Boxing Baudin's

Each morning during this fabulous season of Djeran I wake to the glorious sounds of a large flock of magical Ngolyenoks, the Noongar name for our endemic white-tailed black cockatoo species, leaving their roost site near my house in the Perth Hills. Most of the flock are Baudin's Cockatoos (Calyptorhynchus baudinii), the white-tailed species with a long bill, with a handful of Carnaby's Cockatoos (the shorter-billed variety) among them. Although Baudin's is a common visitor to this area during the non-breeding season, it is not known to breed further north than the Wungong catchment, preferring to migrate to the deep south to breeding sites in the wetter Karri forest.

Over the past few weeks, however, I've observed some very interesting prospecting behaviour.  During mid mornings and late afternoons, when most of the flock has dispersed into the surrounding forest to feed, pairs of Baudin's have floated quietly in to land in the tree-canopy and inspect a variety of nest boxes in my backyard, including those designed for much smaller species like parrots and ducks. In most instances, the male has sat near a box while the female has looked inside, chewed around the entrance, and (with the larger cockatoo box pictured above), climbed inside for a closer look.

This box is a bit small for a cockatoo! Luckily it's reinforced with metal to stop that beak!

As with many creatures (wink, wink!), females are the dominant sex and I've watched them aggressively pushing the males away from the nest box entrances. Some of this behaviour is captured in the below video, which shows a pair of Baudin's inspecting a nest box installed in 2012. This box was successfully used by Maranganna (Australian Wood Duck, Chenonetta jubata) and Dowarn (Australian Ringneck, Barnadius zonarius) last breeding season.
 
White the WA Museum tells me that Baudin's Cockatoos often prospect for nest sites in the Perth Hills at this time of year but still end up moving away to breed, I remain hopeful that this wonderful, endemic, forest-dwelling species of south-west Australian bird might breed here later in 2016. Given the Carnaby's Cockatoo magic we had last year, I think there's a good chance!

You can read more about the breeding biology and conservation of our beautiful black cockatoos at the WA Museum's Cockatoo Care website. Note: For Noongar bird names, I refer to Abbott 2009's paper which states the two white-tailed species were not distinguished.

Prospecting Baudin's from Simon Cherriman on Vimeo.

Eagles at the Museum

Our fabulous West Australian Museum, which is the source of an incredible wealth of knowledge about WA's natural history, is in the process of updating some of its public educational material, which will create a brilliant resource for environmental educators. I am very privileged to have had a few of my images used in a recent information sheet that the museum produced on Wedge-tailed Eagles. My heartfelt thanks to Ron Johnstone, a friend and mentor in ornithology over many years, for creating this opportunity to share these pictures. Visit this link to read this and other extremely detailed and useful information.

Gardening for Wildlife

Gardening for wildlife is easy, educational and fun! As I've found in the past 10 or so years, there are amazing rewards to be had from creating wildlife habitat in your backyard. Today's Ed! Magazine in the West Australian newspaper features a double-page spread I wrote about this very topic. The above image shows the feature article as printed in the paper. Click here to *open and download the PDF version and read all about how you can encourage native animals to share your outdoor space! You can also browse this blog or use the 'search tool' (above, top left) to look for posts I've written that might give you ideas and inspiration on how to engage with wildlife in your area.

*I've noticed the text on this PDF looks a bit odd in some browsers. Downloading the whole document ensures it appears as normal.

Out of the Mud

How animals survive the baking Bunuru (summer) heat, which is becoming increasingly harsher each year, never ceases to amaze me. Humans rely on staying cool at the pool, beach or inside with the air-conditioner on, but our wildlife has evolved a variety of strategies to cope with the harsh conditions. Often the trick to keeping alive involves going underground.

Above is an image I took earlier this year of a wetland that I have been revegetating for over 10 years. As you can see here - it's not very wet! However, recent Djeran rains (which have signalled an unusually 'good' start to this El Niño year), have begun to moisten the soil of Perth Hills creeks, and even allowed some wetlands (including the one above) to begin filling up. The liquid messages have reached our subterranean residents and informed them about the new season of life emerging up top. While checking the water levels of my dam over the past few days, and delighting at how fresh and clean the water is, I've noticed one particularly beautiful animal emerging from beneath the softened clay and becoming active: Booyi, the Noongar word for the Oblong Turtle (Chelodina colliei).

Look closely at the above photo (click to enlarge it) - can you see the turtle in the foreground? When I first glanced at the checkerboard appearance of the dam, I saw nothing but an inundated and very cracked muddy bottom. But then one fragment seemed to be rounder than the rest, and I noticed a long neck begin to move! I watched the Booyi swim very slowly forwards then stop in a small, dappled patch of sunlight, apparently basking for a few rays of afternoon warmth. It was obviously quite cold, as its movements were very slow (Oblong Turtles require a minimum temperature of 18˚C to remain active), and when I moved forward and squatted down to have a closer look, it stayed put (normally these animals are very wary and swim swiftly away at the first sign of danger). As I crouched silently next to the water, the Booyi rose its long neck upwards and pushed its delicate nostrils through the surface to breathe. It was such a beautiful moment to witness from close range!

Being so close to the water made me notice a cloudy section between the cracks, where something had disturbed the mud, and I then spotted a second turtle! This one was still mostly buried beneath a large lump of clay, with only the shape of one side of its shell being visible.

  An active Booyi swims past one that is still well buried beneath the mud (shown by the arrow).

Looking to the opposite bank I then spotted a third turtle attempting to hide between cracks in the mud. As you can see below, this turtle was a little less camouflaged than the previous one: its red-brown stain tells us this individual has come from deep beneath a part of the dam with different coloured mud.

The turtle eventually disappeared deeper, and I noticed it had apparently excavated a small cavity beneath the cracked lump of clay (to its left in the above photo). Oblong Turtles are known to aestivate (go into a state of metabolic 'dormancy') during summer months, and I considered this might even be where this turtle had spent the long summer, when the dam was dry. And after the first rains, perhaps these muddy underwater 'caves' are suitable daytime hiding places while the dam's water is very shallow, and not covering the rocks, logs and reed beds which will offer protection once the water level rises?

I began searching the dam more thoroughly and spotted one more Booyi. This individual was in a very unusual position, hiding on its side in a large crack in the clay, a very well-concealed spot. Before I moved closer to photograph it, I noticed the turtle's eye was closed (or maybe both - I could only see one!), a possible indicator the animal was brumating (a term used to describe dormant behaviour triggered by cold temperatures, the 'opposite' to aestivating).

The water might have initially brought them out, but with only small patches of low autumn sun hitting the water, these solar-powered animals swim a fine line between stop and go!

It's not only adult turtles that find refuge below ground. You can read more about how the young of this species start their lives in this news post. In the meantime, I will observe the movements of the adult Booyi to see if they remain present in the shallow, clear water, and if their activity increases when the dam fills up and the daily temperatures increase. An interest in natural history means there is no such thing as boredom!

Goanna Tweets

While working at my desk over the warmer months earlier this year, I would often notice a sudden outburst of alarm calls by the resident group of New Holland Honeyeaters (Philidonyris novaehollandiae, known as Bandin / Woorening in Noongar), and peer out the window to see what had disrupted them. At first I usually couldn't see any other animals, but as I watched the birds carefully, I noticed their attention was focused on the upper surface of a thick limb of the ornamental peach tree. Then I could usually make out a scaly head and the tip of a black tail, just visible from beneath, which told me the reptile's identity: a Black-headed Monitor (Varanus tristis).

On one occasion I crept outside and managed to take a few close images of this beautiful lizard (including the one above), before it scurried higher up into the tree and out of reach. You might remember my Mum taking some great photos of this same species (and possibly the same individual!) a few years ago, which prompted me to write a blog post called 'Goanna in the Roof'. Since that time, we've observed at least two different monitors entering and exiting the roof, and delighted not only at them continuing to find refuge in our house, but also because of the free rat control they are likely providing! Next week the Black-headed Monitor will feature in my upcoming Get Green article for the West Australian Newspaper's Ed! Magazine, as shown below (click to enlarge and read).

Bush Skills for Youth

As an environmental educator, it is always a great thrill to spend time with a brilliant group of young, upcoming naturalists, especially in the magic setting of some Perth Hills bushland. Today's 'All About Eagles' workshop in John Forrest National Park was no exception. I had the privilege of working with Kathy Levett from the East Metropolitan Regional Council's "Bush Skills for Youth" program, and we ran a workshop for 12-16 year-old children who gave up a morning of their school holidays to learn about Wedge-tailed Eagle ecology through a hands-on educational workshop.

The format of the day involved a talk in the National Park's Margaret Forrest centre about eagle biology, then a walk up into the hilly country to search for eagles and experience a deep valley, like the ones may resident Perth Hills 'wedgies' call home.

During the walk, I was thrilled to talk to some young boys and girls who were wearing camouflaged clothes and even carrying a short length of rope "just in case he needed to climb a tree!!" This gave me fond memories of my early teenage years when I first began to explore the vast hills forest and discover eagles in the wild.

After a break for morning tea we got stuck into the real fun part of the activity - building eagle nests! The 30 children divided into three groups and each gathered their own sticks, carefully prepared the lining of fresh eucalypt leaves and constructed the most realistic eagle eyrie they could. I was very impressed with how accurately the kids undertook the construction - they would make a good bunch of eagles!

Last time I conducted this activity was back in 2012, but the happiness on the children's faces told me it was still a fun and enjoyable way to learn ornithology. And what better setting than an outdoor bush classroom?!

We completed the morning with a 'bush detective' activity which involved the children doing a treasure hunt for various prey remains (bones and feathers) that I hid in and around the completed eagle nests. It was great to watch the kids search high and low around their nest, making sure they left no stick unturned! A final discussion on the identify of each prey animal consumed gave everyone a real insight into what it's like to conduct research on eagles in real life.

Thanks so much to Kathy and EMRC for the opportunity to be involved in such a fantastic environmental education program, and to Rolf Perey from Guildford Photographics for documenting the morning with an eagle-eye for detail! I'd also like to thank the Department of Parks and Wildlife for their cooperation in allowing us to use the National Park facilities. I'm looking forward to the next eagle workshop already!

A Damsel in Distress

As I knelt down to get closer to a wonderful chorus of breeding Moaning Frogs in a small Perth Hills wetland earlier tonight, I suddenly noticed the above Banded Orb-weaving Spider (Argiope trifasciata) right in front of my face! I was reaching for my camera when I heard a sudden fluttering sound and glanced back to see a damselfly (which may have been disturbed by my movement, or attracted to my head-torch), caught in the web. In seconds the ferocious female arachnid moved to seize her prey.

The Banded Orb-weaving Spider clutches one wing of her damselfly prey.

Within seconds the spider had hold of the damselfly and had dispatched it with a quick bite. I was amazed at how delicately she grasped its individual parts as she pulled it closer towards her body. The orb-weaver then began wrapping up her prey in a special multi-stranded 'glad wrap' silk (one of the many different types of silk spiders produce in their spinneret), for a later meal.

Meanwhile, the strong chorus of Moaning Frogs was continuing all around me. As always, nature presented an unexpected surprise that emphasised a small wetland can support a diversity of creatures, both the ones we see at a glance, and the ones which require a closer look.

Shell Story

I often say to people: "Keep an eye out for the indirect evidence of wildlife, and you will find a story to delight you and brighten each and every day!"

A good example of this evidence arose yesterday. While doing some weeding on the banks of my dam, I noticed a sign of a very special local animal known in the Noongar language as Booyi - the Oblong Turtle (Chelodina colliei). In the above photograph you can just make out the small, white shapes which are the remains of about a dozen (or maybe a Baker's Dozen!) eggs.

Fragments of Oblong Turtle eggs tell us a clutch was laid here nearly 12 months ago.

After a closer look at the fragments of eggshell, I could see these were evidence of the emergence from below the ground of some tiny Booyi hatchlings. How do we know they are turtle eggs? A process of elimination - no other egg-laying vertebrate would lay on or below the ground in this situation, or produce so many eggs (Oblong Turtles normally lay over 20), and few other local animals' eggs are so obviously white, except for birds. When compared to birds' eggs, which have a relatively thick and rigid shell, turtle eggs are much softer with a flexible shell, and after the young break out, the shells curl inwards and shrink.

So why were the eggshells on the surface and not below ground where they were buried? Perhaps when digging their way to the surface, the young turtles disturb the soil and the eggshells are gradually moved upwards. I know a Quenda (Isoodon obesulus) has frequently been digging in this area in the past few months, so maybe its foraging activities unearthed the nest. Of course there is also the possibility that the Quenda (or another predator like a Red Fox, Vulpes vulpes - a key threat to turtle nesting success) actually dug up and ate the contents of the turtle eggs. However, given that these omnivores normally leave a large spoil heap behind an area in which they have been digging, and there was no such evidence of this kind where I found the eggshells, I think these scenarios are less likely (I'm also being optimistic here about a successful breeding event!).

I have observed a female Booyi emerging to lay eggs in the bank of this dam only once before, over a decade ago, but found no evidence of the outcome. This time it was thrilling to think that somewhere out there, along the waterway that flows through my home, a new generation of these fabulous local native reptiles could be making their way in the world. Click here to view an image of a newly hatched Booyi.