Birds. There are a lot of birds in Australia! I count over fifty species of parrots, over twenty five species of dove and pigeons, and over seventy species of honeyeaters and closet kin. All in all there are approximately 800 species of birds living across the Australian continent. But this doesn’t mean that they are necessarily easy to see. There are some interesting explanations of just why this is so, hopefully which I can make clear. But when you do see one, wow! Just look at this picture of a galah, a type of parrot. I bet you have never seen a prettier bird.
First, Australia is a continent of change. Annual patterns in climate are not super predictable and thus animals have evolved to take advantage of moving resources. For example, although an area may get plenty of rain one year, it may not the next year. Species either move and follow the riches or they must hunker down and wait out the hard times, perhaps not breeding, perhaps experiencing population slumps. And so the bird watcher must be flexible in where they go and what they hope to see.
Second, the Australian continent is a nutrient poor landmass and this affects bird populations as you will see. Australia is rather ancient and most mountain building and volcanism ceased millions and millions of years ago. In broad areas, the important nutrients have washed off the land and gotten lost in the bottom of the sea. In some ways it reminds me of a Virginia or Carolina farm that has entered its terminal period because of the soil nutrient losses incurred on it though tobacco and cotton farming over the last two hundred years of potentially poor agricultural practices. So in Australia the density of individuals in any particular population or bird community are lower than what one might expect because the old soils are just plain worn out and don’t provide the plant community with a super abundance of nutrients for excessive and vibrant growth. This in tern affects their fruiting and seed production as well as the insects that eat those things and all other animals up the food chain.
Third, bird watching in Australia can be challenging because the birds have this uncanny ability to hide behind the barest of foliage. Many of the Australian trees have relatively thin canopies (not necessarily true in the few coastal rainforest tracts). It is my understanding that since most of the continent has a fairly harsh climate with hot sun, low precipitation levels, and strong winds, trees minimize water loss by having fewer leaves. It is totally amazing to watch a flock of crimson rosellas zoom in and lite in a treetop fifty feet away and you won’t be able to see a single one! Here is a picture of a crimson rosella and clearly you won’t understand how a big, bright red parrot could disappear. I think that predation pressures on birds has helped shape the evolution of behavior so as to minimize getting eaten!
Fourth, besides the disappearing trick, birds here seem to be constantly on the move, rarely sitting still so the bird watcher can get a decent look. And the thornbills are amongst the worst offenders. I have almost given up trying to identify these little guys! I think all this flitting about is the result of two things. First, as in the above topic, birds don’t want to be someone else’s dinner. A moving target is harder to catch. And second, because of a previous topic, food resources are scarce. It’s hard to know what many species are eating up there but I am guessing if they are insect eaters, the insects are not abundant and if they are nectar eaters (like the many honeyeater species) tiny sips of nectar from hundreds and thousands of different flowers is what it takes to stay alive. So birds have to constantly flit through the canopy to find enough to eat.
Fifth, those bird species that do live in the rainforests have lots of cover to hide in, just as birds do in all rainforests of the world such as those in Costa Rica. The east coast of Oz does indeed have a thin strip of tropical forest stretching in parts from Sydney to northern Queensland. We have spent months plying some of the rainforests around Coffs Harbor on the central coast and have only seen the noisy pita a few times. And that’s just one example from the rainforest. But probably one of the more elusive birds for us, the ground parrot, lives in dense waist-high shrubbery in a coastal heath community not far from rainforest habitat. We have never seen one and most people we know have not seen one either. As their name implies, they stay close to the ground and don’t often fly above the level of the heath. And my is the heath dense! Impossible to walk through; it would probably stop the speeding arrow from a strong bow in a few meters.
Fortunately, there are lots of exceptions and easy to see birds which continue to motivate the dedicated bird watcher. This is a picture of a tawny frogmouth (sorry about the red-eye flash effect). These birds are nocturnal, eat mostly insects, and if located during the day, freeze in the position of a dead branch, hopefully to elude detection. Like for an owl, other species of birds become alarmed if a tawny frogmouth is discovered during the day (they do look like a bird of prey). I once witnessed a poor frogmouth being tormented by a whole mob of birds, the worst offender was the kookaburra who was intent on pulling on the tail feathers of the motionless frogmouth. The frogmouth finally retaliated by opening its mouth as wide as possible, which was very wide, and threatened the kook. He got the message and flew off with the other birds.
I’ll end this post with our favorite Australian bird, the satin bowerbird which we are conducting our research on. We have gotten some stunning video footage of bowerbirds for we always know exactly where to leave the hidden, spy camera! You see, the male builds his bower and maintains it throughout the year. So if you know where to look, you can easily see satin bowerbirds. In these photos, the male is at his bower, displaying to no one in particular. In the first, he’s holding one of his favorite display objects in his beak–a bright blue ring from a bottle. In the next photo he is holding another one of his special objects, a natural-yellowed banksia leaf. In the final photo, he has the best of both worlds, a combination preference we have witnessed countless times with many bowerbird males. Exactly what is the allure of a blue ring and a yellow leaf we will never know :-). But obviously, the female bowerbirds are smitten by this behavior for if they weren’t, the males wouldn’t do it! Ah, female choice drives evolution once again…..