European wild rabbits are relocating to the city in numbers to enjoy the preferable living conditions there, according to a new study.
German scientists say that intense farming is leading to a loss of living space for rabbits in rural areas, compared to urban areas where food scraps are aplenty.
Countryside rabbits also face more predators such as wild birds and mammals, making them relocate to the city.
Cities offer rabbits offer desirable living spaces, as opposed to the countryside, which is being ‘cleared out’ by modern farming, researchers say.
City rabbits were found to have a greater genetic diversity compared to those in rural areas, likely due to interbreeding as a result of reduced populations.
The European rabbit (Oryctolagus cuniculus) is considered as an ‘urban adaptor’ – a species that may make use of human resources and survive in human-dominated areas, but does not necessarily receive an added benefit from living with humans
‘Wild rabbits achieve high population densities wherever they can find enough food and are able to dig warrens in the immediate vicinity,’ Madlen Ziege, a behavioural biologist at Potsdam University, told the Times.
‘There are much higher densities in the city and rabbits can intermingle better despite barriers such as roads.’
The team studied rabbits in eight sites in and around Frankfurt for their study, which is considered a ‘green city’ as more than 50 per cent of its area is covered by greenery, including forests, parks and gardens.
The team sampled a total of 139 rabbits from the eight sites over the course of six months.
They measured the number of residents located within a radius of 1,600 feet (500 metres) from each site and collected DNA samples from their hair and skin tissue.
After analysis, genetic variability among the rabbits population showed a correlation with the move towards the urbanised town centres around the sites, while evidence of interbreeding decreased.
A diverse habitat, increased resources and a low absence of predators are likely explanations for the successful colonisation of cities by European rabbits.
The team studied rabbits in a 500 metre-radius around eight sites in and around Frankfurt, Germany – Bad Vilbel, Flörsheim, Kriftel, Ostpark, Rebstockpark, innerer Grüngürtel, Oskar-von-Miller Straße, Bundesbank
The European rabbit (Oryctolagus cuniculus) – native to the Iberian Peninsula and present in Western Europe since Roman times – is declining in large parts of Europe, but populations in some German cities seemed to be unaffected by the decline.
The species is considered as an ‘urban adaptor’ – one that may make use of human resources and survive in human-dominated areas.
Most of the wildlife in cities occurs within semi-natural patches and other human-made green spaces such as parks, botanical and private gardens.
These areas are likely to harbour small and isolated populations, surrounded by strong barriers to dispersal, such as streets, highways and buildings.
‘Urban habitats can sometimes harbour large populations of certain species and do not always hinder, but might rather facilitate gene flow,’ the study authors say.
‘Green spaces within the urban ecosystem may promote gene flow and may act as sources of genetic diversity [and] while rivers and roads in cities represent barriers to some species they may function as corridors for dispersal and gene flow in others.’
Intense farming and urbanisation are factors that cause major global threats to biodiversity
Other animal species are thriving in cities around the world, including the Eurasian tree sparrow, orchid bees and the ornate box turtle.
However, the study may serve as a reminder of the ongoing loss of diversity in rural areas and a disruption to rural ecosystems caused by building works.
The team warn that habitats are threatened as rural landscapes in Europe are becoming more uniform and ‘less structurally-complex’.
The decline in European rabbit populations is likely occurring in other parts of the continent, including the UK.
As cities expand, urban areas will double in size and cover about 10 per cent of Earth’s landmass, earlier studies report.
Urbanisation leads to the destruction of natural habitats and leaves more surfaces that can’t be penetrated by water, as well as air, water, light and noise pollution.
The team said that only organisms that can cope with or adapt to these conditions can colonise urban ecosystems.
The researchers’ study was published in Nature.