Our ability to conserve and protect wildlife is at risk because we areunable to accurately gauge how our environment is changing over time,says new research out today in Conservation Letters.
The study shows that people may not realise species are declining allaround them, or that their local environment may have changeddramatically since their parents' and grandparents' days, and even intheir own lifetime.
This could be bad news for conservation projects, because if people donot perceive there to be any degradation of the world around them, theymay be less willing to engage in activities to conserve and protect theenvironment.
The new study provides the first evidence of so-called 'shiftingbaseline syndrome' - a conservation theory which says that people'sperception of the environment is determined by what they see now, withtheir own eyes, and does not take into account what things were like inthe past.
To test the theory scientists carried out a survey in the village ofCherry Burton, Yorkshire, to examine whether people were aware ofchanges in local bird populations over the last two decades. Theresearchers asked 50 village residents what they thought the three mostcommon birds in the village were 20 years ago, and more recently, in2006. Their answers were rated according to how close they came togetting the three most common birds correct for both dates, which werethe wood pigeon, feral pigeon and starling in the earlier period, and in2006 were the wood pigeon, blackbird and starling.
In addition, villagers were asked to say whether they thoughtpopulations of four easily recognisable birds - sparrows, starlings,bluetits and wood pigeons - had increased or declined in the village inthe last 20 years. In reality, numbers of sparrows and starlings havedeclined in the area over this period, whilst wood pigeons and blue titshave increased.
The results showed that older people could more accurately name thethree most common species in the past, whereas young and old residentswere equally accurate when it came to naming the current common species.This indicates that all villagers are equally knowledgeable about thecurrent state of bird populations, but that younger members of thecommunity are less aware of past changes. Additionally, people whothought that there had been no change in bird populations were morelikely to name birds that are common now, rather than those which weremore common in the past.
For three of the four species, the house sparrow, starling and woodpigeon, the accuracy with which villagers were able to judge whethernumbers of these birds had gone up or down increased with age, showingagain that younger people were less able to accurately recognise howpopulations had changed over time.
These results suggest that wildlife knowledge is not being passed onfrom older to younger people, resulting in 'generational amnesia' wherewhat is perceived as 'normal' by younger residents may in fact be quitedifferent from circumstances a couple of decades ago. The study alsoprovides evidence for the potential importance of 'personal amnesia'where people assume that what they see now is how the world has alwaysbeen.
Sarah Papworth, a PhD student in Imperial College London's Department ofLife Sciences, lead author of the paper, explains: "Our survey resultsindicate that the baseline has shifted in this village: in the course ofa generation, changes in bird populations have been collectively'forgotten' by the community. If this trend continues, this knowledgewill be lost altogether in a couple more generations, and people willhave little idea that their local wildlife was ever any different towhat they see today with their own eyes."
Ms Papworth and her colleagues say that if shifting baseline syndrome isoccurring in relation to bird populations in this Yorkshire village,then it is likely to be occurring in other areas, and in relation toother species and ecosystems too. This is a worry because it meanspeople will more readily accept a degraded environment, if they do notknow things were any better in the past.
Professor E.J. Milner-Gulland, also from Imperial's Department of LifeSciences, co-author of the paper, says that action should be taken tonow to ensure that community members keep themselves up to date withchanges in their environments:
"This could involve encouraging younger members to talk to their eldersabout what their local area was like only a few years ago, or usinghistorical accounts or old photographs to demonstrate changes visually.If we don't do this, then we risk sleepwalking through the degradationof our natural world, without realising what we are losing," she said.
In the meantime, she adds, conservationists may have to take shiftingbaseline syndrome into account when planning activities:
"It is more and more common for people to use local residents'recollections alongside traditional scientific methods when compilingdata on changes in biodiversity over the years. This is a great way toengage local people with conservation and use their valuable knowledge.It's particularly useful in many parts of the world where there has beenno previous scientific monitoring.
"However we do need to be careful to bear in mind that individual andcollective memories of previous environmental conditions can be warpedby time. Nothing can replace long-term independent monitoring ofbiodiversity trends in providing us with a baseline for conservationaction," she concludes.
Source: Imperial College London