INVASIVE SPECIES AND SEABIRDS Lesson 2 Invasive Species

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

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

Invasive Species • Introduced species: also called alien or exotic species q q 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 Lesson 2: Invasives and Biodiversity 2

Invasive Species • Key characteristics of a potentially invasive species q q q q 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 Lesson 2: Invasives and Biodiversity

Invasive Species − Alaska • 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 q q q 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 Lesson 2: Invasives and Biodiversity

Invasive Species − Alaska Islands • Norway Rat (Rattus norvegicus) q Stowaways on ocean-going vessels Lesson 2: Invasives and Biodiversity

Invasive Species − Alaska Islands Lesson 2: Invasives and Biodiversity

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

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

Invasive Species − Juan Fernández Islands 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. Lesson 2: Invasives and Biodiversity

�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 singleisland 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 q q 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

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

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

Invasive Species−Juan Fernández Islands • Coati (Nasua nasua) q q 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 ©Vassil, Wikimedia Commons Lesson 2: Invasives and Biodiversity

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

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

Biodiversity • Biodiversity: variety of life found on Earth • Biodiversity can be applied to any size environment q A specific region or space, e. g. a country, continent, town, backyard • How is biodiversity measured? q q 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 Lesson 2: Invasives and Biodiversity 16

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

Biodiversity on Islands • Island biodiversity is different from other spaces q q Geographical size Unique habitats Distance from the mainland Isolation because surrounded by water • Endemic species q q 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 Pink-footed Shearwater 18

Biodiversity on Islands • Island habitats are vulnerable to changes q q 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: q q Habitat destruction – often by humans Invasive species St. Paul Island vehicle boneyard prior to clean up. Lesson 2: Invasives and Biodiversity

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. Lesson 2: Invasives and Biodiversity 20

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 Horned Puffin and chick ©Ann Harding Lesson 2: Invasives and Biodiversity

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 ©I. Jones Least Auklet eggs preyed on by rats, Kiska Island, Alaska. . Lesson 2: Invasives and Biodiversity

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. Lesson 2: Invasives and Biodiversity 23

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/ Lesson 2: Invasives and Biodiversity 24