Saturday, 17 May 2014

Capricornia's Terns

During my trip to the Capricornia cays of the Great Barrier Reef earlier this year, one group of birds in particular stood out for me – the terns.

Perhaps this is partly because the only new bird I got for the entire trip was a Roseate Tern, but also because they were prominent both in numbers and species. And they’re beautiful! In all, I saw eight different species of tern. 

The gulls and noddies are closely related to the terns, and though the details of their relationships are still being disputed and resolved, they are currently all included under a single family, the Laridae. It seems the noddies represent the oldest lineage of the group, followed by the gulls, and the terns are the most recently evolved, but even so, we are talking about 40-50 million years ago.

So I'll start with the noddies. The Black Noddy Anous minutus is one of the key species we were surveying on the trip, and we counted many thousands of them (see previous posts). They are beautiful birds, but very noisy at their breeding colonies and one could be forgiven for thinking they lived up to their name - anous means having no nous, i.e. "stupid bird". I also saw a single Brown Noddy Anous stolidus - which essentially means "stupid stupid bird" - but didn't manage a photo. It was too smart and flew away!

Black Noddy amongst the pisonia foliage on Northwest Island.

Black Noddies are very vocal, making a range of clicks, churrs, and rattles day and night.

Black Noddies build a nest of pisonia leaves glued together with faeces.

Black Noddy chick on its nest. It's not uncommon for them to fall, or be blown off. Anous?

During the day, Black Noddies will sunbathe, often in sociable groups.

This pair of Black Noddies is in pair-bonding flight: rapid synchronised flying with clicking contact calls.

Silver Gulls Chroicocephalus novaehollandiae are Australia's most common and familiar gull, and are often taken for granted. But they are exquisitely beautiful birds. They generally breed in less accessible locations, often on offshore islands, so it was wonderful to be able to see the various stages of breeding on Heron Island, from eggs through to adolescents, all together. 

Silver Gull eggs hatching - the 'star cracking' is obvious and the egg tooth is visible on the chick's bill.

Silver Gull chick, probably just a day old, waiting for its siblings.

Juvenile Silver Gull - still got a little growing up to do, particularly its tail.

Adult Silver Gull - parent of the juvenile in the previous photo, telling me to keep my distance.

A slightly older juvenile Silver Gull in flight.

Of the terns, I saw a Caspian Tern Hydroprogne caspia first (in Gladstone), Crested Terns Thalasseus bergii were around but less common on the islands than they often are in coastal towns and harbours, and it was good to see a group of eight Lesser Crested Terns Thalasseus bengalensis which I don't see in my more usual southern haunts. And a flock of 20 Little Terns Sternula albifrons, together with the lesser cresteds, were part of an amazing mixed species high tide roost on Northwest Island.

A young Crested Tern at Heron Island.

One of a group of eight Lesser Crested Terns at a high tide roost on Northwest Island.

Scattered amongst the other birds of the high tide roost were 20 Little Terns - they're the grey and white birds with the black bills and caps, and are much smaller than the Lesser Crested Terns.

A Common Tern Sterna hirundo, which aren't really all that common in Australia, had commandeered a buoy just off from the jetty on Heron Island, and another was seen briefly on Lady Musgrave Island.

Common Tern on buoy at Heron Island.

As I mentioned, the Roseate Tern Sterna dougallii was the only new bird I came across on the trip - my 590th bird for Australia. 

A small group of Roseate Terns at Heron Island, though I saw my first a few days earlier on Northwest Island. Three of these are in breeding plumage - red bills and legs, full dark caps; but one looks like a young bird with dark bill, patchy forehead, and black legs.

Reversed colour schemes of a Black Noddy and Roseate Tern - Lady Musgrave Island.

Roseate Tern in partial breeding plumage - full black cap but black rather than red bill. 

But perhaps my favourites were the Black-naped Terns Sterna sumatrana and Bridled Terns Onychoprion anaethetus.  I had previously only seen these species in small numbers and usually from quite a distance, so to see so many so close was very special. 

A Black-naped Tern, still ruffled from a bout of preening.
Black-naped Terns ready to take flight on Heron Island.
Black-naped Terns, Heron Island.
Black-naped Terns over the jetty at Heron Island.

Bridled Tern, Heron Island.

The bold colour scheme of an adult Bridled Tern. The white leading edge to the forewing is distinctive, even in flight.

Bridled Tern chick on Northwest Island.

Juvenile Bridled Tern on Lady Musgrave Island.

Bridled Tern, Heron Island.

Bridled Terns are distinctive and graceful in flight.

A little birdie flying high, dropped a message from the sky...

Tuesday, 6 May 2014

Girilambone Railway Station

The railway line between Nyngan and Bourke in north-western NSW is no longer operational and is in a sorry state of disintegration. Once the final section of the Main Western Railway Line that ran from Sydney to Bourke, it was damaged by serious flooding in 1989. Following further damage to the line through efforts to relieve floodwaters around Nyngan, it was not considered financially viable to repair and maintain, so it was abandoned.

In its day, it was the longest stretch of straight railway line in the world (187 km), passing through the small villages of Girilambone, Coolabah and Byrock. The terminus in Bourke was completed in 1885.

The track is now largely overgrown and in places the rails sag unsupported where once there were bridges or trestled elevated sections. In Girilambone (population 221) the old dilapidated railway station crumbles beside the highway. On our way back from a trip to Cunnamulla (in Queensland, a further 257 km up the road from Bourke), we stopped briefly to have a look…

Girilambone Railway Station, once the reason for the village's existence, was opened in 1884. It closed in 1986, before the line itself was abandoned, and is slowly falling apart. 

Parcel rates notice - it must date from the early '70s as weights are in kg (metrication in Australia began in 1970) but passenger services beyond Dubbo ended in 1974. 

Sunday, 4 May 2014

Bowra Non Birds

While at Bowra Station in south-western Queensland for a four-day stint of bird banding (see previous post), and despite being fairly flat out on that activity for most of that time, it was, of course, impossible not to notice the abundance of life (other than birds) busying about in the landscape.

Perhaps most evident were the grasshoppers, prolific in both numbers and species. While not having the time to pay the attention to them they deserved, I reckon there were easily in excess of a dozen species that made their presence known to even the casual observer. Unfortunately only a few of these ended up being photographed (i.e. the ones that most conveniently flushed and landed on open ground when I happened to have my camera with me) and I missed getting shots of some of the more spectacular ones.

One of the more common grasshoppers at Bowra.
This grasshopper is well camouflaged among the dry grey fallen mulga leaves.
And this reddish grasshopper of unknown species is clearly designed to blend with the red soil. But it appears to be different to the similar but even more cryptic species depicted in the banner at the top of this blog post.

Dragonflies were also prevalent anywhere there was surface water, though numbers were mainly made up of just a few species; notably the Blue Skimmer and Scarlet and Wandering Perchers, all of which tend to settle and pose prominently for photographers (these species must surely be three of the most common and widespread dragonflies in Australia!). But there were also big greenish-yellow types (emeralds?) also darting and flitting hither and thither, and thereby thwarting all efforts at photographic ID determination. 

Blue Skimmer Orthetrum caledonicum (Family Libellulidae)
Scarlet Percher Diplacodes haematodes (Family Libellulidae)
Wandering Percher Diplacodes bipunctata (Family Libellulidae)
This tiny Aurora Bluetail Ischnura aurora, a damselfly rather than a dragonfly, also occurs commonly and Australia-wide (indeed it occurs from India to the central Pacific) but moves more discretely, or at least less noticeably, about the swamp vegetation than the dragonflies.

Butterflies were obvious if not over-abundant, but again just a few common species comprised the majority seen, including Meadow Argus, Lesser Wanderer, Caper White, and one of the grass-yellows (Eurema sp.).

Two Caper Whites Belenois java sipping moisture from the mud beside a billabong.
Caper White in full frontal.
This beautiful hairy caterpillar, about 5 cm long, is possibly a species of Anthela from the Anthelidae family of moths.

The mulga country is characterised by the distinctive nests of mulga ants. These are of the genus Polyrhachis (meaning many or variously spined), of which there are almost 700 species, mainly in Australia, Asia and Africa, with Australia hosting many of these. The mulga ants, probably just a few of the Polyrhachis species and especially P. macropa, are invariably associated with the mulga plant Acacia aneura, and they use the dead fallen mulga leaves (phyllodes, actually) to decorate pronounced rings or levees the ants build around the entrance to their nest. This is thought to be an adaptation to help prevent surface water from flooding the nests during the mulga country's infrequent heavy rainfall events. 

Mulga ants, Polyrhachis macropa, are just a centimetre in length - think I need a macro lens!
This is a comparatively young mulga ant nest, still small with a relatively low 'levee' and fairly minimal decoration with mulga leaves. 

Several large orange wasps were seen but never settled in my presence. The mud nests of wasps are less mobile, however, and I was intrigued to find this one attached directly and firmly to the ground rather that to some more elevated support.

There was the expected diverse range of miscellaneous moths attracted to lights and insect screens around the homestead’s shearing quarters at night, and the odd praying mantis and even a stick insect seen in flight one day, but these were never followed up. The bush flies and mosquitoes attracted attention only through their supreme nuisance value!

That seemingly ever-present Australian spider the golden orb weaver of various Nephila species, was common, in this case probably Nephila edulis. Some of the webs, and the spiders for that matter, were probably the biggest and fattest I've seen. Conditions must be good. The genus name Nephila, incidentally, comes from the Greek words nen = to spin and philos = love, hence love to spin or fond of spinning. And apparently the species name, edulis, which means edible, comes from the fact that the original describer of the species noted indigenous people eating this spider in New Caledonia. I didn't try them! 

A large and fat female Nephila species.

Apart from the odd rabbit and a single black-spotted feral pig, the only mammals I recall seeing were the Red Kangaroos that were not uncommon at Bowra. Though I did see another camper watching by torchlight what must have been a possum at the campground one evening. 

A mother and young Red Kangaroo Macropus rufus - these two were on the main track through Bowra on our way back from banding late one afternoon, but moved into the paddock as we approached. 

We saw surprisingly few reptiles; just a couple of Common House Geckos (Hemidactylus frenatus) in the shearers’ quarters and one unidentified caramel-coloured skink disappearing into the long grass at one of our banding sites at one of our busiest times.

But the frogs were in evidence. The billabong at the campsite hosted good numbers of at least two species, but I don’t know my frog calls at all well yet so don't know what species they were.

The various buildings around the homestead harboured several other species, including a goodly sized Green Tree Frog Litoria caerulea and a smallish Desert Tree Frog Litoria rubella in the bathroom block, and a line-up of six Peron’s Tree Frogs Littoria peroni in the old toilet stalls.

Green Tree Frog Litoria caerulea in the corner of the bathroom.

A small Desert Tree Frog Litoria rubella, also in the Bowra bathroom block.

Five of the six Peron's Tree Frogs Litoria Peroni that make the old toilet stalls their home.

But the real prize was an incredibly incongruous, exquisitely decorated Crucifix Toad (Notaden bennetti) that Karen found plumply plopping along a dry track adjacent to where we’d set up for our second day’s banding. She discovered their ability to secrete copious amounts of sticky defensive ‘frog glue’ as soon as she picked it up, but it was well worth it for the photographs we ended up getting of this amazing outback denizen.

Crucifix Toads are one of very few frogs in Australia that do not exhibit cryptic colouration or patterning, i.e. camouflage. Indeed the opposite is true - they exhibit aposematism, which is a fancy way of saying that they signal to other animals to keep away from them (apo = away, semantic = sign or meaning), in this case through bright yellow/green warning colouration with a range of variously coloured warts and dots in the vague shape of a cross - hence the name. 

The psychedelic Crucifix Toad Notaden bennetti.
The frog is variously called the Crucifix Toad, Holy Cross Toad or Catholic Frog for obvious reasons.

For a bit of anuran esoterica; the glue produced by the Crucifix Toad is composed essentially of a mix of proteins (ranging in size from 13 to 400 kDa) with a high proportion of the amino acids gycine (15.8 mol %), proline (8.8 %), and glutamic acid/glutamine (14.1%), which appear to form large, porous, elastic proteinaceous structures. The glue presumably clogs up the mouths or mouthparts of would be predators and thus acts as a deterrent. Not sure what it might taste like!

The frog was described scientifically in 1873 by Albert Karl Ludwig Gotthilf Günther, a German born British zoologist who was Keeper of Zoology at the British Museum of Natural History from 1875 to 1895. Despite looking, I couldn't find an explanation of the scientific name, though the genus name must surely derive from the Greek noton which means back, and aden which means gland. 

The species name, bennetti, is a little more problematic. It may well be in honour of George Bennett (1804-1893) who was a medical practitioner and naturalist who first visited Australia in 1829, returned in 1832, and finally settled in Sydney in 1836. He was fascinated by the flora and fauna of Australia and his inland travels culminated in the Wanderings in New South Wales ...Being the Journal of a Naturalist (2 volumes), published in London in 1834. He later played a significant role in the newly fledged Australian Museum in Sydney and the Zoological Society, and was agent for John Gould. His second book, Gatherings of a Naturalist in Australasia, was published in 1860. 

Alternatively, as in the case of the Little Crow (Corvus bennetti), which we also saw on this trip, the honour may be to Kenric Harold Bennett (1835-1891), a naturalist with interests in birds, plants and Aboriginal artefacts who was active in central NSW in the second half of the 19th century. Though this seems less likely to me. 

And while I'm on the meaning and history of names, the Green Tree Frog has an interesting tale (pun intended, sadly)! Its specific epithet, caerulea, means blue - rather odd for a bright green frog. The original specimens were described by John White in 1790. White was the surgeon on the convict transport Charlotte, one of the eleven ships comprising the First Fleet, and was then appointed as Surgeon-General for the new colony. Despite a severe dislike for Australia, White developed an interest in its fauna and flora and the potential use of the local plants in medicine. He described many Australian species for the first time in his Journal of a Voyage to New South Wales (1790), including Rana caerulea, which he described as "Blue Frog, fpeckled beneath with greyifh; the feet divided into four toes; the hind feet webbed. Size of the common Frog."
The original name of Blue Frog was apparently due to the fact that the specimens on which the species was described were in preservative. The frog's colour is produced by both blue and green pigments covered in a yellow layer - the preservative destroyed the yellow layer leaving the frogs blueish in colour. 

White's Tree Frog is therefore an eponymous alternative name for the Green Tree Frog (that makes three different colours associated with this one species!), others being Australian Green Tree Frog, Common Green Tree Frog, Northern Green Tree Frog, Dumpy Tree Frog, and perhaps most appropriately for most people, Dunny Frog! A good place to stop.

The good old "Dunny Frog" - this one at the dunnies at the Kalpowar Crossing camp ground in Lakefield National Park (now Rinyirru NP), Cape York, Queensland (Nov 2005).