The cuckoos have gone quiet. I'm still trying to find out the reason for the American line about the bird who "never hollers cuckoo Till the fourth day of July", but in the meantime here are two lyrics which have the bird singing in May as they do here in Skye at any rate. 1)You'll see the resemblance to a Simon and Garfunkel song 2) in Scottish Gaelic with translation, from a photocopy which gives no information on what publication it was taken from
Cuckoo songs
1) CUCKOO (from Gibson Young, ed."Community Song Book" London, J Curwen & Sons, no date but pre-decimalisation of UK currency)

Cuckoo, Cuckoo, Pray what do you do?
In April I open my bill,
In May I sing night and day,
In June I change my tune,
In July Away I fly.
In August Away I must

Cuckoo, Cuckoo, Pray where do you go?
Up high Into the sky,
Far away Over the sea
To Spain I fly again;
Day and night I take my flight.
Cuckoo.
Goodbye to...

2) Do'n Chuthaig (to the cuckoo)

Fàilt' orm fèin, a chuthag ghorm,
Le d'òran ceòlmhor, milis;
'S e seirm do bheoil 's a' Cheitein òg
A thogadh bròn o m' chridhe.

'S ro-bhinnn leam t'fhuaim 's a' mhadainn Cheit',
'S tu air barr gèig' 's an innis,
No 'm feasgar ciùin aig bun nan stuc
'N uair bhiodh an druchd a' sileadh.

Hail to you, Oh blue cuckoo,
With song so sweet and tuneful,
The tune you sing in early May
Drives sorrow from my spirit.

How sweet your chant in May time's morn,
At tree top on the island,
Or calm of eve at foot of hill,
when dew is gently falling.