The finale of Planet Earth II was fantastic – but most species can't hack city living

Singapore's Gardens by the Bay nature reserve. Image: BBC.

The grand finale of the BBC’s Planet Earth II showcased the ingenious strategies that some animals use to thrive in urban environments. Though impressive, these species are in the minority. As the number of people living in cities around the world continues to rise, we should really be turning our attention to those animals that find city living too hard to handle.

Urbanisation represents the most extreme form of habitat loss for most plants and animals. As towns and cities grow, human beings live together in higher densities, and natural habitat is removed and replaced with hard, impermeable structures such as roads and buildings. Harmful pollution increases, as does the noise from industry and traffic, the amount of artificial lighting and the number of introduced predators such as cats.

As remaining pockets of natural or semi-natural habitat (such as remnant native habitat or man-made parks) become more isolated, city-dwelling animals are prevented from venturing out to look for food, resting places or mates, or may risk dying in the attempt. All together, these changes make cities impossible places for many species to live in.

Life in the urban jungle

Typically, we find a lower variety of plants and animals in more built-up areas; and this applies to all groups of wildlife. In a recent global study, researchers estimated that cities accommodate only 8 per cent of the bird species and 25 per cent of the plants that would have lived in those areas prior to urban development. As a vertebrate’s territory becomes more urban, it’s also more likely to be threatened with extinction. In fact, it’s estimated that urban development is responsible for the listing of 420 vertebrate species around the planet as threatened.

It’s the generalist, opportunistic species such as foxes and rats – and, as we see on the programme, some monkeys – which can adapt to a wide variety of environmental conditions. By contrast, creatures that require large areas to source enough food, have specialist habitats or dietary requirements, or those with narrow geographic ranges tend to fare poorly during urban development.

In 2011, the Center for Biological Diversity released a list of ten US species facing extinction as a result of human population growth. Several of these have been directly affected by urban development; including the Florida panther and the Mississippi gopher frog, and the Lange’s metalmark butterfly. There are only 150 of these butterflies left in the world, living in a small coastal refuge in California which, incidentally, is also home to the last natural populations of a number of wildflower species including the Antioch Dunes evening primrose and Contra Costa wallflower.

Bat nap. Image: FBG_Paris/Flickr/creative commons.

Bats are another group of animals that frequently lose out from urbanisation. This is partly because many species are reliant on forests for their food and roosting spots. Yet even bats which we often see in cities can find it difficult to cope with the most built-up areas.

For example, the common pipistrelle is widespread throughout Europe – it can often be spotted roosting in buildings and flying around urban parks. But research at the University of Stirling, using citizen science as part of the Bat Conservation Trust’s National Bat Monitoring Programme, found that this bat was far less likely to be recorded in densely built-up areas, compared to less built-up ones.

Growing greener cities

About half the world’s human population currently live in urban areas, which cover about 3 per cent of the earth’s land surface. Both of these figures are increasing rapidly. At the same time, urban areas are likely to spread fastest in some of the most biologically diverse areas of the world, including parts of Africa and Asia, which will place even more species at risk. For example, one of the areas predicted to undergo the fastest levels of urban development is Africa’s Eastern Afromontane, home to an astonishing array of plants and animals that do not exist anywhere else. Several species of giraffe, which were recently listed as threatened, are also found in this area.

Strategic greenery: Singapore’s solar trees. Image: BaboMike/Flickr/creative commons.

Losing a species to extinction is not just a tragedy for the animal kingdom. Humans rely on biological diversity for a huge array of “services”, which they provide us with; whether directly for food or timber, or indirectly, through nutrient cycling, pollination and the provision of clean water and air.

Yet the situation is not entirely hopeless. There are many courses of action we can take, as individuals on a local level, and as a society by developing sustainable strategies for urban planning. Many studies show that maintaining and expanding green spaces in cities (including gardens) assists with wildlife conservation and enhances human health and well-being. And green roofs and walls can provide habitats for wildlife and reduce the impact of the urban heat island, as well as absorbing rainwater and improving building insulation.

While it’s incredible to see hyenas living in harmony with humans, falcons soaring between skyscrapers and monkeys leaping through the urban jungle, we must also spare a thought for those species which can’t handle city living. As urban environments continue to expand and develop around the world, it’s worth remembering this: if we can make cities more habitable for wildlife, then we humans will benefit too.The Conversation

Kirsty Park is professor in conservation ecology at the University of Stirling.

This article was originally published on The Conversation. Read the original article.



Was the decline in Liverpool’s historic population really that unusual?

A view of Liverpool from Birkenhead. Image: Getty.

It is often reported that Liverpool’s population halved after the 1930s. But is this true? Or is it a myth?

Often, it’s simply assumed that it’s true. The end. Indeed, proud Londoner Lord Adonis – a leading proponent of the Liverpool-bypassing High Speed 2 railway, current chair of the National Infrastructure Commission, and generally a very influential person – stood on the stairs in Liverpool Town Hall in 2011 and said:

“The population of Liverpool has nearly halved in the last 50 years.”

This raises two questions. Firstly, did the population of the City of Liverpool really nearly halve in the 50 year period to 2011? That’s easy to check using this University of Portsmouth website – so I did just that (even though I knew he was wrong anyway). In 2011, the population of the City of Liverpool was 466,415. Fifty years earlier, in 1961, it was 737,637, which equates to a 37 per cent drop. Oops!

In fact, the City of Liverpool’s peak population was recorded in the 1931 Census as 846,302. Its lowest subsequent figure was recorded in the 2001 Census as 439,428 – which represents a 48 per cent decline from the peak population, over a 70 year period.

Compare this to the population figures for the similarly sized City of Manchester. Its peak population also recorded in the 1931 Census as 748,729, and its lowest subsequent figure was also recorded in the 2001 Census, as 392,830. This also represents a 48 per cent decline from the peak population, over the same 70 year period.

So, as can be seen here, Liverpool is not a special case at all. Which makes me wonder why it is often singled out or portrayed as exceptional in this regard, in the media and, indeed, by some badly briefed politicians. Even London has a similar story to tell, and it is told rather well in this recent article by a Londoner, for the Museum of London. (Editor’s note: It’s one of mine.)

This leads me onto the second question: where have all those people gone: London? The Moon? Mars?

Well, it turns out that the answer is bit boring and obvious actually: after World War 2, lots of people moved to the suburbs. You know: cars, commuter trains, slum clearance, the Blitz, all that stuff. In other words, Liverpool is just like many other places: after the war, this country experienced a depopulation bonanza.

So what form did this movement to the suburbs take, as far as Liverpool was concerned? Well, people moved and were moved to the suburbs of Greater Liverpool, in what are now the outer boroughs of the city region: Halton, Knowsley, St Helens, Sefton, Wirral. Others moved further, to Cheshire West & Chester, West Lancashire, Warrington, even nearby North Wales, as previously discussed here.

In common with many cities, indeed, Liverpool City Council actually built and owned large several ‘New Town’ council estates, to which they moved tens of thousands of people to from Liverpool’s inner districts: Winsford in Cheshire West (where comedian John Bishop grew up), Runcorn in Halton (where comedian John Bishop also grew up), Skelmersdale in West Lancashire, Kirkby in Knowsley. There is nothing unique or sinister here about Liverpool (apart from comedian John Bishop). This was common practice across the country – Indeed, it was central government policy – and resulted in about 160,000 people being ‘removed’ from the Liverpool local authority area.

Many other people also moved to the nearby suburbs of Greater Liverpool to private housing – another trend reflected across the country. It’s worth acknowledging, however, that cities across the world are subject to a level of ‘churn’ in population, whereby many people move out and many people move in, over time, too.

So how did those prominent images of derelict streets in the inner-city part of the City of Liverpool local authority area come about? For that, you have to blame the last Labour government’s over-zealous ‘Housing Market Renewal Initiative’ (HMRI) disaster – and the over enthusiastic participation of the then-Lib Dem controlled city council. On the promise of ‘free’ money from central government, the latter removed hundreds of people from their homes with a view to demolishing the Victorian terraces, and building new replacements. Many of these houses, in truth, were already fully modernised, owner-occupied houses within viable and longstanding communities, as can be seen here in Voelas Street, one of the famous Welsh Streets of Liverpool:

Voelas Street before HMRI implementation. Image:

The same picture after HMRI implementation Image: 

Nonetheless: the council bought the houses and ‘tinned them up’ ready for demolition. Then the coalition Conservative/Lib Dem government, elected in 2010, pulled the plug on the scheme. 

Fast forward to 2017 and many of the condemned houses have been renovated, in a process which is still ongoing. These are over-subscribed when they come to market, suggesting that the idea was never appropriate for Liverpool on that scale. 

At any rate, it turns out that the Liverpool metropolitan population is pretty much the same as it was at its peak in 1931 (depending where the local borough boundaries are arbitrarily drawn). It just begs the question: why are well educated and supposedly clever people misrepresenting the Liverpool metropolis, in particular, in this way so often? Surely they aren’t stupid are they?

And why are some people so determined to always isolate the City of Liverpool from its hinterland, while London is always described in terms of its whole urban area? It just confuses and undermines what would otherwise often be worthwhile comparisons and discussions. Or, to put it another way: “never, ever, compare apples with larger urban zones”.

In a recent Channel 4 documentary, for example, the well-known and respected journalist Michael Burke directly compared the forecast population growths, by 2039, of the City of Liverpool single local authority area against that of the combined 33 local authority areas of Greater London: 42,722 versus 2.187,708. I mean, what bizarre point is such an inappropriate comparison even trying to make? It is like comparing the projected growth of a normal sized-person’s head with the projected growth of the whole of an obese person, over a protracted period.

Having said all that, there is an important sensible conversation to be had as to why the populations of the Greater Liverpool metropolis and others haven’t grown as fast as maybe should have been the case, whilst, in recent times, the Greater London population has been burgeoning. But constantly pitching it as some sort of rare local apocalypse helps no one.

Dave Mail has declared himself CityMetric’s Liverpool City Region correspondent. He will be updating us on the brave new world of Liverpool City Region, mostly monthly, in ‘E-mail from Liverpool City Region’ and he is on twitter @davemail2017.