Common Redshank

If you sometimes feel exasperated with those bag-of-nerves Common Redshanks Tringa totanus on shorelines during the day, you may be surprised when you hear them migrating at night. Their nocturnal flight calls sound quite lazy, even chilled-out.

Common Redshank epitomizes a tendency found in all waders. As a sentinel of the marsh, its excitability means that it has a wide range of calls signaling different levels of alert. At night, however, this variability is drastically reduced. Single migrants basically always give the same simple call, with very little variation.

Even migrating flocks of Common Redshank sound more mellow than you might expect, although they do show greater variability than single individuals, mainly concerning the number of notes in the call. We describe here two main ways in which calls in migrating flocks differ from those of single individuals.

tyuu-luu-luu

• low-pitched tyuu-luu-luu with accent only on the first note
• tyuu is diagnostic: higher-pitched, dropping rapidly to the level of notes that follow
• majority of calls have three notes; others may have two, four or five
• roughly Loch Ness monster shape (swimming to the left), with concave neck
• notes may be joined together, with a dip in pitch and amplitude articulating the joint
• frequencies from 1.4 – 4.7 kHz (mean min 1.8 kHz, mean max 3.2 kHz; n = 40)

flocks

When Common Redshanks migrate in flocks, their volatility becomes more evident. The more varied NFCs of flocks are derivatives of tyuu-luu-luu, altered in various different ways.

• longer, more strident tyu-lu-lu-lu-type calls (i)
• more variable, eg in number of notes
• individual notes shorter
• stronger accent on first note, with more prominent harmonics, even in more distant calls (i)
• max frequency tends to be slightly higher than in single birds
• occasionally mumbled version of tyuu-luu-luu with reduced accent on first note and narrower frequency range (j)

Effects of recording quality

• In closer, clearer recordings, harmonics are more likely to appear.
• In distant recordings any weak links between the notes may disappear; indeed, in the most distant recordings all but the first note may disappear.

• Common Greenshank Tringa nebularia NFCs usually have three notes in the same pitch range but can be easily distinguished from Common Redshank as their three notes are essentially the same, a bit similar to the first note of Common Redshank, whereas in this species’ tyuu-luu-luu calls there is nearly always a strong accent on the strongly descending first note and the ones that follow are quieter and much flatter.
• Ruddy Turnstone Arenaria interpres is only a problem in comparison to single-note tyuu calls, or very distant tyuu-luu-luu calls in which anything following the first note is inaudible. In either case, the easiest difference is that Common Redshank tyuu-notes always have a concave slope (ie, steeper near the start), whereas the similar-sounding call of Ruddy Turnstone has a straight or slightly convex descent (ie, steeper near the end).
• Eurasian Whimbrel Numenius phaeopus is only a problem in comparison with mumbled tyuu-luu-type calls, a rare variant in which the accent on the first note is virtually absent, as in j) above.

• mainly at the coast: rarely recorded inland
• nocturnal and diurnal: uses same flight calls day and night
• typically in the middle of the night: but recorded any time between dusk and dawn