27 November 2014

The things we leave behind



Sometimes I wonder what people would be able to deduce about me from looking at my office. If someone came in snooping I'm sure that they would get some understanding of me, even if I was absent, simply by looking at what I leave behind. Of course there are some obvious things. I have what I like to think of as a typical academic's office, messy, possibly chaotic, a sense of personality, perhaps a sense of busy work. Of course not all academics are like this but there are plenty who are, like one of my corridor neighbours Tim Curran. Another neighbour, John Marris, has an immaculate office with everything in its place but, then, he is the curator of our entomology museum and so being precise and particular comes with the territory. Another neighbour, James Ross, also has a extremely tidy office. He is a regular academic, so no real excuse, and I find entering his office quite daunting. There is certainly some reflection of their offices into how they run the rest of their lives.
Adrian's office - typical academic?

Turning to my office in more detail, such a snoop might gaze at my desk. At first glance (and at multiple glances really) there are many chaotic piles of paper. Perhaps evidence of a person that can multi-task and perhaps they use chronological filing? There is a pile of documents on new course development administration, another with an attempt to write a children's story on insect identification, still another of recent papers (on explanatory power in ecology, self-immolation in plants, evolution of sex chromosomes, convergence of lizard morphology on islands and getting DNA from possums), and another with an odd collection of names of potential candidates for the Canterbury Country Under 15 cricket team, Adrian's postgrad students monthly funding, a design for next year's research methods course and a document about the appraisal of the local primary school principal. What would my snoop make of these? Perhaps that Adrian spends a lot of time on teaching committees, perhaps has had kids and likes to write, has a wide range of research interests, is involved in cricket coaching, supervises postgrad research, is proactive about getting ready to teach a course 3 months away, and is involved in governance at the local school. All correct. Looking closer they might observe some D and D dice (so a nerd!) and a dinosaur (so a science nerd!). Looking around my room the snoop would see from my posters that I have an interest in movies and Darwin and my books and 'toys' would confirm it.

As individuals move through the world they interact with other individuals and other elements of their environment. Every interaction leaves something behind, whether intangible, say a memory, or tangible, say a footprint. Individuals are constantly leaving clues about themselves behind. This is one of the reasons that we are uncomfortable with our new online existence, how it is possible for anyone with the right access to know almost everything about you! Of course, there is something even more personal that you leave behind you everywhere you go - your DNA. We live in a sea of DNA. Every living thing around you has DNA. All of the cells that you are constantly shedding have DNA. The DNA ranges from fully functioning in living cells to various states of decay in nonliving cells. Everything you touch, everywhere you breathe, leaves behind DNA. Most times this is in very low quantities but this can still be detectable. One of my students just found that in a few ml of seawater taken at a local shore that we could detect shark and seahorse species that are swimming about in the area! (More on that at a future time) Because of the presence of this sea of genetic material, DNA is a great potential resource for ecologists and conservationists.
A waxtag, complete with possum bites, saliva and DNA

As ecologists we often deal with animals that are difficult to find or detect. Usually, we want to monitor populations to find out if they are increasing, moving, changing in age structure and so on. For many species this is difficult. They might be nocturnal, or cryptic, or in tough terrain, or small, or dangerous, or - well you get the picture. Being able to detect where individuals have been (even if they have moved on now) is a very useful ability. We have cameras that detect motion, tracking tunnels that record footprints in ink, GPS collars that can be attached to an individual and then followed. These are all useful methods. Here at Lincoln we do a lot of work on possum behaviour. One method for inferring possum presence is to put out waxtags which possums happily bite and leave tooth marks on. We can collect these up and know that at least one possum came past and bit the tag. Sometimes we would like more precision. We want to know how many possums came past and bit the tag. Were they males or females? The bites don't tell us that kind of information. However, the possums leave more than just the bite marks, they also leave DNA that is present in their saliva.

In a new study by masters student Juan Duenas, with James Ross and Rob Cruickshank, just published in New Zealand Journal of Ecology, it is confirmed that possum DNA can be collected from saliva on waxtags. More impressively, enough microsatellites (highly variable areas of DNA) can be distinguished to identify individuals (a kind of genetic fingerprinting). The DNA doesn't come easily though as it quickly starts to degrade in the saliva and then on the waxtag itself. The tags were bitten by possums at some point during the night of collection and their DNA was only just good enough, condition-wise, in the morning to actually be decoded. Still, this is a good step forward, we can use the DNA that possums leave behind to find out how many individuals are in an area, where they might have moved into the area from and what the sex ratio might be. This is all information that is very difficult and labour intensive to collect otherwise. The DNA that organisms leave behind is becoming a very powerful tool for understanding the private lives of these individuals. I wonder if my snoop has a DNA kit....

20 November 2014

Rowan Emberson: entomologist

Rowan Emberson has been awarded a Lincoln Medal for his services to entomology. Rowan was a senior lecturer in the department when I first started at Lincoln University. He became a valued colleague with several shared postgraduate students that we supervised. To me, Rowan is one of the last gentlemen entomologists. He is always, precise, well-mannered and well-spoken. To a farmboy from Balclutha this was a new experience and Rowan become a role-model, not just for me but also for a couple of generations of New Zealand-trained entomologists who were influenced by Rowan’s quiet but determined ways. Even after his retirement in the early 2000s he remained an important fellow researcher, especially with our work on the Chatham Islands biota. The following is taken from his nomination.
John Begg, Rowan, Hamish Campbell and Steve Trewick in the Tuku,
Chatham Island

Rowan Emberson became a Lecturer in Entomology at Lincoln College in late 1968. Rowan spent his entire working career of 33 years at Lincoln College/University, including a period as acting Head of Department. Since his retirement in 2002 he has continued his association with the university as an Honorary Senior Lecturer. Rowan has continued to advise many of the entomology postgraduates at Lincoln University over the last decade for both the Department of Ecology and the Bioprotection Centre.

Rowan graduated from Edinburgh University with a degree in forestry, writing his honours dissertation on mesostigmatid mites in soils in ancient pine forest. This led to further study of soil inhabiting mesostigmata for a PhD at McGill University in Montreal, Canada with Professor Keith Kevan. During the last year of his PhD studies, Rowan taught an entomology course at Sir George Williams University in Montreal.

In his first years at Lincoln, Rowan’s research concentrated on mites and beetles, especially Carabidae and Scarabaeidae, and he accumulated a broad knowledge of the New Zealand Coleoptera fauna. Rowan was involved in many ecological surveys, often in partnership with postgraduate students. One major project was documenting the Chatham Island beetle fauna for conservation purposes, which later led to collaboration with geologists on a project to determine the age of the Chatham Islands.
Rowan on a beetle hunt on southern Main Chatham Island.

Rowan, in conjunction with Professor Roy Harrison, established a Lincoln University insect collection in the late 1960s, which became the basis of the Entomology Research Museum (LUNZ). The collection is one of the largest and most diverse insect collections in the country. It is widely used by students and researchers and contains type material of many New Zealand species. The collection was built up in a series of annual summer field trips to different locations from North Cape to Stewart Island that persisted until 1991. Rowan spent considerable time throughout his career, in weekends and holidays, collecting samples to increase the collection.

Rowan’s research interests were broadened through supervising student projects in agricultural entomology. He developed a particular interest in how pest and beneficial insects have adapted to the New Zealand environment. Many of his students have gone on to play important roles in New Zealand’s bioprotection area.
Rowan named numerous species and had a dozen named in his honor.

Rowan has been an active supporter of the Entomological Society of New Zealand, serving as President from 1993–95. With Dr Eric Scott, Rowan compiled the ‘Handbook of New Zealand Insect Names’ and for a number of years prepared submissions on behalf of the Society to the Environmental Risk Management Authority on proposed new introductions. Rowan served on the Westland/West Coast National Parks Board for a number of years.

In his retirement, Rowan has continued to work in the entomology area. He followed up on his studies of the New Zealand and UK faunas of Macrochelidae with a revised classification of the family, which is now widely used internationally by researchers using these mites for control of nuisance flies. Rowan has spent much of the last decade working with Department of Conservation surveying invertebrate diversity for tenure reviews in areas like the Murchison Mountains, Bankside and Coopers Knob. Rowan has also continued his interest in dung beetles, through collaboration in research projects in Thailand and Nigeria. Further, Rowan’s expertise is still being put to good use as a member of the editorial board of the Fauna of New Zealand.

Congratulations to Rowan. This is a well-earned honour.
Always searching!

A small selection of some of Rowan’s 84 papers:

Emberson, RM. 1973: Macrochelid mites in New Zealand (Acarina: Mesostigmata: Macrochelidae). New Zealand Entomologist, 5(2): 118–127.

Emberson, RM. 1995: The Chatham Islands beetle fauna and the age of separation of the Chatham Islands from New Zealand. New Zealand Entomologist, 18: 1–7.

Emberson, RM. 1998: The size and shape of the New Zealand insect fauna, pp. 31–37 in Ecosystems, Entomology and Plants. Proceedings of a Symposium held at Lincoln University to mark the retirement of Bryony Macmillan, John Dugdale, Peter Wardle, and Brian Molloy. The Royal Society of New Zealand. Miscellaneous series 48: 1–143.

Hanboonsong, Y., Chunram, S., Pimpasalee, S., Emberson, RM., Masomoto, K. 1999: The dung beetle fauna (Coleoptera: Scarabaeidae) of Northeast Thailand. Elytra, 27: 463–469.

Scott, RR., Emberson, RM. 1999: Handbook of New Zealand Insect Names: common and scientific names for insects and allied organisms. Bulletin of the Entomological Society of New Zealand, 12: 1–97.

Brown, B., Emberson, RM., Paterson, AM. 2000: Morphological character evolution in hepialid moths (Lepidoptera: Hepialidae) from New Zealand. Biological Journal of the Linnean Society, 69: 383–397.

Emberson, RM. 2010: A reappraisal of some basal lineages of the family Macrochelidae, with the description of a new genus (Acarina: Mesostigmata). Zootaxa 2501: 37–53.

Leschen, RAB., Marris, JWM., Emberson, RM. , Nunn, J., Hitchmough, RA., Stringer, IAN. 2012: The conservation status of New Zealand Coleoptera. New Zealand Entomologist 35: 91–98.

03 November 2014

The answer is blowing in the wind

It is springtime here in Canterbury. That means lambs are frolicking in the fields, cricketers are filling our domains, we go from 12C, three days ago, to 26C days, yesterday. Mostly, the wind has returned (although it never really goes away). Lincoln is a windy place. Our supermarket has windmills in the parking lot! With all of that wind, pollen levels are off the charts as they waft about. It was so windy yesterday that my father-in-law's hearing aid blew away while he was out walking and never seen again! While the wind can cause issues; itchy eyes, storms that knock down trees, slow trips home on the bike, it can also provide benefits; dried laundry, drift on an arm ball, fast trips to work. Perhaps living in a windy environment accustoms one to thinking about how wind can help in moving things about. If you are a species that flies, especially if you are small, then the wind is going to influence how easy it is to move in certain directions. Even organisms that have no wings can still be affected by wind.

Tussock grasslands on top of the Lammerlaw Range
I have worked a lot with spider species. Spiders do not have wings but their distributions are still influenced by wind. In many spider species the young use a line of silk that they produce to lift themselves off the ground in a process known as ballooning. On a warm day, the silk line drifts upwards and lifts the spiderling off the ground. The wind does the rest. At some point the spiderling returns to earth after a short trip.

Another consequence of living in a windy environment is that the local habitats dry out and become prone to fires. A couple of summers ago we had a major fire that burnt out of control through the shelter belts near Lincoln, stopping just a couple of kilometres from the University. We are looking at another dry summer this year. It has been interesting watching what has grown in the areas that were burnt. Usually the plants that have returned are not necessarily the same as those that were there before. Sometimes it depends on what seeds/plants survived the fire but often it depends on which seeds have turned up from outside the burned area. One can ask the question of whether there are certain types of traits that allow some species to colonise first. Being able to be moved by wind could be an important trait. In addition to the plants, we also might want to know about the animals and how they respond to these crises, especially the invertebrates.
Spiders are important predators in most habitats.

Fires are not particularly common in New Zealand, but one area where they can occur in the montane grassland zone. Tussock grasslands tend to be in dry parts of New Zealand where fires can be natural (lightning), accidental (camp fires) or deliberate (set by farmers managing pasture). As more of these areas are transferred into conservation land, it is important that we understand the effects of fire. A great opportunity to study this has been available in the Deep Stream area of east Otago (about an hour inland from Dunedin). This area has never been cultivated and had not been burned for at least 30 years before our study began. Areas were selected to be either burnt in spring or summer as well as control areas with no burning. Invertebrate diversity was then measured in these areas for the three years before burning and four years after burning to examine the effect of fire and the timing of the fire on these populations. We were particularly interested in what happened to the spider communities. Spiders are top predators in these systems and can tell us a lot about the health of these ecosystems. If there are a lot of spiders about then there must be a lot of spider food species.
Jagoba sampling spiders in a cool and windy habitat.

My former PhD student, Jagoba Malumbres Olarte, worked closely with researchers from AgResearch, especially Barbara Barratt, in collecting spiders from pitfall traps and by digging out whole tussock plants and extracting spiders in a Tullgren funnel. The outcome of this work has been published in the journal Biological Invasions. Jagoba found over 4500 spiders in the seven years of samples and sorted them into 66 species and 22 families. Ten of these species were exotic (not native to New Zealand) and increased markedly in the burned samples while native species had significantly less resilience. This is a real concern as it suggests that one reason that introduced species can take over a habitat is because they are better at colonising and establishing after a crisis. Jagoba also looked at some of the traits that might explain the advantage of exotic species. Whether a species could balloon was important for colonising after summer burns. Exotic species tend to be good ballooners and can easily waft into burnt habitats from elsewhere. Jagoba also found that large spiders were able to colonise burnt habitats more easily after both summer and spring burns. This may because larger spiders find it safer to walk through the landscape compared to smaller species. Many of the exotic species, especially the Linyphiids, are large. So the wind does help species move about and gives exotic spider species an advantage over natives. One unintended outcome of burning native grasslands is that this provides exotic species with a way into these areas to colonise and then dominate, reducing the local native diversity. More worryingly, any crisis that impacts on an area, say landslides, floods, human modifications, will result in the same benefits for these ballooning, large, exotic spiders. The answer to why introduced species do so well in New Zealand really is blowing in the wind.