Monthly Archives: April 2016

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PhD students do the weirdest things

Category : PhD Life

Lately, I have had some very peculiar reactions when explaining the current chapter of my PhD that I am working on. Maybe I’m not explaining it perfectly, or most eloquently, but these reactions include: staring; bemusement and confusion; and outright laughing-in-my-face, before asking me, “so this is your… job?” Some friends of mine have taken to calling me up on a weekly basis, putting me on speaker phone to their office colleagues, and asking me questions about what sort of work I have encountered that week- just to prove that I have a strange occupation. So I decided to start documenting the types of things I have found myself doing recently, in case other non-science folk out there fancied a laugh at what crazy scientists do in their day-to-day lives.

I’m writing this on a train, Cambridge bound, for a meeting to discuss – with a group of like-minded scientists – the ways in which we can use model caterpillars (that is, caterpillars made out of either pastry or plasticine) to answer some serious biological and ecological questions. Hannah Rowland and her behavioural ecology and evoultion research group, at Cambridge University, have a lot of experience using pastry caterpillars to mimic cryptic (different ways of camouflaging oneself)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Image: http://www.nytimes.com/2015/08/25/science/evolving-a-defense-mimics-save-themselves.html?_r=0

 

 

or aposymetric (brightly coloured warning signals to deter predators) prey to find out how birds react and learn about how to avoid them. There is also a website bringing together researchers using dummy caterpillars together, called “The Global Dummy Caterpillar Project”. So in the world of ecology and evolutionary research, dummy caterpillars are pretty well known.

 

However, even in the science world, the use of dummy caterpillars is still quite strange and peculiar to some. Within diverse research departments, such as the Institute of Zoology at ZSL, methods used widely by one group can be alien to another. In broad terms, the use of dummy caterpillars in science is considered when one wants to ask questions about either i) the caterpillar (the prey) and their defense strategies against predation or ii) the predator – which predators are the main ones eating that prey? Other questions may come off the back of these, such as calculating predation rates from predators to be able to compare the rate of caterpillar predation in one area compared to another. Other evolutionary questions might be: “will novel patterns of brightly coloured prey be predated on as much as known patterns of brightly coloured prey?” Or “what are the main predators eating prey A?”. But mostly the question is either about the prey or predator.

 

That question about what types of predators are eating the dummy prey, is quite interesting. A few papers have used plasticine as their proxy prey so that when a predator bites into it, it leaves an attack mark or indent- uniquely shaped to that taxa (ie. birds, insects, mammals). A few studies have used this in their research to discover that a certain predator is more beneficial at reducing that prey than others (http://onlinelibrary.wiley.com/doi/10.1111/j.1570-7458.2009.00860.x/abstract;jsessionid=3165BF9A8A0858F5EB05D5903F11BCD5.f02t03?userIsAuthenticated=false&deniedAccessCustomisedMessage=.)

 

These are all very interesting questions and the answers can be interesting too, but what is the point? I can’t answer for other people in finding the value or meaning of their research. But I can start with explaining how the answers I get from my research can be applied in the “real world”.

 

This dummy caterpillar experiment acts as a specific question as part of my PhD [http://www.selvey.nosrednas.co.uk/index.php/about/] The wider question of my work is “Does biodiversity increase the pest control ecosystem service on apple orchards?” The dummy caterpillars experiment will hopefully find out whether the orchards with higher biodiversity have higher caterpillar predation rates from birds. These sorts of questions can build a picture about farmland ecosystem services, such as pollination and pest control. If we can discover that farms with high biodiversity levels have a higher proportion of their pesky pest caterpillars (e.g the codling moth- a major orchard pest – https://www.rhs.org.uk/advice/profile?pid=489) eaten by the orchard’s resident birds, then we could suggest that birds are a key “pest control” ecosystem service. Farmers could potentially nurture this service and increase the prospect of needing to use less insecticides in the future, which are expensive and increasingly under scrutiny. Research is constantly used to ensure chemical usage on farmland is not debilitating the natural wildlife and is safe to be used around people. Therefore bans are quite common for certain chemical pesticides, and the most recent ban is a well known and used insecticide – chlopyrifos, as discussed in this Farmers Weekly article [http://www.fwi.co.uk/arable/aphid-control-challenges-ahead-as-major-insecticide-is-banned.htm]. But birds are not going to be banned, as much I know anyway, so if a free pest control service can be provided by them, farmers may feel a bit more secure about their management regimes – as long as they eat enough caterpillars, that is. And this is what I am trying to find out.

 

I have just commenced this part of the study, which started mid April due to a very cold start to this spring. But before I started I needed to do a bit of pastry rolling and plasticine purchasing to work out which model caterpillar will be best for my study. To test both these prodigies (pastry v’s plasticine) I have been working alongside Dr. Hannah Rowland in Cambridge [http://www.zoo.cam.ac.uk/directory/hannah-rowland], where a newly built aviary allowed me to test my little plasticine caterpillars on four little blue tits*, to see what types of marks they will leave in the plasticine models. I was also able to test to see if there was a colour preference between green or cream, or if the blue tits started to learn that what I was presenting them with was not food, no matter what the colour.

 

 

 

 

 

After randomly presenting all the blue tits with either a green or cream model caterpillar, I found that there was no colour preference and that some blue tits are just a bit more clued up than others! Some clever little birds would only peck one colour once, but other would keep trying newly presented dummies of the same colour. But overall, they all tried each colour once. So from this mini experiment I have decided to use both green and cream in my experiments in the orchards!

 

A perfect peck mark left from a blue tit.

 

 

 

 

So that’s it on the planning phase, next up will be more pictures like this one of me checking some dummy caterpillars in a lovely little orchard. I might even pop in some camera trap pictures of what has been attracted to these dummy caterpillars so far.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I hope I leave you with a little less baffled facial expression to when you first read the words “pastry” or “plasticine” and “caterpillars” in the same sentence. Research must definitely be up in the top 10 most peculiar jobs, but that’s what makes it fun!

 

* These four blue tits were only kept in this experimental aviary for 2 nights before being released back in the wild, and Cambridge University had the correct licenses for their research on blue tits to take place.


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trop pic

Re-posting my first blog: Following oranges through agri-business supply chains

Category : PhD Life

This post was originally published by myself during my time as a PhD student at the Centre for Agri-Environmental Research(CAER) in Reading and you can find the original blog here. After reading this blog you will come to realise that lots of things changed in my PhD after I wrote it – mainly my whole study area. No Brazil and no oranges! On top of that we moved universities; from Reading to UCL. I get to spend time at London Zoo now too, so all that change hasn’t turned out that bad 🙂

Original post May 9th 2014

Seeing as this is CAER’s first blog post (and what a privilege it is to be CAER’s first blogger) I decided to start off a trend of posts to briefly describe what each of the department’s PhD students are currently researching. There is a huge diversity of exciting projects which range from developing conservation management techniques to protect the CR Mauritian Olive White Eye (Gwen Maggs) to understanding the importance of biodiversity in supporting the ecosystem services of apple orchards in Kent (Sean Webber). Not only will this blog thread inform the world outside of CAER what we are all up to, but it will help us understand what each other are actually doing too!

I am still fairly new to PhD life, about 7 months through and only just starting to find my feet. So unfortunately there are no profound results from me yet, but I have outlined some areas of interest of which I would like my PhD to focus on and which I could garner some interesting results in a few years… maybe. Whether these areas of interest will completely change is currently unknown and I would prefer to keep it that way, for sanity reasons.

The topic of my PhD is one very relevant to CAER’s general interests: ecosystem services. This buzzword is everywhere at the moment: within academia, government policies and even multinational corporations that rely on these services provided by the environment to support their global products. One company particularly interested in finding the business value of these ecosystem services is Pepsico, who are the industry partner of my PhD.

Pepsico are the second largest food and beverage business in the world in terms of net revenue. In the UK Pepsico are best known for their Copella, Walkers Crisps, Quaker Oats and Tropicana brands. Pressures are rising from consumers and charities who are targeting companies like Pepsico, Nestlé and Kellogs to source their ingredients more sustainably – especially considering the vast amount of land used in order to grow the ingredients those companies go on to sell. Campaigns and petitions such as Oxfam’s Behind The Brand and Sum Of Us’ palm oil campaign both name and shame Pepsico for not being responsible in making sure their suppliers are sourcing sustainably. Every ingredient Pepsico source will need scrutinising, but I don’t have enough time to look at all ingredients during my PhD so I decided to start with one of the most complicated supply chains: oranges.

Sum of Us made a new version of the Doritos Super Bowl advert, with added deforestation scenes.

Sum of Us made a new version of the Doritos Super Bowl advert, with added deforestation scenes.

Supply chains are complicated at the best of times, with farmers producing ingredients all over the world, middle men providing different services, processors and packagers, buyers and then final consumers. For a brand to be classed as sustainable, audits and compliancy checks must be undergone at each level in the supply chain to ensure each person in this confusing, international network are all acting sustainably. In the past, large international corporations have benefitted from relying on external sources to buy their ingredients, and not having to ask any questions as to where it came from – as long as the price is right. But with consumers becoming ever more savvy about their environment and the impacts irresponsible farming practices could have on natural habitats and endangered species, these large corporations are being forced to take on more responsibility.

Where do I start? It seems quite practical to firstly find the orange groves that the oranges come from which produce Tropicana for the European market. This has turned out to be a tricksy task. Although it is known oranges for the US market come from Florida, it seems the European Tropicana oranges come from São Paulo State in Brazil, but their exact locations are unknown – making assessing environmental risks difficult. If management techniques and inputs such as fertilisers and insecticides are unknown this means there is an unknown impact that production is having on biodiversity, both on farm and in the surrounding landscape, as well as the ecosystem services those orange groves might rely on: water and nutrient cycling, pollination or pest control from praying mantis!

The overall aim of my research is to provide international corporations, of similarly confusing supply chains, with a process to follow or ‘conceptual framework’ to help them identify where environmental, reputational and eventually economic risks lie within their supply chain. If being environmentally sustainable can be economically viable and profitable then surely this is a good move for businesses to make? Nurturing nature and being ‘green’ should not only be practiced when times are economically viable to do so, but it should be engrained into business plans to ensure long term sustainability of a company – especially those which rely on functional ecosystems to produce food and drinks products sold worldwide.