Monday 30 March 2020

Self-Isolating, Species 1 - Chiffchaff

Chiffchaff (Phylloscopus collybita)
The above is an Iberian Chiffchaff at Potteric Carr

Facts & Figures:
Population in 1970: 300,000
Population in 2019: 1,750,000
Change in Population: + 1,450,000
Percentage change: +583.3%
Length: 11.5 cm
Oldest: 7 years 7 months
Eggs: 5-6
Broods: 2

During the current crisis I’m going to attempt to concentrate on one species per day.  Chiffchaffs are one of the earliest summer migrants, and I heard 3 different males during my self-isolating cemetery cycle ride the other morning, so I am starting this new feature with the Chiffchaff.  Chiffchaffs are small Warblers only around the size of Blue Tits, although they are much slimmer than members of the rather rotund tit family.  Chiffchaffs are one of the three members of the Leaf Warblers, which breed in the UK.  The other leaf warblers are the Willow Warbler and the slightly larger and much scarcer Wood Warbler.  

Chiffchaffs are arriving at the moment, and have been doing so since about mid-March.
A brighter than normal Chiffchaff (26 March 2010)

Chiffchaffs are olive-green above, and much paler below.  Often they appear to be colourless below, but sometimes they can be fairly yellow, as was this adult bird I managed to photograph near South Cave several years ago.  Chiffchaffs and Willow Warblers both have a pale supercilium (the eyebrow above the eye).  However, when in very close proximity it is possible to notice a difference in leg colour.  Chiffchaffs usually have black legs, but not always (Willow Warblers usually have pink legs).   
A Chiffchaff showing its black legs

The Chiffchaff is also much more likely to to continually dip its tail, especially in a figure-of-eight motion.  Willow Warblers tend to dip their tail less often, and without a figure-of-eight motion.  A less easily discernible difference is their wing-length.  If the tip of the primary feathers in the wing are compared, the Chiffchaff’s doesn’t extend very far down the tail.  The Chiffchaff doesn’t need such long wings as it only migrates to the Southern Mediterranean or to Northern Africa, but the Willow Warbler is a long distance migrant as it migrates much further south way beyond the Sahara to Western Africa.
A typically dull Chiffchaff

By far the easiest way to differentiate these species is by comparing their songs.  Probably only the male Cuckoo has a simpler song.  The Chiffchaff has a simple two note song, which has been interpreted as “chiff-chaff” in the UK.  In other parts of Europe this has been rendered as ZilpZalp (Germany), tjiftjaf (Netherlands) and siff-saff in Wales.  

A video describing some of the attributes of the Chiffchaff has recently been added to YouTube: https://youtu.be/BqUQV69ylj4

1 comment:

PJ said...

I like this idea of singular focus Michael.