Tag Archives: Nature

There were hummingbirds over the White Cliffs of Dover

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?

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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.

Ménage à trois mutualism

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Relationships involving a “household of three” hold a fascination that is part prurient and part wonderment: prurient for perhaps obvious reasons, and wonderment as it’s sometimes hard enough to make a ménage à deux work! Historically this domestic arrangement has been the lifestyle of choice of a surprisingly large and diverse set of influential thinkers and creative individuals, including Aldous Huxley, Lord Nelson, Carl Jung, Erwin Schrödinger, and Hattie Jacques. Indeed, one of my favourite musicians, David Crosby, wrote a song about such relationships (Triad) which got him kicked out of The Byrds.

In nature, ménage à trois are occasionally encountered and may be more common than we think, and have been on my mind because this week I’ve been talking about mutualistic relationships with my first year undergraduates. Mutualisms are interactions between species in which both benefit, as opposed to exploitative relationships such as predation or parasitism in which one of the partners is at a disadvantage (being eaten is a great disadvantage….) Mutualistic interactions are common and important, and include many (but not all) plant-pollinator interactions, seed dispersal by birds and other animals, mycorrhizal relationships between plants and fungi, and many more. As well as studying plant-pollinator interactions, I’ve a long-standing interest in the full breadth of these examples of “biological barter“, in all their varied forms.

In most cases mutualistic relationships involve pairs of species (for example a plant and a pollinator) although these species pairs are embedded within a larger network of interactions: that plant may have many pollinators, and those pollinators may service other plants. In this sense it requires just two partners to make the interaction work – a “household of two”. More rarely, research on the biodiversity of species interactions throws up examples of “households” involving three species, and a fascinating case has recently been worked out and published by Jonathan Pauli and colleagues. This involves three-toed sloths and their relationship with the algae and moths that colonise the sloth’s fur – you can read the abstract here. In summary, the algae benefit from nutrients provided by the moths living in the fur; the sloths eat the algae to supplement a restricted diet of leaves; the moths benefit from the sloths transporting them to defecation sites where they lay their eggs, then recolonise the sloths. This slothy ménage à trois is a wonderful instance of interdependency within nature.

The other case of a three-part mutualism with which I’m familiar is that between anemonefish, and sea anemones and the algae which are housed in their tentacles. The fish and the anemones provide mutual defence of one another, whilst the algae photosynthesise and provide carbohydrates to the anemone, and benefit from the nitrogenous waste produced by the fish. It’s a system that I’ve done a little work on with marine biologist colleagues, specifically the broad scale biogeography of the interaction and its local assemblage structure, but we’ve not studied the whole three-part system.

What other three-part examples are there in nature? I’d be very interested to hear about any of which you’re aware.

It begs a question as to whether three is an upper limit to the number of species that can engage in such relationships? Are there any four- or five-part mutualisms? Or are these too unstable over evolutionary time, because if one species goes extinct it could cause the extinction of other species? Interesting questions about fascinating interactions!

Ordinary by Choice

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Until the system changed a few years ago it was a requirement of all course leaders at the University of Northampton to attend Award Boards at which the students graduating that year were named and their degree classification confirmed. It was not popular with academics, as you can imagine, as we spent half a day waiting for the turn of “our” course. Typically we would take manuscripts to revise or crosswords to complete, or a good book to read, until such time as it came to our own students. As each student’s name was read aloud, their degree classification was confirmed: “First Class Honours”, “Two-One” (Upper Second Class Honours), “Third” (Third Class Honours), and so forth.

One category was rarely used: “Ordinary by Choice”, meaning that the student had not completed a final year dissertation and had opted to take an Ordinary, as opposed to Honours, degree. It is a phrase that I was always struck by: except for a (perfectly respectable) Higher Education qualification, would anyone elect to be “Ordinary by Choice”? Do we want that for our lives, our country, our society, or even our environment: Ordinary by Choice?

The phrase came to mind last week when I heard about an interview with Owen Paterson, Secretary of State for Environment, Food and Rural Affairs in the current British Government. Paterson, who coincidently studied at the precursor to the British School of Leather Technology here at Northampton, said that in the future it might be perfectly acceptable to build on ancient woodland if the destruction of that site was offset by planting trees elsewhere. A spokesperson for his department later said that it was “highly unlikely” that such development would ever occur on ancient woodland, but that’s not the same as “never”.

In fact such destruction of ancient woodlands is currently being proposed by the development of the High Speed Rail 2 (HS2) line from London to points north. An analysis by the Wildlife Trusts of the currently proposed HS2 route shows that it will pass through “10 Sites of Special Scientific Interest (SSSIs), more than 50 ancient woodlands and numerous local wildlife sites”. Important wildlife sites are perhaps not as safe as government would have us believe.

From the outset let me say that in my opinion this notion of “biodiversity offsetting“, in which one can apparently trade like-for-like in the destruction and recreation of natural habitats, putting back or even enhancing the biodiversity of a region, is pure fantasy dreamt up by government. It can’t be done. It’s not possible. The reason? There are no complete inventories of the biodiversity of any patch of planet earth. None. Not even of a few square metres of arable grassland in rural England, a simple habitat in comparison to the fantastically complex biodiversity of an ancient woodland. Such All-Taxa Biodiversity Inventories (ATBIs) have been proposed in the past, but never completed.

Now I am using a strict definition of biodiversity to include all of the diversity of life within an area, including not only plants, birds, mammals, and large insects, but also the many smaller insects and other invertebrates, algae, protists, fungi, and bacteria. But that’s not what the proponents of “biodiversity offsetting” such as Owen Paterson have in mind when they champion the system. What they really mean is “species offsetting”: for example cutting down an oak forest and replacing it with young oak trees planted some distance way; or destroying a wetland used by over-wintering birds and creating an artificial wetland at another locality. In both cases the species in question will persist: oaks will grow and birds will over-winter. The assumption is that the other elements of biodiversity, the neglected micr0-invertebrates, bacteria, lichens, fungi, and so on, will also return. It may take some time, perhaps hundreds of years, but (goes the logic) they will eventually come back and the habitat will contain the richness of species that there was previously.

This may happen, but not for all species, particularly naturally rare organisms with small populations and low dispersal abilities. The fact that (as I’ve noted) we have no complete inventories of biodiversity for anywhere on the planet means that we currently cannot be certain about how “biodiversity”, as opposed to “some of the larger and obvious elements of biodiversity”, can spread and re-establish. In contrast, all of the available evidence suggests that the historical continuity of a site is vital to its current biodiversity. Let me give you an example, in fact from a data set that I’ve never published.

About the time I arrived in Northampton (in 1995) I started to develop a more serious interest in fungi – moulds, mushrooms, and toadstools. Together with colleagues in the department and some of my students I began to systematically identify the fungi in a long, narrow patch of woodland (the “Shelter Belt”) on Park Campus. Early on I set out a series of 1m x 1m quadrats and every week for two months I recorded which fungi appeared. It was a short survey but very revealing because it was clear that there were differences in the diversity of fungi in different parts of the Shelter Belt, and that some areas had much richer diversity than others, even over a distance of a few tens of metres.

In fact the western side of the Shelter Belt contained almost twice as many species of fungi as the eastern side. In addition there were few species on the eastern side that were unique to that area: most species were also found in the western portion. This is despite the fact that the woodland appeared very homogenous: a linear strip dominated mainly by the non-native Black Pine (Pinus nigra) with an under-storey of common small trees such as Holly (Ilex aquifolium), Elder (Sambucus nigra) and Hawthorn (Crataegus monogyna).

A likely reason for this difference was revealed when we studied some old maps of the area; a sixteenth century map showed that there was a hedgerow on the site of the western part of the Shelter Belt from at least Tudor times, and probably much earlier. This hedgerow may have been planted as a boundary for livestock, or may have been a remnant of an even older patch of woodland that was felled and managed to partition agricultural fields. The presence of plants which are known ancient woodland indicator species, such as Wood Anemone (Anemone nemorosa), Bluebell (Hyacinthoides non-scripta) and Dog’s Mercury (Mercurialis perennis) was further evidence.

So an ancient hedgerow, now erased and replaced by later planting that was at least 50 years old (it appears on Google Earth historical imagery for 1945), was continuing to influence the biodiversity of a site long after it was gone. But that influence was subtle and involved a neglected element of wildlife that is nonetheless vital to the natural world: fungi, which act as decomposers, consumers and recyclers, and without which a woodland could not function.

The definition of “ancient woodland” in England and Wales is an area of woodland that existed prior to 1600 and the Shelter Belt example shows why this definition is important: the history of a site has a huge impact on its biodiversity. Simply planting a new woodland of young trees will not replace what is lost by the destruction of a site with historical continuity of habitat which is supporting slow-spreading species.

Government and the public have a choice: we can sanction the destruction of truly biodiverse sites such as ancient woodland and replace them with ordinary ones, such as new planting of trees on farmland. Is that what we want, an environment in Britain that is Ordinary by Choice?

Two turtle doves……?

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On the Second Day of Christmas my true love sent to me
Two Turtle Doves
and a Partridge in a Pear Tree.

So goes part of The Twelve Days of Christmas, a song that can be dated back to the late 18th century, and which celebrates the period between Christmas Day and the 5th January. The chances are that few people under the age of 50 will have seen the culturally iconic turtle dove in the wild in Britain as it’s a species which has reduced in numbers by a spectacular 93% across Britain since the 1970s, as this graph shows. Not only that, but the British Trust for Ornithology suggests that the turtle dove is “one of the most strongly declining bird species across Europe since 1980”. Clearly this is an issue not just for the U.K. and organisations such as the RSPB have responded with schemes focused on turtle dove conservation.

If you’ve been following the various news items about nature and conservation over the festive period you’d be forgiven for being a little confused by the mixed messages. On the one hand the turtle dove and other farmland species, as well as wetland birds, were shown to be suffering long term declines in the State of the U.K.’s Birds report for 2013. But then we have the National Trust telling us that 2013 was the best year for wildlife for a long while, with nature thriving in the long, hot summer. Which of these is true? Both of them are, of course, it’s just that the scales at which they are assessing their results are very different. Whilst analyses of single years are important and can provide some grounds for conservation optimism, it’s the long term trends that really matter. And for many species these trends are not looking good.

With this in mind it was hoped that the budget announcement by the Department for Environment, Food and Rural Affairs (Defra) might contain some good news for Christmas, but it was not to be: overall, there will be less money available for agri-environmental schemes on UK farms in the foreseeable future, a situation that the RSPB states “falls short of what nature needs for recovery” and the Wildlife Trusts describes as “a missed opportunity to boost investment in wildlife-friendly and progressive farming“. As always, Mark Avery’s blog had some forceful opinions on the subject and is a recommended read on this topic.

On the Twelfth Day of Christmas my true love sent to me
Twelve drummers drumming…..

…hopefully drumming up government support for some real action in 2014, rather than fine words and greenwash, to begin to reverse the loss of our native biodiversity. Happy New Year everyone.

Thank the insects for Christmas (REBLOG)

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It’s become a tradition (ok, only for the past two years, but a tradition has to start somewhere!) for me to post a version of this festive blog entry. I’ve updated the stats for 2013. Hope you enjoy it.

Christmas! A time to relax and enjoy ourselves, to share time with family and friends, and to unwind during the cold and gloom of winter. Whatever your faith, or lack of it, Christmas should be about taking a break and reflecting on the year that has passed. We’re helped in that respect by the ceremonial seasonal trimmings: the Christmas tree, strings of flashing lights, baubles and tinsel. So while you’re kissing a loved one under the mistletoe, admiring that glossy holly wreath, or tucking into your Christmas dinner, spare a thought for the insects.

“What in Saint Nicholas’s name” you are asking ”have insects got to do with Christmas?!” Well, like the turkey, we’d be stuffed without them: they play an essential part in providing us with the things we associate with Christmas. If we had no flies, wasps, bees and other bugs acting as pollinators there’d be no berries on your mistletoe or your holly. Kissing and admiring would be a less festive affair and that’s just for starters. These insects also pollinate many of the vegetables, herbs and spices on your plate, as well as some of the forage that went to fatten your roast bird or tender joint of meat. Not to forget much of what went into the nut roast that’s feeding the vegetarian relatives.

The economic value of insect pollination in the UK was estimated by the recent National Ecosystem Assessment to be about £430 million per year. In fact this is a huge under valuation because the labour costs alone of paying people to hand pollinate those crops would run into billions of pounds. This sounds far fetched but it’s already happening to fruit crops in parts of China. The answer is to encourage wild insects, not artificially managed honey bees, because collectively the former are far more abundant, and often more effective, as pollinators. Their diversity is an insurance against losing any one species in the future. The NEA’s valuation is also too low because it only deals with commercial edible crops, and does not include those we grow in our gardens and allotments. It also does not take account of ornamental crops such as mistletoe and holly, both of which are dioecious species, which is to say that individuals are either male or female, rather than hermaphrodite as are most plants. This means that the plants cannot self pollinate and insects are absolutely vital to their reproduction and to the production of the decorative berries we so value (a holly wreath without berries is just a big spiky doughnut, in my opinion).

Whilst researching the economic value of the annual mistletoe and holly crops for this blog posting last year I had a conversation with Jonathan Briggs over at Mistletoe Matters and he told me that “the mistletoe trade in Britain is entirely unregulated and not documented in any tangible way”, and the same is true of holly. We therefore have no idea what the economic value of these non-food crops actually is. But some back-of-the-red-and-gold-Christmas-lunch-napkin calculations can at least give us an insight. Auction reports for 2013 show that on average the best quality berried holly was selling for £2.50 per kg whilst equivalent quality holly without berries sold for only 80p per kg. In other words, pollination by insects increases the value of that crop by more than 300%! Similarly the high quality mistletoe averaged £1.20 per kg, whilst the second grade stuff was only 40p per kg. And the best holly wreaths (presumably with berries!) were averaging £7.00 each.

These are wholesale prices, of course; retail cost to the customer is much greater. A decent holly wreath will set you back between £15 and £30 whilst online shopping for mistletoe is in the £5 to £20 range, depending on how much you want. The national census of 2011 shows us that there are 23.4 million households in England and Wales, plus there are 2.36 million in Scotland and 0.70 million in Northern Ireland. Let’s round it down and say there’s 26 million households in the whole of the UK. Let’s also be very conservative and estimate that only 5% of those households bought one holly wreath and some mistletoe at a total cost of £20. Multiply that by the small proportion of households buying these festive crops and you arrive at a figure of about £26.5 million! And that doesn’t include non-household use in shops, offices and businesses. So there you have it: an industry worth a few tens of millions (at least) all being ultimately supported by insects.

With pollination, timing is everything, and Jonathan also made the point that spring flowering mistletoe and holly can be important early nectar sources for insects. Therefore despite the poor summer weather in 2012, that year was a good one for mistletoe berries because the pollination happened before the heavy rains began. Despite being quite common plants, rather little research has been done on either holly or mistletoe pollination in the UK and it would make for an interesting student project. The Landscape and Biodiversity Research Group here at the University has for many years been working to understand the ecology of plants and pollinators, and how to best conserve them. In this blog I’ve referred a few times to some ongoing projects researching how the wider landscape is supporting pollinators in habitats such as country house gardens (Hilary Erenler’s PhD work which she completed this year) and urban centres (ongoing PhD work by Muzafar Hussain). There’s also the work completed a few years ago by Sam Tarrant and Lutfor Rahman on pollinator (and other) biodiversity on restored landfill sites. Plus research that’s recently started by Kat Harrold on how whole landscapes support pollinators in the Nene Valley Nature Improvement Area. This is all part of a broader programme of research into the conservation of biodiversity in our region and beyond, including our Biodiversity Index, a contribution to the Shared Enterprise Empowering Delivery (SEED) sustainability project.

Biodiversity matters and its importance to our society is being increasingly recognised by government, business and the public. So if you make one New Year’s resolution on the 31st December, let it be that you will put away your garden bug sprays for 2014 and learn to love the insects (even wasps!) who give us so much and help to support our economy in a very real way. It costs us nothing; all we need to give them is well managed, diverse, unpolluted habitats in which to live. Have a great Christmas everyone!

A Christmas vignette

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This afternoon I booked half a day’s leave to go into Northampton town centre to pick up some final Christmas gifts. A crowd of shoppers in Abington Street was eager to lay their hands on the freebies being distributed by that traditional Yuletide apparition, The Coca Cola holidaysarecomingholidaysarecoming Big American Truck. As red and shiny as Rudolf’s nose, it was pedalling its cheap brand of Christmas sentimentality to a willing audience.

Shopping completed and daylight fading fast, I headed back to the multi-storey car park, again passing the Coca Cola queues, skirting them, determined not to be sucked in.

The car park was cold and ugly, as they tend to be. But on the second floor, level with the bare crown of a tree that emerges from an adjacent pub garden, a mother and her young son stood. Hands full of shopping bags, they had paused to listen to a male blackbird singing as the dusk drew in. As I passed I heard them chatting about its song: both agreed it was beautiful.

Driving out of the car park I wound down my window: it was still singing as I passed the tree.

I could give a very academic spin to this tale and talk about the cultural and spiritual ecosystem services that are provided by such birds, which nourish us in ways that no amount of corporate marketing ever could. But I shan’t: it was a perfect Christmas vignette and a perfect contrast to the earlier soulless commerciality. And that’s sufficient.

The strange and the familiar….. (back from) Brazil Diary 8

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The first bird I identified when I arrived in Brazil on 1st November was a feral pigeon (Columba livia) foraging around the airport; the first bee I spotted, visiting flowers around FUNCAMP, was a honey bee (Apis mellifera). This tells you a lot about the widespread, near ubiquitous distribution of such species, which have been moved across much of the planet, accidentally and on purpose, by human activities. For someone who is deeply interested in biodiversity, seeing these species is both humdrum and interesting. Humdrum because they are so familiar, we see them everywhere we go, they are not exciting and exotic. Interesting because they tell us a lot about the effects that humans have on their environment, how we are altering it by the introduction of non-native species.

Away from the large cities I saw introduced species such as these less and less frequently, such is their association with humans. But of course there were also plenty of native Brazilian species that have become associated with human activities. Some of these had a familiarity about them which transcended the fact that they were species I’d never see in Britain. Black Vultures (Coragyps atratus) are the best example. I would frequently observe them perched on lamp posts in towns, scanning for food or squabbling amongst themselves, and also spotted a huge number feeding on the refuse being piled into a landfill site. Back home I associate this sort of behaviour with various species of gulls. Strange and familiar.

Back in Northampton I’ve been reflecting on my month-long visit to Brazil, catching up with colleagues, telling stories that get more impressive with each iteration. It’s been a packed couple of weeks and Brazil seems a long way away, not just geographically.

The Biodiversity Index did not win the Green Gown Award that it was short listed for, as I previously reported, but it did receive a Highly Commended citation. Green Gown have asked us to produce a video, so a few days after I returned home, and still with a bit of my brain in Brazil, I took part in a short recording session about the Biodiversity Index, which will be released shortly. The video is produced by Jo Burns and her company Amplitude Media. Jo is a graduate of the University of Northampton and this is a nice example of how the University is supporting former students as they develop their careers.

At the end of last week we also got the news that the Biodiversity Index has been shortlisted for a Guardian newspaper University Award in the sustainability category. More recognition for the work we’ve done on that project, and we are very pleased! The result will be known early next year.

As of this week our paper on “How many plants are pollinated by animal?“, published in the journal Oikos in 2011, has notched up its 100th citation according to Web of Knowledge. The less conservative Google Scholar puts it at 164, so the true answer will be somewhere in between. Clearly peers think it’s a useful bit of work. And to think it was almost rejected by Oikos, saved only by an appeal. The idea for the paper arose when I was trying to find a solid figure in the literature for the proportion of plants that are biotically pollinated. Lots of figures were being bandied about, but once you follow the reference chain back through the papers that cite them you find that numbers which are cited as solid facts disappear into speculation and guestimates. Like many of the simple and obvious questions, the assumption is that we “know” the answer. That’s no basis for science-informed policy, but I suspect that it happens all too frequently.

Cockroach with a hint of lemon – Brazil Diary 7

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Hummingbirds have been a continuous feature of my travels around south-east Brazil since day one when I ticked off the Sword-tailed hummingbird from my list at FUNCAMP. Since then I’ve kept a special ear and eye out for their whirring wing beats and rapid, darting movements, partly because they are significant pollinators in these Neotropical plant communities, but also because members of our research group have a long-standing interest in their ecology. Stella Watts for example has worked on hummingbird-flower interactions in Peru, and our friend and colleague Bo Dalsgaard spent a year in Northampton during his PhD research on Caribbean hummingbirds, and we now collaborate on some macroecological questions about hummingbird specialization in relation to current and past climates. And I did some work on their role as (probable) pollinators of some forest Apocynaceae in Guyana during field work in the late 1990s, which remains unpublished. Must write up those data one day…

The bird guide I’m using for this trip lists more than 80 hummingbird species for Brazil, many of which are found within the Atlantic Forest system. Over the last few days we’ve seen several of them in the lowland rainforest around Ubatuba, which proved to be a lot drier and warmer than the montane forest I described last time. It’s been good to have Pietro Maruyama on hand to identify the birds as they flash past. Pietro’s been studying the interactions between these birds and the flowers on which they feed as part of his PhD work, and has recently published a great paper on the subject.

On most days of field work we might see two or three species, but the day before yesterday we saw 11 species in just an hour. We were visiting a private garden belonging to a retired gentleman named Jonas who has been feeding the hummingbirds in and around his property constantly for about 12 years. The day we visited, Jonas had 13 bottles of sugar solution hung up around the house and we estimated that over 100 individual birds were using them. It’s hard to be more accurate as these birds move so fast, disappearing and re-appearing without warning, like hyperactive kids on a outing to a chocolate factory. It’s a quite stunning sight.

The 11 species we observed are about half of the total number Jonas has recorded since he began feeding the birds and there’s a regular annual rhythm to their appearance, presumably in response to temperature and plant flowering in other parts of the country. The density and richness of birds in this one small property is clearly artificial and we saw nothing like it out in the forest. Jonas is concerned that by feeding the birds so frequently (he uses 5kg of sugar a day and replenishes each feeder several times) he might be negatively affecting plant pollination in the surrounding forest. I doubt that this is the case and reassured him that his efforts were probably positive, certainly compared to some of the other activities that go on around the area, such as building, clearing forest, agriculture, and so on. Assuming that food availability limits the population size of these birds (which may or may not be the case) then feeding the hummingbirds should result in a population increase in that area which will spill out into the wider forest. Similar arguments apply to feeding garden birds in the UK, particularly in the winter.

As I watched the birds crowd and jostle around the feeders, frequently erupting into conflict and chase, I reflected that my trip to Brazil was passing as swiftly as the waft from a hummingbird’s wing on my skin. These last few days in lowland rainforest and restinga vegetation were spent conducting another two surveys of wind versus animal pollination, to add to the previous ones. This lowland forest is very similar in structure to the montane forest 1000 m higher, whilst the coastal restinga forest has rather shorter trees and is also drier. The coastline is stunningly beautiful but there’s a clear tension between its roles as a tourist destination and as an area of rich biodiversity. Humans are often drawn to such places and may unintentionally destroy what they so value, one of the ironic aspects to ecotourism as an ecosystem service.

Over the last few days I’ve been talking a lot with the students who are accompanying us, about their research data and what it means. One of our ongoing themes is the idea of flower colour, shape, smell, etc., as hypotheses about the likely pollinators of those flowers, a notion captured in the idea of “pollination syndromes”. For some flowers the syndromes are probably good predictors, for example the red tubular hummingbird-pollinated species of Fuchsia, Aeschynanthus and other Atlantic Forest plants. But there are also lots of examples of plants with flowers that don’t fit the conventional, “classic” syndromes. Yesterday on a 6km hike we encountered a species of Piper with very oddly smelling flowers, which by general agreement we described as “cockroach with a hint of lemon”. We have no idea what pollinates this plant, though we have some predictions. The genus Piper with its deceptively simple flowers has long fascinated me, ever since I undertook a short postdoctoral project on some Australian species in 1993-94. Hopefully Andre and Coquinho will spend some time observing the plants with their digital movie camera when they are in the forest next month; the results could be fascinating.

The Brazilian students I have met are a committed, passionate bunch who believe strongly in the importance of the natural heritage they are studying and trying to conserve. Though I’ve come and gone from their country like a hummingbird to a feeder, I hope I’ve made some impression on them. They’ve certainly impressed me and I’ve learned a lot from them, from their professors, and from the places we’ve visited. It’s been an amazing adventure but it’s time to come home now and see my family and friends, and colleagues. Over-and-out from Brazil.

It’s called rainforest for a reason, right? Brazil Diary 6

4 Replies

Tropical rainforest is not glamorous. The sanitised, technicolour, televisual view of rainforest that we see in nature documentaries, of whizzing butterflies, flash-dancing birds, and flamboyant flowers, presents only part of the story. Rainforest is dirty, wet, and it smells, of mould and mud, and dead leaves and flowers, and rotting wood. By day it hums and chimes and fizzes with a thousand animal conversations, and green dominates all: colour is as rare as it is welcome. By night those conversations, of insects, frogs, mammals, and birds, increase one hundred-fold. With the night come also the insects (silent or whining) that bite and suck your blood, while above your head in the roof space of your bedroom, bats awaken and chirp and scuttle, flitting out to hunt.

Always, day and night, there is water in the form of rivers, streams, ponds, and pools. And rain; or the threat of rain; or the aftermath of rain. For the four days we have spent in Santa Virginia field station in the Serra do Mar state park it has rained every day, all day, all night. It’s called rainforest for a reason, right?

For the persistent habitué of the rainforest, nothing remains dry for long, clothes and bedding are constantly damp, wood and leather obtains a greyish grape-bloom. It is a difficult environment in which to live and work, particularly for a European used to a particular climate and situation. No, rainforest is not glamorous. But it has a glamor, in the old English sense of casting a spell over those it has charmed into visiting its depths and trying to know its ways. The visitor to tropical rainforest who appreciates its biological richness and functioning is always charmed, and returning to it feels like a return to something very special indeed.

Although I have conducted field work in tropical rainforests in Africa, Australia and other parts of South America, one reason why I have long wished to visit the Atlantic Rainforests of Brazil is that John Tweedie, whose life and career I am researching, wrote frequently in his letters to William Hooker about his love of the forest in South Brazil. And the forest has not disappointed me: it is beautiful and wonderful, even if wet and, because of its altitude of around 1000 metres a.s.l., quite cold.

One of the most spectacular aspects of the Atlantic Rainforest is the sheer abundance and diversity of epiphytic plants, a sub-type of rainforest communities that can only be supported in areas of high rainfall such as this. Over the last couple of days, Andre, Coquinho, Vini and I have hiked a couple of forest trails despite the rain, and orchids and ferns, bromeliads and forest cacti were more abundant than I’ve ever previously seen. These plants are generally thick and complex in form, as they store water internally in leaves and stems, or within tanks formed of overlapping leaf bases. On one short section of trunk, up to waist height, we counted six different orchid species mixed together, and saw at least 20 species along a 3km trail on Sunday. Coquinho has been putting together a checklist of the orchids around the field station and it currently numbers 130 species. Astounding diversity!

As we walked and slid and macheted our way through a 9km trail on Sunday, the ringing calls of male Bare-throated bellbirds (Procnias nudicollis) were resounding through the forest, whilst smaller birds played hide and seek from our binoculars. Still scoring plants for wind and animal pollination, as I previously described, we recorded 75 plant species in flower along the trail, but most of them we encountered only once or twice. Diversity and rarity go together in these plant communities. No wonder Tweedie loved the Atlantic Rainforest; there is always something new to collect and the climate under the trees is cooler than in the open pampas grasslands of Argentina, where he was based. Perhaps the rain made him think of his home in Scotland? It’s called rainforest for a reason, right?