Monthly Archives: May 2016

Does naming your study animals introduce observer bias?

I think, that most, if not all entomologists, will confess to a bit of funding envy when talking with those of their colleagues who work with the “undeserving 3%”, the large charismatic mega-fauna and the modern dinosaurs. The terminology gives us away, although the evidence is overwhelmingly on our side (Leather, 2009).  As entomologists, particularly those of us working in the field, we are used to reporting numbers collected in the tens of thousands (Ramsden et al., 2014 ), if not the hundreds of thousands (Missa et al., 2009) and  even a short six-week study can result in the capture of thousands of ground beetles (Fuller, et al., 2008).  Naming our subjects, much as we love them, is not an option, even if we wanted to. Even behavioural entomologists counting individual flower visits by pollinators are used to dealing with hundreds of individuals.   In the laboratory, although numbers may be smaller, say tens, we still assign them alphanumeric codes rather than names, even though one might look forward to counting the number of eggs laid by the unusually fecund moth #17 or hope that aphid #23 will be dead this morning as she is becoming a pesky outlier for your mortality data 🙂

Our colleagues who work with mammals in the field, seem however to adopt a different strategy. It appears quite common for them to name their animals as the following examples from Twitter make clear.

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From her dissertation field note book, Erin Kane @Diana_monkey but not yet published.

Published data in McGraw et al., (2016) are from another study where the animals are not named.

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Anthropomorphic judgement values

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Anne being very involved with her cheetahs, although the paper (Hillborn et al., 2012) does not mention them by name.

 

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Another example of subjects with names Hubel et al., 2016), but this time named in the paper.

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Although in the description of methodology and results animals are referred to as subjects, the Table gives it away! (Allritz et al., 2016).

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Another example of named subjects (Stoinski et al., 2003).

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More named subjects (Dettmer & Fragaszy, 2000), but as these were captive the names almost certainly not chosen by the observers.

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In this case (Blake et al., 2016), use no human-based names either in the methods or tables, so exemplary, although of course I have not seen their field note books 🙂

My concern, highlighted by these examples, is that by naming their study animals, the observers are anthropomorphising them and that this may lead them to inadvertently bias their observations. After all, the names have not been chosen at random, and thus could influence the behaviours noted (or ignored). I say ignored, because of two very specific examples, there are more, but I have these two to hand.

Victorians used birds as examples of good moral behaviour, erroneously believing them to be monogamous, probably because of seeing the way they fed their chicks cooperatively. Tim Birkhead (2000)* quotes the Reverend Frederick Morris who in 1853 preached  “Be thou like the dunnock – the male and female impeccably faithful to each other,”  and goes on to point out that despite a hundred years of ornithological science it was not until the late 1960s that  the promiscuous behaviour of female birds was revealed, interestingly enough coinciding with the new moral code of the 1960s.

Descriptions of penguin homosexual behaviour and their penchant for acts of necrophilia so shocked George Levick’s publishers that they removed them from his 1915 report but printed them and privately distributed them to selected parties marked as “Not for Publication” (Russell et al., 2012).  He also transcribed his descriptions of this ‘aberrant’ behaviour in Greek in his notebooks, presumably to make it less accessible.

And finally from me, this recent report about ‘sacred and ritualistic’ behaviour in chimpanzees Kuhl et al (2016),   where, I feel the authors have really allowed themselves to over-anthropomorphise with their subjects, very much to the detriment of scientific  detachment.  I have yet to find an entomologist who agrees with their interpretation. http://www.nature.com/articles/srep22219

AND NOW SOMETHING NEW for my blog, an embedded comment/riposte. I thought that it would be useful to get a response from someone who works on large charismatic mega-fauna and who names their subjects.  Anne Hilborn, whom many of you will know from Twitter as @AnneWHilborn, has kindly agreed to reply to my comments.  In the spirit of revealing any possible conflicts of interest I should say that I taught Anne when she was an Ecology MSc student at Silwood Park 🙂

Over to you Anne…..

“Hello, my name is Anne and I name my study animals.”

Decades ago this might have gotten me jeered out of science, the assumption being that by naming my study animals I was anthropomorphizing them and that any conclusions I drew about their behavior would be suspect. Thankfully we (at least those of us who have the privilege of working on megafauna) have moved on a bit in our thinking and our ways of doing science.

There are two parts to Simon’s concern about naming study animals. One is that naming leads to anthropomorphization, the second is that the anthropomorphizing leads to biased science. I would argue that the naming of study animals doesn’t necessarily increase anthropomorphism. On the Serengeti Cheetah Project we don’t name cheetahs until they are independent from their mother (due to a high mortality rate).  During my PhD fieldwork I spent a lot of time following a young male known as HON752MC (son of Strudel).  Several months after I started my work he was named Boke. My interest in his behavior, my chagrin at his failures and happiness when he had a full belly didn’t change when he was named. Many of us get emotionally attached on some level to our study animals, whether they have names or numbers.

An interesting thing to ponder is that if naming does lead to anthropomorphizing, does it only happen when human names are used? What human characteristics am I likely to attach to cheetahs named Peanut, Muscat, Strudel, Fusili, or Chickpea?

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As to whether anthropomorphism leads to biased science… it definitely can if, as Simon points out, certain behaviors are not recorded because they do not fit the image of the animal the researcher had in their head. I don’t have any data on this, but I suspect this is extremely rare now days. Almost all researchers have had extensive formal training and know the importance of standardized data collection. I study cheetah hunting behavior, and I record how long a cheetahs spends spend stalking, chasing, killing, and eating their prey. I record the number of animals in the herd they targeted, how many second the cheetah spends eating vs being vigilant, and at what time they leave the carcass. No matter my personal feelings or attachments to an individual cheetah, the same data gets recorded.

Research methods have advanced a lot in the past decades and we use standardized methodologies and statistics expressly to prevent bias in our results. Anthropomorphism is just one possible source of bias, others include wanting to prove a treasured hypothesis, the tendency to place plots in areas where you suspect you will get the best results, etc..

As Adriana Lowe (@adriana_lowe ) puts it “Basically, if you’ve got a good study design and do appropriate stats, you can romanticise the furry little buggers until the cows come home and it won’t have a massive effect on your work. Any over interpretation of results would get called out by reviewers when you try to publish anyway.”

Simon points out examples of people being shocked when birds didn’t follow the dictates of contemporary human morality. I would like to think that biologists no longer place human values on animals. I can admire hyenas because the females are bigger bodied and socially dominant to males, but that doesn’t mean I draw parallels or lessons from them to human society (not in the least because the females give birth through their elongated clitoris and the cubs practice siblicide). As scientists we are capable of compartmentalizing, of caring deeply for our subjects, of shedding a tear when Asti turns up with one cub when previously she had five, without that changing the way we record data. In our training as biologists, we are taught not impose our own feelings or values on our study animals. We may find infanticide in lions (Packer and Pusey 1983), extra pair copulations in birds and primates (Sheldon 1994, Reichard 1995), or siblicide in boobies (Anderson 1990) to be repugnant, but we record, analyze, and try to publish on the phenomenon all the same.

To go on the offensive, there are ways naming study animals actually improves data collection.

Again, Adriana Lowe “If you’re doing scan sampling for instance, so writing down all individuals in a certain area every 10 minutes or so, names help. At least for me, it’s harder to remember if someone is M1 or M2 than Janet or Bob, particularly if you have a big study troop/community. So it can improve the quality of the data collected if you’re less likely to make identification errors.”

Because of our own training and peer review, assigning emotions or speculating about the intent on animals rarely makes it into scientific papers. However the situation is very different for those of us who wish to present our results outside of the ivory tower. While fellow scientists might be willing to wade through dry descriptions about how M43 contact called 3 times in 4 minutes when he was no longer in visual contact with M44, the public is not. Effective science communication needs a story and an emotional hook to draw people in. It is much easier to do that when you tell a story about Bradley and Cooper and not M43 and M44.  I will admit this does get into grey areas with the type of language we use outside of scientific papers. I tell stories about the cheetahs in my blog posts and even assign emotions to individuals. But if I am answering questions from the media or the public, I am still very careful not to make any definitive claims about behavior that haven’t been backed up by statistical analysis.

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Here I use language and make assumption in tweets that I never would in a scientific paper.

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There are a lot of issues that negatively affect the objectivity of science ie. the majority of funding going to well established entrenched researchers, papers being reviewed primarily by people from the same school of thought, the increasing pressure to have flashy results that generate headlines, but naming of study animals is not high on the list.

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So now, over to you the readers, what do you think? Please comment and share your views or at the very least, please cast your vote.

VOTE NOW

 

 

References

Allritz, M., Call, J. & Borkenau, P. (2016) How chimpanzees (Pan troglodytes) perform in a modified emotional Stroop task. Animal Cognition, 19, 435-449.

Anderson, D. J. (1990) Evolution of obligate siblicide in Boobies. 1. A test of the insurance-egg hypothesis. American Naturalist, 135, 334–350.

Birkhead, T. (2000) Promiscuity: An Evolutionary History of Sperm Competition and Sexual Conflict. Faber, London.

Blake, J.G., Mosquera, D., Loiselle, B.A., Swing, K., Guerra, J. & Romo, D. (2016) Spatial and temporal activity patterns of ocelots Leopardus pardalis in lowland forest of eastern Ecuador.  Journal of Mammalogy, 97, 455-463.

Dettmer, E., and Fragaszy, D. 2000. Determining the value of social companionship to captive tufted capuchin monkeys (Cebus apella). Journal of Applied Animal Welfare Science, 3, 293-304

Fuller, R. J., Oliver, T. H. & Leather, S. R. (2008). Forest management effects on carabid beetle communities in coniferous and broadleaved forests: implications for conservation. Insect Conservation & Diversity 1, 242-252.

Hillborn, A., Pettorelli, N., Orme, C.D.L. & Durant, S.M. (2012) Stalk and chase: how hunt stages affect hunting success in Serengeti cheetah. Animal Behaviour, 84, 701-706

Hubel, T.Y., Myatt, J.P., Jordan, N.R., Dewhirst, O.P., McNutt, J.W. & Wilson, A.M. (2016) Energy cost and return for hunting in African wild dogs and cheetahs. Nature Communications, 7, 11034 DOI:doi:10.1038/ncomms11034

Kühl, H.S., Kalan, A.K., Arandjelovic, M., Aubert, F., D’Auvergne, L., Goedmakers, A., Jones, S., Kehoe, L., Regnaut, S., Tickle, A., Ton, E., van Schijndel, J., Abwe, E.E., Angedakin, S., Agbor, A., Ayimisin, E.A., Bailey, E., Bessone, M., Bonnet, M., Brazolla, G., Buh, V.E., Chancellor, R., Cipoletta, C., Cohen, H., Corogenes, K., Coupland, C., Curran, B., Deschner, T., Dierks, K., Dieguez, P., Dilambaka, E., Diotoh, O., Dowd, D., Dunn, A., Eshuis, H., Fernandez, R., Ginath, Y., Hart, J., Hedwig, D., Ter Heegde, M., Hicks, T.C., Imong, I., Jeffery, K.J., Junker, J., Kadam, P., Kambi, M., Kienast, I., Kujirakwinja, D., Langergraber, K., Lapeyre, V., Lapuente, J., Lee, K., Leinert, V., Meier, A., Maretti, G., Marrocoli, S., Mbi, T.J., Mihindou, V., Moebius, Y., Morgan, D., Morgan, B., Mulindahabi, F., Murai, M., Niyigabae, P., Normand, E., Ntare, N., Ormsby, L.J., Piel, A., Pruetz, J., Rundus, A., Sanz, C., Sommer, V., Stewart, F., Tagg, N., Vanleeuwe, H., Vergnes, V., Willie, J., Wittig, R.M., Zuberbuehler, K., & Boesch, C. Chimpanzee accumulative stone throwing. Scientific Reports, 6, 22219.

Leather, S. R. (2009). Taxonomic chauvinism threatens the future of entomology. Biologist, 56, 10-13.

McGraw, W.S., van Casteren, A., Kane, E., Geissler, E., Burrows, B. & Dsaegling, D.J. (2016) Feeding and oral processing behaviors of two colobine monkeys in Tai Forest, Ivory Coast.  Journal of Human Evolution, in press.

Missa, O., Basset, Y., Alonso, A., Miller, S.E., Curletti, G., M., D.M., Eardley, C., Mansell, M.W., & Wagner, T. (2009) Monitoring arthropods in a tropical landscape: relative effects of sampling methods and habitat types on trap catches. Journal of Insect Conservation, 13, 103-118.

Packer, C. & Pusey, A.E. (1983) Adaptations of female lions to infanticide by incoming males. American Naturalist, 121, 716–728.

Ramsden, M.W., Menéndez, R., Leather, S.R., & Wakkers, F. (2014) Optimizing field margins for biocontrol services: the relative roles of aphid abundance, annual floral resource, and overwinter habitat in enhancing aphid natural enemies. Agriculture Ecosystems and Environment, 199, 94-104.

Reichard, U. (1995) Extra-pair copulations in a monogamous gibbon (Hylobates lar). Ethology ,100, 99–112.

Russell, D.G.D., Sladen, W.J.L. & Ainley, D.G. (2012) Dr. George Murray Levick (1876-1956): unpublished notes on the sexual habits of the Adélie penguin.  Polar Record, 48, 387-393

Sheldon, B. C. (1994) Male phenotype, fertility, and the pursuit of extra pair copulations by female birds. Proceedings of the Royal Society B: Biological Sciences, 257, 25–30.

Stoinski, T.S., Hoff, M.P. & Maple, T.L. (2003) Proximity patterns of female western lowland gorillas (Gorilla gorilla gorilla) during the six months after parturition. American Journal of Primatology, 61, 61-72.

 

Post script

I said that entomologists don’t name their study animals but they do name their pets. Some of our PhD students had an African flower

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Soulcleaver; despite his name he seems quite cute when viewed side-on, perhaps even with a cheeky grin, although as an entomologist I couldn’t possibly say that 🙂

beetle, Mecynorhina ugandiensis, which they named Soulcleaver, and I know that some beekeepers name their Queens https://missapismellifera.com/2016/03/17/the-decay-of-spring/

 

*note that Tim Birkhead also falls into the very trap that he describes by using the word promiscuous in the title of his book, a human judgemental term relating to moral behaviour, multiple mating would have been more appropriate.

 

 

 

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It’s never too early to get it right – children’s books can be accurate as well as fun

Making insects more appealing to children, (and adults), by making them look cute, cuddly and more like humans, is not a bad thing in itself, there is however, a line that should not be crossed.

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These two books for children written almost a century apart, are exact opposites. In Sibylle von Olfers’ Etwas von den Wurzelkindern published in 1906, we see the most incredibly detailed and accurate biological drawings.  The insects are pretty much recognizable to

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The Wurzelkindern getting the beetles spruced up for spring

species as are the flowering plants; the grasses are so accurately portrayed that the following conversation occurred on Twitter.

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Two plant scientists are able to discuss the grasses, so accurately are they drawn.

Contrast this with Birgitta Nicolas’ 2009 Der kleine Marienkäfer und seine Freunde.

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Here the insects have four legs*, humanised faces and hands and feet, although to be fair, the bumblebee does have pollen collectors (or is perhaps wearing leg warmers). The plants are heavily stylised and although one can guess at their families, I could not for example decide if the member of the Rosaceae pictured was Prunus, Malus or Pyrus, although being pink. it is most likely meant to be a Prunus.  The language used, despite the Gothic characters in von Olfer’s book, is at the same level, so meant to be read aloud by a parent or puzzled through by a beginner, yet the treatment of the wildlife is so different.  Von Olfers’ charming and accurate illustrations provide a visual treat of exploration and learning, while Nicolas’ heavily stylised daubs rely on the texturing present, i.e. fake fur for the squirrel, fuzzy felt for the bumble bee etc.  What harm would it have done to have at least given the insects the right number of legs and in the right place, all on the thorax.  The bee might also have liked to have had the right number of wings**, I might then have been able to forgive her the humanised faces, it is a story after all 🙂

As Aristotle said “Give me a child until he is seven and I will show you the man.” Early habits die hard and if you learn that insects have four legs as a young child, confusion must ensue and make it harder to learn and retain the truth later on. First perceptions and impressions have a habit of sticking with us in later life, best to get the facts right at the beginning.

So if looking for an insect or natural history themed book for a young relative, I would recommend that you buy Sibylle von Olfer’s book and if your German or Google Translate is not up the job, you can get it in English https://www.amazon.co.uk/Tale-Root-Children-Etwas-Wurzelkindern/dp/3946190146/ref=sr_1_7?ie=UTF8&qid=1462291724&sr=8-7&keywords=etwas+von+den+wurzelkindern

Post script

Whilst clearing the attic in our new house*** in the Languedoc area of France, I came across this edition of Pinocchio published in 1959,

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which as well as bringing back nostalgic memories, I had the same edition as a child, but in English, is a great example of getting the insects right. The keen-eyed of you will notice it has a cricket on the front cover, but unlike the Walt Disney version in which Jiminy is definitely not a cricket, Libico Maraja, the illustrator, had obviously looked at crickets closely and carefully before putting pen to paper.

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Pinocchio meets the talking cricket – he does not have a name in the original version of the story.

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Even when anthropomorphised he still retains essential features such as legs joined to the thorax and complete with tarsi.

*although if you look closely, this insect, which I think is meant to be an aphid, does seem to have six legs 🙂

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**at least the ladybird has elytra and wings 

***our retirement dream house and where I hope to write all the books that I have planned to write over the last twenty-odd years and never got round to doing 

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Entomological classics – The Tullgren (Berlese) Funnel

Although pitfall traps are great tools for getting an idea of what insects are running around on the soil surface or just below it, if you want to really understand the soil fauna you need to dig further down 🙂 There are a number of methods that you can use, sieving and flotation being very common (Southwood & Henderson, 2000). This is generally how entomologists sampled soil arthropods for many years (Greene 1880) despite the extra manual and time-consuming effort needed by the entomologist in addition to the initial digging. A more ‘natural’ and less time-consuming method is to let the arthropods do the work for you. Surprisingly, it was not until the beginning of the 20th Century that an Italian entomologist, Antonio Berlese (1863-1927) came up with a more efficient and easy to use method. In essence he surrounded a 50 cm diameter metal funnel with a water jacket that could be heated,

Berlese Fig 1

Berlese funnel – direct heating version

either directly or indirectly using a Bunsen burner. The funnel was filled with soil or leaf litter and an alcohol filled tube placed at the base of the apparatus. The heat from the water jacket drives the insects and other arthropods down towards the collecting tube where they can be sorted at leisure. A much easier method than sieving and sorting. Berlese was very pleased with

Berlese Fig 2

 

Berlese funnel – indirect heating verison

his invention, and proudly comments “..consumes about three cubic meters of gas per day The above means that at a cost of about a lira I easily get in a day the same number of small animals that ten people with all the attendant discomfort and incredible patience would not be able to collect in the same time* He points out that it is particularly good for collecting Collembola, Symphylids, Thysanurans and Pauropoda.

The first modification of the Berlese funnel was a minor one, that of Swedish entomologist, Ivar Trägårdh (1878-1951), with the water heated by spirit lamps instead of Bunsen burners, which meant that it was much more portable (Trägårdh, 1910).

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First modification of the Berlese funnel, spirit lamps instead of Bunsen burners (Trägårdh, 1910).

The next modification was that of the German entomologist Anton Krausse (1878-1929). His design restricted the heated water jacket to the top part of the apparatus to drive the fauna downwards to the collecting tube and reduce the weight of the system. It was, however, still heated by a Bunsen burner.

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The Krausse modification of the Berlese funnel (taken from Krausse, 1916).

A few years later, a Swedish arachnologist, Albert Tullgren (1874-1958) came up with a major modification, using an electric lamp to heat the surface of the soil or litter sample. The idea being that the drying effect was gradual and unidirectional and allowed the small insects and other invertebrates more time to find their way down to the collecting vessel before they died.

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The Tullgren modification (Tullgren, 1917).

Tullgren points out that his apparatus is much cheaper to make and run. Interestingly, neither Berlese or Tullgren made any attempt to compare the efficiency of their methods for different components of the soil and litter fauna, presumably because they were just interested in collecting rather than comparing habitats. As far as I can tell the first person to compare and test different methods of using the funnels, e.g. having different strength of light bulbs and drying methods was Trägårdh (1933) who also compared different substrates with different initial water contents. Further work in the 1950s by the late, great, Amyan Macfadyen, additionally improved the reliability of the methods and interpretation of the data (MacFadyen, 1953, 1961). The Berlese or Berlese-Tullgren or Tullgren funnel, is now, and has been for over fifty years, an accepted part of the armoury of those studying the smaller members of the litter and soil, although there are a number of designs and descriptions.

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From Smart (1949) Instructions for collectors (my Dad’s edition), here described as the Berlese funnel. The text also suggests that the heat can come from above e.g. a light source or even used outside with the sun ‘beating’ down on to the surface.

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The illustration from Instructions for Collectors (my edition, (Cogan & Smith, 1973)) described in the text as Berlese funnel with Tullgren modification

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Another example, this one from Southwood (1966) with no water jacket and a heating/drying unit at the top, with a light source at the bottom to attract(?) the soil fauna.

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The Tullgren funnel array in use at Harper Adams University – light bulb for scale.

To use the above version you put your soil or litter sample in the upper part of the funnel which is removable, the lamp creates a temperature gradient, according to the manufacturers of approximately 14°C in the soil sample. To avoid the heating and drying effect, the soil arthropods, sieve themselves through the gauze to the collecting tube attached to the base of the funnel. In this version you can adjust the position of the lamp so that the drying process can be either slowed down or quickened up.

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One of my PhD students, Fran Sconce (@FranciscaSconce) with her Tullgren funnels; the happy smile a testament to how much easier they are to use than manual sieving and flotation techniques 🙂

References

Berlese, A. (1905) Apparecchio per raccogliere persto en in gran numero piccoli artopodi. Redia, 2, 85-89.

Cogan, B.H. & Smith, K.G.V. (1973) Instructions for Collectors No 4a Insects, British Museums (Natural History) London

Greene, J. (1880) The Insect Hunter’s Companion: Being Instructions for Collecting and Describing Butterflies, Moths, Beetles, Bees, Flies, Etc.  

Krausse, A. (1916) Ein neuer automatischer Ausleseapparta besonder für terrikole Insekten un Milben. Zeitschrift für Angewandte Entomologie, 3, 303-304

Macfadyen, A. (1953) Notes on methods for the extraction of small soil arthropods. Journal of Animal Ecology, 22, 65-77.

Macfadyen, A. (1961) Improved funnel-type extractors for soil arthropods. Journal of Animal Ecology, 30, 171-184.

Smart, J. (1949) Instructions for Collectors, No 4A Insects, British Museum (Natural History), London.

Southwood, T.R. (1966) Ecological Methods, Chapman & Hall, London

Southwood, T.R.E. & Henderson, P.A. (2000) Ecological Methods, 3rd Edition, Blackwell Science, Oxford.

Trägårdh, I. (1910) Om Berlese’s apparat för snann och effecktiv insamling af små leddjur. Entomologisk Tiddskrift, 31, 35-37

Trägårdh, I. (1933) Methods of automatic collecting for studying the fauna of the soil. Bulletin of Entomological Research, 24, 203-214.

Tullgren, A. (1917) En enkel apprat för automatiskt vittjande av sällgods. Entomologisk Tidskrift. 38, 797-100

 

Post script

Modern Berlese funnels have totally morphed away from the original design and are much easier to use and deploy and store. You can also, very cheaply and easily make your

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 http://www.nhbs.com/title/195607/standard-berlese-funnel-single?bkfno=211231&ca_id=1495&gclid=CK6qyrHgocwCFa0W0wodDcAJ7g

own http://www.carolina.com/teacher-resources/Interactive/constructing-berlese-funnels-study-invertebrate-density-biodiversity/tr19101.tr

 

 

 

*a joint effort by me and Google Translate 

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