Leaf Beetles and Mobile Homes

I had no intention of talking about leaf beetles today - indeed I scarcely knew anything about them and the idea had never occurred to me. Until Sunday.

On Sunday I was walking with some like-minded people along a quiet road in the Tallaganda Ranges a little to the east of Canberra. The Tallagandas contain some beautiful wet eucalypt forest, a reasonable proportion of which has now been preserved from the creeping blight of exotic pine plantations and dedicated as Tallaganda National Park.

Eucalyptus obliqua, E. viminalis and Fishbone Ferns Blechnum spp., Tallaganda NP.

On the road we found a busy crowd of odd-looking little animals, seemingly in mud-like shells, demolishing a eucalypt leaf - I was at a complete loss to explain them, to my embarrassment. There wasn't much left of their leaf, but I was concerned for their safety on the road, quiet though it was, and tried to move them and the leaf to the edge of the road. They were much more active than they first seemed however and all tumbled off to the side and proved impossible to move without risking damage to them.

A very odd little gathering!

Back in Canberra I consulted Kim Pullen, an entomologist with CSIRO (for those outside Australia, this is the Commonwealth Scientific and Industrial Research Organisation, an icon of Australian research, though shamefully starved of funds by recent governments). He put me firmly on the right track, on which I've since done a little more of my own research, though readily available information isn't plentiful.

However I think I've got enough to share a little story which I found fascinating. Our little characters are leaf beetle larvae, Family Chrysomelidae, subfamily Cryptocephalinae. Normally we don't worry too much about sub-families for day to day use, but when species numbers are as high as they are in insect families, and notably among beetles, it is a practical necessity. As a case in point, there are some 700 species of Cryptocephalines in Australia alone. 

First, a little background (bearing in mind I claim no expertise in matters invertebrate). The leaf beetles, Chrysomelidae, contain at least 3000 species in Australia, in more than 250 genera. Both adults and larvae specialise in eating plant tissue, including, as you'd expect in Australia, both eucalypt and acacia leaves.

A leaf beetle, probably of the same subfamily as our subjects, effectively
chewing an Eremophila leaf, Whyalla Conservation Park, South Australia.

The best-known are probably the numerous species of the genus Paropsis, or tortoise beetles. A major part of the secret to their success is in being one of the few groups of organisms in the world which have managed to unravel the chemical binding of proteins to the tannins in eucalypt leaves. These greatly limit the availability of essential nitrogen to those munching on them, making them pretty unattractive to most leaf-eaters.

Tortoise beetles - larvae above, adult below - demonstrating their disdain for the chemical
defences in eucalypt leaves. The larvae, moreover, exude deadly hydrogen cyanide from glands in
their rear ends - enough to kill a meat ant outright.

 

Another Chrysomelid is well-known to orchid growers - the Orchid Beetle Stethopachys formosa (subfamily Criocerinae) specialises in eating orchid flowers, notably the summer flowering hyacinth orchids, Dipodium spp. They really appreciate the nice warm conditions in greenhouses!

Orchid beetle on lunch - Dipodium punctatum, Rosedale, south coast New South Wales.

So, what's the story of our little friends on the Tallaganda road? Kim Pullen tells me that the only way to even allocate them to a genus would be to raise them to adulthood, but my fostering skills are not up that, even if I was willing to rip them from their friends and family. As the the female beetle laid each egg on the ground, she caught it in the 'foot' of her rear legs and coated it in droppings, which are composed of eucalypt leaf material. When the egg hatched, the little beetle larva broke a hole at the front of the case and with the assistance of its front 'legs' moves about the forest floor eating the litter. I am told by Kim that Dr Chris Reid of the Australian Museum in Sydney, an expert on Chrysomelids, considers them an important player in the cycle of litter breakdown in eucalypt forests 

An enlarged view of a section of the above photo shows some of the larvae protruding from their mobile homes. These homes provide both physical protection and effective camouflage in the litter.

As they grow they add to the case with their own droppings, and when the time comes they pupate within it, eventually emerging as an adult beetles.

A small story in the bigger scheme of things, but it fascinated me and I hope you found something of interest here too.

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American Camels

I think some people are surprised to realise that there are camels in America. Even more, I suspect, are taken aback to learn that camels actually arose in North America, some 45 million years ago. Over their long history in that continent - which ended only very recently - some 90 camelid species in 35 genera arose, from tiny delicate gazelle-like animals to huge six metre high giraffe-like camels. Some six to seven million years ago one of the larger of these species crossed the then dry Bering Strait into Asia; its descendants eventually reached Spain. Two descendant species still live, both in the genus Camelus, inhabiting some of the harshest lands on earth. The Bactrian Camel (C. bactrianus) adapted to the summer-baking and winter-freezing stony deserts of the central Asian steppes, while the Dromedary (C. dromedarius) settled in the hot sandy deserts of south-western Asia and north Africa. Both were domesticated between four and six thousand years ago (Bactrians first), to the extent that there are now no wild Dromedaries in their home range, and very few wild Bactrians, though there are nearly 20 million domestic Dromedaries and about a million domestic Bactrians.

Feral Dromedary, Musgrave Ranges, central Australia.
The ancestors of inland Australia's feral camel population - the only wild Dromedaries in the world -
were brought here from British India as pack animals in the nineteenth century.
There are at least 600,000 of them, representing a serious environmental problem, especially to scarce water sources.

Probably less than a thousand wild Bactrian Camels survive, deep in the Gobi Desert.
Recent genetic work suggests that domestic Bactrians have changed enough that the wild animals
merit different species status, as C. ferus.
Photo courtesy of National Geographic.

More recently - some three million years ago - another opportunity arose for the North American camels to expand their range. This was the collision of South America with the North, providing major two-way access between the continents via the Panamanian Land Bridge. 

Two species derived from the invasion. Widespread in open habitats of the continent was the Guanaco Lama guanicoe; more specialised is the much smaller and more delicate-looking Vicuña Vicugna vicugna which is limited to the high northern Andes, over 3500 metres above sea level.

 

Guanacos, Torres del Paine NP, Chilean Patagonia.

Vicuña near Chivay, southern Peruvian Andes.

It has been estimated that 50 million Guanacos once roamed the plains and mountains, but now perhaps 1% of that number survive, mostly in the far south; only in the southern tip of Argentina do they maintain a presence in the plains. Vicuña numbers are slightly lower than that, but they were never as numerous and numbers actually appear to be increasing. However many, even most, wild Vicuña populations are heavily managed for regular shearing, with some even kept permanently in large corrals, which prevent natural gene flow. A second domestication of most of the remaining wild Vicuñas may be underway.

The Guanaco hot-spot is Torres del Paine, where large herds are still ubiquitous. Further north things are dire for them. The northern sub-species L. g. casilensis numbers less than 4000 animals now, in southern Peru and northen Chile.

Northern Guanacos, above and below, Atacama Desert near San Pedro, northern Chile.

These harsh high deserts support both species.

Vicuñas, Aguada Blanca National Reserve, southern Peru.

Guanacos live either in family groups - a male defending several females and offspring, or as troops of males waiting their chance, sometimes for years, or as solitary mature males, hanging around the periphery of territories, challenging the incumbent males. 

(All subsequent Guanaco photos were taken in Torres del Paine NP.)

Guanaco herd, females and young.

The single young - called chulengos - are born in summer after an 11 month gestation, weighing up to 15kg, a sixth of adult weight. They are suckled for 15 months; all these characteristics are adaptations to a harsh climate. Nonetheless mortality is high (up to 15% in the first 10 days in Torres del Paine), the main cause being Puma predation.

Chulengos on the park boundary - the adults easily leap the fence (below).

Fresh Puma-killed chulengo.

Males will fight viciously for hours with intruders, with exhausting chases; just when the struggle seems to be over with one party completely beaten, the tables can turn in an instant and it all starts again.

Despite these dramatic scenes, when we moved on after nearly an hour
neither party seemed to have any ascendancy.

As with their Old World relatives, both species were domesticated early - thousands of years ago. Both of the domesticated animals have evolved so far from their wild ancestors that they are now regarded as separate species. Guanacos gave rise to Llamas (Lama glama) and Vicuñas to Alpacas (Vicugna pacos). The much larger Llamas were developed as pack animals - huge caravans of Llamas traversed the vast Inca empire, carrying goods for hundreds of kilometres. Alpacas on the other hand were bred to be producers of valuable fibre. Large herds of both roam the high Andes, usually in the care of shepherds.

Llamas, Machu Picchu, Peru.

Alpacas (and Andean Geese) near Chivay, southern Peruvian Andes.

Mixed mob of Llamas and Alpacas with young shepherd, near Chivay, southern Peruvian Andes.
The Llamas have nearly bare faces.
The coloured ear tags, denoting ownership, are a part of a very old tradition.

And the ancestors of all these animals, back in North America? They survived until very recently, perhaps only 15,000 years ago, during the last glaciation. Savage climate change alongside hunting pressures and perhaps changed fire regimes from newly arrived humans probably interacted to eliminate them, along with many other large grazing animals, including several South American camel species.

So now, if you want to see wild camels in the land they evolved in, you're going to have to go to South America. And really, that's not a hardship...

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Mareeba Wetlands: sweeter than sugar

There is a constant tension in near-coastal Queensland between the sugar cane industry and reaction to its impacts on ever-dwindling natural tropical and sub-tropical habitat, from rainforest to savanna woodland. Mareeba, inland from Cairns, is not on the coastal strip where most sugar is grown, but in the early 1990s the industry was seeking new areas to expand as opportunities on the coastal strip became limited. An area north of Mareeba, on the escarpment plateau 400 metres above sea level, was earmarked as an option. It was an area of tropical savanna woodland, of a type quite widespread but not well protected in reserves. Most importantly however in the selection of the area for further cane growing, was the existence of the Mareeba-Dimbulah Irrigation Scheme, based on the Tinaroo Dam on the Atherton Tableland to the south. It supports a major fruit-growing industry and in the past a large tobacco crop, though this has become much less significant in recent years.

Mareeba is approximately at the end of the red arrow;
as can be seen it is well north of the Tropic of Capricorn.

Savanna woodland, Mareeba Wetlands Reserve.
Eucalypts and shrubs grow over a grassy understorey. Massive termite mounds reflect the
significance of a huge biomass of grass-harvesting termites to the local ecology.

The proposal was to open a new area to sugar cane utilising the run-off from water which had passed through the irrigation channels. This wasn't necessarily a problem in itself, but fortunately appropriate studies were required, and these studies determined that there were serious environmental constraints on that site relating to soil types and the potential for downstream salinisation issues. 

However a group of far-sighted locals saw the potential for creative alternative uses for both the water and the land, based on the knowledge gained through the existing research. They formed the Mareeba Wetland Foundation (which has since evolved into the Wildlife Conservancy of Tropical Queensland) to press for the creation of the Mareeba Tropical Savanna and Wetland Reserve. (It is still known to all and sundry as simply the Mareeba Wetlands so I'll continue to do so to.) They proposed a 2000 hectare savanna reserve featuring a series of gravity-fed ponds. One might argue that a wetland has no place in a savanna, but many natural wetlands have been drained, so I'd just see it as compensating for some of these. The loss of some woodland - well-represented locally - is balanced by the recreation of wetland and associated habitats which have been lost locally.

Their proposal was sufficiently well-researched and convincing to persuade the federally-funded Regional Infrastructure Development Program to support it, and local, state and commonwealth governments, as well as local business, especially the tourist industry, offered assistance. The reserve opened to the public in 1999. By then the wildlife had already offered its approval, and it had become one of the most significant Brolga and Sarus Crane roosts in north Queensland. A walk around the biggest lagoon is likely to be accompanied by the wonderful wild bugling of cranes drifting down from the sky.

Mareeba Wetlands, with the visitor information centre visible across Clancys Lagoon.
The walk around this lake, with the promise of coffee and treats at the little cafe at the end of it,
is a delightful introduction to the reserve.

The local Muluridgi people were granted title over the reserve in 2011, and the reserve is now operated as a partnership. All staff are volunteers. The magnificent visitors' centre was built with assistance from local industry.

A closer view of the Clancys Lagoon Visitors' Information Centre (VIC).

The VIC deck - an excellent location to enjoy the view and the wildlife (with or without coffee).

Another view from the deck.

There are several research and monitoring projects ongoing, including on the cranes and on the rare and little-understood Buff-breasted Buttonquail, but one very obvious one to the visitor is the captive breeding and release program for the glorious but seriously threatened Gouldian Finch.

The Gouldian Finch breeding aviary (above and below) backs on to the VIC, and faces the
wetlands and woodlands to which they are steadily being released.

The Gouldian Finch Erythrura gouldiae is truly an exquisite bird, named by the great 19th century
ornithologist John Gould for his wife and work partner, the artist Elizabeth Gould.
Once found throughout northern Australia, numbers have plummeted due to a complex of factors,
among which changed fire regimes seem likely to be the most significant.

 Waterbirds can be seen from the deck, though Clancys Lagoon is big and they will not necessarily be close.

Comb-crested Jacana Irediparra gallinacea from the VIC deck.
Its enormous toes for distributing its weight on the leaves can be seen in this photo.

The creek by the VIC entrance can be excellent for frogs, including one of my favourites.

The White-lipped Tree Frog Litoria infrafrenata is reputedly the world's largest tree frog - it can be close to 14cm long.
It is found in north Queensland and beyond into New Guinea and associated islands.

Out in the woodland there are many resources for wildlife, including flowers and grasses.

Broad-leaved Paperbark Melaleuca viridiflora is found across northern Australia.
The species name is from these (sort of) greenish flowers, but unfortunately they are just as likely to be red!

Thysanotus juncifolius, one of the glorious fringe-lilies.

Native Rice Oryza australis; the seeds are tiny but prolific and feed many animals.

Such grasses support several finch species, among others.

Black-throated Finches Poephila cincta (a declining species, above) and
Chestnut-breasted Manikins Lonchura castaneothorax harvest the reserve's grass seeds.

 

Pheasant Coucal Centropus phasianinus, a wonderfully scruffy and shambling big bird.
Throughout the world 60% of cuckoo species actually nest and raise their own chicks in the
conventional way, but in Australia this is the only one to do so.

Squatter Pigeon Geophaps scripta, a striking tropical ground-dwelling pigeon.

Male Leaden Flycatcher Myiagra rubecula, a monarch flycatcher.
This species migrates between the tropics and south-eastern Australia, where it breeds.
I might even have seen this bird in Canberra!

But as is the way in Australian tropical savannas, reptiles are almost as obvious as, and probably more abundant than, the birds.

Tommy Roundhead  Diporiphora australis on a Mareeba termite mound.
Australia has the most diverse arid land lizard fauna in the world, and the basis
of this proliferation is the huge mass of termites.

Snake-eyed Skink Cryptoblepharus virgatus; another who doubtless dines on the termite smorgasbord.

And finally, one of the most exciting things I've seen, in that I've looked for it in vain for many years (most recently in Kakadu NP in summer, supposedly the best place and time to look). The spectacular big Frill-necked Lizard Chlamydosaurus kingii has normally gone into winter torpor in a tree by May, when I was last there. Our luck was in however as this beautiful beast was awake and just outside the VIC.

The only member of their genus, they can grow to nearly 90cm long, and this was a big one.
The loose frill can be erected into a fearsome ruff if the owner feels the need to protect itself,
but this lovely obviously wasn't too stressed by our presence.

I can't guarantee you'll see a Frilly if you go to Mareeba Wetlands - though you certainly won't see this one if you don't go! - but I can guarantee you'll see a rich and beautiful part of Australia, and you'll see what can be done if enough people use their imagination, initiative and determination to make things better.

Next time you're up that way, don't miss it!

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