“Wolves and wildcats: late-Quaternary mammalian response to abrupt
climate change”
A review of a seminar by Prof. Danielle Schreve
Professor Danielle Schreve from
Royal Holloway University
recently presented a seminar at University College London. The talk addressed concepts of 'disharmonious faunas'
and vertebrate response to late-Quaternary climate
change, before moving on to findings from a cave in Ebbor Gorge, Somerset. Since the cave’s
discovery, over 100 tonnes of material have been removed, most of which was put
through a 500μm (micron) sieve. This allowed the extraction of faunal
remains including: reptiles, birds and molluscs. Some of the species at this site may have
existed in environments that they were less adapted to. Animal remains from this cave may provide
clues into the timing of different species presence in Britain towards the end
of the last Ice Age,
and their reaction to abrupt changes in climate. This review will begin to
discuss some of the findings so far as presented by Professor Schreve.
Species found in the cave included a mixture of animals that exist
in Britain today, and some which now possess a very different range.
This really highlights the effect of climatic and environmental
changes on species distribution.
Some of the animals found in the cave included:
(1) Species here today: water vole, wood mouse and
pygmy shrew.
(2) Present in Britain, but not in this area: mountain hare, common vole.
(3) Extant, but not in Britain:
collared lemming, steppe lemming, narrow-skulled vole.
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The collared lemming has
already been discussed in a previous post: Brace et al (2012).
This site provides a great example of how this species, and others have changed
their distribution during the late-Quaternary. Prof. Schreve
highlighted that the collared lemming, Norway lemming and steppe lemming now possess circumpolar, Scandinavian, and Siberian
distributions, respectively. However, at Ebbor Gorge, the cave shows evidence (from
raptor pellets) that all species existed at this site, in the UK, during
the same time period. Similarly, there are changes in some of the larger mammals.
For example, there was a turnover between the stadial (more cold-adapted) Arctic fox to the interstadial (more warm-adapted) red fox, immediately before the end of
the last Ice Age. Clearly, the Arctic fox currently lives at high-latitudes, in regions of Arctic tundra, and is not adapted to the current interglacial climate,
giving a great example of just how recently fauna in the UK has changed.
Red fox (left) and Arctic fox (right)
Evidence for hominins?
Prof. Schreve suggested that in terms of humans there was currently not solid
evidence of their existence at the site in the Lateglacial sediments. Still, a
number of remains have shown signs of bone marrow extraction, as well as
indication of burning through discolouration. This may be evidence of hominin presence at the cave site. However, the recent discovery of a struck flint artefact
in older deposits indicates
the presence of hominins at some point in the past, though the precise dating has
not yet been confirmed.
In all, this cave provides a great
record for late-Quaternary
environmental change, and associated faunal
turnover. Though, as of yet it is not yet clear how far back the cave goes-
Professor Schreve said that:
"The site offers a unique perspective on mammalian responses to abrupt
climate change at the end of the last Ice Age and we've been overwhelmed by the richness of the fossil remains. The next stages of the research will be to explore
deeper into the sediments and get a
firm handle on the age of the oldest finds through radiocarbon dating".
This cave provides a fantastic example
of the variety and turnover of fauna
within Britain during the last ice age. So far in this blog we have discussed extinctions, the role of
humans and the migration of animals within Europe during previous glacial cycles. This cave has the
potential to give some great insight into late-Quaternary fauna, and it will be
exciting to see how it develops in the future!
Many thanks to Professor Schreve for allowing me to write up her seminar.
Many thanks for your post, Emma. A very stimulating read and it sounds like a great seminar. Is there a delay/lag time between the change in climate and the associated mammalian response, and if so, could we use that 'response time' to predict how fauna might respond to future climatic change? I would be very interested to hear from you.
ReplyDeleteHi Dan!
DeleteSo a lot of animals will show a lag with climate, plus many areas act as refugia from abrupt changes. If this is the case, fauna may survive well into environmental conditions that they are would not usually be adapted to. Although the radiocarbon dating will help identify the nature of this response, the ages have not yet been determined as the site is not published. All of this will start to come to light when the researchers publish their findings.
Though, i think you make a very good point. Animal response to climate change, especially with those species that are still around today, will be a great indicator of how fauna will respond in the future!
Thanks for the comment!!
Another well written and fascinating article! The way in which this particular article is structured has really helped me to thoroughly understand the subject. I was also very interested by how relatively recent the shifts in fauna have occurred, and the ways in which this is explained through on-going observation. Will the use of radiocarbon dating be able to further specify the presence of hominins, or is this just looking into the over-arching time period of the cave itself?
ReplyDeleteI look forward to reading more on this topic!
Hi! Thanks for the comment i am glad that you could follow it, it's an interesting topic! So, if the age is quantified for the artefact this will help attribute the object to the hominin group responsible for it. E.g. Neanderthals/ humans. Radiocarbon is a great dating method and it's half life can be detected for around 50,000 years (which is why it is so useful for this time period) allowing the object to be dated and calibrated, so that it can be attributed to a certain point in time. If the age of this object is determined, it will be useful in interpreting any other evidence of hominins that may be found in the cave!
DeleteAnother article that I have enjoyed. I look forward to hearing more!!
ReplyDeleteThanks for the lovely comment! Still many more to come.
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