Threatened and Endangered Species

Manatees are tropical to subtropical in distribution and, with few exceptions, Florida is the northern limit of their natural winter range. The availability of warm-water habitat during winter is critical for the future persistence of the population in Florida.

USGS works with partners to assess manatee distribution and habitat use throughout the Northern Gulf of Mexico.

The Gulf sturgeon, Acipenser oxyrinchus desotoi, has been listed as Threatened since 1991. Beginning in 1986, USGS has been investigating sturgeon population abundance and ecology throughout its range, but mostly in the Suwannee River.

Critical information predicting condition changes in manatee habitat resulting from the alteration of freshwater flows to estuaries is needed to develop the PSRP Detailed Design and PSRP Operations Plan components and complete consultation under the Endangered Species Act.

Unexplained heterogeneity in statistical models of animal responses to their physical environment is reasonable to expect because the measured habitat resources are a constraint on—but not the sole determinant of—abundance, survival, fecundity, or fitness. The ecological understanding and reliability of management predictions based on animal habitat models can be improved by shifting focus from...

Cold-water fishes like trout, salmon, and charr are especially vulnerable to shifting conditions related to climate change; for example, warmer temperatures and more variable hydroclimate. Native cutthroat trout of the southern Rocky Mountains now only occupy a tiny fraction of their historic habitats because of stressors such as non-native fishes, habitat fragmentation, and detrimental land...

It's hard to imagine a better job than doing fieldwork with the USGS Coastal Ecology crew as they work to keep tabs on the Gulf sturgeon population.

USGS and Oregon State University (OSU) have joined forces to support USFWS with research needed help manage and recover the endangered Hawaiian duck, locally known as koloa maoli. Hybridization of koloa with feral Mallards on O‘ahu and Maui is believed to have resulted in complete introgression in those populations (Engilis et al. 2002), and Kaua‘i is the only island that likely supports a viable...

The federally endangered nēnē, or Hawaiian Goose, once present on most of the Hawaiian Islands, was found only on Hawai‘i Island by 1900. This remnant population was reduced to as few as 30 individuals by 1952 due to the combination of unregulated hunting, introduced mammalian predators, and large-scale habitat degradation. Nēnē have been restored to a few places like Hawai‘i Volcanoes National...

The palila is an endangered species of Hawaiian honeycreeper which exists only in subalpine forests dominated by māmane and naio on Mauna Kea Volcano. The diet of this finch-billed bird is unusually restricted; immature seeds, flowers, and insects found on māmane trees are critical to its existence. Māmane also is the preferred nesting substrate of the palila. Federal court orders have resulted in...

The Samoan swallowtail is a large and strikingly marked butterfly endemic to the Samoan Archipelago. Once widespread and common, its populations have declined dramatically, and it now appears restricted to the island of Tutuila, an area representing approximately 5% of its former range. There are few insects that are commonly thought of as indicators of ecosystem health, but the Samoan swallowtail...

Hawai‘i has more endangered species than any other state - over 394 species. In spite of this fact, there is not a central clearing house for information on the status and trends of these species. Information is spread over the following areas: 1. USGS maintains some information on Forest Birds. 2. USFWS maintains summary data on listed and proposed plants. 3. The University of Hawai‘i maintains...