Category Archives: Uncategorized

Differences in the shape of wildlife population declines can guide conservation action

Our paper analysing wildlife population declines is just out today in Journal of Applied Ecology!

The Applied Ecologist's blog

In this post Martina Di Fonzo discusses her paper ‘Patterns of mammalian population decline inform conservation action‘ published in Issue 4 of Journal of Applied Ecology, online today.

Wildlife monitoring programmes play a key role in understanding ecological systems and this information forms the basis of many management decisions and conservation actions. Monitoring population declines, in particular, is an important step in tackling biodiversity loss, as severe population reductions anticipate species extinctions.  In our recent paper, we explore how differences in the shape of mammalian wildlife population declines can act as useful trigger points within monitoring programmes, to highlight when and where rapid management intervention is required.

This study builds on our previous analyses, in which we identified three principal decline-curve types of increasing severity: quadratic concave (i.e. recovering), exponential concave (i.e. decelerating), and quadratic convex (i.e. accelerating) decline-curves (Figure A).   In our new study, we investigate whether the presence of different decline-curve types within 85 mammalian population time-series is dependent…

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Blog: Postdoc-ing for Dummies

I really enjoyed reading these tips about how to get the most from a postdoc. Thank you for blogging about this, Natalie!

NATALIE MATOSIN

Feb 2016. It’s been over a year since I submitted my PhD thesis, and I’m finally starting to settle into postdoc shoes. Although I’m feeling relaxed about it now, I look back and realise that I felt very overwhelmed during the transition from PhD to postdoc. It came in waves, where I felt like I was totally on top of things and adapting really quickly to the new work and environment, to feeling like I was completely out of my depth. I had lost my safety net, and was starting to develop a serious case of imposter syndrome.

During one wave of ‘what-the-hell-is-happening-to-me’, I decided it would be helpful to think about what was the purpose of being a postdoc, what I should be aiming to get out of it, and whether I was ticking all things off the “postdoc bucket list”. I found some articles online written by other postdocs, detailing the various issues that they had faced. However I didn’t really…

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New Paper: Historical data as a baseline for gibbon conservation

Thinking back..

A rescued gibbon undergoing rehabilitation at Kalaweit Gibbon Conservation Centre, Kalimantan, Indonesia; Photo by M. Di Fonzo

There are four surviving species of gibbon in China today (eastern hoolock gibbon Hoolock leuconedys; black crested gibbon Nomascus concolor; Hainan gibbon N. hainanus; Cao Vit gibbon N. nasutus), all of which are threatened with extinction.   In order to gain a better understanding of the processes that led to their heightened risk of extinction Sam Turvey, Jennifer Crees and I carried out an analysis of historical gibbon population records found in local Chinese gazetteers, dating back from the 1600s (the ‘Late Imperial’ period) to the present day.

We found that northern and eastern gibbon populations disappeared first, followed by a progressive range contraction towards southwestern China (which is consistent with the ‘contagion model’ of range collapse).  This pattern of loss can be explained by known patterns of regional human population density and demographic expansion during the Late Imperial period. Historically, northern China accommodated higher human population densities, followed by a migration of the ‘Han’ people to areas south of the Yangtze river from the mid-1500s onwards.  Next, there was a westward expansion of people away from areas of high population density in the southeast, which lead to the progressive colonization (and encroachment on gibbon habitat) of the southern uplands by Ming and Qing Dynasty settlers (so-called ‘shed people’).

Our study also highlighted a significant increase in the rate of gibbon population extirpation across China from the second half of the nineteenth century onwards, most likely in response to the well-documented destructive environmental policies and human population explosion that occurred during this period.   Finally, our analyses identified that gibbon populations occurring at lower elevations in China have been more vulnerable to extinction as a result of greater historical human population growth and habitat conversion in these more accessible regions.   In fact, today’s populations are largely restricted to medium/high-elevation montane forests.

In addition to documenting the dynamics of past gibbon extinctions, we hope that our analyses of long-term Chinese gazetteer records can provide some important historical insights to inform conservation management of the country’s highly threatened remnant gibbon populations.

Resscued gibbons in Katimantan, Indonesia

A helping hand; Photo by M. Di Fonzo

Reference: Turvey, S. T., Crees, J. J., and Di Fonzo, M.M.I. Historical data as a baseline for conservation: reconstructing long-term faunal extinction dynamics in Late Imperial–modern China. In press in Proceedings of the Royal Society B.

This study was reviewed by the BBC on 5/08/15:  http://www.bbc.com/news/science-environment-33776466

Dealing with overdispersion in ecological data

Jonathan Rhodes describes his new book chapter on “Dealing with overdispersion in ecological data”.

Rhodes Conservation Research Group

Check out my chapter in Gordon Fox, Simoneta Negrete-Yankelevich, and Vinicio Sosa’s new ecological statistics book.

MATLAB Handle Graphics Zero-inflated data

Ecological data rarely meet the assumptions of the standard probably distributions that are used in most statistical models – in particular, our data are often overdispersed (that is, the variance of our data is higher than can be acommodated by standard distributions). One particularly common source of overdispersion is zero-inflation where our data have too many zeros. See a previous paper of ours on zero-inflation here. But how do we deal with these types of non-standard data issues!

In this chapter I address this by focussing on how we can use mixture models (which are combinations of two or more probability distributions) to deal with the general issue of overdispersion. I demonstrate that, not only can mixture models help to account for overdispersion, but they are also very useful for…

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10 best reviewer comments in meme: part 2

Very funny memes – especially while in the middle of responding to reviewer comments on two papers at once! Thank you for collecting these, Kiran…

The testy toad

As a follow on from my earlier post entitled “10 best reviewer comments in meme” and after having myself gotten some reviewer comments back last week, I would like to present 10 more memes from the website Sh*t my reviewer say. Enjoy!

1. Reject – More holes than my grandad’s string vest!

hgg15

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