arrival and departure of migrants in spring. The table below shows the average arrival dates of summer visitors taken from bird reports of five counties spread from southern England to the Shetland Islands. Data is not available for all species from these selected counties but few county bird reports provide average dates at all, most give first and last dates. Look at species like Turtle Dove and Cuckoo and see how the average arrival dates are spread. As we might expect, average arrival in Hampshire is earlier than in the West Midlands and so on. With so many birdwatchers contributing to bird reports its perhaps not too surprising that average arrival dates are often earlier than those collected by bird observatories where just one or two people contribute information from a small area.

Table 2: Average arrival dates of summer visitors 

Species
Hampshire
West Midlands
Leicestershire
Lancashire
Shetland
Garganey
20 March
2 April
5 April
na
-
Montagu's Harrier
1 May
-
-
-
-
Osprey
11 April
-
31 March
6 April
-
Hobby
15 April
24 April
17 April
-
-
Quail
17 May
10 May
15 May
na
-
Stone Curlew
31 March
-
-
-
-
Little Ringed Plover
20 March
21 March
15 March
27 March
-
Wood Sandpiper
6 May
-
8 May
4 May
-
Arctic Skua
11 April
-
-
-
15 April
Sandwich Tern
22 March
-
-
29 March
-
Common Tern
7 April
12 April
9 April
12 April
1 May
Arctic Tern
23 April
-
16 April
17 April
30 April
Little Tern
12 April
-
-
24 April
-
Black Tern
24 April
-
27 April
28 April
-
Turtle Dove
17 April
27 April
27 April
3 April
13 April
Cuckoo
4 April
12 April
13 April
19 April
9 May
Nightjar
7 May
17 May
-
-
-
Swift
18 April
24 April
21 April
21 April
10 May
Wryneck
27 April
-
-
-
9 May
Sand Martin
17 March
22 March
11 March
12 March
30 April
Swallow
23 March
1 April
20 March
27 March
22 April
House Martin
31 March
8 April
28 March
4 April
27 April
Tree Pipit
31 March
9 April
7 April
6 April
1 May
Yellow Wagtail
2 April
3 April
29 March
9 April
5 May
Nightingale
16 April
22 April
21 April
-
-
Redstart
5 April
11 April
14 April
12 April
28 April
Whinchat
17 April
24 April
22 April
20 April
4 May
Wheatear
12 March
20 March
15 March
11 March
31 March
Ring Ouzel
30 March
20 March
10 April
24 March
17 April
Grasshopper Warbler
14 April
19 April
17 April
17 April
-
Sedge Warbler
9 April
16 April
11 April
14 April
9 May
Reed Warbler
16 April
25 April
22 April
18 April
22 May
Lesser Whitethroat
18 April
22 April
22 April
23 April
6 May
Whitethroat
11 April
15 April
16 April
20 April
5 May
Garden Warbler
13 April
22 April
20 April
21 April
10 May
Wood Warbler
22 April
23 April
24 April
23 April
13 May
Willow Warbler
26 March
28 March
29 March
31 March
20 April
Spotted Flycatcher
29 April
4 May
2 May
1 May
13 May
Pied Flycatcher
15 April
21 April
27 April
17 April
7 May

Generally speaking there is far less information about the timing of departure of winter visitors such as thrushes, swans, geese and ducks. Recording departure dates are more difficult as you need to record every day until you see the last one. By submitting your records regularly to BirdTrack we will be able to investigate the timing of departure for a wide range of species. Migration Watch was able to record the departure of Redwing, Fieldfare and Brambling and this gave us a good insight into the timing and pattern of departure. Very few bird reports provide information of the departure dates of winter visitors and even fewer are able to present average dates. The table below gives average departure dates of winter visitors in Hampshire and West Midlands.

Table 3: Average departure dates of winter visitors

Species
Hampshire
West Midlands
Bewick's Swan
16 March
-
Whooper Swan
-
-
White-fronted Goose
30 March
-
Scaup
10 April
-
Long-tailed Duck
6 May
-
Velvet Scoter
3 May
-
Hen Harrier
9 May
-
Merlin
23 April
-
Purple Sandpiper
23 April
-
Jack Snipe
17 April
21 April
Water Pipit
17 April
21 April
Fieldfare
1 May
4 May
Redwing
24 April
19 April
Great Grey Shrike
6 April
-
Brambling
19 April
20 April
 

References

  • Cox, A. 2003. Hampshire Bird Report 2002. Hampshire Ornithological Society. www.hos.org.uk
  • Emley, D.W. 2003. The Birds of Staffordshire, Warwickshire, Worcestershire and the West Midlands 2001 Annual Report 68. West Midland Bird Club. www.westmidlandbirdclub.com
  • Loxton, D. & Sparks, T. 1999. Arrival of spring migrants at Portland, Skokholm, Bardsey and Calf of Man. Bardsey Observatory Report 42: 1998.
  • Mackay, A.J. 2002. The Leicestershire and Rutland Bird Report 2001. The Leicestershire and Rutland Ornithological Society.
  • Pennington, M. 2003. Shetland Bird Report 2002. Shetland Bird Club. www.nature-shetland.co.uk
  • White, S.J. 2003. Lancashire Bird Report 2002. Lancashire & Cheshire Fauna Society No 104. www.lacfs.org.uk

Why record birds?

Autumn migration