SciBlogs

Archive March 2010

Of birds, dinosaurs and new fossil discoveries Brendan Moyle Mar 26

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In New Zealand we have a lot of interest in birds- this probably reflects both the uniqueness of our avifauna and it’s extinction pressures. Also, there’s not a lot of charismatic mammals to distract us. New Zealand is also a good place to understand the modern evolution of some bird groups. Many birds are secondarily flightless, none more so than the ratites (of which we have many moa and kiwi species).

In terms of ancient evolution of birds however, it is the fossil discoveries in China (western Liaoning) and Spain (La Hoyas) that are becoming quite exciting. Since the discovery of Archaeopteryx in 1861, the number of fossils with avian and reptilian features has expanded. These families all occur in the late Jurassic and early Cretaceous periods. The timing of the evolution of modern birds has been fairly well-established. (Albeit the long evolutionary history of this group does not rule out an earlier- perhaps even Triassic- origin).

Last year Nature[1] published the description of a new fossil from the late Jurassic in China. The species has been named Anchiornis huxleyi and more significantly, is the oldest troodonitid fossil that has been found. The troodontids are part of a small group of families that map out the reptile-bird transition. This group is known as the Paraves- it consists of the troodontids, the dromaeosaurs and the avialae (of which the most famous fossil example is Archaeopteryx).

The Fossil
Link
(Link to Nature website)

Anchiornis is another feathered dinosaur. For paleontologists, it also solves a temporal paradox. It’s appearance in the fossil record before Archaeopteryx means the evidence that feathers predate the evolution of flight has been discovered. Many of our other feathered dinosaur fossils (e.g. Microraptor) date to after Archaeopteryx.

Anchiornis is essentially a small, bipedal theropod. It’s long limbs indicate an active, agile animal. The early bird like features of this fossil are its deathers and elongated forelimbs. The most intriguing aspect of the fossil however, is that the feathers are present on all four limbs. This also is the case with Microraptor. Hence, these fossils are pointing towards a more complicated evolution of flight. It appears that the evolution might have gone through a four winged stage until the flight feathers were lost on their legs and feet.

The transition between theropod reptiles and birds has been well-established. There are many new fossil species and families that now map out this evolution. We have transition fossils now that date before and after Archaeopteryx. Creationists should take note.

Theropod Phylogeny
Link
(Link to Nature Website)

What is going to be of even more interest is the new fossil discoveries that are still being made in these western Chinese Jurassic stratas.

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Reference

[1] Hu, D., Hou, L., Zhang, L. and Xu, X. (2009). A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus. Nature 461, 640-643.

Australian Brolga Photos Brendan Moyle Mar 24

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Brolgas are a type of crane (Grus rubicunda). Their population is stable and ranges over north and eastern areas of Australia, plus some areas of Papua New Guinea.

The brolga is not migratory. It is an omnivorous species and quite opportunistic.

Brolgas pair up for breeding purposes. Females will generally lay 2 eggs. Juveniles slowly develop the adult and conspicuous red markings over two to three years.

While in the Mary River looking for crocodiles, we came across this pair with a juvenile in tow. Not one to turn down an opportunity, I got in some photos of the family as they waded amongst the lilies.

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Crab Spider Photos Brendan Moyle Mar 23

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The crab spiders are one of the arachnid world’s ambushers. Rather than employ webs, they wait for prey to close, before seizing them with their long front legs.

The principal adaptation to this capture system is large, elongated front legs. This is aided by a body that is often superbly camouflaged.

New Zealand’s crab spiders tend to be drawn from two main genera. One of these has a characteristic, blunt abdomen. These spiders belong to the genus Sidymella, which alas has not been fully described. Hence I’m unable to make a more specific identification in this case.

This particular spider had a body-length of about 4-5mm.

#1 Body View

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#2 This view gives a better view of the spines on the front leg. Click the link to the larger image for a better view

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#3 This angle gives a better view of the chelicerae and palps

Link to larger image

Australian Fig Bird Photos Brendan Moyle Mar 11

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One of the characteristic birds of the Australian outback is the figbird. I spotted this male feeding near Darwin last year.

#1 Starting


#2 I can taste it


#3 Eating time


#4 Finished

What conservationists really want on the whaling front? Brendan Moyle Mar 09

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There’s something that always make me wince whenever the media makes claims about what conservationists want. This was brought home with TV3 announcing that conservationists opposed the government’s moves on commercial whaling.



Actually conservationists are a very diverse lot. We don’t all jump on the anti-whaling band-wagon promoted by some governments and NGOs. This doesn’t mean we are pro-whaling. Let me be clear, I’d like to see Japan cease whaling (as a personal preference). The problem is much of the whaling debate isn’t about conservation, it’s about the principles some countries and NGOs adhere to.



Let’s consider the strategy we’ve been using to persuade whaling countries to stop. In 1982, the IWC agreed to a 5 year moratorium in a vote. The relevant text was

Not withstanding the other provisions of paragraph 10, catch limits for the killing for commercial purposes of whales from all stocks for the 1986 coastal and the 1985/86 pelagic seasons and thereafter shall be zero. This provision will be kept under review, based upon the best scientific advice, and by 1990 at the latest the Commission will undertake a comprehensive assessment of the effects of this decision on whale stocks and consider modification of this provision and the establishment of other catch limits.



The immediate consequences of this was Canada left the IWC. Japan, Russia, Norway and Peru took reservations against it on the basis that the IWC scientific committee had recommended against the moratorium



Canada still harvests hundreds of beluga, narwhal and bowhead annually. So the goal of preventing whaling in that IWC member has been an abject failure.



The principal whaling countries’ reservations meant that they could also continue whaling. (Japan shifted to scientific permits after it later withdrew its reservation). Other whaling countries like Norway and Iceland have continued with commercial permits. And it should be mentioned that many IWC members- even anti-whaling countries like the USA- still issue aboriginal harvest permits.



So has the strategy of political and protest action succeeded? Is the fact that Japan now subsidies its whaling industry as a matter of principle a success? Is the fact that Norway continues to take hundreds of whales commercially a success? Is the fact that Canada told the anti-whaling movement to get stuffed and does it anyway a success? Is the fact that even anti-whaling countries still whale a success?



After nearly thirty years, it’s become increasingly obvious that the strategy of being a hardline, anti-whaling country fails the most basic litmus test. It’s not working to end whaling- it is a bad strategy that is failing.



Indeed, it may be counter-productive if this prompts Japan to support their whalers with subsidies and Japanese consumers are prompted to consume more whale meat as an issue of nationalistic pride. There’s a very good reason why most countries gave up whaling. The economics don’t really work. Converting an economic issue to a matter of principle, doesn’t seem to help whales out a lot.



The second reason I don’t get enthusiastic about saving the whales is this diverts resources from where they are needed. The whale populations that are being harvested are often rated as being of least concern, or very low risk species buy the IUCN*. On the other hand several river dolphin species in Asia are recognised as critically endangered. Most of our native birds are more at risk of extinction than minkes. While various NGOs were pouring money and effort into saving the ‘least concern’ minke whale, the baiji quietly slipped into extinction. The great white shark is now thought to be rarer than the tiger, but there are no like campaigns to save it. The Indian gharial is even rarer and sliding backwards.



Nearly a third of all amphibian and reptile species are estimated to be in serious risk of extinction. We are at a point where thousands of species are at much greater risk than minke whales. Yet the choice is to take those resources we have and put them into "stopping whaling". Trying to save a small set of species not actually threatened by whaling, and giving up on so many more species that are in more urgent need, isn’t the optimal approach. And the fact that this strategy to stop whaling has not succeeded in 30 years feels like a colossal waste of money.



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* IUCN risk rankings for commonly harvested species are:

1) The bowhead whale Balaena mysticetus is Least Concern, but with three subpopulations at elevated risk.

2) The common minke whale Balaenoptera acutorostrata is Least Concern.

3) The Antarctic minke whale B. bonaerensis is Data Deficient

4) The Gray Whale Eschrichtius robustus is Least Concern

5) The Narwhal Monodon monoceros is Near Threatened

6) The Beluga Delphinapterus leucas is Near Threatened



The IUCN threat categories are (ranked in risk)

Extinct (EX)

Extinct in the Wild (EW)

Critically Endangered (CR)

Endangered (EN)

Vulnerable (VU)

Near Threatened (NT)

Least Concern (LC)















Six-eyed spiders Brendan Moyle Mar 08

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Most modern spider families have 8 eyes. Within New Zealand however, there are three families that have 6 eyes. These are the tiny Oonopidae, the native Segestriidae and the introduced Dysderidae.



The Dysderids have one cosmopolitan species present- Dysdera crocata. This species is relatively common around its usual prey. This happens to be the garden slater (known elsewhere as the wood louse). The species has a very characteristic colouring. The cephalothorx and limbs are a striking red-orange colour, and the abdomen is cream. The chelicerae or fangs also appear to be disproportionately large, but the species is harmless.



I took a number of photos of one of these Dysderids this weekend. The setup was the Sony alpha a700, Sigma EM-140 ringlight flash, Tamron 90/2.8 macro lens with extra magnification from a 6x Raynox adapter.



#1 Getting the good side



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#2 Dorsal view



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#3 Look, 6 eyes

Do our wildlife laws need reviewing? Brendan Moyle Mar 04

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Following the conviction of three gecko smugglers in New Zealand, it was reported that Conservation Minister Kate Wilkinson may overhaul wildlife laws after a German gecko smuggler was sentenced to 15 weeks jail and two other men admitted their roles in the smuggling operation.

While I’m not against stiffer penalties, anybody familiar with NZ laws is aware that the maximum penalties are very severe. Native wildlife is protected by the Wildlife Act, the Conservation Act if the animals are sourced there, the Trade In Endangered Species Act, and our Biosecurity Act.

The sanctions available to the courts are not inadequate. The real problem is that such sanctions cannot be set at levels that deter. Wildlife smuggling rings long ago, worked out that you can easily set up someone with low wealth to be your fall guy. So for tiger-parts into China, you just bribe a bus or train driver and pickup the stuff later.

If you want deterrence, the rule of thumb is that the expected sanction has to match or be greater than the reward. Let’s suppose you want to smuggle some NZ animals. You think there’s a 10% chance you’ll get caught, and you will be paid $50,000 for your part in the conspiracy. That means you’re balancing a ‘win’ of $50,000 against the 10% risk of being caught and fined. For the two choices to be equal, the courts would have to be giving out a fine of $500,000. They can’t and they don’t.

So, we know that sanctions have to be pretty high to deter wildlife smugglers. Therein is the problem. The guys that run these conspiracies pick people of poor wealth to take the risks. The courts can’t fine them enough to deter, because the couriers can’t pay those fines.

If we look at the 1993 Price Conspiracy- which smuggled birds into New Zealand from Australia, there were 6 conspirators. Three were unemployed, one was a sickness beneficiary, one was self-employed and one was an agriculturalist. The conspiracy moved Australian parrots worth hundreds of thousands of dollars into New Zealand in a small aircraft. Only one individual was fined ($5000) and the rest received jail terms of 6-12 months. The reason was simple- the conspirators didn’t have the wealth to fine to be a proper deterrent.

The fact is you can’t set fines and other criminal sanctions at a level that really deters. For decades, wildlife conspiracies have got around that problem by getting low-income people to take the risks. And courts can’t set sanctions on low-income people at a level that actually deters.