Few animals, like the cassowary , represent what those terrifying animals that lived tens of millions of years ago must have been like. Despite its appearance, it is a relatively modern animal – although it is still a dinosaur, like all birds. Its lineage dates back to sometime between the late Oligocene and mid-Miocene, between 24 and 15 million years ago, at which point it split from the lineage of its closest evolutionary relatives, the emus .
Four species of cassowary are known in the world, three of them still alive, all distributed in the same region: the island of New Guinea, Yapen, the Bismarck archipelago, the Raja Ampat islands and two small areas of the northeast coast from Australia. The three species are considered by the IUCN in the category of least concern.
All species are characterized by their robust and strong legs , in which the second toe —the innermost— has a terrible dagger -shaped claw , which can exceed 12 centimeters in length. Although this trait, along with videos and accounts of its aggressiveness, has earned it the unfortunate title of “the world’s most dangerous bird,” it actually only attacks humans when it feels truly threatened and finds no way to escape. They are born runners , they can reach speeds of up to 50 kilometers per hour, and amazing jumps of more than a meter and a half; if in an encounter, they have the option, escape will be their priority.
It has a very striking plumage. It lacks the typical feathers of flying birds on the wings and tail, long, divided, regular and asymmetrical. Cassowary feathers look like they were taken from some kind of prehistoric dinosaur , fine, stiff and keratinous, sometimes so hard that they can resemble the spines of a porcupine.
But perhaps the most striking feature of the cassowaries is their helmet , a ridge of keratin covered with skin, which they wear on the top of their heads, and grows with age.
the four species
The unicarunculate cassowary ( Casuarius unappendiculatus ) inhabits the entire northern coast of New Guinea, Yapen Island, and Raja Ampat Batanta and Salawati Islands. It is a large and imposing animal; the male can exceed 30 kilos in weight, and the adult female 55 kilos . They reach the height of a person. It constantly suffers from the loss of its habitat, and in some regions it is even preyed upon by hunters; its population is estimated between 10,000 and 20,000 individuals, and decreasing.
Traveling south, in the central belt of New Guinea and the island of New Britain, we found the lesser cassowary ( C. bennetti ). As its name indicates, it is the smallest of those who remain alive; It weighs between 17 and 26 kilos and measures no more than a meter and a half. So far we do not have data on its population, although it is thought to be relatively stable.
The largest of the three species occurs in the southern half of the island of New Guinea, on Malucu Island, and off the northeastern coast of Queensland, Australia. An adult specimen of the common cassowary ( C. casuarius ) can weigh 85 kilos and one meter ninety in height, making it the second largest and heaviest living bird in the world, after the ostrich. Its population is estimated between 20,000 and 50,000 individuals, and decreasing.
We have fossil evidence that, during the Pleistocene period, between 2,500,000 and 11,700 years ago, the so-called pygmy cassowary († C. lydekkeri ) lived on the island of New South Wales. There is only one fossil of this animal, and a very limited one: the distal end of the tibiotarsus, that is, the lower part of the calf. But it was enough to identify it as a cassowary, related to the lesser cassowary, but of a different species.
The cassowary and its ecosystem
The cassowary is an omnivorous animal . It can feed on fungi, insects, small reptiles and mammals. It has no qualms about scavenging if it finds a body, but it is not usual. Their largest food source, however, is fruit . It can even eat fruits that are toxic to other animals. In fact, cassowaries are the largest frugivorous animals in the region they inhabit.
They eat an enormous number of fruits per day, and the seeds are capable of withstanding passage through the digestive tract . In this way, these large birds help to disperse the seeds. But in addition, digestion helps many of those seeds to increase their chances of germinating and to make it happen faster. up to 35 % of the plants you consume benefit from these effects .
This facilitating function with respect to seeds makes cassowaries a key part of the forests they inhabit , helping to maintain them and promoting their recovery.
Unfortunately, in New Guinea there is a constant demand for cassowary meat for human consumption. And although attempts have been made to regulate their hunting, and they are beginning to be raised on farms —to avoid indiscriminate hunting—, so far it has not been possible to achieve a level of sustainable hunting of cassowaries .
REFERENCES:
BirdLife International. 2016. Casuarius bennetti. IUCN Red List of Threatened Species. DOI: 10.2305/IUCN.UK.2016-3.RLTS.T22678111A92755192.en.
BirdLife International. 2017. Casuarius unappendiculatus. IUCN Red List of Threatened Species. DOI:
10.2305/IUCN.UK.2017-3.RLTS.T22678114A118134784.en
BirdLife International. 2018. Casuarius casuarius. IUCN Red List of Threatened Species. DOI: 10.2305/IUCN.UK.2018-2.RLTS.T22678108A131902050.en.
Bradford, M. G. et al. 2010. Consequences of southern cassowary ( Casuarius casuarius , L.) gut passage and deposition pattern on the germination of rainforest seeds. Austral Ecology, 35(3), 325-333. DOI:
10.1111/j.1442-9993.2009.02041.x
Evans, J. W. 1962. The History and Significance of the Fossil Casuarius lydekkeri.
Records of the Australian Museum, XXV(10), 235-238. DOI: 10.3853/j.0067-1975.25.1962.662
Worthy, T. H. et al. 2014. Phylogenetic relationships of the Australian Oligo-Miocene ratite Emuarius gidju Casuariidae. Integrative Zoology, 9(2), 148-166. DOI: 10.1111/1749-4877.12050
