A Rocha USA Blog

By John Humphreys

I subscribe to the BRILLIANT “Parasite of the Day” web page.

As the organizers put it – “The United Nations declared 2010 the International Year of Biodiversity. In celebration of the enormous diversity of parasites and to highlight their importance, we created this blog, which showcased a species of parasite every day. Now that 2010 is over, we will continue to add more parasites from time to time.”

All the way through 2010, all of us subscribers were entertained, educated and disgusted in equal measure by the extraordinary variety of organisms which make their living off other creatures.
Some are more-or-less tolerable for the host: the mistletoe, which all of us love to kiss under, is not often lethal to the tree it grows on and the ubiquitous head louse is merely an irritation to us, although has school districts and parents up in arms when they see it.

Some are genuinely spectacular – like the largest flower in the world, sported by the rainforest parasite Rafflesia arnoldii. Others are actually parasitoids rather than parasites because, simply, they always kill their host – the newly discovered and very worrying “white nose syndrome”, a fungus that chokes hibernating bats, is a case in point.

Then there are the plutocrats of the parasite world – the hyperparasites, who parasitize parasites themselves. An example is the tiny wasp Caenacis inflexa, which attacks other wasps like Eurytoma rosae and Glyphomerus stigma…which themselves are parasitic on  the “gall wasp” Diplolepis rosae…the ecology of plant galls is endlessly fascinating.

Of course, there are some genuinely terrifying creatures like the nightmare-inducing tongue-eating louse and the ghastly crab-controlling barnacle.

Now, many of these beasts…and plants…and fungi…have exquisitely exacting tastes. They may only target one single organism to live off. While this type of deal must have some advantages for the parasite, there is one enormous downside: your host dies out, you die out.

Which leads me to the tick, Ixodes neuquensis. It is only found on a gorgeous little opossum-like creature, the (confusingly named) ‘mountain monkey’ Dromiciops gliroides. This charming little thing lives in South America and its forest home is being torn down.
When it goes, when it is gone forever, and two things will happen.

Firstly, we will never see it alive again. Films don’t do the same for me, sorry. It will be gone, and nothing this side of the Second Coming can bring it back.

Secondly, a variety of living creatures dependent on it will join it in oblivion. Not just the tick and other parasites; this marsupial mammal is the only known way that a unique plant –Tristerix corymbosus, a type of mistletoe - can spread its seeds (see http://en.wikipedia.org/wiki/Dromiciops_gliroides and http://en.wikipedia.org/wiki/Tristerix).

Ironically this mistletoe only parasitizes two cacti. So the whole ecosystem is teetering on the edge of oblivion. As I say ad nauseam, the only way for you and I to do anything about this is to help preserve the forest. And spread the word. Thanks for reading.

Cute, almost gone.

Lights Out for Birds

by John Humphreys

Millions of birds die each year by slamming into illuminated skyscraper windows at night.

What a ghastly waste of life. And so avoidable!

There are a number of projects across the continent that are trying to do something. The problem is particularly bad at the time of peak migration, when – of course – birds are doing a lot of flying over and through cities at night.

New York City Audubon has, for the last five years, asked the owners of skyscrapers to switch lights off at night, and has requested that late workers ‘draw blinds or use desk lamps rather than using ceiling-mounted lighting’. The problem is that these poor birds get dazzled, baffled and disoriented by artificial lights, especially when flying lower than normal in bad weather. Happily, such initiatives really work – there are far fewer carcasses found at the base when the suggestions are heeded (of course, predators tend to vacuum up dead and dying birds really quickly, so researchers have to patrol the ground below when studying the problem). If you are interested, see Audubon's work on the parallel problem in Spring.

 The city of Toronto is making great strides, too. The “Fatal Light Awareness Program” reports that ‘each year in Toronto, over a million birds are killed by colliding with buildings.’ They have a sad (dead) woodpecker as their logo. In response, they are developing bird-friendly development guidelines for Toronto and run their own “lights out” campaign.

 I am cheered by these projects, but cannot be too sanguine. These are two cities out of many  – admittedly major ones – that are only just getting their act together as to how big a danger these lighted buildings pose to migratory birds. These skyscrapers are the inanimate version of those lines of 'kill-all" hunters that greet flyover birds in Malta and elsewhere in Europe. For details of this decidedly unsporting approach to hunting, see this piece by BirdLife International.    

How many other cities have this problem with no one to care about it? Not just in the North American continent – globally?

The unintended massacre of birds by buildings has to be added to intentional killing and habitat destruction as a MAJOR issue in the decline, worldwide, of so many of our bird species: not just the obvious rare ones, but many common ones too. The majority of our bird species globally are in decline. Now is the time to act. Get better informed by visiting the key scientific sites of Audubon and BirdLife International.

*Humphreys is a biochemist working in pharmaceutical software. Mad about natural history since the age of 5, he is an ardent conservationist and pragmatic environmentalist.