Blown Away: Breeding time for Ravens

I knew the easterly wind would try its best to blow me out of the tree. It howled across the shrubland with enormous force as I pushed my way through the entangled wattle thicket toward the nest. The raven was very well hidden, except for a few tail feathers which protruded above the basket of sticks, telling me it was incubating. As I discarded my shoes for much sturdier, comfortable bare feet, the wind roared across my eardrums. It’s strength increased with every metre I pulled myself into the low Flooded Gum. WHAT a breeze!

The nest was only about 6 metres up. I was nearly under it when an enormous gust sent the trunk bending sideways. My adrenalin was pumping softly, keep me focused but not frightened. Another huge burst of air, the leaves swished against me, as though like clutching fingers they sought to rip me from the trunk. The wind dropped slightly for a moment and I stood, stretching upward with the camera, pointing it downward at the nest and snapping a few shots. One. Two. Not the right angle to even think about using the viewfinder. I hadn’t seen the incubating bird fly off but this didn’t surprise me. Any feathered animal flapping up would be carried a hundred metres sideways in seconds!

I could feel another gust coming; it had been ‘still’ for too long. I slunk into the fork supporting my feet, folding up like a Koala. Whhiiieeeeeeeewww! A massive gust hit me, sending the whole trunk lurching over like a piece of rubber. It was like being on a bucking bull with the fieriest attitude! The gale persisted and I swayed around, clinging on for dear life. I had several thoughts of the tree-top snapping off, sending me plummeting downward with it. Although I wasn’t that high, it would still hurt.

It was difficult to see into the nest in the first couple of photos, but eventually I managed to grab a shot which revealed the contents.

The above picture shows a typical clutch of eggs laid by the Australian Raven (Corvus coronoides). They are nothing short of beautiful, one of the prettiest eggs of all Australian birds. July is the month when this, one of our earliest breeding songbirds, begins to nest. In the Perth hills, ravens (and NOT crows, as they are often mistakenly called) are a common songbird. Their usual clutch is 4, but I will never forget the first nest I discovered at the age of 16 which contained 6. The eggs are laid inside a deep cup which is almost always made of carefully woven strips of bark. Ravens collect bark directly from tree trunks and tear it into strips with their beak before adding it to the nest. Occasionally you will find bits of man-made fibre too, like the blue twine in the above photo. The raven’s cozy cup forms the inner lining of the large stick nest, a bulky structure which is normally conspicuous at the very top of the tree. Every time I see a nest belonging to this species, or the closely related Little Crow (Corvus bennetti; - which is not found in Perth), the term ‘crow’s nest’ pops into my head. The platform at the top of a ship’s mast is a fitting analogy with the real thing.

Despite my battle with the wind, I was happy to scale the tree as it was lucky to find a raven’s nest less than 10 metres off the ground. In the Perth hills the species normally builds in a fork over 20 m high, often at the top of a very tall Marri tree. Today’s Flooded Gum on the sandy Coastal Plain north of Perth was much lower, but in any case ravens like to have a good view over the habitat surrounding their nest. This is presumably to see intruders (like me!) approaching, allowing a fast getaway.

After snapping a dozen photos, I thought I’d better quit while I was ahead, so I slid down the tree-trunk like a fireman. Another nest, another thrill, another wonder from the natural world. There’s nothing like climbing to a nest in the top of a gum tree.

Spot the nest - top right-hand fork in the tree on the left.

 

Cuckoo

A person whistling a dog? A descending trill? A piercing whistle that resonates in your eardrums? You might have heard some unusual bird calls over the last few weeks. It’s quite possible you are listening to one or two of the four species of cuckoo which have arrived in the Perth region recently. The above photo shows one of these: a Pallid Cuckoo (Cacomantis pallidus). This fella was perching on a fence at the edge of farmland just north of Perth, and I watched him zip down and grab a caterpillar a few times. I’ve heard this bird calling from several places around the hills too.

As with many birds, learning to their calls is often the best way to identify them. Have a listen to these recordings, and see if you can recognise one (or more) of them from your local area. Even better, next time you’re out gardening, pay attention to the different bird calls around your house. You might even find that you have cuckoos in your area!

Wood Ducks

I climbed the 15 metres into the canopy to inspect this large nest box, installed in a Parkerville tree in 2010. A few weeks ago I’d seen a pair of Australian Wood Ducks perching on a branch next to it. To my excitement the female began laying, making short visits to the box to deposit one egg per day. My last check revealed 4 eggs... but today I was thrilled to find FIFTEEN, covered in beautiful, soft down feathers. These help to keep the eggs warm while the female is off foraging. Fifteen is a typical clutch size for Wood Ducks, but there is a record of more than 20!! However this is likely to be a ‘double clutch’, laid by two females during the same period; all the eggs in such clutches would be unlikely to hatch.

Keep watching this News section for updates on the progress of these wonderful eggs.

Nest Boxes: a day in the trees

Who’d have thought that this little girl would be wearing a jumper with a picture of me on it!!?? I laughed when I saw the ‘crazy monkey’ hanging upside down as I thought about the number of times I’ve been described this way by people who’ve watched me climb trees.

I had great fun installing a nest box for a pair of Red-capped Parrots which have been frequenting the garden of my friends Cherie and Ryan. Cherie has been brilliant at planting a native garden, and wanted to encourage birds onto her block even more, so I installed this parrot box today. I couldn’t have done it without little Hayley’s help!

Earlier today I put another nest box up; its size was at the other end of the scale to the smaller one pictured above! This box was designed for Red-tailed Black Cockatoos, and went high into a large marri tree at a block in Sawyers Valley. Brad and his son Thomas are fanatical about Black Cockatoos, and regularly have all three species in their garden, so they ordered their box a few weeks ago.

Brad, Sallyanne and Thomas live on a fabulous bush block and are lucky to have a huge range of local native animals visit them regularly. This is because, like many private blocks in the Perth Hills, they have retained the native vegetation of Jarrah and Marri trees which local wildlife needs. However, one thing that is missing from their place are HABITAT TREES. These are large trees more than 100 years old which bear hollows, vital for a HUGE variety of invertebrates, plus most parrot species, owls, possums, bats and some reptiles to live in. Without habitat trees the biodiversity values of bushland decrease severely. If you look at the picture below, you can see that all trees pictured are only 20-30 years old at most.

In order to increase the potential for more species to breed in bush with younger trees, you can easily fix the ‘habitat problem’ by installing nest boxes to restore the animals’ homes! Here are Brad and Thomas pictured with their ready-to-install cockatoo box.

After a lot of ‘monkeying around’ in the chosen tree, which involved setting up a few ropes and pulleys, the box was ready to be hauled into position. I set up a one-way hauling system so large nest boxes can go up but not slip back down again! Thomas jumped in to lend a hand and his dad took some photos of the action:

I secured the box in place with a length of chain and some old hosepipe (to protect the tree!) and installation was complete! Only 15 minutes later we heard a few Red-tails calling from trees just metres away from the box! Let’s hope they find it soon, and with any luck they’ll be rearing young inside. Let’s finish with a ‘Cockatoo’s-eye view’ from the new nest tree, with Brad and Thomas waving from below.

Cockburn Wetlands Centre

What are these children up to? If it looks like they’re gathering sticks into a big pile, that’s because they are! But this is not for a bonfire... it’s for an eagle nest...

The Wedge-tailed Eagle activity at the Cockburn Wetlands Education Centre this morning began with about 25 wonderful children filing in to sit on the mat inside, ready for the presentation. I gave a half-hour talk about my pet subject, and was impressed by how such young children knew so much and eagles and birds of prey. One boy even new that the scientific name for a Barn Owl is ‘Tyto’!! Not bad for a boy under 10 years old.

The fun began outside when we broke into two groups and rushed around collecting sticks (I’d brought piles from my backyard and spread them over the centre’s lawn), ready to make our own eagle nests! Each group empathised with an eagle as they placed the sticks in the low fork of a tree, working out that some had to be woven together to maintain their structure. Imagine doing this with just a beak! Eventually the nests were lined with green leaves, and an old cricket ball in one of them made a very accurate, pretend eagle egg!

We then did some ‘hide and seek’ as I hid some bones of eagle prey animals in and around each eagle nest, and the kids had to collect one item each. Then we talked about all sorts of funny things like dead animals, bones, teeth, fur, and learnt how much lighter a bird bone is than a mammal bone.

To finish off the morning I did a quick show and tell with my climbing equipment, talking to the children about how I climb trees safely. All the kids had a quick swing on my rope before heading home. Thanks so much to Vicki, Clare and Denise for inviting me to Cockburn Wetlands centre and providing such a great working environment. An extra thank you to Denise for taking all the photos too!

It was such a lovely day outside, the sun shining, children running around enjoying the outdoors and learning about the environment. Is there a better way to spend the school holidays?

Nest Boxes: School Holidays

It was exciting to be back at the Hills Forest Discovery Centre for the second time in 3 days! This time, Gill and I were there to conduct our nest box workshop, aptly named ‘Home Among the Gum Trees’, as part of the DEC’s Nearer to Nature winter school holidays program.

We started the day with a powerpoint presentation from both Gill and I, to give some background to the day and enthuse the children about tree hollows. Then we dived straight into the building! Were lucky to have 16 children who were so well behaved and very keen to work together on their boxes. Consequently all had finished their box by mid afternoon and were excited to take it home to hang in a tree in their backyard.

With some time up our sleeve before parents arrived, it was a great opportunity to take the group on a bushwalk through the forest. On the walk we talked about the loss of habitat trees which contain natural tree hollows, and how boxes were an important way to help replace them.

Hopefully the children are proud of their new boxes and have local wildlife living in them very soon!

Lord of the Sky

Today I gave a talk about Wedge-tailed Eagles to a fabulous group of 11 visitors and the DEC’s Nearer to Nature centre in Mundaring. I’ve done many similar such talks, but this one was made extra special by ‘Chips’ - a beautiful adult male Wedgie. Chips was brought in by his owners Dave and Jenny Pettet, who are extremely dedicated wildlife rehabilitators. One of the most important aspects of Dave and Jenny’s work is using their captive birds (which include several species of Australian raptor) to educate others about their biology. Raptors are uncommon birds seldom observed so seeing one up close has a large impact on adults and children alike.

Chips was brought out during the talk and was a fantastic live example of an eagle, making my job of describing eagle features very easy. He also captivated visitors by demonstrating how affectionate these birds are, tucking his head under Dave’s chin for comfort. Amazingly he also began watching the other ‘eagles’ in the room - those that appeared in various movie clips I showed in the presentation. An ever-alert eagle!

Below are some photos of Chips - you can see the relative size of him compared to David below. Note that Chips, being a male, is a small example of this species, with the females being about 10 cm taller, with much longer wingspan and are stockier overall.

Keep an eye on the Nearer to Nature website for next time you can come and encounter the Lord of the Sky.

Black Duck Clutch

Today I did a quick check on our female Pacific Black Duck and found her incubating her clutch inside the nest box! When she left to forage later in the evening, I returned to the box to see her eggs all covered up with beautiful warm down, plucked from her body. I uncovered the down just enough to snap this photo of her 10 eggs, then quickly covered them and climbed down from the tree again.

How exciting! I’ll keep a close watch on this box and hope to post a short film with footage of her incubating very soon. Watch this space :-)