Much like the previously covered Dingoes (see episode 243: Down Under With Dingoes), the quirky Kookaburra is an icon of Australia’s wildlife. Famed for its cackling ‘laugh’, this large kingfisher is a much loved and common sight in Australia’s native eucalyptus forests.
Taxonomy, evolution and history
The Laughing Kookaburra is a member of the order Coraciiformes, which contains birds with heavy heads, short necks and legs and large bills, including other kingfisher species, bee-eaters, mot mots and toadies. There are 4 species of Kookaburra found in Australia, New Zealand and the islands that surround them, including:
- The Rufous Bellied Kookaburra (Dacelo gaudichaud): found across Lowland New Guinea (top left)
- The Spangled Kookaburra (Dacelo tyro): found across the Aru islands and Southern New Guinea (top right)
- The Blue Winged Kookaburra (Dacelo leachii): found across Northern Australia and Southern New Guinea (bottom left)
- The Laughing Kookaburra (Dacelo novaeguineae): found across Eastern Australia and has been introduced into South Western Australia, New Zealand and Tasmania (bottom right)
These images were taken from eBird. Please check out this app and help count birds worldwide! It is provided free by the Cornell Lab of Ornithology.
Quasisyndactylus is an ancient bird species that is small in size with a large, flattened bill that lived around 40-48 million years ago and is the earliest known ancestor of the kingfishers we see today [1]. When scientists carried out genetic studies of the Australian Kookaburra species, they found that across their wide ranges there is very little genetic variation, despite the changes the continent has gone through over thousands of years. This means that the birds likely were able to utilize habitat across the whole of Australia, giving some hope for the species resilience in the face of climate change and habitat loss [2].
A Quasisyndactylus longibrachis fossil (image taken from http://evolutionaryvertebratezoology.blogspot.com/2012/01/messel-on-tour.html)
The Kookaburras Cultural Connotations
The Kookaburras instantly recognizable cackling laugh and its charismatic looks and personality has given these merry kingfishers a permanent place in Australian cultural history. The Aboriginal people have many tales about the Kookaburra in their Dreamtime Stories, the unique myths and legends that different tribes hold. The tendency of the birds to ‘laugh’ at dawn meant that they were associated with the rising of the sun, and in Aboriginal creation myths they were important for the turning of the day to night and the waking of all the other animals. Despite this, in some myths the so called ‘derisive laughter’ of the birds meant that some native people viewed them as bringers of misfortune.
When early settlers arrived, they were understandably a little freaked out by the cackling sounds emanating from the dense bush and eucalyptus trees, and often referred to the noise as the ‘cackling of a madman’ or a ‘laughing demon’. However, over time, people gained appreciation of these feisty kingfishers, and after they were frequently observed predating on snakes, they were viewed as ‘brave snake killers’, ridding hard working rural people of the verminous reptiles. They have been displayed on postal stamps, military badges, sports teams’ uniforms, in art, music and poetry. Now these cheery birds are an essential part of Australia’s fauna and flora [3].
An image from the Marylebone Cricket Club tour of Australia in 1936/37 that cemented its place as a snake killer (image from Kookaburra, King of the Bush, Sarah Legge).
The kookaburra being utilized as a symbol of Australian nationalism during the wartimes and its incorporation into the badges of several military units. (Image from Kookaburra: King of the Bush, Sarah Legge)
Range and Habitat
The laughing Kookaburra can be found from the tip of Cape York in Queensland down through the East Coast to the Eyre peninsula in Southern Australia. The species was also introduced into Western Australia and Tasmania.
There are two recognised subspecies of the laughing Kookaburra:
- Dacleo novaeguineae novaguineae : the slighter larger of the two that can be found throughout the range.
- Dacleo novaeguineae minor: slightly smaller of the two, they are suspected to have slightly larger clutch sizes and are found only in the Cape York Peninsula.
Their habitats can be anywhere from 16-244 hectares, although larger groups may need larger territories. Kookaburras need tree hollows to nest in, usually in Eucalyptus forests, but sometimes in wooded or cleared farmland, so they can be found anywhere where such trees exist. They are a frequent delight in city parks and even suburban gardens, although I would imagine they may not be so welcome when you’re trying to sleep in a little bit!
Kooky physiology, sibling rivalry and family ties
The laughing Kookaburra is the largest kingfisher in the world, and somewhat unusually the female is slightly larger than the male. The birds have forward facing toes that are joined at the base of the foot for one third of their length, a distinct feature called ‘syndactyly.’ [4] They have a bony ridge on their skull where their extra tough muscles attach, allowing them to have the strength to bash their prey, as often seen with snakes, earning them the moniker of the valiant snake killer [5]. Animal anatomists took an extra close look at the Kookaburras eyesight, as they were known to be able to detect prey from very high above and rotate their heads to be able to use binocular rather than monocular vision, like falcons have been known to do. They were found to have an area especially rich in receptors called the fovea (we have one just like it, only not as spectacular as the Kookaburras) that gives them an exceptional ability to detect the movement and the position of prey [6].
One feature of their physiology has a more sinister role to play. Juvenile kookaburras have a hook on their upper beak that disappears as the bird grows, which most researchers believe is used to kill their siblings in the nest. Talk about sibling rivalry!
In fact, studies of Kookaburra nests have shown that one third of nestlings die within days of hatching, with much of this being attributed to siblicide [7]. Likely this is to reduce competition for food, as the second biggest killer of juvenile Kookaburras is starvation. It’s a tough life being a baby Kookaburra; if your sibling doesn’t clock you over the head with their killer beak, you’re likely to starve!
But its not all siblicide, starvation and sadness; kookaburras form tight, nuclear family groups of a monogamous pair and up to 6 helpers that assist the breeding pair with feeding young. The females will often leave the group within the first year after they hatch and fill a spot in another group or form a new group with an unattached male. Researchers are not entirely clear why they do this, as fledgling survival isn’t improved in the presence of more helpers, but they suspect it could be a way to ensure all members can reduce their parenting effort by spreading the load between them all [8]. Many hands (or should that be beaks?) make light work after all! Even their cackles are group dependent; researchers analyzing recording of Kookaburra dawn and dusk choruses found that each group has a unique signature in their songs that helps to identify them and mark and defend their territory [9]. So, their cackles aren’t just a load of noise.
Threats and conservation
Fortunately, the Laughing Kookaburra is currently listed as Least Concern on the IUCN red list [10] with a 2019 assessment putting an estimated number of birds at around 65,000,000 and population trends staying stable. Approximately 590 birds are in captivity in zoos across the world [11], which means there has been plenty of great behavioral and husbandry research. Kookaburras are protected under Australian law, along with many other iconic Australian birds.
But despite this positivity, these kooky kingfishers could be just as at risk as so many species across the globe. Birdlife Australia has reported a 50% decline in sightings between 2000 and 2019 [12], and there are big concerns about habitat destruction and fragmentation Kookaburras are especially dependent on Eucalyptus trees for nesting and so loss of eucalyptus forests will have a big impact. As seen in the 2020 fires in Australia, Eucalyptus trees are unfortunately very flammable because of their gummy resin and oily leaves, so they are fuel for the sadly increasing, devastating megafires. If we can work together globally to combat climate change, hopefully we can reduce the chance of wildfires. In Australia, the more land we can protect the better, to keep home for the wonderfully kooky, quirky, kookaburra.
References
[1] https://animals.sandiegozoo.org/animals/laughing-kookaburra
[2] Dorrington, A. Joseph, L. Hallgren, W. Mason, I. Drew, A. Hughes, J.M. Schmidt, D.J. (2020) ‘Phylogeography of the blue-winged kookaburra Dacleo leachii across tropical northern Australia and New Guinea.’ Emu – Austral Ornithology, 120 (1) pp 33-45
[3] Kookaburra: King of the Bush, Sarah Legge, 2004, Csiro Publishing
[4] The Life of the Kookaburra and Other Kingfishers, W Eastman, 1970, Angus and Robertson Publishing
[5] Kookaburras, Veronica A Parry, 1970
[6] Moroney, M.K and Pettigrew, J.D. ‘Some observations on the visual optics of kingfishers (Aves, Coraciformes, Alcenidae).’ Journal of Comparative Physiology, 160(2), pp 137-149
[7] Legge, S. (2000) ‘Siblicide in the cooperatively breeding laughing Kookaburra (Dacleo novaeguineae).’ Behavioural Ecology and Sociobiology, 48(4), pp 293-300
[8] Reyer, H.U. and Schimdl, D. (1988) ‘Helpers have little to laugh about: group structure and vocalisation in the Laughing Kookaburra Dacleo novaeguineae.’ Emu ; Austral Ornithology, 88(3), pp 150-160
[9] Baker, M.C. (2004) ‘The chorus song of cooperatively breeding laughing kookaburras (Coraciiformes, Halcyonidae: Dacleo novaeguineae): characterization and comparison among groups.’ Ethology, pp 110(1), pp 21-35
[10] https://www.iucnredlist.org/species/22683189/92977835
[11] http://www.belfastzoo.co.uk/animals/laughing-kookaburra.aspx
[12]http://datazone.birdlife.org/species/factsheet/laughing-kookaburra-dacelo-novaeguineae
Massive Thank You to Rachael Da Silva from the UK! Please follow her on Instagram and her wildlife artwork at tilly_mint08
