The Tawny Frogmouth (Podargus strigoides)

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The Tawny Frogmouth (
Podargus strigoides), a #BeakoftheWeek contender from last year,  is a weird and wonderful member of the Podargidae family.

Adult tawny frogmouth, perching in daylight, Queensland

Adult tawny frogmouth, perching in daylight, Queensland

Alongside oilbirds, potoos and some nightjars, frogmouths are part of the wider order of birds known as Caprimulgiformes. Literally meaning ‘goat-milker’ in Latin, this peculiar name is said to have derived from folk tales regarding the feeding habits of the European nightjar, thought to surreptitiously suck the milk from goats in the depths of night!

The Tawny Frogmouth was first described in 1801 by the great English naturalist John Latham who was able to study and name many species of Australian birds from specimens finding their way into England’s growing natural history collections at the turn of the 19th century. In his first great ornithological work ‘A General Synopsis of Birds’ he actually focuses on the unusual bills of these then so-called ‘goatsuckers’ as follows: 
“The bill in this genus is very short, and hooked at the end. Gape vastly wide: on the edges of the upper mandible seven or more stiff bristles.”

Tawny Frogmouth 2

Ornithological painting from the Natural History Musuem’s collection of First Fleet artwork: “Strigoid Goatsucker”, native name “Birreagal”

One of the earliest known images of these birds is part of the collection of artworks created during the First Fleet expedition of the 1780s that saw the formation of the first European colony in Australia. Over half the natural history artworks focus on birds, with a number acting as iconotypes (where an image has survived but the specimen it was taken from (usually the earliest known to science) has not).

This fantastic painting, noted as a type and labelled around its time of creation as depicting a ‘Strigoid Goatsucker, native name Birreagal’ was re-examined in 1970 and confirmed as being detailed enough to accurately identify as Podargus strigoides.

Tawny frogmouths can be found throughout Australia and Tasmania and are known to live in most available habitats- from forests and woodland to heaths and urban areas. Known for their ‘cryptic plumage’, their colouration is variable, but usually consists of greyish upperparts, streaked with barring and vermiculation in blacks and brown with females usually having darker feathers.

Frogmouths have often been confused with owls, seemingly as a result of their nocturnal habits, brilliant camouflage and expressive faces alongside some quirks of historic synonymy. Confusingly, some of the most commonly used names for the Tawny Frogmouth are ‘Birreagal’ and ‘mopoke’, a name also shared by the boobook, a small Australasian owl. The Latin name strigoides itself reiterates this, with strix meaning owl, and oides meaning form. Many resources continue to refer to frogmouths as ‘false owls’ or simply ‘tawny frogmouth owls’ for good measure; there are however a number of key differences between these taxa.

Unlike most owls with their strong legs and curved, pointed bills for killing prey, the tawny frogmouth has an extraordinarily wide, chunky bill ideal for catching and consuming insects. So too, during daylight hours frogmouths tend to perch on branches, utilising their extraordinary camouflage to blend in with their surroundings and avoid detection. Unlike owls, they gather most of their food by ‘pouncing’ from low branches to the ground where they mainly feed on worms, slugs, snails, reptiles, frogs and small mammals.

Tawny Frogmouth family- these birds have some of the most fantastical looking chicks.

Tawny Frogmouth family, New South Wales. Frogmouths have some of the most fantastical looking chicks.

Tawny Frogmouths breed between August and December with both sexes sharing incubation duties. Their nests are fairly loosely formed structures, primarily comprised of sticks and usually creating a platform between forked tree branches to safely raise their young  (having an average clutch size of 2 to 3 eggs) from the ground. These birds have distinctive ‘soft and low’ pitched calls, most commonly sounding like sequential bursts of ‘oom-oom-oom’ sounds, and are known to loudly bill-snap when threatened:


You can find out more about which species are related to the Tawny Frogmouth at OneZoom. For now though, I’ll end this post with a passage from another historical text, The Birds of Australia of 1911, which brilliantly captures the appearance and character of these birds:

‘The Frogmouths are beautifully soft-plumaged birds, with a motley of grey, brown, black and white markings. In the coloration then they resemble the dead bark of the bough on which they sit. To render it still more difficult of detection, the bird does not sit across the bough, but along it, assuming the stiff attitude of a rugged branch broken off short. The eyes are large and adapted to the diminished light of night, the brighter light of day seemingly making them dazed and inert. In both these characters they resemble the Owls. Their disposition is however, much milder, and they can be handled by day without attempting to offer any resistance. They are invaluable insect feeders, and capture their food, Cicadas, Phasmids and Beetles, &c., on the branches of the trees. After swallowing an insect they bring their mandible together with a loud snap, as if in satisfaction over the tit-bit.’

References
Handbook of the Birds of the World Alive, Podargus strigoides: http://www.hbw.com/species/tawny-frogmouth-podargus-strigoides (accessed April 2016)

White, John, A General Synopsis of Birds: Vol 2, Part 2, London, Printed for Leigh, Sotheby, & Son (1801). Available via Biodiversity Heritage Library:  http://www.biodiversitylibrary.org/item/105238#page/7/mode/1up

The First Fleet Expedition and Collections, Natural History Museum London- Library and Archives Collections: http://www.nhm.ac.uk/nature-online/art-nature-imaging/collections/first-fleet/art-collection/index.dsml (accessed April 2016)

Australian Museum, Podargus strigoides factsheet: http://australianmuseum.net.au/tawny-frogmouth (accessed March 2016)

Lucas, Arthur Henry Shakspere & Le Souëf, W. H. Dudley, The Birds of Australia,  London, Whitcombe and Tombs Limited (1911). Available via Biodiversity Heritage Library:
http://www.biodiversitylibrary.org/item/114952#page/9/mode/1up

Images and Audio

Adult tawny frogmouth, Queensland by Tatters is licensed under CC BY 2.0

“Strigoid Goatsucker”, native name “Birreagal” from the Natural History Museum’s collection of First Fleet artworks, available online: http://www.nhm.ac.uk/nature-online/art-nature-imaging/collections/first-fleet/art-collection/nathist.dsml?sa=1&lastDisp=gall&notes=true&beginIndex=264&desc=true

Tawny Frogmouth family, New South Wales by tinykettle is licensed under CC BY-NC 3.0

Audio recording of Tawny Frogmouth (Podargus strigoides) call, XC150467, by Marc Anderson. Accessible at: http://www.xeno-canto.org/150467