pollination and dispersal networks, or hybridiza-
tion. We illustrate both these forms of alteration in
this section, reserving mention of other equally
important forms of change, such as the develop-
ment of extensive thickets of non-native plant
species (Meyer and Florence 1996; Henderson et al.
2006), to later sections.
Predators and browsers
As often noted, it is the introduction of vertebrate
predators, such as cats, rats, dogs, and mongooses,
which have caused some of the worst problems
(Cronk 1989; Groombridge 1992; Benton and
Spencer 1995; Keast and Miller 1996). Feral cats are
a feature of innumerable islands. They are oppor-
tunistic predators, eating what is most easily
caught. Cats were introduced to the sub-Antarctic
Marion Island in 1949 and at one stage it was
estimated that there were about 2000 of them, each
taking about 213 birds a year, and thus in total
killing well over 400 000 birds per annum, mostly
ground-nesting petrels. Given these loses, only by
eradicating the cat from the island could the long-
term survival of the native bird species be ensured
(Leader-Williams and Walton 1989). Cats have been
present on another sub-Antarctic island, Macquarie,
for a lot longer, and in that case have been responsi-
ble for the loss of two endemic bird species. The
combination of cats and mongooses on the two
largest Fijian islands has resulted in the local extinc-
tion of two species of ground-foraging skinks of the
genusEmoia: they survive only on mongoose-free
islands. In the Lesser Antilles, three reptiles have
been extirpated from St Lucia within historical time,
coincident with the introduction of the mongoose.
Domestic dogs can also be devastating, and feral298 ANTHROPOGENIC LOSSES AND THREATS TO ISLAND ECOSYSTEMS
(continued)Common name Scientific name Origin Islands invadedBrazilian pepper tree Schinus terebinthifolia South America Hawaii, Norfolk, Mauritius, St. Helena
Chilean guava Ugni molinae Chile Juan Fernández, Chatham
Gorse Ulex europaeus Western Europe Hawaii
Succulents
Cook feet Carpobrotussp. South Africa Balearics
Coirama Kalanchoe pinnata Madagascar Hawaii, Galápagos, Kermadec
Coastal pricklypear Opuntia dillenii Central America Canaries
Common pricklypear Opuntia ficus-indica Mexico Hawaii, Canaries
Trees
Black wattle Acacia mearnsii Australasia New Zealand, Hawaii
Sycamore Acer pseudoplatanus Europe New Zealand, Great Britain, Ireland, Madeira
Shoebutton ardisia Ardisia eliptica South Asia Hawaii, Okinawa, Jamaica
Australian pine Casuarina equisetifolia Australasia Hawaii, Réunion
Embauba Cecropia peltata Tropical America Hawaii, Tahiti, Raiatea
Red quinine tree Cinchona succirubra Ecuador Galápagos, St. Helena
Cinnamon Cinnamomun zeylanicum East Indies Seychelles
Paper bark tree Melaleuca quinquenervia Australasia Hawaii
Fire tree Myrica faya Macaronesia Hawaii
Cluster pine Pinus pinaster Mediterranean Hawaii, New Zealand
Sweet pittosporum Pittosporum undulatum Australia Norfolk, Lord Howe, Jamaica, Azores
African tulip tree Spathodea campanulata Africa Hawaii, Fiji, French Polynesia, Samoa
Honduras mahogany Swietenia macrophylla Central America Sri Lanka
Diseases
Avian malaria Plasmodium relictum unknown? Hawaii