Spring is a season of intense activity — not only for our fauna and flora but for me, as this is when I’m busiest leading tours, walks, and carrying out bird surveys. It’s frustrating that the season when I have least time to write is the very time there’s the most to write about. On the plus side, I’m outside seeing it all first hand! I’ll try to make up for my recent lack of posts with plenty of summer offerings, including looks at some of the interesting things I’ve seen during the past three months.
It hasn’t been hard to find birds nesting and feeding young. For many species this continues into the summer months. Australian birds tend to have long nesting seasons (and smaller clutch sizes) compared to cooler-climate northern hemisphere species (see Ford 1989). This allows them to raise two and sometimes more broods, or at least have another try if the first one fails — which happens often. A nest success rate of less than 50% is not uncommon among small birds. This might be due to predation of the eggs or young, parasitism by cuckoos, an unexpected shortage of food, severe weather, bushfire or human interference. It’s amazing small birds manage to reproduce at all when you think of the many dangers they face.
Let’s take a look at some of the nests I’ve found during my travels this season, plus a couple of favourites from last year thrown in. Each is ingenious in its own way.
(First, I’d like to stress that when taking photos I always have the interests of the birds foremost. Whenever I find a nest I move away promptly to avoid keeping the parents away from eggs or young. Photos are taken using a long focal-length lens from a distance or, occasionally, snapped quickly from close-up before moving well away.)
During my bird survey work this spring, it seemed there was always a Rufous Whistler nearby. Both male and female are fine singers. Legendary birdman and poet of the mountains Graham Alcorn once wrote: “The Rufous Whistler sings as if he’d burst…” while field guide author Graham Pizzey described the song as impetuous and spirited, and “the most ‘Australian’ of spring sounds”.
So it was no surprise to find a pair nesting in a low branch of a River Oak (Casuarina cunninghamiana) along the Capertee River. That’s the male brooding the young in the photo below. It’s a no-frills nest which the female has made of grass stems, rootlets and many casuarina needles so it blends in with the tree foliage. A bit of cobweb and somehow it all manages to hold together.
Eastern Yellow Robins, on the other hand, seem to put more effort into decorating. You can usually recognise a yellow robin’s nest by the strips of bark attached vertically to the outside. When the nest is in an upright fork of a tree this ensures great camouflage, mimicking the way bark hangs in a fork. They tend to decorate the nest in the style of whatever branch it’s placed on, adding moss and lichen if that matches the tree. The inside is lined with fine grasses and dry leaves.
I found this nest (above) in a rainforest gully in Blackbutt Reserve, Newcastle. The two chicks haven’t yet opened their eyes but are already growing their juvenile feathers. When they first leave the nest they have streaky brown plumage, which makes them look very different to the adults. As soon as I moved away from the nest, an adult bird appeared with a large fly to feed the chicks.
Here’s another Eastern Yellow Robin on a nest much higher in a River Oak — the same tree the Rufous Whistler nest, above, was in. Small birds of different species often nest close to each other. It helps with nest defence if there are more eyes to watch for predators. Being different species, they forage in different ways so competition isn’t a problem.
It was interesting to see the nest of a Western Yellow Robin in the Stirling Range, Western Australia during September. Like its eastern counterpart, it decorates the nest with those vertical strips of bark.
If you want to see how a robin attaches these strips, check out Geoff Park’s wonderful photos on the Natural Newstead blog: Sunshine and gold.
A more delicate nest containing two finely speckled eggs (photo below) was encountered in a sapling eucalypt on one of the Regent Honeyeater planting sites in the Capertee Valley. I moved away and soon a Fuscous Honeyeater came in and settled down to incubate. It’s always gratifying to find birds using the trees planted as habitat for them.
Many honeyeaters nest in the outer foliage of trees. This makes it hard for large predators to gain access. One of the most beautiful honeyeater nests belongs to the Striped Honeyeater — a deep, hanging basket made of soft plant down, dry grass, cobweb, and sometimes wool.
It’s not the only species that weaves wool into its nest. Another is the Olive-backed Oriole, which also builds a hanging cup, though not as deep as the honeyeater’s.
Below is another Striped Honeyeater in its nest which I photographed a few years ago. Compare the two nests and look closely at the way they’re attached to the branches. Imagine the work involved in building them.
Walking into the rainforest a quick movement in the foliage catches your eye; there’s a good chance it’s a Brown Gerygone. It’s tiny. How on earth does it build such an elaborate hanging nest? The entrance hole is covered with a hood, forming an upward-angled tunnel which both hides the entrance and keeps it rain-proof (left side in the photo below). The long tail at the bottom is characteristic of all the gerygone species’ nests. I think this helps to make it look more like a clump of hanging vines, and perhaps less likely to attract the attention of predators.
You can’t see the Spotted Pardalote’s nest because it’s inside a tunnel, though you can often find the little hole in the bank where the bird has burrowed in. Amazingly, the tunnel can be up to one and a half metres long! At the end is a chamber where it builds a dome of shredded bark.
This male (below) is carrying a fly down to the burrow, a sure sign he’s feeding young. Spotted Pardalotes spend most of the year in the eucalypt canopy where they forage for insects and lerps. It always strikes me as odd that a bird usually found high in the treetops nests in a hole in the ground. I wonder what led to such divergent habits.
The Willie Wagtail prefers much more exposed sites and, having adapted well to living close to humans, sometimes builds in unexpected places. I’ll devote a whole post to this some time, but today I’ll show you two I found this spring.
The Willie’s nest is one of the neatest — a perfect cup constructed of grasses and fine plant matter bound tightly with cobweb. It’s sometimes lined with animal hair. One pair had built their nest on top of an electric light on the outside of the Glen Alice Community Hall. I’m not sure how often this light is turned on or whether it had any effect on incubation. In any case, the eggs had hatched successfully and there were two small chicks in the nest. In the photo below you can just see their short tails poking out from under the adult’s belly. The light (if on) would no doubt attract a good supply of food for the chicks in the form of moths and other night-flying insects.
The same day I noticed another Willie Wagtail nest high in a River Oak. On the next branch down was a larger bowl made of mud — a Magpie-lark’s nest. The Willie has a predilection for nesting in the same tree as Magpie-larks (also known as peewees or mudlarks), an association which probably benefits both of these feisty black-and-white birds. There’s increased vigilance and strength in numbers. Both are fearless nest defenders, and combined they would surely make things difficult for any predator that happened to come near.
The Mistletoebird builds one of the most remarkable nests of any Australian bird. It’s shaped like a baby’s bootie and it stretches, starting off tiny and getting bigger as the nestlings grow. Spiderweb, soft plant material, dead flowers, bits of insects and perhaps caterpillar nest webbing contribute to the unique construction. The one in this photo has already been used — I hope the young fledged successfully.
I’ll finish with a favourite. The Black-faced Monarch’s nest not only cradles life inside, but is almost a living thing itself. Covered in thick green moss it matches its mossy rainforest environment perfectly.
The beauty of these nests is born of function and the need for camouflage, but you can’t help admiring the artistry of the creatures that somehow constructed each one using nothing but their bill as a tool.
Beruldsen, Gordon. 2003. Australian Birds Their Nests and Eggs. G & E Beruldsen, Kenmore Hills.
Everyday nature trails, 8th May, 2013: “The craft and artistry of nest building” (a delightful blog post looking at nests the author found in Spain and Britain).