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Message: <blockquote data-quote="redshank2" data-source="post: 1672242" data-attributes="member: 80551">As I said in a previous post; yes these species have evolved to deal with predation of eggs and young by ground predators. The difficulty is that these are not the only pressures facing a species. Losses may also occur on migration or on wintering grounds due to hunting, climate change (natural or manmade) or loss of habitat for wintering or refuleing on migration. These species evolved to deal with predation in a natural ecosystem; the modern world especially the western european landscape is far from natural.As habitat area is reduced and populations corespondingly shrunk breeding sucess may be reduced by factors such as low genetic diversity and difficulty finding mates. Losses of young even if to natural predaators may become a limiting factor on population maintainence or growth. Additionally bear in mind that many of the predators left in this country are not the apex predators of their ecosystem; potentially in a truly natural environment their numbers would instead be controlled by larger predators now extinct. An example might be that Terns are evolved to deal with gull predation in a natural ecosystem, however Gulls colonies are naturally predated by White-Tailed Eagles. Possibly if the Eagles were more widespread Gull numbers would be lower and therefore predation on the Terns decreased. Additionally for colonial nesters whilst in a large colony there may be enough adults always present at the colony to drive off predators smaller colonies may not be big enough to do this effectively.Maybe for some species however this does not hold true for marshs and wetlands which formerly would have also been much more extensive; hence for breeding ground-nesting waders the UK would historically have been very suitable. I would also note that in the case of Stone Curlew whilst undoubtedly many areas of the UK have only become suitable habitat for it due to forest clearance over the centuries there are special areas such as the brecks that may have been open land suitable for open country species even thousands of years ago.Tom</blockquote>

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