Nocturnal Birds

Not all of our bird life is active when we are. There are a whole suite of birds that only become active once the sun goes down. Nocturnal birds are elusive, mysterious and often less well understood than their day-active cousins. They are essential regulators of food webs as predators of mammals, birds, frogs and invertebrates. Adaptations to nocturnal life such as exceptional eyesight, hearing and a good sense of smell, give this special group of birds unparalleled hunting prowess. As nocturnal birds are cryptic in both plumage and behaviour, they can be difficult to detect.

There are a wide range of different nocturnal birds. Within the owls, there are five masked species belonging to the Tyto genus, and five Ninox or ‘Hawk owl’ species , distinguished by large yellow eyes. Owls hunt with their powerful talons and rip into prey with small curved beaks. We also have the genus Podargus or ‘Frogmouths’, which differ from Owls in hunting with their big, flat beaks. There is also the genus Eurostopodus and Caprimulgus or ‘Nightjars’, and the genus Aegotheles or ‘Owlet-nightjar’.  
Then there are also birds like the Bush Stone-curlew and the ever elusive Night Parrot that are nocturnal as well and a range of day-time birds like Willie Wagtails, Eastern Koels and Masked Lapwings that will also call a lot at night, particularly during their breeding season.

Identifying Nocturnal Birds

Sometimes finding nocturnal birds requires more than your eyes. Listening for mobbing by day birds, can help you locate an often highly camouflaged owl or nightjar. You can also find nocturnal birds through the signs of their activity such as regurgitated pellets or prey remains. White wash, the paint-like areas of urates from faeces, is often typical under roosts of many nocturnal birds. To identify which species of bird you are looking at, remember to look at body size and beak shape first, and plumage characters second. Of course you may also be woken by the amazing call of one of our nocturnal species. Take a listen to some of our nocturnal birds by checking out their fact sheets below and see which you may have heard. You can download a pdf guide to all Australian nocturnal owls, frogmouths and nightjars here. 
 

Threats to Nocturnal Birds

Nocturnal bird habitat is increasingly at risk from rapidly expanding urbanisation and development pressure. Deforestation and habitat fragmentation continues to escalate in both urban and rural areas in Australia, with only 16% of Australia now forested and the 2019/2020 bushfires have significantly impacted the distribution of many of our nocturnal birds. In urban areas, large hollow-bearing trees, which are used annually by most nocturnal birds to nest, are often removed for safety and to reduce risk to infrastructure. For many nocturnal birds these old, hollow-bearing trees take several hundred years to develop and are now critical habitat in urban environments - further, there is fiece competition from native and introduced animals for the remaining hollows. Whilst retaining hollow-bearing trees is essential for many owl species, understorey vegetation is important for many other night birds. Grass owls nest on the ground in open grassy areas under tussocks or sedges, whilst Nightjars often nest in scrapes on the ground amongst leaf litter.
The urban environment does impact nocturnal species differently. Some, such as the Powerful Owl seem to be more common in our cities now. These owls can do well in forested urban green spaces due to a ready source of prey (e.g. possums, birds and fruit bats), however increasing rates of development pressure are threatening key habitat features like tree hollows and roosts and collisions with cars and windows are signficantly impacting the population of many nocturnal species. If we wish to keep owls and other nocturnal birds in our urban neighbourhoods, targeted management practices that work to retain or rebuild key habitat features and mitigate threats are essential. 

In North Queensland, populations of Barn, Masked and Grass Owls have dramatically declined as the use of pesticides to protect sugar cane crops from rodents has increased. Owls can be killed by ingesting poisoned rodents. Insectivorous nocturnal birds, such as Frogmouths and Nightjars are also highly susceptible to secondary poisoning, particularly from termiticides. To avoid secondary poisoning pest control needs to use poisons that have no secondary transfer, and that are single dose rather than multi dose.

If you are interested in getting involved in a nocturnal bird citizen science project, find out about our Powerful Owl Projects running in Sydney and Brisbane. Its a great way to learn about some of our amazing nocturnal birds and contribute directly to the research and conservation of a threatened species.