Monthly Archives: February 2014

Rewilding redux

Brazil river 2013-11-29 12.13.12

In an earlier posting I briefly mentioned George Monbiot’s current fascination with the concept of rewilding and provided a link to an animated video he had narrated.  As my first year lectures on species interactions and community structure have come to an end, one of the students on the course has pointed out that George has recently narrated another video called “How Wolves Change Rivers”, which deals with the effects of the reintroduction of wolves to Yellowstone National Park in the USA.  Following a 70 year absence, the presence of the wolves resulted in a trophic cascade which significantly changed, in a positive way, both the biodiversity and the functioning of the Yellowstone ecosystem, as well as aspects of the physical geography of the National Park, notably river behaviour.

It’s only a short video (four and a half minutes in length) and I strongly recommend that you watch it.  Not only is it powerful in its imagery and its music, but it’s also underpinned by some powerful, peer-reviewed science.  For example see this review by William Ripple and Robert Beschta, from Oregon State University, of the positive effects cascading from the presence of wolves in just the first 15 years following reintroduction.  

At the end of my lecture on Thursday I showed the video to my class and the response was very positive; the students seemed to be impressed and I hope it brought home the importance of what I’d been talking about this term, that ecological interactions matter.  Given the flooding problems we’ve experienced in Britain this winter, some of which seems to be related to how our rivers and flood plains are (mis)managed, perhaps there’s a case to be made for reintroducing wolves, bears and beavers to the Somerset Levels or the Thames Valley.  Given that these areas lie in the heartlands of Conservative and Liberal Democrat voting, it’s not likely to happen under the current coalition government.  But we can dream.

There were hummingbirds over the White Cliffs of Dover

Hummingbird bowl from BM

Biogeography has been on my mind of late, in part stimulated by thinking about the work we’re writing up on the frequency of wind versus animal pollination in plant communities in different parts of the world that I mentioned in one of my earlier Brazil posts.  André has added more communities to the data set following some field work in Uruguay, and we are collaborating with Bo Dalsgaard and his colleagues in Denmark on analysing how historical and contemporary climates may have shaped the patterns we’re seeing.  It follows on neatly from the previous work Bo has done on climate and hummingbird-flower interactions.  I’ll report back when we have more to say.

The other reason for thinking about biogeography is that a couple of recent scientific reports have captured my attention.  The first dealt with new fossil discoveries of species related to that enigmatic South American bird the hoatzin (Opisthocomus hoazin).  The report can be read here but in summary, the evidence suggests that the bird family to which hoatzins belong was once much more widespread and may have originated in Europe.  Hoatzins are not the only such example: hummingbirds, which are also currently restricted to the Americas, were found in Europe in earlier times, according to reports from back in 2004 and more recently in 2007.  It appears that contemporary biogeography may not reflect past biogeography for some (perhaps most?) groups of species.

As a lesson in contemporary biogeography, it’s often been pointed out that the famous Vera Lynn song The White Cliffs of Dover falls short in its scientific accuracy:

There’ll be bluebirds over
The White Cliffs of Dover
Tomorrow, just you wait and see

Bluebirds are members of the genus Sialia, a group of three species which do not naturally occur in Britain, in fact are not present in Europe at all.  So you’re not likely to hear them singing in southern England.  But perhaps the genus was present in the distant past?  Who knows?  In the meantime we may have to change the lyrics to the song.  Unless the writer was predicting what might happen in the future when continental drift means that Europe and the Americas will be much closer together.

The other report that caught my eye was of an interesting study that has compared plants and birds in cities across the globe, and looked at how urbanisation reduced the diversity of the native species compared to non-urban areas nearby.  However I do hope that the lead author was being misquoted when she said that: “Owing to the fact that cities around the world share similar structural characteristics – buildings, roads etc – it is thought that cities share a similar biota no matter where they are in the world”.  She goes on to say that they had discovered that some species: “are shared across cities, such as pigeons and annual meadow grass, but overall, the composition of cities reflects the unique biotic heritage of their geographic location”.  Well yes, of course:  any of our undergraduate students taking the second year module in biogeography could have told you that!  As a serious hypothesis to test it lacked rigour: few tropical birds and plants could survive in temperate-zone cities, for example.  There’s more to the study than just this, of course, as you can see from the abstract. Nonetheless it was an odd statement to make in my view.

The Wikipedia definition of biogeography that I linked to at the beginning of this post is perhaps a little limited in its scope:  “the study of the distribution of species and ecosystems in geographic space and through geological time” doesn’t cover the species interactions that have been a focus of my research, for instance.  Perhaps “macroecology” fits it better, though (as I’ve mentioned before) there’s been a lot of debate in the scientific literature about where biogeography ends and macroecology begins, or whether the two are synonymous.  My own view is that the two overlap considerably, but that macroecology is bringing a lot of new tools and approaches to the study of organisms at large spatial scales.  Whether that warrants the definition of a different discipline is debatable, but like all such debates (e.g. the difference between ecology and natural history as recently discussed on the Dynamic Ecology blog) it provides us with a way of reassessing our own views on the work we do, which is always a good thing.

Who protects our biodiversity?

2012-10-29 15.37.10

Our elected politicians and councillors regularly pay lip service to the environment, to the need to be “sustainable”, and to the importance of conserving biodiversity. How many of them really believe this?

Fewer than half, if Derby Council is a representative sample.  Last night they decided (by one vote) to destroy almost fifty percent of The Sanctuary Local Nature Reserve, to build a cycle track.  Whilst not the most critical area for nature conservation in the country, The Sanctuary is nonetheless an important local urban site for a wide range of nesting birds, some of them rare and declining in the UK.  There’s a great video from a drone flight over the Reserve that gives a sense of the place, which I’ve never visited but nonetheless feel aggrieved at losing.  It diminishes us all when decisions such as this are made.

The fact that this was designated as a Local Nature Reserve by Derby Council in 2006, following a much-trumpeted opening ceremony, presided over by the then-Home Secretary Margaret Beckett MP in 2004, shows what a shower of hypocrites some of our local politicians really are.  I was first made aware of the campaign to save The Sanctuary by a guest post over on Mark Avery’s blog.  As requested, I wrote to Derby Council as follows:

To whom it may concern,

Following recent national publicity about the proposed development of The Sanctuary Local Nature Reserve (LNR) at Pride Park in Derby, I wish to object in the strongest possible terms about this initiative.

The Sanctuary LNR is a site of county-level importance for nature conservation and its disturbance would be a sad indictment of the council’s attitude towards the environment. It would also set a disturbing precedent for other councils to ignore nature conservation designations purely for economic development.

I look forward to hearing in the national media that this development will not go ahead.

I also posted links on all of the Facebook groups of which I’m a member, sent it to students, and so on. And despite strong objections to the Council from local and national sources, councillors decided that it was better to follow the money rather than listen to the people.

So much for democracy.  But as I said above, it also sets a precedent for the loss of Local Nature Reserves nationally: apparently they are dispensable.  In a recent post I gave an indication of how I feel about biodiversity offsetting and the mind set of politicians who support it.  The events of Derby don’t give me any more confidence that our elected representatives really care about nature, beyond sound bites and posturing.  Protection of sites for nature conservation seems to be as much a throw of the dice as any rational strategy in the UK.