1. ©Ram Papish INVASIVE SPECIES AND SEABIRDS Lesson: 2 Invasive Species and Biodiversity

2. Key Concepts Invasive species  Characteristics  Alaska Islands and Juan Fernández Islands, Chile Biodiversity  What is it and why is it important? Islands and seabirds  How is island biodiversity unique?  Invasive species on islands with seabirds: A bigger threat 1 Lesson 2: Invasives and Biodiversity

3. Invasive Species Introduced species: also called alien or exotic species  Not originally from a place  Arrive through human activities Species arriving on their own via wind, flying, walking, etc. are NOT considered introduced species Invasive species: an introduced species that significantly impacts an ecosystem and poses a threat to the environment, human health, or the economy 2 Lesson 2: Invasives and Biodiversity

4. Invasive Species Key characteristics of a potentially invasive species  Few natural controls on the population  Reproduce quickly  Can adapt to many different habitats  Able to migrate easily  Generalists, i.e. can eat a variety of foods and live in a variety of habitats  Efficient defenses and/or are aggressive predators  Overcome natural barriers to dispersal 3 Lesson 2: Invasives and Biodiversity

5. Invasive Species − Alaska 4 Lesson 2: Invasives and Biodiversity Introduced invasive plants, rats, fishes, snails, birds, frog, mussels, and other organisms threaten the native ecosystem Fragile island ecosystems are being threatened by rats, cattle, reindeer, and foxes Rats are particularly devastating to nesting seabirds  Approximately 50 million seabirds nest on Alaska’s coast  87% of the seabirds in the United States nest in Alaska  80% of the world’s endangered Red-legged Kittiwake population breeds on St. George Island in the Pribilofs

6. Invasive Species − Alaska Islands 5 Lesson 2: Invasives and Biodiversity Norway Rat (Rattus norvegicus)  Stowaways on ocean-going vessels

7. Invasive Species − Alaska Islands 6 Lesson 2: Invasives and Biodiversity

8. Arctic Fox (Alopex lagopus) and Red Fox (Vulpes vulpes)  Both are native to mainland Alaska  Arctic fox is native to the Pribilof Islands  Neither is native to Aleutian Islands  Introduced for the fur trade ©Wikicommons, USFWS Invasive Species − Alaska Islands ©Pam Goddard, Thalassa Arctic Fox (Alopex lagopus) ( Vulpes lagopus pribilofensis) Red Fox (Vulpes vulpes) 7 Lesson 2: Invasives and Biodiversity ©Robin West, USFWS

9. Cattle & Reindeer  Intentionally introduced for food Invasive Species − Alaska Islands Cattle, Chirikof Island, Alaska 8 Lesson 2: Invasives and Biodiversity Reindeer, St. George Island, Alaska ©Ann Harding

10. Invasive Species − Juan Fernández Islands Lesson 2: Invasives and Biodiversity 9 Chile The Juan Fernández Islands are located 670 km (416 mi) off the coast of Chile. They are composed of 3 main volcanic islands; Robinson Crusoe, Alejandro Selkirk, and Santa Clara.

11. Invasive Species − Juan Fernández Islands Introduced invasive plants, goats, rabbits, coatis, feral cats, mice, and rats threaten the native ecosystem. Islands are home to two Critically Endangered single- island endemic land birds 2/3 of all native plants are endemic to the islands Nesting habitat for four threatened seabird populations that breed only on Chilean Islands  Two species are single-island endemics (entire world population is on one island, Alejandro Selkirk)  Two species breed only on the three islands in Chile 10

12. Invasive Species − Juan Fernández Islands European Rabbit (Oryctolagus cuniculus)  Introduced on islands as a food source for marooned sailors Lesson 2: Invasives and Biodiversity 11 At right: Pink-footed Shearwater eggs ejected from seabird burrows by European Rabbit disturbance in the breeding colony. : © Juan Fernández Islands Conservancy, 2002

13. Invasive Species − Juan Fernández Islands Lesson 2: Invasives and Biodiversity 12 ©Peter Hodum Feral goats (Capra hircus)  Introduced for food on long sea voyages during European exploration and colonization in the 18 th and 19 th centuries

14. Invasive Species− Juan Fernández Islands Coati (Nasua nasua)  Two pregnant females were brought from Perú to Robinson Crusoe Island in 1935 to eliminate the rats  By 1972 the population had grown to 4,000 Lesson 2: Invasives and Biodiversity 13 ©Vassil, Wikimedia Commons

15. Invasive Species− Juan Fernández Islands Lesson 2: Invasives and Biodiversity 14 Feral and domestic cats  Introduced as pets ©Peter Hodum Pink-footed Shearwater killed by feral cat.

16. Invasive Species− Juan Fernández Islands Norway Rat (Rattus norvegicus)  Stowaways on ocean-going vessels Lesson 2: Invasives and Biodiversity 15

17. Biodiversity Biodiversity: variety of life found on Earth Biodiversity can be applied to any size environment  A specific region or space, e.g. a country, continent, town, backyard How is biodiversity measured?  Species richness: the number of species present  Genetic variation: differences in the physical features of individuals within a species  Ecological communities: groups of species co-existing  Habitat: natural environment where groups of species live 16 Lesson 2: Invasives and Biodiversity

18. Biodiversity: Ecological Communities Species evolve together Every species has a role Interconnected roles make up a food web 17

19. Island biodiversity is different from other spaces  Geographical size  Unique habitats  Distance from the mainland  Isolation because surrounded by water Endemic species Biodiversity on Islands 18 Pink-footed Shearwater  Specially adapted to the unique habitat features of a location such as an island  Restricted to a certain area and not found anywhere else in the world Lesson 2: Invasives and Biodiversity

20. Biodiversity on Islands Island habitats are vulnerable to changes  Most lack predators so species have lost defenses  Population sizes are often small  Genetic diversity may be low  Species are concentrated in small areas Significant threats to island biodiversity include:  Habitat destruction – often by humans  Invasive species St. Paul Island vehicle boneyard prior to clean up. 19 Lesson 2: Invasives and Biodiversity

21. Island Habitats and Invasive Species Non-native species are a direct threat to island biodiversity. A successful invasive species can decimate native populations of animals, severely impacting the food web and the balance of the ecosystem. May drive native species to extinction or extirpation via competition or predation. Seabirds are at particular risk. 20 Lesson 2: Invasives and Biodiversity

22. Seabirds and Invasive Species Seabirds are at particular risk from invasive species Burrow or nest on the ground, easy prey Evolved without land-based predators No effective defenses ©Ann Harding Horned Puffin and chick 21 Lesson 2: Invasives and Biodiversity

23. Seabirds and Invasive Species Seabird populations are higher on predator free islands Ecosystems productivity (e.g., guano, poop fertilizer) is reduced when seabird populations decline 22 Lesson 2: Invasives and Biodiversity ©I. Jones Least Auklet eggs preyed on by rats, Kiska Island, Alaska..

24. Summary Invasive species: an introduced species that significantly modifies or disrupts an ecosystem and poses a threat to the environment, human health, or the economy. Biodiversity: the variety of life on earth. This concept can be applied to any size region such as islands, continents, and backyards. Invasive species are a threat to biodiversity. Island seabird populations are particularly vulnerable to invasive species. 23 Lesson 2: Invasives and Biodiversity

25. Resources & References Alaska Department of Fish and Game www.adfg.alaska.gov/index.cfm?adfg=invasive.main U.S. Fish and Wildlife Service www.fws.gov/invasives/ Global Invasive Species Database www.issg.org/database/welcome/ Coastal Conservation coastalconservation.ca/about-us/ Island Conservation www.islandconservation.org/ Oikonos oikonos.org/ 24 Lesson 2: Invasives and Biodiversity