Category Archives: Butterflies

Are tropical plants and animals more colourful? Not according to a new study!

The notion that tropical ecosystems are somehow “different” to those at higher latitudes is a pervasive one in ecology and biogeography, that has its roots in the explorations of 18th and 19th century Europeans such as von Humboldt, Darwin, Wallace, and Belt. All of these authors expressed their amazement at the biological riches they observed in their tropical explorations, and how different these habitats were to those they knew from home.

In many ways the tropics are special, of course and we know that they contain many more species than most other parts of the world; indeed my own work has shown that the tropics have significantly more types of functionally specialised pollination systems, and that the proportion of wind pollinated species is lower in tropical communities. However tropical plants are not, on average, more ecologically specialised (that is, they do not use few species of pollinator) and, as the recent guest blog on Dynamic Ecology argued, there is a growing body of evidence to say that overall tropical interactions between species are not stronger and more specialised than those in the temperate zone (though there are others who dispute this and it’s an ongoing debate).

One of the central tenets of the “tropics are special” idea is that the tropics are more colourful; or rather that the biodiversity of the tropics tends to be more garish, gorgeous, and spectrally exuberant, than that of other parts of the globe. Now a new study by Rhiannon Dalrymple, Angela Moles and colleagues, published in the journal Global Ecology and Biogeography, has challenged this idea for flowering plants, birds, and butterflies in Australia, using sophisticated colour analysis rather than relying on human impressions. Following that link will take you to the abstract and you can read it yourself; however I wanted to summarise their findings by quoting from the first section of the discussion in the paper:

“Contrary to predictions…[our]…results have shown that tropical species of birds, butterflies and flowers are not more colourful than their temperate counterparts. In fact…species further away from the equator on average possess a greater diversity of colours, and their colours are more contrasting and more saturated than those seen in tropical species.”

It’s a really, really interesting study that, as the authors say, runs counter to all of our expectations. Gradually ecologists and evolutionary biologists are testing some long-standing assumptions about the tropics and the results are proving to be a challenge to preconceived ideas about patterns in the Earth’s biodiversity.

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Full disclosure: senior author on the paper Angela Moles was my co-author on that Dynamic Ecology blog, based on which we’ve written a short review article that (hopefully) will be published soon. Other than that I have no vested interest in the study.

The All-Ireland Pollinator Plan 2015-2020

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In the last 12 months we’ve seen the release of the National Pollinator Strategy for England and the USA’s Strategy to Promote the Health of Honeybees and Other Pollinators. Now the Republic of Ireland and Northern Ireland have joined forces to produce the All-Ireland Pollinator Plan, a strategy for 2015-2020 that has been released today. Follow that link and you can download a copy.

This appears to be the first cross-jurisdiction pollinator plan in the world and, as such, is to be welcomed; as I said in my reflections on the National Pollinator Strategy, biodiversity does not respect political boundaries.

How much do we really understand about pollination syndromes?

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Ecologists and evolutionary biologists have, for many years, sought to document repeated patterns that they see in nature; to understand the processes that determine these patterns; and to make predictions about how and when they are going to be observed in the future or in other parts of the world. There are many examples of such patterns, including: cyclical population dynamics of species such as lemmings; the occurrence of specific types of plant communities (e.g. rainforest, grasslands) in areas with particular climates; and convergent evolution of unrelated species to similar ecological niches, such as large, predatory placental and marsupial mammals (e.g. the dog and wolf family compared to the Tasmanian “wolf”).

An example of convergent evolution that has fascinated botanists since the 19^th century is the idea of “pollination syndromes”, which are sets of flower characteristics that have repeatedly evolved in different plant families due to the convergent selection pressures applied by some groups of pollinators. Thus, red, scentless flowers producing lots of nectar are typical of many hummingbird pollinated plants in the New World, whilst white, night-scented flowers often signify moth pollination. Good examples of plant species possessing these archetypical flower traits are have been used as text book examples for decades, repeatedly used to illustrate the predictable and specialised nature of some plant-pollinator interactions.

The problem is that until recently the pollination syndromes have rarely been subjected to critical tests of their frequency and predictive value (Ollerton et al. 2009 and references therein). It’s been tacitly assumed that (after more than 150 years of study) we clearly know all there is to know about them, even though there have been criticisms levelled at the syndromes since their inception, a fact that has been subsequently ignored (Waser et al. 2011).

However in the last 20 years biologists have begun to seek answers to questions such as: How often do plant species conform to the expectations of the classical pollination syndromes? How good is our ability to predict the pollinators of a plant based just on its flower characteristics? What is the role played by flower visitors that do not conform to the predictions of the pollination syndromes? Similarly, what is the role of animals that steal nectar or pollen, or act as herbivores, in shaping flower traits? What new examples of convergent evolution of flower traits remain to be discovered?

Research conducted in many different parts of the world has addressed these questions, questions which some biologists had assumed were already answered or which were not worth asking in the first place. And the answers to them are proving to be both surprising and controversial.

For example, the most comprehensive test of the frequency and predictability of pollination syndromes that has been conducted to date (Ollerton et al. 2009) concluded that only a small proportion of the 352,000 species of flowering plants could be categorised into the pollination syndromes as classically described. Likewise, they estimated that the predictive power of the pollination syndromes was about 30%. Other studies have shown that “secondary” flower visitors can be just as, or more, effective pollinators than the “primary” pollinator predicted by the syndromes (e.g. Waser & Price 1981,1990, 1991); that floral antagonists can play an important a role in shaping flower traits (e.g. Junker and Parachnowitsch 2015 and references therein); and that there are still examples of convergent evolution to “unexpected” pollinators waiting to be discovered in less well researched parts of the world, which in fact is most of the world (Ollerton et al. 2003).

Recently the very prestigious journal Ecology Letters published a paper that has challenged the challengers. Rosas-Guerrero et al (2014), by using a statistical technique called meta-analysis underpinned by a review of the available literature, suggested that pollination syndromes are much more predictable than Ollerton et al. (2009) concluded, and perhaps as high as 75%. However some of my collaborators and I see problems with their approach to studying pollination syndromes that have biased the conclusions that they draw, and therefore undermined the robustness of those conclusions, which we set out in a response to their original paper (Ollerton et al. 2015). We originally tried to publish this in Ecology Letters but for some reason the journal was not interested; it’s therefore freely available from Journal of Pollination Ecology if you follow that link.

I won’t go into the detail of what we perceive as problems in Rosas-Guerrero et al.’s approach to testing the syndromes (you can read the paper for yourself) but in summary they relate to how the literature review was conducted (which failed to include all of the studies that could have provided data for their meta-analysis); the significant bias in the current literature because plant-pollinator interactions are not studied randomly (biologists are often drawn to large-flowered plants possessing those archetypical, classical flower traits associated with particular syndromes); the variation in how different researchers determine the effectiveness of the pollinators in their system, meaning that these studies are not always comparable; and issues around annual variation in pollinator identity and presentation of data.

Despite providing a focus and framework for understanding pollination biology for over 150 years, the pollination syndromes continue to surprise us and to provide a vital antidote to scientific hubris: we really do not understand nearly as much about them as we assume.

In an era when we are more and more concerned about loss of pollinator diversity, including extinction at both a species- and country-level, do these debates really matter or are they of purely academic concern, of interest to a few botanists and ecologists? As you might expect, I’d argue that they do matter: there are still some fundamental aspects of pollination ecology that we don’t completely understand, or have only recently been seriously addressing, some of which I’ve worked on myself and which I’ve highlighted in this blog. These include the number of flowering plants that require animal pollination, the diversity of pollinators at a global and regional level, the relative importance of different types of pollinators, and whether or not plants and pollinators are more specialised in tropical compared to temperate communities. Without some of this fundamental knowledge we are unable to make effective arguments, policies and strategies for conserving pollinators.

References

Junker RR, Parachnowitsch AL (2015) Working towards a holistic view on flower traits—how floral scents mediate plant–animal interactions in concert with other floral characters. Journal of the Indian Institute of Science 95:43–67.

Ollerton J, Johnson SD, Cranmer L, Kellie S (2003) The pollination ecology of an assemblage of grassland asclepiads in South Africa. Annals of Botany 92:807–834.

Ollerton J, Alarcón R, Waser NM, Price MV, Watts S, Cranmer L, Hingston A, Peter CI, Rotenberry J (2009) A global test of the pollination syndrome hypothesis. Annals of Botany 103:1471–1480.

Rosas-Guerrero V, Aguilar R, Marten-Rodriguez S, Ashworth L, Lopezaraiza-Mikel M, Bastida JM, Quesada M (2014) A quantitative review of pollination syndromes: do floral traits predict effective pollinators? Ecology Letters 17: 388–400.

Waser NM, Price MV (1981) Pollinator choice and stabilizing selection for flower color in Delphinium nelsonii. Evolution 35:376–390.

Waser NM, Price MV (1990) Pollination efficiency and effectiveness of bumble bees and hummingbirds visiting
Delphinium nelsonii. Collectanea Botanica (Barcelona) 19:9–20.

Waser NM, Price MV (1991) Outcrossing distance effects in Delphinium nelsonii: pollen loads, pollen tubes, and seed set.
Ecology 72:171–179.

Waser NM, Ollerton J, Erhardt A (2011) Typology in pollination biology: lessons from an historical critique. Journal of Pollination
Ecology 3:1–7.

Garden pollinators for PAW no. 4 – Gatekeeper butterfly (Pyronia tithonus)

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For my fourth contribution to Pollinator Awareness Week I’m going to highlight the Gatekeeper (Pyronia tithonus), a butterfly that I featured on this blog last year. As I noted in that post, it’s fairly rare to have Gatekeepers in an urban garden which indicates that the shrubs and hedges grown by myself and my neighbours are providing the right microclimate for the adults. In addition the overgrown lawns of some adjacent gardens give opportunities for egg laying as the caterpillars are grass feeders.

Adult butterflies are very well camouflaged when resting with their wings folded. They take nectar from a range of plants in my garden but particularly love the dark, heavily scented infloresences of the buddleia variety pictured here. They also visit the wild blackberries scrambling through the hedge that separates us from next door’s garden and probably pollinate those flowers. Although it’s often said that butterflies are poor pollinators compared to bees, due to their general un-hairiness and habit of holding themselves above the stamens and stigmas in a flower, it very much depends on the type of flower. We have an unpublished manuscript that I hope to submit to a journal later this year showing that butterflies are actually better pollinators of one grassland plant than bumblebees.

Pollinator Awareness Week – 13th – 19th July 2015

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Next week has been designated Pollinator Awareness Week (PAW) by Defra and there are events and profile-raising activities going on all over the country.

The motivation behind the PAW is (quote) “to bring attention to the essential needs of pollinators and the simple actions that we can all take to help pollinators survive and thrive”.

With that in mind, next week I intend to produce one blog post a day that highlights, with photographs, a pollinator (or group of pollinators) that I’ve found in my own urban garden in Northampton. The purpose is to illustrate the diversity of pollinators that even a town garden can support, something about their fascinating life histories, and the different ecological requirements of these pollinators that our gardens can provide. For some of them I’ll even discuss the garden crops that they pollinate. First post will be on Monday.

If you, or the group you work with, are doing something for Pollinator Awareness Week feel free to share it in the comments section below.

Plantlife’s road verge advice could negatively affect pollinators

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Did anyone else hear the item on Radio 4 this morning about Plantlife’s road verge campaign and associated petition? I listened carefully to the discussion and am broadly supportive of what they are trying to achieve. But I was immediately struck by a comment that local councils should cut the verges “from mid July onwards” because most plants will have set seed by then. I’ve seen this advice given before and whilst it might be an appropriate option for plants, it could severely impact local pollinator populations.

The printed advice that Plantlife is offering (which can be found here) states that if it’s only possible to cut a verge once a year:

“Cut the full width of the verge….between mid July and September. This allows plants to flower and, importantly, gives time for seed to be set.”

This misses a vital point: between mid-July and September there is still an abundance of flower-visiting insects that require these flowers to provide resources for their nesting and egg laying activities, or to build up reserves of energy to allow them to hibernate, particularly newly-mated queen bumblebees.

Where’s the evidence to support my assertion? It’s been demonstrated by a number of studies, but I’ll point you in the direction of a paper that came out of the PhD work of one of my former students, Dr Sam Tarrant, who now works with RSPB. If you look at Figure 4 of this paper, you’ll see that on restored landfill sites the abundance of pollinators in autumn surveys (conducted September-October) was just as high as for summer surveys. On nature reserves, which are routinely cut from mid-July onwards (see Figure 2), this was not the case.

Climate change means that flower-visiting insects are now active in the UK for a much longer period of time than was previously the case, up to at least November in the south of the country. I agree with Plantlife that road verges are important habitats for plants and other wildlife. But advice that suggests cutting floral resources at a key time of the year for these insects is simply misguided. A cut between October and December would be much more appropriate.

I don’t use Twitter so if anyone could point this at Plantlife’s account I’d be interested to see what their reaction is.

How good is the evidence base for pollinator declines? A comment on the recent Ghazoul and Goulson Science correspondence

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In a recent issue of the journal Science, Dave Goulson and colleagues presented a review entitled “Bee declines driven by combined stress from parasites, pesticides, and lack of flowers”. This stimulated Jaboury Ghazoul to submit a letter to Science criticising the Goulson et al. paper from a number of perspectives, but particularly the paucity of the evidence base for pollinator declines. Dave and his co-authors robustly responded to that letter, as you might imagine. In some respects this was an unsatisfactory exchange, however, as the focus was largely on agricultural pollinators, rather than pollinators of all plants (including the majority non-cultivated species) and I think that (perhaps with more space?) Dave could have outlined the evidence in more depth.

The most striking statement in Jaboury’s letter was that the “evidence for pollinator declines is almost entirely confined to honeybees and bumblebees in Europe and North America”.

Now, even given the fact that Jaboury was possibly referring specifically to agricultural pollinators, that is a very extreme statement to make. Underlying it is the suggestion that global concerns about declining pollinator biodiversity (a subject I’ve discussed repeatedly on this blog) is underpinned by a taxonomically and geographically thin evidence base. Is that really true? I don’t believe so and I think it’s worth presenting a brief overview of the evidence, not least because Dave’s review and the resulting correspondence is pay-walled at the Science site (though if you Google the titles you might, just might, find copies posted on the web…)

Let me state from the outset that I have considerable respect for both Jaboury and Dave, as individuals and as scientists. I’ve known Dave since we were postgrads together in the early 1990s, and have had occasional contact with Jaboury through conferences and via email. So this isn’t meant to be a criticism of either of them. But I do believe that the evidence for pollinator declines is considerably more robust than Jaboury acknowledges, and even more wide ranging than Dave and colleagues describe in their response (though in fairness, most of the bee evidence was cited in their original review).

Here’s a summary of where I see the evidence base at the moment; it’s not meant to be a full review, by any means, but rather to give a flavour of the taxonomic and geographical breadth and depth of the evidence as it currently stands:

Wild bees (including bumblebees, and solitary and primitively eusocial bees) – significant reduction of abundance and diversity at local, regional and country-levels documented in Britain (Biesmeijer et al. 2006, Ollerton et al. 2014), Holland (Biesmeijer et al. 2006), Europe as a whole (Kosier et al. 2007, the recent IUCN Red List by Nieto et al 2014), North America (Grixti et al. 2007, Cameron et al. 2011, Burkle et al. 2013), South America (Morales et al. 2013; Schmid-Hempel et al. 2013), China and Japan (Xie et al. 2008; Williams et al. 2009; Matsumura et al. 2004; Inoue et al. 2008), and South Africa (Pauw 2007).

Honey bees – colony declines documented in Europe and North America (see reviews by NRC 2007, Potts et al. 2010) and evidence that global demand for honey bee pollination services is outstripping supply (Aizen and Harder 2009).

Hoverflies (Syrphidae) – diversity declines documented in Holland and Britain (Biesmeijer et al. 2006).

Butterflies and moths – diversity and abundance of Lepidoptera has declined in the UK (Gonzalez-Megias et al. 2008, Fox 2013), whilst in North America some 50 species are IUCN criteria Red Listed and there is particular concern about the iconic Monarch butterfly. Likewise a significant fraction of butterflies in other parts of the world are of conservation concern, e.g. Southern Africa, Australia, and Europe.

Flower-visiting wasps – reduction in country-level diversity in Britain (Ollerton et al. 2014).

Birds and mammals – the major vertebrate pollinators have recently been assessed at a global level by Regan et al. (2015) using IUCN Red List criteria. They concluded that: “overall, pollinating bird and mammal species are deteriorating in status, with more species moving toward extinction than away from it. On average, 2.5 species per year have moved one Red List category toward extinction in recent decades, representing a substantial increase in the extinction risk across this set of species”.

Of course a number of the studies cited above have shown that some species are doing better than others and a proportion of the taxa they have assessed are stable or even increasing in abundance (including managed honey bee colonies in some parts of the world). But the current evidence base, as I see it, is pointing towards significant declines in pollinator abundance and diversity at multiple spatial scales across all regions that have so-far been assessed with any rigour, for a wide range of taxa.

I’m happy to receive comments on this topic, particularly pointing me to major sources of evidence that I’ve not covered, or if you disagree with my conclusions.

References

Aizen and Harder (2009) The global stock of domesticated honeybees is growing slower than agricultural demand for pollination. Current Biology 19: 915–918.

Biesmeijer et al. (2006) Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands. Science 313: 351–354.

Burkle et al. (2013) Plant-pollinator interactions over 120 years: Loss of species, co-occurrence, and function. Science 339, 1611–161.

Cameron et al. (2011) Patterns of widespread decline in North American bumble bees. Proc. Natl. Acad. Sci. U.S.A. 108: 662–667.

Fox (2013) The decline of moths in Great Britain: a review of possible causes. Insect Conservation and Diversity 6: 5–19.

Gonzalez-Megias, A. et al. (2008) Changes in the composition of British butterfly assemblages over two decades. Global Change Biology, 14: 1464-1474.

Grixti (2009) Decline of bumble bees (Bombus) in the North American Midwest. Biol. Conserv. 142, 75–84 (2009).

Inoue et al. (2008). Displacement of Japanese native bumblebees by the recently introduced Bombus terrestris (L.) (Hymenoptera: Apidae). J. Insect Conserv. 12: 135–146.

Kosior (2007) The decline of the bumble bees and cuckoo bees (Hymenoptera: Apidae: Bombini) of Western and Central Europe. Oryx 41, 79–88.

Matsumura et al. (2004) Invasion status and potential ecological impacts of an invasive alien bumblebee, Bombus terrestris L. (Hymenoptera: Apidae) naturalized in Southern Hokkaido, Japan. Glob. Environ. Res. 8, 51–66.

National Resource Council (2007) Status of Pollinators in North America. National Academies Press, Washington, DC.

Nieto et al. (2014) European Red List of Bees. Publication Office of the European Union.

Ollerton et al. (2014) Extinction of aculeate pollinators in Britain and the role of large-scale agricultural changes. Science 346: 1360-1362.

Pauw (2007) Collapse of a pollination web in small conservation areas. Ecology 88: 1759-1769.

Potts et al. (2010) Declines of managed honey bees and beekeepers in Europe. Journal of Apicultural Research 49: 15–22.

Regan et al. (2015) Global Trends in the Status of Bird and Mammal Pollinators. Conservation Letters DOI: 10.1111/conl.12162

Schmid-Hempel et al. (2013) The invasion of southern South America by imported bumblebees and associated parasites. Journal of Animal Ecology 83: 823–837.

Williams et al. (2009) The bumblebees of Sichuan (Hymenoptera: Apidae, Bombini). Syst. Biodivers. 7: 101–189.

Xie et al. (2008) The effect of grazing on bumblebees in the high rangelands of the eastern Tibetan Plateau of Sichuan. Journal of Insect Conservation 12: 695–703 (2008).

How do animals respond to solar eclipses? Please share your observations.

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If you have been anywhere in the Palearctic during the past 48 hours then you can’t have missed the fact that we experienced that most rare of astronomical phenomena, a solar eclipse. The eclipse was total only as far north as the Faroe Islands and Svalbard; further south it was partial and here in Northampton the eclipse was perhaps 80-90% total.

It’s been big news with lots of public interest. As well as explaining the astronomy of eclipses, various commentators on current affairs and science programmes have talked about how animals respond to eclipses. This is a topic that’s intrigued me ever since the August 1999 eclipse. During that event I was carrying out field work in a Northampton grassland and as the eclipse reached its maximum the bumblebees and butterflies on the site stopped flying and foraging, and settled into the grass. Once the eclipse had passed they carried on as before. I don’t have any hard data to demonstrate the effect, it was purely an observation of what was happening around me.

Since then I’ve waited over 15 years for the next opportunity to observe how solar eclipses affect animal behaviour. Unfortunately there are few pollinators flying at the moment so I had to content myself with watching the gulls, woodpigeons, carrion crows and other birds on the Racecourse park adjacent to the university.

This time I took some video footage before, during and after the eclipse, noted the birds’ behaviour, flying, calls and singing. And guess what? As far as I could tell the eclipse had no effect on the birds! They behaved as if nothing was happening. Even a mistle thrush than had been singing all morning from a perch in one of the boundary lime trees continued its song as the moon passed in front of the sun.

That really surprised me! I was expecting the birds to at least reduce their activity as has been noted in previous eclipses. But they didn’t as far as I could tell. Perhaps it was the type of birds I was observing? Or the time of year? Or the fact that the eclipse was only partial? Lots of questions but it’s difficult to do repeat observations for this kind of science – the next British total eclipse is not until 2090!

What did you see? Did you notice any effect of the eclipse on animal behaviour? Or did you, like me, see no effect of the eclipse. I’d be interested to hear your observations.

Monitoring the biodiversity impact of the new Waterside Campus

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All human activities can potentially have an impact on the biodiversity of the local environment in which they occur. That impact can be positive or negative, depending upon how the activity is managed, how impact is mitigated, and the metrics that we use to measure the effects that are occurring. This is particularly true of large infrastructure developments such as big buildings, housing developments, roads, and, a category close to home for me at the moment, new university campuses.

I’ve written before about the University of Northampton’s plans to build the new Waterside Campus on brownfield land close to the River Nene, here and here. It’s a huge project, likely to cost in excess of £330 million on a site covering about 20 hectares.

As you might imagine, such an ambitious scheme has not been without its controversies and there is much debate within the university about changes to how we work and interact with colleagues and students, provision of teaching and research spaces, etc. There’s also been much discussion within the town, though the general feeling amongst the public (as far as I perceive it) is that bringing the university closer to the centre of Northampton will provide a much-needed economic boost and add significantly to the town’s life.

But what effect will such a development have on the wildlife in and around this peri-urban site, given that it’s in the middle of the Nene Valley Nature Improvement Area and very close to internationally important bird sites?

Over the past few months, together with my colleague Dr Janet Jackson, I’ve been taking part in meetings with the Waterside project’s landscape architects (LUC), other partners from the NIA project board, and the local Wildlife Trust. We’ve been discussing the current plans for the green infrastructure of the campus and thinking about how these can be enhanced. It’s been a fascinating process as initial disagreements have been negotiated towards compromises and additions that everyone is happy with, balancing budgetary, function and space restrictions with habitat creation and landscape enhancement.

There’s too much been discussed to give a full account at this stage, and it’s possible that some details will change over time, but the current Ecology Strategy document produced by LUC shows that there will be more than 10 hectares of habitat creation on the site, including species-rich grassland, woodland patches, brown and green roofs, swales and damp areas, and recreated brownfield habitat. The latter is particularly exciting and something of an experiment, as much of the (albeit limited) current wildlife interest on the site relates to the brownfield element, including the “urban tundra“.

To put the 10 hectares into perspective, the adjacent Wildlife Trust Local Nature Reserve of Barnes Meadow is only 20 hectares in area, so it’s potentially increasing that site by 50%. It’s rare for academic ecologists such as Janet and myself to be able to influence large building developments, so this has been an exciting opportunity for us to make a contribution that (if all goes to plan) will have a positive effect on biodiversity conservation in the Nene Valley.

But how will we know if the Great Waterside Experiment has been a success and that the biodiversity of the new campus is at least as rich, and preferably richer, in species than it was before building took place?

Monitoring of the wildlife is key to this. Fortunately we have some base-line surveys of birds, plants and invertebrates (including bees and butterflies) from before building started that we can compare with later surveys during and after the campus build. That process has already started, and with my colleague Dr Duncan McCollin and with two keen second-year students, Jo and Charlie, we have already completed three winter bird surveys to get a sense of how the current site clearance and ground works is affecting the presence of birds in and around the development, including those using the River Nene. The plan is to continue these surveys up to and after the campus opens in 2018, to give us a data series showing the influence of the campus on bird diversity and numbers.

The initial results are currently being analysed and it appears that the current phase of building has reduced overall bird diversity by about 30%, and that red and amber status birds (of most conservation concern) have been affected more than green status birds, as this figure demonstrates (click on it for a closer view):

These rough figures hide a lot of detail, however. For example, there has been some addition of species in 2014-15 that were not recorded in 2012-13, including Coot, Treecreeper and the amber-status Stock dove. More importantly, some of the amber status birds that we didn’t record on site in 2014-15, we know from additional surveys are still present in habitats within 500 metres of the development, for example Dunnock, Green woodpecker, and Bullfinch. Similarly, red status birds such as resident Starling, and winter migrant Fieldfare and Redwing occur within at least one kilometre of the site. Hopefully as the building work progresses towards completion these (and other) species will return, so at the moment we’re not too concerned by their disappearance from the site.

Later in the spring we will conduct a couple of breeding bird surveys, and continue surveying for the next few years until the campus opens in 2018. Only then will we see exactly how successful our influence has been. In the mean time I’ll report back as and when we have more data to share.

Evolving a naturalist – happy birthday to me!

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Somehow, today is my 50th birthday. So I thought I’d mark it with a short post about my personal evolution as a naturalist and, ultimately, professional scientist.

One of the great things about the internet and social media such as Facebook is that you can make exciting discoveries on a weekly basis. Recently I found out something that means a lot to me on a very personal level: I discovered that a family* who lived in the same street when I was growing up in Sunderland in the 60s and 70s have digitised some old home movies and made them available on YouTube. In our digital age in which every phone and camera can capture and share events as they happen, it’s sometimes easy to forget that owning a movie camera in the 60s was quite a rarity and the majority of kids living at that time were never filmed.

These movies are exciting not just because one of them shows me aged about 5 years (in the blue shirt) playing with friends (I’m there from 3’53”) but because it documents, in colour and moving pictures, one of the reasons why I became a professional naturalist with a deep fascination for biodiversity.

The grassland in which we are erecting a tee-pee is not some country meadow, the kind of wild rural landscape cited by so many other naturalists as inspiring their childhood fascination with natural history. These grasslands had arisen spontaneously on cleared demolition sites, following the removal of Victorian terraced housing and tenement blocks, some of which were slums and others that had suffered bomb damage in the Second World War (now that does make me sound old!)

Up until the 1950s this area had been very built up, with the houses, shops and pubs serving the local families who were employed mainly in the shipyards and coal mines to the north of the town. You can get a sense of how urban it was from this 1898 map of Southwick; the places I refer to are just south-west of The Green to the left of the map.

Following demolition the sites were left to their own ends, and were colonised by plants, insects, birds and mammals from patches of habitat closer to the river that had either been cleared of buildings earlier in the century, or which had never been built upon at all. There are some nice areas of magnesian limestone grassland nearby along the higher banks of the River Wear valley, and typical calcicole plants such as Greater Knapweed (Centaurea scabiosa) could be found on these post-demolition grasslands. In fact, in the absence of horse chestnut trees, we used to play a version of conkers using the unripe seed heads of Greater Knapweed. Was that an echo of earlier children’s games in Britain, prior to the introduction of horse chestnuts in the 17th century? Apparently similar games were played with snail shells and hazelnuts.

If you watch the opening minute of this piece of footage from the same series, and ignore the girls posing and playing in the foreground, the background reveals a rich flora of plants, with butterflies hopping between flowers. The first bird species that I can remember identifying, and being fascinated by its bright colours, was Goldfinch (Carduelis carduelis) feeding on the seeds of tall thistles in the very area where this was filmed. The first butterfly that I could put a name to was the Small Tortoiseshell (Aglais urticae), also feeding on thistles, but this time on the nectar-rich flower heads, as a pollinator. We’d collect its caterpillars from the nearby nettles and raise them in jars.

So you don’t have to have had a rural upbringing to appreciate and benefit from nature, and to later influence your profession and passions, any piece of land can inspire interest in kids, regardless of its origin, if nature is left to colonise. Unmanaged, semi-wild green space within towns and cities has huge value, both for wildlife and for the culture of childhood. They need to be protected just as much as rural nature reserves, including the generally disparaged but actually biodiverse “brownfield” sites, as Sarah Arnold has discussed in a recent blog post.

Some of the riverside grasslands still remain and I hope that they are fascinating new generations of kids with their colour and diversity and flouncing butterflies. But the post-industrial grasslands on which I played and looked for bugs and flowers are all gone; they were cleared and built upon in a flurry of housing and retail development in the 1980s. Perhaps in the future they may return if those buildings are themselves demolished and the land allowed to lie undisturbed for a while. That is what nature does: it ebbs and flows across our landscapes in response to human, and natural, interventions, endlessly changing and endlessly fascinating to the curious minds of children and scientists, no matter how old they are.

*My sincere thanks to the Scrafton family who took the original footage, made it available on YouTube, and gave me permission to use it in this post.