Why is it called "A murder of Crows" and "a parliment of Rooks" Where do we get collective nouns from?

Question

And what is the most obscure (in terms of connection) colective noun in the animal world?

Answer 1

The first collection, in English, of collective nouns, is 'The Book of St Albans'. Printed in 1486 the book was popular. In its next printing it was called 'Treatyse on Fysshynge with an Angle', that is, angling or rod fishing but it was the same book with an additional section. It is thought that there may have been earlier books 'The Book of St Albans' collected the terms from.
Some of the collectives are based on rural use others seem to have poetic origins. In England today a badgers den is called a sett while in the 15th century the phrase read a cete of badgers.

An escargatoire of snails
A mellificium of quotations
A bend of willows

Answer 2

Many collective nouns were first recorded in the late-fifteenth-century Book of St. Albans, by Dame Juliana Barnes.

Ones I found quite amusing are:
A Bloat of Hippopotamuses
A Romp of Otters
A Prickle of Porcupines
A Bevy of Swans
An Intrusion of Cockroaches.

Answer 3

These terms began in upper-class field sports. Intellectual people have fun creating more and more terms for groups of things outside of sports, on the lines of certain fanciful medieval Company Terms.

Answer 4

Isn't that interesting. Wow! There are a bunch of them. Take your pick of the weirdest one!
zeal of zebras
drift of swine
dray of squirrels
storytelling of rooks
business of ferrets
flight of dragons
weyr of dragons

Answer 5

Write a book containing the phrases and get it published.