Winter this year has been cold and wet, and I’ve gotten sick more than once, so no field trip happened this month. I have however been reading ‘Where Song Began’ by Tim Low, which has been very interesting, and has taught me a lot of things about Australian (and international) birds and biogeography that I didn’t previously know.
‘Where Song Began’ presents evidence that many of the world’s birds – including all of the world’s songbirds and parrots – are descended from species that originally evolved in Australia or Gondwana and dispersed from here to populate the rest of the world. The book also explores the complex interrelationships between Australian birds and vegetation, including bird dispersal of seeds and pollen explaining some national and international plant species distributions, and the role of nectar-feeding and bird-driven pollination in the development of Australia’s characteristic suite of big, loud, aggressive, gregarious, often colourful birds. It’s a very interesting book, and I recommend it to anyone interested in learning more about Australian bird ecology and evolution.
‘Where Song Began’ starts with a discussion of how sugar as an abundant bird food-source (in nectar and other forms) drove the development of large, aggressive birds such as honeyeaters. Subsequent chapters discuss parrots (many of which are also large and aggressive), lyrebirds (very large), and cassowaries (frankly enormous), amongst other species.
A repeated message is that, compared to much of the rest of the world, Australia has BIG birds. Certainly we have very small bird species as well, and other continents support very large birds, but on the whole, the birds that most Australians are most familiar with tend to be larger in size than the majority of birds most familiar to people in many other parts of the world.
This then got me thinking about other books I’ve read over the years that referenced bird sizes, and my own gradual journey to the understanding that Australia’s birds are actually quite large by most standards.
Growing up, one of my favourite novels was ‘Freckles’ by Gene Stratton Porter. The story was written in the early 1900s and is about a young man named Freckles who is hired by a lumber merchant to protect a valuable patch of timber in the Limberlost Swamp in Indiana from illegal felling by timber thieves. Freckles falls in love with the swamp, and the rich diversity of plant and bird life there, and adopts a breeding pair of vultures, which he refers to as his ‘chickens’. The ‘chickens’ are identified in the book as Cathartes atrata or ‘Black Vulture of the South’. When I was a child we didn’t yet have internet, so I was never able to look up Freckles’ chickens and see what they looked like, and a Google search today has found no species named Cathartes atrata, so I’m assuming the name has been changed in the last 100+ years, or possibly the species has gone extinct. I have found an American species called Coragyps atratus, aka Black Vulture, which has a southerly distribution, and belongs to the family Cathartidae, so perhaps that’s it, although it might not be. (I also found this historic bulletin entry recounting what sounds like the first official listing of the presence of Cathartes atrata in Virginia in the late 1800s, which is cool.)
When Freckles first sees the vultures he’s startled by their size. To quote the book: ‘He had seen some owls and hawks of the swamp that he thought might be classed as large birds, but never anything like this, for six feet it spread its big shining wings. The sun glinted on its sharp, hooked beak. Its eyes glowed, caught the light, and seemed able to pierce the ground at his feet.’
As a child, this was always a bit confusing to me, owls and hawks being not terribly larger than most birds of my acquaintance, and significantly smaller than wedge-tailed eagles and emus, both of which live in my local region and formed my original baseline for ‘large birds’ (indeed, the park down the street from my house had captive emus, so I literally grew up beside birds that were originally taller than me). I could concede that the vultures were pretty big, but couldn’t understand why Freckles thought the owls and hawks counted as ‘large birds’.
I’ve never been overseas, and am therefore only familiar with most international bird species through pictures, many of which lack meaningful size comparisons (and to be perfectly honest, I don’t look up international bird species very often, unless I have a particular reason to). It wasn’t really until last year that I actually understood how much larger my familiar suite of ‘normal-sized’ birds is compared to the suites of ‘normal-sized’ birds common to many other parts of the world. Last year I read ‘Wild Hares and Hummingbirds’ by Stephen Moss, a naturalist from the Somerset Levels in the UK. Throughout the book he mentions multiple species of birds common to his local patch, many of which I’d never heard of, and which I decided to look up on online. So many little tiny, brown, twittery things. I would not have the slightest hope of being able to tell them apart, but Stephen Moss was rattling them off like they were as easy to tell apart as a corella from a sulphur-crested cockatoo. This brought home to me rather abruptly that huge numbers of great big, loud, obvious, colourful, easily-identified birds are probably rather unusual by many people’s standards.
As I mentioned above, Australia – including my local patch – has its own share of little brown twittery things, but they don’t form the majority of the bird fauna I see on a regular basis – by my standards these are small to very small birds, and species the size of galahs and magpies are ‘average sized’. I’m now coming to realise that my perception is skewed, and the birds I consider to be ‘average’ or ‘medium’ in size are, globally speaking, large birds. I would like to thank the above-mentioned authors – and all those photographers on the internet – for helping me to come to this realisation and gain a greater understanding of both Australian and international bird species and the similarities and differences among them.
Also, I highly recommend the three books I mentioned – they’re all really good reads.