Dinosaurs with Di …
A fascinating morning on yet another beach with Dianne Bennett. Di is a dinosaurologist and local treasure who leads tours to see the famous dinosaur tracks of the Broome sandstone. It’s not a boat tour, no champagne and lobster just a walk on the rocks, a wealth of knowledge, enthusiasm and all at a very reasonable price.
The Broome Sandstone dates to 130 million years ago give or take a few million. It slowly built up in layers. Sometimes conditions were suitable for preservation of footprints, sometimes not. Tracks are found at several levels. Di showed us two very different sets of tracks belonging to Sauropods and Theropods.
Dinosaurs come in two big flavours Ornithiscians and Saurischians. The Ornithiscian pelvis resembles that of birds, the Saurischian pelvis that of lizards. The general consensus is that birds are living dinosaurs descended not from the Ornithischia but from the lizard-hipped Saurischia. Each of these main divisions are further divided. The tracks we saw were from Sauropods and Theropods which are both Saurischians.
The Sauropods were long-necked, long-tailed, small headed herbivores. Not all Sauropods were immense, some were only 5 or 6 metres long but the largest animal to ever walk the earth was a Sauropod around 30 metres long and weighing something in the order of 70 tonnes..
I have no idea how accurate this depiction is except that the feet fit what we found to a tee. The back foot is bigger than the front foot and comes up close to it at every stride …
and here it is heading from right to left across what was a mud flat and it was way bigger than a modern elephant.
Once the search pattern was established Sauropod footprints were all around us. Theropod footprints are smaller and were not impressed so deeply in the mud. Di pointed out the first then they too became easier to find.
Theropods walked on their hind legs. Diets were varied, herbivory, insectivory and carnivory were all represented. T. rex was a carnivorous Theropod but never visited Broome. Here is a Herrerasaurus to represent the group.
Three toes facing forward, a hind claw that may not have reached the ground or make a big impression if it did …
The local aboriginal people have stories about Marala, the Emu-Man. This print is considerably bigger than an emu’s and your average emu doesn’t leave prints in solid rock. It’s easy to see why they were impressed.
Sadly the Broome sandstone doesn’t seem to have preserved any body parts. We have no dinosaur skeletons to put in the museum. But we can follow in the footsteps of immense creatures that preceded us by 130 million years and raise our gaze to the Reef Egrets, Kites and Gulls – living Theropods.
We made contact with Dianne Bennett through Broome Visitor Centre. You can also find her on Facebook or ring her on 0457 681 265.
To The Beach …
A few of the gulls are watching for food but most of the gulls are watching the gulls watching for food. Piracy may well ensue.
In the same fashion my beady eyes detected a small gathering of people at a rock pool a hundred metres away. Unlike seagulls the group were only too happy to share their find. In fact they were interested to see if I would lift it out of the water for a better photo.
Blue-ringed Octopuses are found all around the coasts of Australia, New Zealand, Papua New Guinea, Indonesia, Fiji and Japan. They are ambush predators and possess one of the deadliest toxins you can find. Envenomation is reportedly painless. Paralysis ensues and without treatment is fatal. No antivenene is available.
The WA government advises
“Warning: Be careful when handling dead shells, empty cans and bottles, as these are great places for the deadly blue ring octopus to hide!”
Despite their relative abundance encounters are rare, envenomation really rare and fatalities are exceedingly rare. Apparently just three instances have been recorded, two in Australia and one in Singapore. A four year old boy could have been the fourth but was quickly intubated and ventilated and survived.
Take care at the beach, the carpark is a dangerous place.
Still Swatting Mozzies …
I’ll be visiting the Mangroves frequently because, like Tilly, a recent commenter from Kingaroy or some place in Queensland, I still need a male. It’s another Whistler, the Mangrove Golden. My best efforts to date are not up to scratch. Meanwhile I take whatever is offered. Like this young male Red-headed Honeyeater …
Presently he’s merely blushing but when he’s all grown up he will be positively glowing.
The rump is also scarlet so the shot of one with its back to the camera looking over the shoulder is on the wanted list.
The Broad-billed Flycatcher is another adorable denizen of the mangroves.
Once again the male is more striking, darker above and brighter below than the female but not all birds are sexually dimorphic. In the Yellow White-eye sexes are similar.
They may not be scenically splendid but they are the nursery for enormous numbers of sea creatures and protectors of the coast against storms. And they have birds.
Australia is home to about 45 species of mangrove in 18 families. They like the tropics, Darwin Harbour has about 36 species, Broome about a dozen. Species drop out as you head south. By the time you get to Victoria there is just one – Avicennia marina. Tasmania has none. As well as the right amount of sunshine each species needs the right amount of tidal inundation.
Birds enjoy the mangroves everywhere but the opportunities for mangrove specialists are much better in the north where there are large patches of mangrove forest.
The birdo who wants to photograph these specialists must first work out the tide and then do battle with mud and mosquitoes. The birds rarely sit still for you and the tangle of roots and branches complicates things further. One bird that has eluded me on previous visits is the male White-breasted Whistler. The females are confiding, almost brazen but drab. The males are gorgeous if you can get a clear view of them. Perhaps their skulking behaviour is to make up for their lack of camouflage. Now that I live here I can afford to sit and wait (don’t scratch those bites) …
Holy Egrets, Batman …
These two are much easier to tell apart than the crested terns …
except they are both the same species, Egretta sancta (sacred egrets so named in 1789 because they were supposedly venerated by some Polynesians). They are found along rocky coasts in the Pacific ranging as far north as Japan and as far south as New Zealand. They are fairly common around the Australian coast except Victoria where they are infrequent and Tasmania where they are absent. There are plenty around Broome.
The popular name is Eastern Reef Egret but they are also called Pacific Reef Heron or any other permutation of the words. They are not the only egret or heron to occur in white and grey forms. In my experience the grey ones outnumber the white ones. The cause of the difference is unknown but stable polymorphisms like this can occur where two forms of a gene (allele) exist for a particular spot on a chromosome and having one of each (heterozygosity) confers an advantage compared to two of the same (homozygosity). The advantage may be due to body colour or it may be due to some other unsuspected effect of the gene combination.
The short greeny-yellow legs distinguish the white ones from other egrets. Distinguishing the grey ones from White-faced Herons should pose no problem if relatively sober.
Oranges and Lemons …
My first visit to Broome was in 1996 in pursuit of the shorebirds that visit Roebuck Bay. I played a minor part in an expedition that captured, examined, marked and released a few thousand birds. Broome has its beaches, camels and dinosaur footprints but the main attraction for me will always be its birds.
High tide this morning was at 08.22, a very civilised time to hit the beach. Once there I came upon a mixed flock of terns. There were a few Crested Terns and lots of their smaller cousins, Lesser Crested Terns. The big guys are found all around the Australian coastline whilst Lesser Cresteds are only found along the coasts of the northern half. Both are found far and wide overseas but not at high latitudes or in the Americas.
Both are white birds with black caps and a crest. Their calls and behaviour are very similar. So how does a southerner spot the difference? Size can help when both are present but their is an easier way. Their beaks are as different as orange peel and lemon peel …
A New Adventure …
but an old plan. Let’s go live in Broome.
Allied – the careful movers – took splendid care of the furniture. Gayle, Fifi and Bobby McGee chased them across the Nullarbor in our latest camping solution.
Our timing was perfect. The last cyclone of the season had knocked over the Pardoo Roadhouse just a week or so before we left. The northern big wet had turned to a settled (we hope) dry and Victoria had not quite dipped into ice-age conditions.
We couldn’t dawdle on the way but we did have time to look in on the sealions at Point Labatt near Streaky Bay SA.
Broome is where the desert meets the sea. As I drove past the airport on the way into town I couldn’t help thinking how different this place is to the the Australia that most Australians live in. This could be arabia!
The Final Leg …
The time had come to turn for home. The route would take us through the centre of the continent, a region that is generally dry. Alice Springs for example has about 28 cm (11 inches) of rain a year. This year has been different, La Niña has brought roughly twice the normal amount.
With a long road ahead we stopped for essential supplies at Katherine. The bottle shop wouldn’t be open until 2pm and we wouldn’t be served until our ID had been run through a Police Check. We didn’t wait.
We camped just north of Mataranka. The total distance since leaving home passed 10,000km. The bird list had reached 266. Bird of the day was Gouldian Finch.
Timber Creek …
Pine Creek was our furthest north on this trip. The locals were so thrilled that they let off fireworks to celebrate our achievement. Or, perhaps, it was merely the case that our visit coincided with Territory Day, Jul 1. There was an organised display on the oval preceded and followed by an informal celebration of the right to blow your face off. Fireworks can still be purchased for personal amusement in the Northern Territory.
A day’s drive from there took us to our furthest west on the trip, Timber Creek. Similar in size to Pine Creek but without the gold or railway artifacts. Just as interestiIng though are the Gregory Tree and the Nackeroo Monument. No rare parrots but instead this area is often called the Finch Capital of Australia. It had lived up to that title on a previous visit so here we were again.
At the caravan park there were bats in the trees and freshies in the creek.
The crocodiles are fed twice a week and we arrived on feeding day.
The birding spots are around the creek, the Victoria River, Gregory Tree and up the hill at the Nackeroo Monument. The Nackeroos were an army unit set up in 1942 as an observation and geurrilla unit on Australia’s northern coast. Travel was by horseback, resupply was irregular. It was a pretty tough gig especially in the wet. There is a poem on the monument, author not stated …
Somewhere in Australia where the sun is a curse, And each day is followed by another slightly worse, And the brick red dust blows thicker than the shifting desert sand, And the men dream and wish for a fair and greener land. Somewhere in Australia where the mail is always late, Where a Christmas card in April is considered up to date, Where we never have a pay day and we never pay the rent But we never miss the money 'cause we never get it spent. Somewhere in Australia where the ants and lizards play, And a hundred fresh mosquitoes reinforce the ones you slay, So take me back to good old Sydney where I can hear the tramway bell, For this god-forsaken place is just a substitute for hell.