The New Wild: Why Invasive Species will be nature's salvation

Abstract

BOOK REVIEW The New Wild: Why Invasive Species will be nature’s salvation Fred Pearce (Beacon Press; Boston; 245pp; £29.99) ISBN 9781848318359 Humans spent a part of their evolution as followers of migrating herds in Africa. We lived off the herds and became a locally adapted migratory ape. Because of this, we were able to leave Africa and colonise the rest of the world. We move about by itchy instinct, and now have the means to move faster and faster, further and further. We have become the ultimate invasive species. This has led to problems*most notably threats to biodiversity*because our travels are often accompanied by many life forms, pests, diseases and some species that become invasive. Many of the world’s problems hinge on this issue. For example, we now know that bubonic plague, which brought about the Black Death, spread to Europe along the Silk Road, repeatedly prompted by climatic episodes. The European conquests of both of the Americas and Africa were also facilitated by introduced invasive diseases. Fred Pearce, in his book The New Wild: why invasive species will be nature’s salvation, argues that most invasive species and hybrids, far from being bad news, will enhance biodiversity. Among other things, Pearce suggests that efforts to stop invasive species are mostly in vain (with some exceptions, such as rats and cats on islands). He also tries to stand many other conventional ecological concepts on their heads by employing a mixture of travelogue and quotes delivered in a glib and often rude style. There is, however, a stark lack of balance in his approach to his chosen topic. Pearce does not actually say we should give up all attempts at preventing invasive species; instead, he takes a sort of journalistic flip-flop approach, which sees him come close to but never actually suggest that we all ought to give up trying to stop invasive species. Is he right? Certainly in the United States and Britain, there are issues with how the policy about invasive species is formed. There have also been serious problems in the field, particularly in post-apartheid South Africa, where the Working for Water program has been bungled by politicians. The complex issue of invasive species is particularly relevant to Ireland, given that it is a very large island with a significant amount of native biodiversity. Oddly for a journalist based in Britain, Pearce hardly mentions Ireland; the only one that I could find refers to the Hottentot fig in Dublin. So how would the Irish situation reflect Pearce’s ideas? I will limit my comments to Irish mammals, because that is what I know about, but the same will be true for many other animals and plants, especially freshwater plants and other life forms. In Ireland we encounter invasive speciesrelated problems with mammals, especially with the hybridisation of hares in Ulster and deer across the Republic of Ireland. The Irish hare has bred with the introduced European brown hare, and red deer have hybridised with Japanese sika deer. If you care about the genetic survival of native, locally adapted forms, you should be concerned about such hybridisation. However, I think the conservation of locally adapted forms, especially on an island such as Ireland, is a core value in concerns about the island’s biodiversity. We also have a situation with bank voles and greater white-toothed shrews in Ireland. Both mammals are introduced species, and when they occur together they cause ‘invasional meltdown’, which leads to the decline and probable extinction of native field mice and the pygmy shrew (it should be pointed out that the pygmy shrew is also an early introduction). If we care about the genetic survival of locally adapted forms, we should be concerned about the threats these invasive mammals pose. According to Professor Ian Montgomery of Queen’s University, such invasive species threaten to turn our island ecosystem into ‘an ecological junkyard’. However, if we consider the rabbit, by far the most abundant mammal on the island, the issues become more complicated. The rabbit, which was introduced well before the Norman Invasion, adapted over a long period to become the wild mammals we know today, and they...