This morning I started the first in a series of weekly two-hour seminar sessions with my final year undergraduate students on their Biodiversity and Conservation module. By this stage in their BSc programme the students are being weaned off lectures and being encouraged to take a more critical perspective on the published scientific literature. Each week we deal with a specific issue relating to biodiversity such as: measuring biodiversity; current trends; spatial patterns; biodiversity and ecosystem services; and how much is there still to discover about biodiversity?
This morning we focused on the Living Planet Report 2016, the latest installment of an annual assessment of the rate and extent to which we are losing animals across the globe. The report, which came out last month, generated a lot of media attention with headlines such as “World wildlife falls by 58% in 40 years” and “World on track to lose two-thirds of wild animals by 2020“.
As preparation for the seminar I asked the students to read the first chapter of the report and then during the session I divided them into groups of three in order to take stock* of the report and answer a series of questions such as:
What do you understand by the “Anthropocene”?
What do you understand by the “Living Planet Index” (LPI)?
How do the LPIs vary across the planet and across taxonomic groups?
What is the evidence base for these trends?
Which LPIs show the greatest declines and which LPIs show the least declines? Can you account for these patterns?
Which LPI trend do you consider to be the most worrying, and why?
By way of a counter-point to the media hype, and to consider one potential area of criticism of the report, I also ask the students to look at critiques written by Simon Leather (You don’t need charismatic megafauna to go on an exciting safari) and Ryan Clarke (What about the little things?). In both of these posts the bloggers take the report to task by pointing out that it ignores the vast majority of animal life, i.e. invertebrates such as insects, crustaceans, and so forth.
Simon and Ryan have a valid point, of course, but the fact of the matter is that we simply don’t have the same quality of long-term population data for invertebrates as we do for birds, mammals, fish, reptiles and amphibians. The exception to that is the butterflies which the Living Planet Report does discuss, devoting a whole page to grassland butterflies. It also states (p20) that “Methods to incorporate invertebrates and plants are now in development”.
Although the hype around the report is a bit over the top, nonetheless this focus on the best possible data sets does emphasise the fact that the world’s biodiversity is declining in species richness and abundance. The final question I ask the students is whether, in their opinion, we on the verge of a “Sixth Mass Extinction” (as the report suggests). A show of hands at the end showed that about half think “yes”, a quarter think “no”; and a quarter (myself included) said “we don’t know”. It was a nice demonstration of the complexities around coming to any kind of consensus when it comes to reports such as this.
All-in-all it was a great session, the students really engaged with it and raised some very interesting points. I’m looking forward to the rest of these seminars, they promise to be very stimulating.
*Before anyone comments, yes, I know that the photo shows a pillory not a set of stocks. But we don’t have a set of stocks at the university, only a pillory. Exactly why we have a pillory on campus is another matter…..