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Willow Warbler Phylloscopus trochilus [Linnaeus, 1758]
Other Names
Trends & Distribution
Breeding & Survival
Biometrics
Books & Links
Order:
Passeriformes
Family:
Sylviidae
BTO Codes:
WW , WILWA
EURING No:
13120
Number in Britain:
2 million territories (Summer)
Conservation Status:
UK:
AMBER
European:
Not a species of concern
Global:
Least Concern
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Status in UK:
(A) Migrant Breeder, Passage Visitor
Subspecies:
trochilus , acredula recorded in Britain (of 3 subsp. in the world)
.
Length:
11 cm
Wingspan:
19 cm
Weight:
M/F: 10 g
Scientific name from:
Gr.: phullion =a leaf + skopos =a watcher
and Gr.: trokhilos =a bird mentioned by Aristotle, prob. the Wren
World Distribution:
BREEDS: Europe, nw Asia, WINTERS: tropical & s Africa
Habitat:
Open woodland, scrub, shrubby tundra
Diet:
Insects and spiders, also berries in autumn
TitBit:
The Willow Warbler is almost unique amongst birds in that it moults all of its feathers twice in a year, on the breeding grounds and again on the wintering grounds; the reason for this is unclear but may have to to do with the length of the migration (from
n Europe to s Africa)
Population and Distribution
Population Trend:
Regional Trends:
Distribution:
New Atlas )
British Population Size:
Summer:
2 million territories
in 2000
First Record:
1718
[Fossil evidence from
Devensian (last) glaciation, 10-120,000 yr ago]
Habitat Occupancy (in the Breeding Season):
Most frequent in:
Scrub
Also common in:
Coniferous Wood
And found in:
Deciduous Wood
Relative Frequency in Each Habitat:
Average Day of First Arrival:
31 Mar
European Population Size:
Summer:
31 to 60 million pairs
(Trend in Numbers )
Birds in Europe
Listed on the Appendices/Schedules of:
Bern(III), Bonn(II)
Survey Results:
Breeding and Survival
Egg Size:
15 x 12 mm
Egg Weight:
1.2 g (of which 5 % is shell)
Number of Nest Records:
197
Clutch Size:
5 - 7 eggs
5.93 ± 1.08 (2 - 9) N = 1874
Incubation:
13 - 14 days
12.78 ± 0.92 (11 - 15) N = 1873
by the:
Female
Fledging:
13 - 16 days
14.47 ± 1.57 (12 - 16) N = 4726
as:
Altricial, downy
Source:
British Trust for Ornithology (2005) Nest Record Scheme data
First Clutches Laid:
12 May (2 May - 11 Jun)
Number of Broods:
1(2)
Trends in Breeding Productivity
Number Ringed:
28906
Adult Survival:
0.319
Juvenile Survival:
0.239 (in First-Year)
Age at First Breeding:
1
year
Typical Lifespan:
2
years
Maximum Recorded Age:
10yr8m
Biometrics
Ring Size:
AA
Wing Length
Adult:
66.3 ± 4.4
Range
62 - 71 mm, N =35993
Juvenile:
64.8 ± 2.8
61 - 69 mm, N =41601
Male:
68.9 ± 5.7
66 - 71 mm, N =11930
Female:
63.2 ± 1.6
61 - 65 mm, N =7344
Weight
Adult:
8.88 ± 0.89
Range
7.50 - 10.40 g , N =31141
Juvenile:
8.74 ± 1.23
7.40 - 10.20 g , N =33348
Male:
9.31 ± 0.71
8.20 - 10.50 g , N =9756
Female:
8.50 ± 0.86 .
7.40 - 10.20 g , N =6217
Source:
British Trust for Ornithology (2005) Ringing Scheme data
Other Names
Gaelic:
Ceileiriche-giuthais
Welsh:
Telor yr Helyg
Danish:
Løvsanger
Dutch:
Fitis
Finnish:
Pajulintu
French:
Pouillot fitis
German:
Fitis
Hungarian:
Fitisz füzike
Icelandic:
Laufsöngvari
Irish:
Ceolaire Sailí
Italian:
Luí grosso
Norwegian:
Løvsanger
Polish:
Piecuszek
Portuguese:
Felosa-musical
Spanish:
Mosquitero musical
Swedish:
Lövsångare
Local Names: Willow Wren
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