Birdsong has evolved over immense periods of time, and with Australia’s Robins, you can hear that evolution in the songs these birds sing today.

Where we live in southern Australia, there are four closely related, ‘red-breasted’, Robin species (note these are Australian Robins of the Petroicidae family – unrelated to the European or American Robins):

The Rose Robin, Petroica rosea, found in dense, wet forests
The Flame Robin, Petroica phoenicea, which prefers more open areas in heavy forest
The Scarlet Robin, Petroica boodang, common in open woodland
and the Red-capped Robin, Petroica goodenovii, found across the drier inland of the country.

You can see that each of these species are adapted to successively drier habitats.

Over geological time, Australia has gradually ‘dried out’, with the wetter forest types that formerly covered much of the continent now being largely restricted to coastal and highland areas. Thus the wetter forests are the older habitat, and the drying inland a new habitat to which Robins have adapted.

So I’m surmising that the wetter forest species, the Rose Robin, is probably the ‘oldest’, and the others have evolved from that species, leading to the Red-capped Robin being a more recent species adapted to a drying continent.

If so, then each ‘drier country’ species may be expected to have evolved successively. You can see a graduation in their plumage patterns, such as the successively larger size of the forehead ‘flash’, the darkening of the back and the deepening red of the breast color.

I was curious to find whether this was also reflected in their songs – whether you could hear evidence of a successive development in their song structure.

Here are the songs of these four Robin species:

As you can hear, each has a fairly recognisable, and quite pretty, little song. To assist appreciating what is going on in each bird’s song, I’m presenting sonograms of each.

The Rose Robin has what could be called a di-phonic melody, there are two melodic components to it, a higher pitched one, and a lower, the song weaving these together to create a lilting pattern.

The Flame Robin’s song doesn’t show these two clear upper and lower components. Instead they have been integrated into a more singular melodic line, although still showing a lot of rising and falling, ‘lilting’ movement.

By the time we get to the Scarlet Robin however, the single melodic line has ‘levelled out’ to being almost on one pitch.

So you can see a successive relationship quite clearly in the songs of the Rose, Flame and Scarlet species, which each have a similar dainty, twittery song.

However, the Red-capped Robin seems at first to have an utterly different song. It still has that dainty quality, but rather than the melodic ripple of the other red Robins, it is comprised of two repeated syllables. When you look closely at a sonogram, each syllable is actually a rapid trill, with chipping, ‘grace-notes’ before and after.

Is the Red-capped Robin’s song actually related to that of the other red Robins, when it sounds so different?

Lets go back to the Scarlet Robin’s song. If you look closely at the sonogram (and you can just hear it too if you have ‘quick’ ears), you will see a tiny pair of trills hiding among the sonic structure. One is almost not there at all, but the other is clear enough. It is the same trill structure as the Red-capped. And you can also find that the melodic components in the other Robin’s songs have de-volved to those little ‘grace-notes’ that bookend the Red-cap’s trills.

So you can both see and hear a progressive relationship in the songs of these four closely related Robin species that matches the changes in their chosen habitats.

Australia has other related Robin species, for instance the yellow robins, which look and sound quite different and are thus likely to be less closely related to the ‘red’ robins, and the Hooded Robin, who’s song does show similar structures and can easily be seen as just a ‘red’ robin that has lost its ‘red’.

What this leads to is an appreciation that, when you are outdoors surrounded by birdsong, you are hearing not just a unrelated variety of avian vocalisations, but a soundscape that has evolved.

It may not be evident until you listen closely, but you can actually hear the evolutionary history of our planet in the birdsong around you.

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These pics were not easy to get, as thornbills are continually on the move – even on this crisp and cold morning, when we awoke to our first overnight frost of the winter.

Such cute little fluffballs!

Chipping away continually as they glean out their breakfast from among the eucalypt leaves.

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After 11 years of deep drought in southern Australia, we have finally had record-breaking rains, and the landscape is coming back to life.

Most notably, the frogs have been very active, calling from wherever water has come to rest.

This recording is of a frog chorus from our bush dam, and features several species, most notably Pobblebonks, Limnodynastes dumerilii , or Eastern Banjo Frogs, with their wonderful, musical patterns of plonking notes. Also calling are two species of tiny Crinias, or Brown Froglets; c. signifera and c. parinsignifera, plus Spotted Marsh Frogs (loud “Tack!”s) and Brown Tree Frogs (whistling; “Weep-eep-eep-eep”)

With multiple species call in close proximity to each other, each needs to make itself heard. They do this by either focusing their calls into specific tonal bands (crinias and Brown Tree Frogs), or setting up rhythmically-spaced patterns of calls (Pobblebonks and Marsh Frogs).

This sonogram depicts a 15 second excerpt from the recording, and shows each species’ vocalisation quite clearly. (Time on this sonogram runs on the horizontal axis, and frequency on the vertical)

1. group of Pobblebonks
2. Spotted Marsh Frogs
3. Crinias
4. single Brown Tree Frog
5. “Roark” variation call of Pobblebonk (which sounds utterly different to its usual “Plonk!” call, but you can see it occupies the same frequency band).

The species here (especially those wonderful Pobblebonks) are featured on our album “Frogs, Frogs, Frogs“, along with a fascinating diversity of other frogscapes from around Australia.

Below is a sample from the album:

‘Frogs, Frogs, Frogs!’ – album sample by Listening Earth

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It is getting on for late summer, and the dawn chorus around our home is thinning out – it is still rich, but not as diverse or layered as even a few weeks ago.

On this recording, made at first light, you can hear the chipping of our numerous Yellow-tufted Honeyeaters as they wake up, the rich song of a Grey Shrike-thrush, a Yellow Robin, distant Kookaburras, the warm, booming calls of Bronzewing Pigeons, twittery reels from a Blue Fairy-wren, and the lovely caroling of Magpies.

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Yesterday I heard that a neighbour had located a nest tree nearby.

This season an adult pair have raised one healthy chick, and I spent some time not far from the nest tree, observing the juvenile bird as it rested and stretched on a windy afternoon.

Usually birds don’t like having the wind at their back, because it gets under their feathers, but this young bird didn’t seem to mind being ruffled at all.

Unlike the adult bird, with its white face, the juvenile has a soft rufous head. Another diagnostic of this species is that the wings when folded are longer than the tail.

Square-tailed Kites are rare birds where we live, their stronghold being Queensland, Northern Territory and SW WA. It has been thought that they didn’t breed below 35º S, but we’re at over 37º S, so it feels pretty special to have them doing their family thing around here.

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The last couple of weeks the bush has been booby trapped with their webs – when I have been walking or bike riding I often come back veiled in cobwebs.

So, in the cool of the morning I was out with my camera to photograph them as they lay in wait for their prey.

Jewel Spider

Golden Orb spider

Golden Orb spider, belly up.

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We recently received an email from a listener asking whether we had any recordings of Pied Butcherbirds from ‘up north’.

These wonderful Australian songbirds occur almost throughout the country, and in broad regions such as the outback, the south-west or the far north, their songs are subtly different.

Personally, I feel the Pied Butcherbirds from the outback sing the most melodiously, and recordings of them have appeared on several of our albums, notably Spirit of the Outback.

However our listener wrote: “Where I live now in the northern suburbs of Perth, the Pied Butcherbird sings a very different song. You can still hear what bird it is, but the song I love so much of their northern cousins just isn’t there.

So, I dug around in our audio library and found this recording made in a suburb of Darwin at dawn. As well as the Pied Butcherbird going through his repertoire, you’ll hear house geckos ‘chapping’, the distant calls of a Koel Cuckoo, and at one point, a domestic Peacock!

You may download this audio file by clicking on the arrow link in the player. Enjoy!

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Transcribing birdsong to musical notation is problematic, if not well-nigh impossible. Birdsong is just too sonically complex.

However the songs of some species do lend themselves to musical interpretation, and the sublime melodic phrases of Australia’s Pied Butcherbird have long fascinated musicians.

Our Spirit of the Outback album begins with a recording of a Pied Butcherbird singing languorously at 3am, its voice echoing off the walls of Ormiston Gorge in central Australia. The bird sings beautifully, and it has always been among our favourite nature recordings.

(See our blog about this recording here).

Recently we heard that an Anglo-Trinidadian composer, Mark de Brito, had been inspired by our recording, and adapted the Butcherbird’s song into a short piece for flute with piano accompaniment. He has entitled the piece ‘Saraband for a Butcherbird’ – a saraband being a slow dance in three, with an emphasis on the second beat.

Mark writes:

“I wrote the Saraband piece in February 2008. The flute part is intended to be a close transcription of the recording of a pied butcherbird from ‘Spirit of the Outback’. The piano part, which somewhat resembles the style of Erik Satie, has a very different rhythmic structure. The piano part also has repeats (AABB), and this has the effect of dividing up the birdsong in a very arbitrary fashion. The harmony worked because I could adjust the length of silences in the flute part to fit.

“While the technical choices I made in writing the piece were very simple, the resulting piece is actually quite intricate in phrase structure. The piece raises some interesting philosophical issues about music and nature.”

I think Mark’s piece works well, being both enjoyable to listen to as music, and authentic to the original birdsong. I’ve heard many attempts to bridge the gap between the human language of music and the organic sounds of birdsong. The French composer Messiaen’s transcriptions come to mind as successful efforts, with new-age pastiches being far less so.

Mark’s piece avoids simply reducing the Butcherbird’s vocalisation to being ‘a tune’. And his piano accompaniment lends an otherworldly and serene air that, for me, reflects the mystery of the natural environment.

What do you think?

Note: Mark has made his piece freely downloadable. Click on the download link on the audio player at the beginning of this blog.

Here is our original Pied Butcherbird recording, which can be heard in full on our ‘Spirit of the Outback‘ album (available from our website as CD or download))

Pied Butcherbird at Ormiston Gorge, 3am by Listening Earth

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I have been out early today with my new 100mm macro lens to photograph the delicate Brown-clubbed Spider Orchids, (Caladenia phaeoclavia), that are flowering on the south side of our ridge. They are no longer in their prime and the end of their sepals are starting to wither, but they are still very beautiful.

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