About Me

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Canberra-based naturalist, conservationist, educator since 1980. I’m passionate about the natural world (especially the southern hemisphere), and trying to understand it and to share such understandings. To that aim I’ve written several books (most recently 'Birds in Their Habitats' and 'Australian Bird Names; origins and meanings'), run tours all over Australia, and for the last decade to South America, done a lot of ABC radio work, chaired a government environmental advisory committee and taught many adult education classes – and of course presented this blog, since 2012. I am the recipient of the Australian Natural History Medallion, the Australian Plants Award and most recently a Medal of the Order of Australia for ‘services to conservation and the environment’. I live happily in suburban Duffy with my partner Louise surrounded by a dense native garden and lots of birds.

Tuesday, 31 December 2019

Farewell to 2019!

Continuing my tradition of recent years, to mark the changeover of years I've selected just one photo* from each month of 2019. As ever I don't make any pretences to photographic excellence, but have chosen the pictures because of their associations, and in most cases because they are ones I've not previously used this year in a blog posting. 
It's been a remarkable year for us, marking the next stage of our life. To celebrate we did a bit of extra natural history travelling (of course): tropical Queensland in January;  Africa (Tanzania, Kenya and South Africa) in May-June; Brazil (accompanying a tour) in July-August; Costa Rica (reconnoitering for a tour next year); western Victoria, chasing wildflowers primarily, in September.

(*Actually that turns out to be a lie; for a couple of months there were other pics I just had to share. Sorry, but only a little bit sorry.)

Cairns Birdwing Ornithoptera euphorion, Lake Barrine, North Queensland. The main reason for going
to the tropics in the Wet is for the wealth of wildlife; we saw many things we'd not previously seen,
including this magnificent animal, Australia's biggest butterfly with a 15cm wingspan.
It is limited to coastal tropical Queensland.

Striped Possum Dactylopsila trivirgata, Lake Eacham, North Queensland.
This is an animal I'd long wanted to see, and it came to a feeding station near our accommodation,
attracted by some honey smeared on the tree (not by us). Its main food however comprises wood-boring larvae;
it chews through wood with chisel-like teeth and uses the long fourth toe to extract the morsel.

Sparring Eastern Grey Kangaroo males Macropus giganteus, Namadgi National Park,
south of Canberra. These two weren't seemingly intending serious harm but were
definitely testing each other's strength and resolve. Note how the tail acts as a fifth limb.

Robber Fly Ommatius coeraebus, Nowra, southern New South Wales.
When visiting I often prowl Lou's parents' substantial garden, and I'm usually rewarded.
Lucky I'm not smaller! Robber flies are fearsome predators, perching like this to watch for
prey insects flying by, which they pursue and capture with their spiny legs, stab with the short
powerful proboscis, inject with paralysing and digestive enzymes, and devour in the air.
Even wasps and dragonflies are not safe.

Filamentous lichens on a dead branch, Shanahans Mountain, southern Namadgi National Park,
south of Canberra. This is a memento of a nice walk we did on a sunny autumn day.

Greater Flamingo Phoenicopterus roseus and Cape Buffalo skull, Serengeti National Park, Tanzania.
I'm surprised I selected this one of all the possible amazing animals we saw in Africa, but this
juxtaposition appealed to me.
But in the end one wasn't quite enough for East Africa, so I've sneaked in this one of a Cheetah family,
mother and three youngsters, in the evening in Amboseli NP, in front of mighty Mount Kilimanjaro,
making a rare appearance from the clouds.
These two young ones had dropped behind and were playing chasing games.  
Gemsbok Oryx gazella, Augrabies Falls NP, northern South Africa. There are four species of oryx, big arid
land antelopes. Gemsboks are from southern Africa, centred on the Kalahari Desert.
This one was quite at home in the dry rocky wilderness of Augrabies.
Southern Tamandua Tamandua tetradactyla, the second-largest South American anteater (up to 150cm long),
which I had longed to see for ages. This one appeared in a cattle paddock at Pousada Aguapé in the southern
Pantanal late in the afternoon. It was clearly aware of us, but seemed to have very poor eyesight.
We eventually left it to its own pottering devices in fading light; I was thrilled.

Crowned Tree Frog Anotheca (or Triprion) spinosa, Tapirus Lodge, Costa Rica.
This is a remarkable-looking frog with a spiny 'crown', living in bromeliads and related plants in the rain forest,
where our equally remarkable local guide located it for us in the rain. Eggs are laid in a flooded
tree hollow, where the female returns to feed the tadpoles by laying unfertilised eggs for them to eat.

Male Resplendent Quetzal Pharomachrus mocinno, Savegre Valley, Costa Rica; through early morning mist.
One of the most sought-after birds in this country of wonderful birds.

 Common Heath Epacris impressa, Mount Zero, northern Gariwerd/Grampians NP, western Victoria.
There are quite a number of plants endemic to the range, but I chose this widespread species
because I love the fact that this healthy plant is virtually growing out of the sandstone.
It is Victoria's floral emblem, and also comes in pink and white.

Red-bellied Black Snake Pseudechis porphyriacus breakfasting on an unfortunate - and inattentive - Heatwole's
Water Skink Eulamprus heatwolei at Tidbinbilla Nature Reserve, just south of Canberra.
It was odd to watch such a drama played out at close range, and in total silence.

Hoary-headed Grebe Poliocephalus poliocephalus, Molonglo Pond, just down the road from our home.
The adult (sexes are identical, and both play similar roles in chick care, so not sure who this is) was carrying
the baby around the pond, hidden under its wings. At this moment it popped its head out to be fed.
It was a delightful encounter.
The sun through bushfire smoke over Canberra, late afternoon but still high in the sky, 17 December.
The nearest fires to us are over 40km to the east but at times the smoke is choking and stinging here.
Between here and the coast three ferocious fires have burnt some 200,000 hectares so far (23 December),
mostly in national parks (but it will be more by the time you read this).
To the north over 400,000 hectares have burnt in the Greater Blue Mountains World Heritage Area, and are still burning.
Only rain will put these fires out, and none is expected for at least a month...
This one was taken three days later, 20 December, mid-morning. It was an opportunistic shot, with just my phone.
I wouldn't normally post such a photo, but it really does give you an idea of conditions here
(and throughout much of eastern and southern Australia at the moment).
This is looking through the smoke across Lake Burley Griffin in central Canberra, to the other shore
only a couple of hundred metres away. Much of eastern Australia is burning in unprecedented December temperatures,
but our government doesn't deem this the right time to even discuss climate change, let alone meaningfully address it.
This is not how I wanted to end my year in photos, but anything else would have been dishonest.
However I can add an addendum, as a balance. I won't forget either the horrors of these fires or the shame of our government's contempt for the land, but neither do I want to forget the joy that I took from the world this year, as always, so here's another of my year's highlights.
Big male Leopard in a massive rock outcrop overlooking Serengeti NP, Tanzania.
Like most people I'm awed by big cats, and this year was an astonishing one for us in that regard.
So, that's one version of my year, but there could have been others. Perhaps I've prompted you to muse too on your year's natural history highlights - that can be a very satisfying and even therapeutic thing to do.

Thank you reading this, and if you're a 'regular' reader I greatly appreciate that support. May 2020 bring you lots of natural pleasures and surprises, and I look forward to sharing some with you.  

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Thursday, 19 December 2019

"I Thought There Was Only One!"; of zebras, ostriches and more

The year is winding down, but there seems so much to do still. Accordingly this will be a fairly low-key post, based on a comment I heard with regard to our African adventure earlier this year, both while there from our companions on the East African tour, and since getting home. "But I thought there was only one zebra (ostrich, giraffe etc)!"

Fair enough too; we usually just refer to such animals in one-word terms, strongly implying that this is exactly the case. 'Zebras' for instance; even if we're aware of the more formal name of Plains or Common Zebra we usually tend to just go for friendly informal 'zebra'.
Plains Zebras Equus quagga, looking Africa-postcardish in the magnificent Ngorongoro Crater in Tanzania
(one of the most satisfying days of my natural history life by the way).  And you might like to entertain yourself
by thinking of how many other names there are with a 'q' in both genus and species name.
This is quite understandable; almost any zebra that you're likely to see either in captivity or in the wild in Africa will probably belong to this species. This post is intended as an introduction to a few often unsuspected animals, not an in-depth study, but a couple of questions probably need to be asked about this one. Why 'zebra', and why the stripes? Unfortunately if you really wanted to know the definitive answer to either of these questions, you've come to the wrong place. My trusty old big Oxford Dictionary reports that it appeared in English for the first time in 1600, in a work translated from Portuguese. It suggests that the word originated in a Congolese language and appeared in similar forms around the same time in Italian, French and Spanish too. However I understand that other sources suggest a possible Latin origin, though the nexus seems pretty vague. I'm inclined to go with the Oxford, based on a long relationship.
Plains Zebra and foal (and bonus Yellow-billed Oxpecker), Tarangire NP, Tanzania.
The foal's stripes will darken age.
And the stripes? There is an array of suggestions, the most popular of which relate to camouflage, either referring to broken shadows or the 'dazzling' effect of swirling patterns of fleeing animals. Social aspects have been mooted, wherein stripes stimulate a zebra to groom other zebras, or the unique patterns of individuals assist in recognition. A couple of more recent suggestions, both evidence-based, are interesting. One shows that biting flies, which rely on homing in on polarised light, are confused by the stripey patterns. Another demonstrates that black stripes can be up to 10 degrees C hotter than adjacent white ones, which sets up small air convection currents which in turn assist in evaporative cooling. Have fun working your way through all those options!

We do know about the quagga part of the name though. This is a Khoekhoe word (once referred to as Hottentot) from South Africa, referring to an abundant sub-species which was hunted to extinction by 1880. Only one photograph exists (from an animal in London Zoo), plus 20-odd skins. Curiously the Quagga lacked stripes over most of the back half of its body. Which brings us to the point of this post; there isn't just one 'zebra' and this isn't just true at the subspecies level. Before we look at the other two zebra species, let's see what differentiates the Plains Zebra from them.
Plains Zebra, Lake Mburo NP, Uganda.
The key factor is the stripes (unsurprisingly!); in the Plains Zebra they run right under the belly,
and body stripes are much wider than those of either of the other two. There are no small transverse stripes
across the rump and top of the tail, and no stripe along the spine.
While the Plains Zebra is found in much of eastern Africa, and across northern Namibia to the Atlantic, the Mountain Zebra Equus zebra is limited to scattered mountain populations in southern South Africa and western Namibia. In the 1930s there were perhaps only 100 left, but numbers have increased with sustained conservation programs.
Mountain Zebra, Goegap NR, South Africa. They seem to like it rocky, hot and dry;
Goegap, near Springbok in the north-east of the country, meets these requirements well!
Notice the white belly and narrow body stripes, which suddenly get dramatically wider on the hips.
The little stripes across the spine above the tail and on it, and the obvious throat dewlap are also distinctive.
The third zebra species lives in the opposite corner of the continent, scattered in a few reserves in northern Kenya and Ethiopia, while it has has been extirpated in Djibouti, South Sudan, Eritrea and Somalia. Grevy's Zebra E. grevyi is the largest living wild horse, and rangier than the other zebras. This was the hippotigris ('tiger horse') which appeared in Roman arenas and parades. It is listed as Endangered, though populations seems to have stabilised.

Grevy's Zebra, Buffalo Springs NR, northern Kenya.
It has narrow body stripes and white belly like the Mountain Zebra, but no broad bands on the hips,
and a dark stripe down the spine bordered by a white strip on either side, plus noticeably bigger ears.
But ostriches? Surely there's only one ostrich?! No, there are actually two. The Common Ostrich Struthio camelus has two quite separate big ranges, across southern Africa, up from northern South Africa, and across a huge swathe of the Sahel from the Red Sea to the Atlantic with a 'tongue' of occupation down through Kenya and Tanzania.
Common Ostriches, Tarangire NP, Tanzania. The two ostriches are the world's largest birds;
a male can be nearly three metres tall and weigh over 150kg. Females and immature birds are
very similar.
The Somali Ostrich S. molybdophanes was described as a separate species back in 1883 but this was rapidly rejected, and until this millennium it was regarded as a sub-species of Common Ostrich. Only in 2014 was it reinstated as a full species, based on various physical and genetic characters, and the fact that the two live side by side in Ethiopia.

Somali Ostriches, Shaba NR, northern Kenya. The most obvious distinction from Common Ostrich
is in the blue-grey (not pinkish) legs and necks. The male is also 'very' black, as opposed to sort of 'off black'.
There are other differences too. 
Male Common Ostrich (Lake Nakuru NP, Kenya) above; male Somali Ostrich (Shaba NR, Kenya) below.
The Common has mostly dark irises, and a smooth crown with bristly hairs;
Somali has pale irises and a bare crown with a little horny protrusion.
Add caption
At Shaba we encountered another Horn of Africa relative of a widespread and well-known species too. The Common Warthog Phacochoerus africanus is a familiar pig across much of sub-Saharan Africa.
Common Warthog, Ngorongoro Crater, Tanzania. It really is a remarkable creature.
In northern Kenya, Ethiopia and Somalia is a closely related warthog, an arid land specialist, the Desert Warthog P. aethiopicus. It's been known for a long time, but it's not a part of the world that most nature-watchers tend to visit.
Desert Warthogs, Shaba NR, Kenya. They are very similar to Common Warthogs, but have very
different dentition, lacking incisors entirely and with muscles that allow considerable side to side movement.
Presumably this assists with mastication of hard tubers and roots.
And finally I mentioned giraffes. No, it's OK, there really is only one Giraffe species Giraffa camelopardalis. Well, so far anyway; a number of reputable recent studies strongly suggest there are more. The eminent - and sadly recently late - Colin Groves in a 2011 publication believed there were eight species! We'll stick with the orthodoxy for today though, which generally recognises eight subspecies. Here are some of them; they are really quite distinctive.
Cape Giraffe G. c. giraffa, Augrabies Falls NP, northern South Africa.
The spots are dark and not as angular as others, and extend to about the knees.
From north and north-eastern South Africa and into Zimbabwe and Mozambique.

Masai Giraffe G. c. tippelskirchi, Serengeti NP, Tanzania.
The spots here are very 'splintered' and go right down to the hoofs. Tanazania and southern Kenya.

Reticulated Giraffe. G. c. reticulata, Shaba NR, northern Kenya. Arguably the most striking giraffe,
with big angular chestnut spots on a white background.
An arid land giraffe, from north-eastern Kenya and adjacent Ethiopia and Somalia.

Rothschild's Giraffe. G. c. rothschildi, Lake Nakuro NP, Kenya.
Its large dark spots often contain paler lines, which can be seen on the male on the left
(though you may have to click on the photo to enlarge it).
From a small area here in south-western Kenya, plus northern Uganda and adjacent South Sudan.
As I said, these very different giraffes are still regarded as the one species, but I have a feeling that that may not be the case for much longer. 

Well, not for the first time that's probably more than I meant to say, but I hope you've found something to interest you here. If nothing else you may have met some special animals whose existence you may not hitherto have known about. Either way they're worth considering.

Enjoy the last days of 2019, and may 2020 bring you lots of natural history adventuring! I'll be back once more before the end of the year, for my annual year's highlights, via one photo per month.

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Thursday, 5 December 2019

Nitmiluk National Park; sandstone spectacular

Kakadu National Park in the Top End of the Northern Territory of Australia, protecting some 20,000 square kilometres of woodland and sandstone escarpment, is one of the world's great parks (see here and here for a little more about it). However it doesn't end there. To the south the Arnhem Land Plateau continues and is now protected in Nitmiluk NP, of a slightly more modest - but still huge - 3,000 square kilometres. Located some 240km south-east of Darwin, and just 30km north-east of Katherine, its gorges and pools have long been popular visitor attractions and the two most popular such sections - Leliyn (Edith Falls) and Nitmiluk (Katherine Gorge) - were declared as protected areas in the 1960s.
Sublime Nitmiluk Gorge, from a boat tour.

Approximate location of Nitmiluk NP; Kakadu continues to the north of it all the way to the sea.
This map (courtesy of Wikipedia) gives a general idea of the locations mentioned in this posting,
though doesn't identify all of them, due to the scale. Kakadu adjoins along the northern boundary,
and the north-eastern one, down to the Katherine River.
In 1979 the Jawoyn people, traditional owners of what is now Nitmiluk NP, launched a claim for the land under the Aboriginal Land Rights (Northern Territory) Act 1976, which had been recently passed by the Federal Government. There was initially a (sadly predictable) backlash from sections of the non-Indigenous community, especially in Katherine, seemingly encouraged by the then Northern Territory government. Malicious claims that the popular swimming areas would be closed added to the tension. Nonetheless, after a decade of hearings, the claim was successful and the land 'handed back' to the Jawoyn owners in September 1989. Immediately, as previously agreed, it was leased to the Northern Territory government for joint management as national park; this followed the precedent set for Kakadu NP in 1985. The Jawoyn language and culture is still strong and active, and is an important part of Nitmiluk management and interpretation for visitors.

Jawoyn art site on the wall of Nitmiluk Gorge.
While we're at 'the gorge', let's continue there. In reality it is a series of 13 gorges, most of which are not readily accessible. We took a four-hour boat trip with accredited guide, a memorable experience; it included disembarking and walking across rocks to continue the journey into the next gorge in another vessel. The hundred metre high gorge walls glowed in the afternoon sun.
A lower section of Nitmiluk Gorge.
Ferns clinging to the sandstone walls, where it is moist and sheltered.
Just above however, is dry savannah woodland exposed to the full sun.
Freshwater Mangrove Barringtonia acutangula, Nitmiluk Gorge.
One of the highlights of the trip for us was the opportunity to see Freshwater Crocodiles Crocodylus johnstoni up close.
Freshwater Crocodile sunning on a log in the gorge. The long narrow jaw evolved for catching fish.
For a bit more on crocodiles in general, see here.

For our stay at Nitmiluk we camped at Leliyn (shown only as Edith Falls on the map above); it was much busier than our preferred camping but, despite that, it was one of the loveliest - and birdiest - public camp grounds we've ever stayed in. We enjoyed the 2.7km Leliyn Loop Walk and walked from it along the track to Sweetwater Pool as far as Long Hole Pool (this is actually the beginning/end of the 60km five-day Jatbula Track, which joins Leliyn to Nitmiluk Gorge).
Relatively lush riverine forest along the Edith River in a dry sandstone landscape.

Top (or Upper) Pool on the circuit track, seen from above.
Top Pool Falls, an excellent plunge pool for swimming.

Long Pool and falls; arguably an even better place to cool off, not least because less people go there.
On our walk across the plateau above the river we inevitably encountered some interesting plants - here are a few of them. 
Acacia helicophylla is a very distinctive spindly wattle found only at Leliyn and at Gunlom Falls in Kakadu.

Grevillea heliosperma is a pretty small tree of the sandstone of the northern tropics.

Fern-leaved Grevillea Grevillea pteridifolia is found even more widely across northern Australia,
but I never tire of seeing or sharing it.
Emu Apple Owenia vernicosa is a small to medium tree of tropical woodlands in the cedar family, Meliaceae.
It is widely used by Jawoyn and other peoples for various medicinal purposes.
But I mentioned before the superb bird life around the camp - those which immediately follow were taken from directly over our camp, some from our camp chairs! It was of course a big advantage that the eucalypts (and to my shame I can't recall what they were) were in full flower.
Banded Honeyeater Cissomela pectoralis; a small nomadic honeyeater of the north,
following the flowering. It is the only member of its genus.
Bar-breasted Honeyeater Ramsayornis fasciatus, another small tropical honeyeater, which
seems not to move around as much as the previous species. It probably switches more to
insects and spiders when the flowers are scarce.
Yellow-tinted Honeyeater Ptilotula flavescens, larger than the others, demurely clad.,
usually found not far from water.
Paperbark Flycatcher Myiagra nana. As the name suggests it is often found around paperbark swamps, but
not in this case. John Gould recognised it as a separate species from the widespread Restless Flycatcher
M. inquieta, but it was then regarded as a subspecies for decades until it was separated out again in 1999.
It never does to underestimate Gould's perspicacity!
(See here for a few notes on him in one of the first blog posts I ever did.)
Northern Rosella Platycercus venustus, a rosella that seems to be not nearly as approachable as the ones
from our part of the world. More sombrely coloured too, and found across the Top End and the Kimberley.

Hooded Parrots Psephotellus dissimilis on the other hand are restricted to the Northern Territory,
and within that to the southern Top End. Nitmiluk is a noted hot spot for them, though this
one was just outside the park, in the small town of Pine Creek. One of a group of three small
tropical and formerly subtropical parrots which nest in hollows excavated in termite mounds.
The Golden-shouldered Parrot of a couple of tiny sites on Cape York Peninsula is Endangered,
and the Paradise Parrot from further south now extinct.

Blue-winged Kookaburras Dacelo leachii somehow seem more menacing (and even manic) than their
Laughing relatives. This female (russet, not blue, tail) was attempting to obtain handouts by menace
from people waiting to board the boat at Nitmiluk Gorge.
The Great Bowerbird Chlamydera nuchalis is the largest of its family, widespread and familiar
across northern Australia. It too isn't above cadging scraps and this one was hanging around
the campground cafe.

Red-tailed Black Cockatoo Calyptorhynchus banksii flying over the Leliyn Loop Walk.
This is a huge cocky, 60cm long, and much commoner in the north than further south.
This one seems to have lost (or perhaps is moulting) an outer tail feather.
If you go to Katherine, perhaps on your way between Darwin and Alice Springs, you're likely to go to Nitmiluk Gorge and you certainly should; there's a lot more to Nitmiluk however and I'd urge you to investigate. You'll not be sorry.

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