Light without flight

Stephens Island wren (Traversia lyalli) drawn by John Gerrard Keulemans

 This week's birds comes once again from New Zealand's extinct passerine birds fauna. I have previously posted about the heaviest bird capable of flight, the kori bustard. Today I introduce you to the Stephens Island wren (Traversia lyalli), weighing around 20 grams and the lighest  bird that is known to have been flightless. It was also one of only three known flightless passerines, all of which were island birds. Were, because sadly they are all extinct.

Flightlessness in birds is common on islands and is an artefact of an evolutionary history devoid of typically mammalian predators. This is evident in New Zealand which has the greatest number of flightless bird species than any other landmass. Subsequently, it is flightlessness that contributes significantly to predation vulnerability and ultimately extinction, another common occurrence on islands in recent times. And it is exactly this which led to the demise of the Stephens Island wren.

Stephens Island, or takapourewa is located at the northernmost tip of the Marlborough Sounds on the South Island of New Zealand. Up until the 1890s it was free from human impact and pests, and had become the last remaining outpost for the Stephens Island wren.  This changed when it was decided that the island would make a perfect place for a lighthouse. The remoteness and untouched nature of the island is beautifully highlighted by Prof. Richard Holdaway who said that it would have been like stepping back in time. Unfortunately for the little wren species, that moment marked beggining of the end. On such a small island, only 1.84 sq km, there is not much place to hide if you are a bird that can't fly, and especially from a cat. The lighthouse keeper, Lyall (from who the wren gets it's species name) had just that, a cat! According to legend Tibbles the cat made short work of the little wren and has been credited with single pawdedly wiping out an entire species. This of course is not true since the bird was previously found on the mainland. There is an historical account of what did happen on the wiki page.

One last thought I will leave you with is this question; if Stephens Island is 3.4km away from the mainland and the Stephens Island wren was flightless, how did it get there?

Can we see the forest for the trees?

 This year is the "International year of Forests". Check out the UN page here and get amongst it. 

James Randi is hilarious

"Comforting News About Our Departed Celebrities"

Seeing science

Watch this video to see some facinating images. The ruby-tailed wasp (below) and the cell division in the cress seedling are my two favourites.

Ruby-tailed wasp (Chrysis ignita): Image from the Wellcome Image Awards taken by Spike Walker

The cause of suffering?

I used to be a Christian. I no longer believe in a god. Things like this are part of the reason. One, or a bunch, of 'christians'-sure they may be extremists, but seemingly claim to be Christ like nonetheless-who blame gays and lesbians for the destruction and suffering caused by an earthquake in Christchurch, New Zealand. How disgusting! It actually makes me feel sick.

Unfortunately, this is not an isolated incident. This type of bullshit is commonly spouted by fundamentalist groups following natural disasters, or acts of god, as insurance companies ironically refer to them. Hurricane Katrina which devastated New Orleans in 2005 was another natural distaster blamed on homosexuals. A group called Repent America have a steaming pile on their website regarding this belief. But, it's not only fundamentalist christians who get on this bandwagon. Not to be outdone, muslim extremists chime in with similar grabage. A cleric, Hojjat ol-eslam Kazem Sediqi said "Many women who do not dress modestly lead young men astray and spread adultery in society which increases earthquakes,".

I admit that all religious people are not like the above mentioned groups, but to me that doesnot change the following beliefs. According to the bible, koran, torah and a whole host of religious texts, god created the heavens and the earth. That would imply that he controls them. Therefore he is responsible for both earthquakes and hurricanes. I don't see any love in that.

On somewhat of a side note, but still related to the earthquake in NZ, my friend Claire lives in Christchurch. Fortunately she is dong well and uninjured etc. However, like a huge proportion of the city, she has no power or running water. Without water you can't flush the toilet. But Claire and her flatmates??? have remedied that problem with what could almost be described as a luxury outdoor 'dunny'. Check out the pics here. Click the facebook like to make her loo world famous.

In further search of our origins

As usual, thanks wikipedia

Chimpanzees are our closest extant relatives on the evolutionary tree. Some anthropologists use chimps as model organisms to study how human societies may potentially have formed. I briefly mentioned one of the most famous anthropologists of this sort, Jane Goodall, in the post about the New Caledonian crows. Jane Goodall is famous for observing chimps in Gombe Stream National Park, in Tanzania making and using tools. She also observed chimps killing and eating smaller primates, a behaviour that was not previously suspected.

Importantly, the Gombe chimps are forest dwellers, but early human ancestors were most likely savanna dwellers. This means that in order to understand early human evolution it is more appropriate to study model organisms inhabiting a similar habitat. Jill Pruetz of Iowa State University recognised this, which led her to study a group of savanna dwelling chimps in Senegal. Here she made some remarkable observations. Like the Gombe chimps, the chimps of Fongoli make tools to 'fish' for termites. In addition to the fishing however, the Fongoli chimps make 'spears' for hunting. The chimps, mostly females it seems, roughly sharpen sticks with their teeth to make rudimentary spears to poke into the sleeping holes of bushbabies. If the chimps detect blood on the spear they smash open the hole to retrieve their prey.

Evolution is largely driven by environmental factors. In forests the monkey population is large, but in the savanna woodlands monkeys are scarce. Jill Pruetz says that "hunting bush babies is a creative way to get protein", and speculates that the reason that females engage in this activity more commonly than males is that females are slower and often weighed down by infants, making hunting monkeys difficult.

 National Geographic has some absolutely beautiful photos and videos of the Fongoli chimps. If you don't have time for the videos (I could only get the first one to load), you should definitely look at the photos.

The 'avian wolf'

Photo courtesy of wikipedia

 The kea (Nestor notabilis), is a large alpine parrot (the world's only alpine parrot) endemic to New Zealand. Kea are highly intelligent birds and have been described as neophiles. This combination has made the birds infamous, often seen causing damage to parked cars by ripping out the beading around windows and even removing valve caps from tyres and deflating them. See the video below, narrated by the man. When you are camping in kea country it is advised to rise early and pack up your tent before the birds get there and "investigate" your tent. When doing a bit of reading about kea, I found the most intriguing video. I won't say much about it other than it is a two minute clip of kea, a parrot, doing something that might surprise you. Click here to watch it.

The video above is taken from a BBC doco entitled "The smartest parrot". You can watch it here where it is broken into three parts. Remember the clever crows from a week or so ago? Well, similar experiments have been done with kea with similar results.