Invasive Species

Introduced rats are notorious predators of birds and their nests worldwide, but especially on remote islands. Rats ( Rattus exulans ) first arrived in Hawai‘i with Polynesian colonists about 1,000 years ago, resulting in deleterious consequences for native birds and ecosystems. Since Western contact in 1778, two additional rat species have become established in Hawai‘i, including the highly...

If invasive plants are producing pollen and nectar used by native pollinators, what happens when a manager decides to control the invasive plant? Northern Prairie Wildlife Research Center is addressing this question and has found that pollinators are adept at changing their resource acquisition strategies as abundantly flowering invasive species decline. In addition, it appears that the invasive...

The pesticides 3-trifluoromethyl-4-nitrophenol (TFM) and niclosamide selectively target larval sea lampreys (Petromyzon marinus) because they have a much lower capacity to detoxify these lampricides by forming glucuronide conjugates compared to typical non-target fishes. However, if lampricide uptake overwhelms a fish's detoxification capacity, non-target mortality can result. Non-target mortality...

Many species of amphibians and reptiles are declining or facing population threats in the West related to habitat loss, habitat alteration, introduction of non-native species, and other factors. Our work focuses on the status and trends of resident herpetofauna and how to better manage their habitats. Much of the effort is undertaken with cooperators, particularly with other agencies in the...

The Ridgway’s rail is a federal and state listed endangered species that occurs in wetlands along the Pacific Coast and from the Lower Colorado River drainage to southern Baja California. Three subspecies of Ridgway’s rail are found within the United States: the California Ridgway’s Rail, Yuma Ridgway’s rail, and Light-footed Ridgway’s rail. All three subspecies have declined since 1900 as a...

Riparian woodlands are highly productive ecosystems that support a disproportionately high fraction of regional biodiversity. They are also one of the most endangered terrestrial systems in temperate North America, and have been reduced to just 5% of their former extent in California and throughout the American southwest. These losses have been accompanied by steep declines in numerous plant and...

Dr. Robert Fisher and his colleagues have teamed up with the U.S. Fish and Wildlife, The Nature Conservancy and multiple universities to conduct several types of studies that will address high priority issues related to reptiles in the Pacific Basin Islands. These studies will provide new information about species diversity, endemicity, biology and demography of reptile fauna and will lay the...

Bat Research Bats are nocturnal, flying mammals that eat insects or fruits, pollinate flowers, distribute seeds, and are important to many ecosystems. Across North America there are 45 species of bats, many of which are threatened or endangered. One species of federally endangered bat, the Indiana bat (Myotis sodalis), is a medium-sized, gray, black, or chestnut brown bat living primarily in...

Adult sea lamprey abundance in Lake Erie increased during the past decade, exceeding pre-control levels and causing extensive mortality on some strains of stocked lake trout (Markham 2015). Control agents speculate that this increase may be due to an uncontrolled larval sea lamprey population in the St. Clair River because other known sources of larval sea lampreys are regularly treated with...

Managing a species with intensive tools like reintroduction may focus on single sites or entire landscapes. For mobile species like the federally-threatened Chiricahua leopard frog (Lithobates chiricahuensis [CLF]), both suitable colonization sites and suitable dispersal corridors between sites are needed. Following the eradication of the invasive American bullfrog (Lithobates catesbeianus) from...

Turtles are among the most recognizable and iconic of animals. Any animal with a shell and a backbone is a turtle whether they are called turtles, tortoises, or terrapins. In fact, terrapin is an Algonquian Native American name for turtle. Worldwide there are 356 turtle species on all continents except for Antarctica. The United States has more species than any other country with about 62...

Since the mid-1990s, several species of non-native, giant constrictor snakes, such as Burmese pythons and boa constrictors, have surfaced in localities throughout southern Florida. Several are known or suspected to be breeding and appear to be spreading northward. Increasingly, media and other reports of sightings or encounters with these animals have emphasized the dangers they could impose on...