440 



Non-native Spetit's — Our Livinii Rt'S(mrces 



For further information: 



Chandler S. Robbins 



National Biological Service 



Patuxent Wildlife Research Center 



1 1410 American Holly Dr 



Laurel. MD 207(IX-4'oi5 



14. American Ornithologists' Union. Allen Press. 



Lawrence, KS. 

 Robbins. C.S.. D. Bystrak, and PH. Geissler. 1986. The 



Breeding Bird Survey: its first fifteen years. 1965-1979. 



U.S. Fish and Wildlife Service Res. Publ. 157. 196 pp. 

 Schorger, A.W. 1952, Introduction of the domestic pigeon. 



Auk 69:462-46.1. 

 Schwartz, C.W., and E.R. Schwartz. 1949. A reconnaissance 



of the game birds in Hawaii. Board of Commissioners of 



Agriculture and Forestry, Hilo. HI. 168 pp. 



Smith, P.W. 1987. The Eurasian collared-dove arrives in the 



Americas. American Birds 41 (5): 1371-1379. 

 Vance. D.R., and R,L. Westemeier. 1979. Interactions of 



pheasants and prairie chickens in Illinois. Wildlife 



Society Bull. 7(4):221-225. 

 Wiley, J.W. 1985. Shiny cowbird parasitism in two avian 



communities in Puerto Rico. Condor 87:165-176. 

 Willet, G. 1933. A revised list of the birds of southwestern 



California. Cooper Ornithological Club, Pacific Coast 



Avifauna 2 1 . 204 pp. 



Non-native 

 Animals on 

 Public Lands 



by 



Charles A. Drost 



Gary M. Fellers 

 National Biological Service 



Non-native plants and animals have become 

 part of our surroundings, in cities, agricul- 

 tural areas, and wildlands. While there are many 

 beneficial purposes for non-native animals, 

 such as for food and sport hunting and as agri- 

 cultural animals, the introduction of some has 

 had major negative economic consequences 

 (Palmer 1899), and adverse effects on native 

 wildlife, plants, and habitats. The British ecolo- 

 gist Charles Elton, in a major review of intro- 

 duced species, described the increasing number 

 of invasions as constituting "one of the great 

 historical convulsions in the world's flora and 

 fauna" (Elton 1958, p. 31). 



Non-native species are significant problems 

 on large areas of state and federal public lands, 

 and areas set aside to protect native plant and 

 animal communities are not immune to such 

 hami. Science and conservation journals have 

 devoted entire issues to the threats posed by 

 non-native plants and animals in nature reserves 

 (e.g.. Usher et al. 1988). In a compilation of 

 threats to U.S. national parks, non-native plants 

 and animals were the inost often reported threat, 

 and were reported by the most areas: feral cats 

 (Fells catus). feral dogs iCaiiis faniiliaris). and 

 wild pigs (Siis scrofa) were the non-native ani- 

 mals cited most often (NPCA 1977). 

 Non-native species present serious threats, but 

 at the same time, coordinated eft'orts on public 

 lands offer the best possibility for controlling 

 some harmful non-native species, and protect- 

 ing both native plant and animal communities 

 and human interests and needs. 



We compiled information on non-native ani- 

 mals on public and private land-management 

 areas by conducting a mail survey to assess 

 their occurrence and management status in 

 land-management areas. Survey results repre- 

 sent contributions from 937 national parks, 

 national forests, national wildlife refuges. 

 Bureau of Land Management field areas, and 

 state and private land-management areas. The 

 results reflect those species that land managers 

 considered of greatest concern, and their gener- 

 al distribution on public lands. Non-native 

 invertebrate animals, particularly forest insects 

 and agricultural pests, cause severe economic 

 and environmental damage as well (OTA 1993). 

 but were not the focus of this survey. 



Distribution and Effects 



The forests, parks, refuges, and other areas 

 that responded to the surveys identified 205 

 non-native animal species as species of man- 

 agement concern. As a group, non-native mam- 

 mals were most often reported by land man- 

 agers as problem species, accounting for 60% 

 (823 of 1,370) of the reports received (Table 1 ). 

 Twenty-eight non-native mammal species were 

 listed for the areas surveyed, with feral cats and 

 dogs and wild pigs reported most often (Table 

 2). Feral cats and dogs are nearly ubiquitous 

 (Figure) and are of concern because they prey 

 on native birds and mammals (Van't Woudt 



Table 1. Non-native species reported from U.S. national 

 forests, parks, refuges, and other land-management areas. 

 "Species introduced" is the total number of non-native 

 species of each group that are known to have been brought 

 into the United States (fish from Courtenay and Stauffer 

 1984; amphibians and reptiles from Smith and Kohler 

 1977: birds from Long 1981; mammals from Lever 1985). 

 "Established" is the number of species that have estab- 

 lished successful long-term populations. "Species report- 

 ed" is the number of species noted in mail surveys sent to 

 U.S. land-management areas, and "Number of reports" is 

 the number of areas reporting each species. 



Table 2. Non-nafive animal species most commonly 

 reported in national forests, parks, and other U.S. land- 

 management areas. 



