Swallows and Humans in Wales: historical and modern feeding strategies

Species History

Barn swallows (Hirundo rustica) have been noted as commensal with humans and livestock throughout recorded history. One of the first records comes from Pliny’s Natural History where it is explained:

[Hirundines] Thebarum tecta subire negantur quoniam urbs illa saepius capta sit, nec Bizyes in Threcia propter scelera Terei.

[Swallows] do not enter under the roofs of Thebes, because that city has been so often captured, nor at Bizye in Thrace on account of the crimes of Tereus. (Rackham 1947, 336–7 (X. 34))

A sitting swallow with forked tail in colour drawn for the Aberdeen Bestiary.

Swallow in the Aberdeen Bestiary, f.47v. Image used by permission of the University of Aberdeen.

Pliny’s account implies that swallows normally nested in human habitations – otherwise it would not be unusual for swallows to be absent from the roofs of Thebes or Bizye. In Britain the swallow’s use of human habitation is attested in the archaeological record at Anglo Saxon Fishergate, York, although swallows are more often attested at cave sites (Yalden and Albarella 2009, 15). The twelfth-thirteenth century medieval European bestiary tradition also describes swallows living in human habitations:

What is cleverer than to possess the unbounded freedom of flight and to entrust one’s home and offspring to the houses of men, where nothing will attack them? For it is good to see how the young are accustomed to the company of men from the day they are born, and hence are safe from the attacks of creatures that prey on birds. (Barber 2006, 165)

A manuscript illustration of swallows returning to community nests under eaves of building.

Swallows in the BL Harley MS 4751 bestiary, f. 52v.

Likewise, the thirteenth century De Animalibus by Albertus Magnus describes four species in the swallow family (=hirundines: possibly distinguishing the swallow, swift, house martin and sand martin), of which two can be found in human habitations:

Quatuor inveniuntur generum, quae videlicet in domibus, et quae exterius in muris et quae in terra super flumina, et quae vocantur marinae. (Stadler 1916, 1500)

Four genuses of them are found: the ones in homes, the ones outside in walls, the ones on the ground above rivers, and the ones called “marine.” (Kitchell & Resnick 1999, 1633).

And in Britain, Alexander Neckam also described two species of the swallow family found in human habitations in De Naturis Rerum (c.1190 CE):

Sunt autem hirundinum diversae varietates. Quaedam enim domos inhabitantes in eis nidificant, quaedam in fenestris vitreis nidos limo oblitos artificose suspendunt, quaedam in abruptis montium mansionem eligunt. (Wright, 1863)

There are also different varieties of hirundine: Those which nest in inhabited buildings, those which hang nests made of old mud from glass windows, and those which choose houses in steep mountains.

Swallows were also noted as commensals by the first early modern British naturalists. Richard Carew (Chynowerth, Orme & Walsham, 2004, 25) describes them nesting in Cornish tin mines as well as caves in cliffs. Willughby (1678, 212) explains more simply: ‘these birds build in chimneys.’

Cardiff University’s Swallows

Cardiff University Sports Fields is a 33-acre site in south Wales with facilities for football, rugby, American football, lacrosse and Frisbee™. The site has eleven grass pitches and an artificial turf 3G. It hosts practice sessions and matches for local and national teams as well as for teams affiliated with the university. The site is also used by swallows, who have visited every summer in living memory. They are especially common in the garages and go in and out through small holes under the eaves. They also use puddles formed by the use of washing and irrigation equipment to gather mud and to drink.

Their most startling behaviour however, is their exploitation of human activity on the fields. When grounds staff are dragging string lines across pitches the swallows fly across the lines, using them as drag nets. Most impressively, they frequently swoop around and in front of the tractors (which move at 10-15 mph), making use of the insects thrown up by the rake and the mowers. They fly close to ground level, veering off at angles to catch prey. This may be a learnt behaviour: The swallows also follow the tractors when the tractors are in-transit moving equipment, or rolling fields. These activities are not beneficial to them as they do not throw up mud and insects, meaning the swallows are not following the tractors advantageously but compulsively. This kind of exploitation of human behaviour may be one factor that has made swallows so successful (Turner 2010, 46).

Image shows driver's view of swallow swooping in front of tractor.

Swallow to side of tractor at Cardiff University

Image shows three swallows (one in the air, two on the ground) collecting mud from a puddle.

Swallows gathering mud at Cardiff University

Culhwch ac Olwen

Culhwch ac Olwen (Culhwch) is a story with an Arthurian frame currently dated to the twelfth century. It appears to have been written in south Wales, placing it in the same landscape as modern day Cardiff University (Roberts 1991; Rodway 2007). In the story, Culhwch falls in love with a giant’s daughter called Olwen. Olwen’s father, Ysbaddaden Bencawr sets Culhwch and his companions a series of impossible trials before he will give consent for a marriage.

The most relevant metaphor from the story comes from a hyperbolic description of Culhwch’s horse early in the text. The horse throws up clods of earth as it gallops:

Mal pedeir gwennawl yn yr awyr uch y benn (Bromwich and Simon Evans 1997, 3)

Like four swallows in the air above his head.

Previous readers have explained the clever word-play used here. Culhwch’s love is called Olwen, which is gwenn-ol (=gwennawl, swallow) in reverse. Further, wherever Olwen walks, four flowers spring up in her step whilst Culhwch’s steed throws up muddy clumps like a gwennol (swallow), a reverse of Olwen’s footprints (Bromwich and Simon Evans 1997, xciv). Finally, the term gwennol (swallow) is attested in later times to refer to the soft ‘frog’ part of a horse’s hooves, which is the part throwing up the mud (Davies 1997, 131). These readings are sophisticated, but may have missed an obvious reason that the metaphor seemed so appropriate, as we shall explain shortly.

Immediately before this reference, two greyhounds are also said to pass in front of the horse like ‘sea-swallows’:

Mal dwy morwennawl yn darware yn y gylch (Bromwich and Simon Evans 1997, 3)

Like two sea-swallows frolicking around him

The term morwennol (sea-swallow) is used here instead of gwennol (swallow). In modern times, this is the name used for the tern (Sterna spp.), but the term is also strikingly similar to the ‘Irundo… vocantur marinae’ in the extract from Albertus Magnus given in the species history section. From context, Albertus Magnus seems to have been using the term to refer to another type of hirundine, most probably the sand martin (Riparia riparia). The Welsh dictionary corpus, Geiriadur Prifysgol Cymru also records two dictionary glosses from the seventeenth and eighteenth century which also translate the term ‘morwennol’ as sand martin, which lend weight to this translation. However, the term in ‘Culhwch’ may not require an exact translation. Here the two metaphors and species names are so close that the additional term may have simply been used as a variant, to keep the story sounding fresh. In this case, the imagery being evoked is not just of birds flying above a horse, but actually crossing in front of it, just like the swallows around the tractors at Cardiff University.

The swallow metaphor is later parodied in the sixteenth century Araith Wgon (Jones 1934; Sims-Williams 2011). The mud a horse throws up is:

… yn debygach i bedair morwennol noc i bedair tywarchen ddayarol. (Jones 1934, 8 (ll.6-8))

… more like four sea-swallows than four clods of mundane earth.

Here the point seems to be to make fun of the phrase with ironic hyperbole: The mud cast up by the horse here is so romantic and beautiful it does not even seem like it even comes from the ground. The use of this third very similar metaphor may suggest that the metaphor was a stock one, and that the imagery used in the metaphor was based on a common experience.

Although these metaphors are used to describe different things in the different extracts, they all have something in common. In each of the metaphors, swallows (or ‘sea-swallows’) are compared with fast moving things which play around and cross in front of a running horse. Apart from the word-play discussed above, these metaphors may have seemed so appropriate because they exactly fit how the swallows fly around workers and livestock. Swallows are strongly associated with cattle and horses in pasture in Britain (Henderson, Holt, and Vickery 2007). Much of this is due to their appetite for insects associated with livestock like horse flies and hover-flies, but these species also stir up invertebrates where they work (especially with fast riding and ploughing), exactly like the tractors do at Cardiff University Sports Fields.

Image shows manuscript illustration of a black bird with a forked tail chasing three flies or moths.

Swallow from the ‘Bestiary of Love’ by Richard de Fournival, in the University of Oxford Bodleian MS. Douce 308, from 1481-c.1515, f. 98r.

I am not aware of an exactly corresponding metaphor elsewhere in medieval and renaissance literature, but it is worth noting the swallow is frequently used as a metaphor for swiftness. For example, in the Middle English romance of ‘Sir Ferumbras’ (c.1380), Charles the Great rides as fast as a swallow (Herrtage 1879, 132 (l.4232)). In Stewart’s (1535) poetic Scots version of the ‘Scotorum Historia’, a rumour of death is described as ‘swift as ane swallow’ (Stewart 1858, 170 (l.25,232)).

The evidence for our reading of ‘Culhwch’ remains tentative because we cannot be sure the metaphor was originally applied to the swallow. Two of the three passages give morwennol (sea-swallow) instead of gwennol (swallow). However, the significance of the word gwennol for word play and the close correspondence between the text and our case study of swallows provides some corroborating evidence for the identification. This metaphor of swallows playing around horses therefore may well represent the long history of swallows exploiting human landscapes.


Thanks are due to the other staff at Cardiff University Sports Fields for assisting with photographs and encouraging research especially Mark Royle, Robert Abel and Paul Lidster.



  • Barber, Richard. 2006. Bestiary. Woodbridge: Boydell Press.
  • Bromwich, Rachel, and D Simon Evans. 1997. Culhwch and Olwen. Cardiff: University of Wales Press.
  • Chynowerth, John, Nicholas Orme & Alexandra Walsham. 2004. The Survey of Cornwall, Richard Carew. Exeter: Devon and Cornwall Record Society, New Series, Volume 47.
  • Herrtage, Sidney J. 1879. Sir Ferumbras. London: Early English Text Society. Also available online: https://archive.org/details/sirferumbras01herrgoog.
  • Jones, D Gwenallt. 1934. Yr Areithiau Pros. Cardiff: University of Wales Press.
  • Kitchell, Kenneth Francis, and Irven Michael Resnick. 1999. Albertus Magnus: On animals: a medieval summa zoologica. Baltimore: Johns Hopkins University Press.
  • Rackham, H. 1947. Pliny Natural History: Books VIII-XI. Harvard: Loeb Classical Library.
  • Stadler, Hermann. 1916. Alburtus Magnus: De animalibus libri XXVI: nach der Cölner Urschrift. Beiträge zur Geschichte der Philosophie des Mittelalters 15–16. Münster: Aschendorff. Also available online: https://archive.org/details/albertusmagnusde00albe.
  • Stewart, William. 1858. The Buik of the Croniclis of Scotland. Edited by William B. Turnbull. Vol. 2. London: Longman, Brown, Green, Longmans, and Roberts. Also available online: https://archive.org/details/buikcroniclissc00turngoog.
  • Willughby, Francis. 1678. Ornithology. Edited by John Ray. London: Royal Society. Also available online: https://archive.org/details/ornithologyFran00Will.
  • Wright, Thomas. 1863. Alexandri Neckam: De naturis rerum libri duo with a poem of the same author. Rerum britannicarum Medii aevi scriptores, or Chronicles and memorials of Great Britain and Ireland during the Middle ages 34. London: Longman, Roberts, and Green. Also available online: http://gallica.bnf.fr/ark:/12148/bpt6k67907s.


  • Davies, Sioned. 1997. “Horses in the Mabinogion.” In The Horse in Celtic Culture, Medieval Welsh Perspectives, edited by Sioned Davies and Nerys Ann Jones, 121–40. Cardiff: University of Wales Press.
  • Henderson, Ian, Chas Holt, and Juliet Vickery. 2007. “National and Regional Patterns of Habitat Association with Foraging Barn Swallows Hirundo Rustica in the UK.” Bird Study 54 (3): 371–77. http://dx.doi.org/10.1080/00063650709461497.
  • Roberts, Brynley F. 1991. “Culhwch Ac Olwen, The Triads, Saints’ Lives.” In The Arthur of the Welsh. Arthurian Legend in Medieval Welsh Literature, edited by Rachel Bromwich, Alfred Owen Hughes Jarman, and Brynley F Roberts, 73–95. Cardiff: University of Wales Press.
  • Rodway, Simon. 2007. “The Where, Who, When and Why of Medieval Welsh Prose Texts: Some Methodological Considerations.” Studia Celtica 41: 47–89.
  • Sims-Williams, Patrick. 2011. Irish Influence on Medieval Welsh Literature. Oxford: Oxford University Press.
  • Turner, Angela. 2010. The Barn Swallow. London: T & A D Poyser Natural History.
  • Yalden, Derek William, and Umberto Albarella. 2009. The History of British Birds. Oxford: Oxford University Press.


To cite this post : Lee Raye, “Swallows and humans in Wales: historical and modern feeding strategies”, Medieval Animal Data Network (blog on Hypotheses.org), Nov, 20th, 2017. [On line] http://mad.hypotheses.org/972


Dr Lee Raye is a grounds person at Cardiff University and a tutor in literature and history at Swansea University and at the Academy for Distance Learning. Lee is especially interested in providing ecosensitive readings of medieval and renaissance sources in order to write species histories.

Facebook: https://www.facebook.com/NaturalHistoryL/

Academia: http://swansea.academia.edu/LeeRaye

Email: lee.raye<at>gmx.co.uk

Lee Raye’s other posts

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *