james h c fenton
WWW.FENTON.SCOT
REWILDING
Herbivores
at the core of
ecological
processes
I have just finished reading the book Rewilding by Paul Jepson & Cain Blythe (the
illustrated edition, Icon Books 2021). It makes one rethink one’s whole
understanding of terrestrial ecology. In summary, the book concludes that large
herbivores have a major role to play in shaping the vegetation pattern across
landscapes. However, because over much of the planet we have made large
herbivores extinct, the current ecosystems we see as ‘natural’ are in fact no such
thing. The book says that ‘rewilding’ should be about bringing back large
herbivores to ecosystems, and thereafter allowing them to develop naturally;
allowing the natural processes which have largely been lost.
“Advances in ecological science have firmly positioned herbivores at the
core of processes that produce vibrant ecosystems across all scales from
the local to the planetary.” [page 137]
In relation to this, I have noticed a contradiction in the approach taken to
rewilding in the Scottish Highlands to that promulgated elsewhere in Europe: in
most of Europe rewilding is about reintroducing large herbivores, whereas in the
Highlands it is about removing them – or at least making them functionally
extinct. I have argued for quite a few years that the vegetation pattern of the
Highlands is one of the most natural remaining in Europe because the area
retained a significant population of large herbivores (red deer) throughout the
postglacial period; and for most of postglacial history the herds were unmanaged
(although hunted), as described in my recent paper. Where else in Europe is this
true?
I have one cavil with the book, though, and that is that it does not recognise this
contradiction between the Highlands and elsewhere. The book, in passing, accepts
the narrative that high densities of deer in the Highlands are caused by the
‘hunting estate model’, and that there are too many deer as evidenced by the
absence of trees. This seems to be an aberration that goes against everything else
the book is saying!
I would argue that reducing deer numbers for the sake of encouraging trees is not
‘rewilding’ as defined in the book, but instead it is humans expressing their will on
the landscape to make the vegetation pattern accord with what ‘should’ be there.
It is the opposite of ‘self-willed land’ and could almost be called ‘dewilding’. In the
same way that the commonly used phrase ‘natural regeneration’ is based on ‘non-
natural’ levels of grazing (by making herbivores functionally extinct); what is
natural about this?
The point is in effect illustrated in the book: it quotes research [page 83]
suggesting that one area of Arctic Russia would have hosted a rich megafauna,
with 1 sq km of land supporting:
1 mammoth
5 bison
7.5 horses
15 reindeer
0.25 lions
1 wolf
This is mind boggling! – especially when compared with the measly 3-4 red
deer/sq km being promoted by conservationists in the Highlands (low enough to
encourage trees). My latest paper argues that, in fact, herbivore density is
determined by food availability, and that upland vegetation in Scotland can support
an order of magnitude more grazing than the exceedingly low level that enables
trees to survive in the landscape. Hence the open landscape (too simple?!).
March 2023
Dr James Fenton, Seil Island, Scotland
www.fenton.scot ecology@fenton.scot
Web design by James Fenton
Xara Web Designer Coyright 2023
*NEW*
January 2023
A Field Guide to Ice
Click here for details
*NEW*
January 2023
The role of grazing
in maintaining
open landscapes in
temperate regions
Click here for details