In bestiaries, there were all kinds of animals, many of which existed, many of which did not. However, in some bestiaries, there are an overwhelming amount of birds. Sometimes half the bestiary or more was devoted to just birds, lots of which were fictional. And in medieval poetry, birds are used both symbolically and as characters. Chaucer specifically seemed to use birds on every other page, and doesn't seem to use other animals of any type nearly as often. Was there some fascination with birds that had a concrete source? Was it just that they were the most common animal at the time? Were there medieval bird watching clubs? Is there any way to tell if this interest, and others like it, were just those of these particular artists, or were these things widely popular among others?
As far as Western European literature in the later Middle Ages goes, the abundance of birds has a lot to do with the established conventions of courtly culture. Late medieval love poetry, and courtly poetry more generally, relies heavily on a sort of set-dressing based on an idealised notion of spring. This might be familiar from the ever-popular opening to the Canterbury Tales. April, Chaucer tells us, brings invigorating rains, the sweet west wind, the movement of the sun into Aries, and the singing of birds:
And smale foweles maken melodye,
That slepen al the nyght with open ye
(So priketh hem nature in hir corages),
And little birds, which lie awake all night, sing songs because nature so strongly urges them in their hearts...
If you want evidence of how this central role of birds in springtime (ie, the time appropriate to love) worked as part of a larger imagistic tradition, you need look no further than the poetry of John Lydgate. Lydgate is the great reworker of Chaucerian convention; he vamps inexhaustibly on the language, images and ideas the Chaucer gives him. It’s no surprise that he also employs birds in the set-dressing of springtime. There are literally hundreds of examples (Lydgate was an incredibly prolific poet!), but here’s a favourite of mine:
The honysoucle, the fresshe primerolles,
Ther leves splaye at Phebus uprysyng,
Thamerous foules with motytes and carolles,
Salue this sesoun every morwenyng,
...
Whiche sesoun prikkes fressh corages,
Rejoyseth bestes walking in ther pasture,
Causeth byrdes to syngen in ther cages,
Whanne blood reneweth in every creature,
The honeysuckles and the fresh primroses spread their leaves at the rising of the sun; the amorous birds greet this season every morning with motets and carols... This season stirs young hearts, delights beasts walking in their pastures, causes birds to sing in their cages, when the blood renews in every creature...
To write a courtly poem (or even, as is the case in this Lydgate example, to insert courtly movements into other kinds of poetry) demands a springtime setting, and the presence of birds – particularly birdsong – was one of the key elements by which that setting could be quickly and recognisably established. Naturally, this convention didn’t originate with Chaucer or the Chaucerians. The association of birdsong with spring as part of a larger conventionalised set of spring imagery goes back at least as far as the Classical poets. Here’s a bit of Virgil that Chaucer had certainly read and quite probably often had in mind:
ver adeo frondi nemorum, ver utile silvis
...
avia tum resonant avibus virgulta canoris,
It is spring that decks the groves in leaves, spring that serves the woods... the remotest thickets then resound with birdsong...
The ur-text of medieval Western European courtly literature was the thirteenth-century Roman de la Rose of Guillaume de Lorris and Jean de Meun, and here birds are also unsurprisingly used to establish a springtime of love:
Les oiselets silencieux
Par le temps sombre et pluvieux,
Et tant que sévit la froidure
Sont en mai, quant rit la nature,
Si gais, qu'ils montrent en chantant
Que leur coeur a d'ivresse tant
Qu'il leur convient chanter par force.
The birds, silent while they were cold and the weather hard and bitter, become so gay in May, in the serene weather, that their hearts are filled with joy until they must sing or burst.
And here is (probably!) Chaucer’s version:
The briddes that haven left her song
While thei suffride cold so strong,
In wedres gryl and derk to sighte,
Ben in May for the sonne brighte
So glade that they shewe in syngyng
That in her hertis is sich lykyng
That they mote syngen and be light.
The birds that had left their song while they endured such strong cold, in weather dark and terrible to see, are so glad for the bright sun of May that they show through song that there is such a desire in their hearts that they must sing and be happy.
And the theme abounds elsewhere; in debate poems like the late twelfth-century The Owl and the Nightingale (which opens in ‘one sumere dale [a summery dale]’), in songs like the early thirteenth-century Mirie It Is (‘while sumer ilast, with fugheles song [It is merry while summer lasts, with birdsong]’), and Bryd one Brere (Bird on a Briar), in Arthurian romances and any number of miscellaneous lyrics. One could no more talk about love without spring than spring without birds; by the time that Chaucer was writing, the conventions were inextricably knit.
That’s the basic answer. But there’s something more complex going on with poets and birds, particularly in Chaucer’s case, that deserves some attention. Birds do something that other animals, generally speaking, don’t: they sing. Perhaps more than any other group of animals, birds have an association in the cultural imagination of the medieval West with voice, with communication and with poetry. Think back to the Canterbury Tales opening; birds ‘maken melodye’. In Middle English, the verb to make doesn’t just mean to produce or create, as it does for us. It also has the sense of “to compose, to write, to versify” (definition 5). Chaucer’s Squire, we are told, ‘koude songes make and wel endite [could make songs and write well]’ (Canterbury Tales, I. 95), and Older Scots poets would even call themselves “Makars” (makers). For Chaucer in particular, and for the tradition more widely, birds are not just springtime scenery but symbols that draw explicit attention to the production of speech and of poetry.
Examples abound here. The classic one is the sweetly singing white Raven in the Manciple’s Tale, who unwisely tells his master Apollo about his lover’s infidelity and is cursed with black feathers and a croaking voice. A very popular reading of the tale, most famously defended by Louise Fradenburg, is that it articulates an anxious, cautious response to the idea that skilled speakers (rhetoricians, poets, etc.) can safely offer advice or criticism to the powerful. But there are plenty of other relevant examples; in the Parliament of Fowls, most obviously, the cacophony of birdsong is reimagined as a spirited debate about choosing mates (incidentally, another meaning of “make”). In the House of Fame, a talking eagle carries the poetry-hungry narrator into the heavens while comically expostulating the physical principles of air that make speaking (and, Chaucer wryly notes, farting) possible. The cockerel of the Nun’s Priest’s Tale is so proud of his singing voice that he allows himself to be deceived into a near-fatal performance by the cunning fox (another animal associated with voice, due to a pun on the Latin word vox). Chaucer’s birds are, fundamentally, speakers; he consistently employs them to signpost the fact that we should be paying particular attention to what is being said, and how, and what the consequences of speaking might be.
Chaucer didn’t invent this idea. The aforementioned Owl and the Nightingale is classically raised as an example for the earlier association in English literature between birds and speech/debate/rhetoric. But Chaucer does use it a lot, and those poets who followed after him are greatly invested in it too. John Lydgate’s Churl and the Bird is a fable which mulls over the question of whether or not to trust in the advice offered by a speaking bird – James Simpson has very compellingly shown how Lydgate elaborates his source to make the discourse between the bird and the churl an allegory for the poet-patron relationship. Richard Holland’s Buke of the Howlat, which reimagines the Parliament of Fowls, Robert Henryson’s Fables, which springboard off the Nun’s Priest’s Tale, and John Skelton’s Speke Parott all very much continue in this vein. One has to be mindful of the limits of an interpretative argument, obviously, but I don’t think it’s much of a leap to suggest that medieval authors might have taken a particular interest in birds because they are animals that were particularly associated with making sound.
Finally, I want to touch very briefly on the prevalence of birds in bestiaries, which can’t necessarily be explained by the above reasons – although it’s worth noting that the wealthy patrons of luxury bestiaries were also the sort of people who might patronise courtly poetry, so there’s perhaps a link there. I suspect – and you might want to take this with a pinch of salt – that it’s got more to do with an encyclopaedic tradition going all the way back to Aristotelian natural history that firmly separates “birds” and “beasts” (and, to a lesser extent, fish). Pliny’s Historia Naturalis, for instance, devotes separate books to land animals, fish, birds and insects (books VIII–XI). The book on animals (XII) within Isidore of Seville’s Etymologiae deals with all the other animals and then concludes with birds (vi) and other flying beasts (vii). Bartholomaeus Anglicus’s De Proprietatibus Rerum puts birds (XII) and other animals (XVIII) into separate books. These works, and works like them, are the main sources of the medieval bestiaries. Bestiaries tend to be a bit more jumbled up, of course, but get all their raw material from these works – works which, by distinguishing clearly between birds and beasts, were perhaps more likely to have provided a higher proportion of detail about birds than we might have expected.
Continued below.