As with, I suspect, an embarrassingly high number of scientific papers this one was conceived over a mug of something warm and caffeinated, but unlike most of my other publications I finally have something charismatic to talk about!

Whales are big news (pun intended), and the commercial hunting of whales is a sensitive and emotive topic, with what could probably be described as a collective embarrassment regarding the mass slaughter carried out during the 20^th centaury, and subsequent collapse of global whale populations. However a by-product of this generally frowned upon practice – and some frankly anally retentive bookkeeping – is an exceptional and unique record of the whales caught during this period. The International Whaling Commission required a record of all whales hunted, the approximate location of their capture, as well as details on their size to be noted down. The net result is a staggering record of over 2.8 million individual whales harvested from 1900 onwards.

Now the reason I know all of that is because of that caffeinated beverage in a small café in Hobart, during a visit to the University of Tasmania’s Institute of Marine and Antarctic Research. The idea behind the visit was to test the effectiveness of a method for predicting population declines that incorporated classic abundance based early warning signals^1,2 along side shifts in trait dynamics³ on data from real-world population collapses. Our original intention was to simulate population collapses due to overharvesting and look for early warning signals (EWSs) before the collapses occurred. However one of the key aims of EWSs is to make them applicable to species of conservation interest, and whilst brainstorming the best way to approach this we realized that data might already exist which would allow us to test these methods – data that describe the dynamics of populations prior to documented collapses, that include information on the body size of individuals. And thus this Nature Ecology & Evolution paper was born – where we identify both abundance based and trait-based EWSs up to 40 years prior to the collapse of whale populations.

For me a few really interesting secondary results came out of this. The first was the sheer scale of the whaling effort during the 20^th centaury – at its peak over 30,000 Blue whales were removed in a single year, with similar peaks seen in the other three species we looked at. So perhaps it shouldn’t have been as surprising as it was to see dramatic changes in the body size of these whale populations – a decline of over 4m in Sperm whales caught over a 80 year period. What is fascinating to me is the interaction between the ecology of each species and the techniques developed to hunt whales, and how this impacts the trend in body size over time; Sperm whales decline in size consistently through time, probably because they are relatively slow moving, where as for faster species landed body sizes initially increase (in line with technological advancement⁴) and then decline as all the large individuals are removed.

This paper felt in many ways cathartic – that we can use this data from a barbaric period of commercial excess to develop and test methods that might be applied to the current diversity crisis feels good. And whilst we are still a long way from making perfect predictions about the fate of biodiversity in the Anthropocene, every step towards this goal helps.

The paper in Nature Ecology & Evolution is here:

http://go.nature.com/2skjWUY

This paper was made possible by a Swiss National Science Foundation International Short visits grant, and an ERC Starting grant (#337785) to A.O

References

1. Dakos, V. et al. Methods for detecting early warnings of critical transitions in time series illustrated using simulated ecological data. PLoS One 7, e41010 (2012).
2. Scheffer, M. et al. Early-warning signals for critical transitions. Nature 461, 53–9 (2009).
3. Clements, C. F. & Ozgul, A. Including trait-based early warning signals helps predict population collapse. Nat. Commun. 7, 10984 (2016).
4. Basberg, B. L. Technological change in the Norwegian whaling industry. Res. Policy 11, 163–171 (1982).

Our formidable team of biodemographers and associates, The Residuals, conquered yet another 114km-long SOLA race around Zurich.

Big thanks to our captain, Omar, for the great organisation!

written by Megan

My name is Megan, and I was an intern in this lab over the summer in the Biology Undergraduate Summer School, or BUSS program. That’s a very simple way of summing up all the amazing experiences I had thanks to the program and my host lab, and I think it would be best to start this blog post by talking about the BUSS program itself.

The BUSS program aims to unite students from all over the world with varying levels of experience in different biological fields to teach them new and exciting things. It was inspirational to witness the kind of devotion amongst all the people I had the pleasure to meet. The program allowed me to learn about topics from various fields, especially those outside of what I was used to. Seminars, retreats, and interactions with some of the top researchers reminded me of why I enjoy science so much. I was guided through by these amazing mentors as well as my peers who attended the program with me and the two months went by very quickly.

 
Zürich in summer (photos taken by Megan)

I worked with Koen van Benthem in theoretical biology on modelling techniques and gained new skills in different programming languages, practiced giving scientific presentations, and even learned to LaTex. My project itself was working on increasing the biological significance of Inverse Integral Projection models which use maximum likelihood to estimate parameters such as survival and growth within populations. As always, it was difficult to get started on a new project, but my host lab was very supportive. I learned many techniques and got to discover what theoreticians do. I also got to hear about all the things the other members of the lab do; and they’re all truly extraordinary people who really care about their work. Perhaps most importantly, it was very obvious to me that this lab works well as a unit. There was so much friendship and it was a wonderful environment; that’s an extremely important thing when you’re learning.

Altogether it was an extraordinary experience, and thank you to all who allowed me to come here and took the time to make feel so welcome.

Click the BUSS logo for more information on the program

As researchers and conservationists, a key component of our work is to make our research findings accessible to everybody and engage with the general public. This is particularly important for sensitive and ‘political’ topics such as the recolonisation of the Swiss territory by large carnivores.

Gabriele talks to adults and children about his work on bears in Turkey and wolves in Switzerland, as part of the Grimm’s special exhibition organised by the Zürich Zoological Museum. If you are keen to learn more and talk to Gabriele, do not miss the next opportunity on Sunday 29th January 2017 at 11:30 in the museum main building.