Salamanders, ospreys, snapping turtles, and beavers all live in aquatic habitats. Salamanders lay their eggs in small freshwater pools and feed on insects. Osprey habitats include rivers, bays, and swamps and the birds feed on fish and other animals in the water or on land. Snapping turtles live in fresh or brackish water and feed on plants, fish, frogs, and snakes. Beavers build lodges on islands, pond banks, and lake
shores and eat a variety of shrubs, grasses, and crops.
Based on the information provided above, which of the following species would best be classified as a specialist?
Environmental Science: A Global Concern
15th EditionMary Cunningham, William Cunningham
511 solutions
Environmental Science: Foundations and Applications
1st EditionAndrew Friedland, David Courard-Hauri, Rick Relyea
251 solutions
Environmental Science: A Study of Interrelationships
16th EditionBradley Smith, Eldon D. Enger
438 solutions
Environmental Science: Toward A Sustainable Future
13th EditionDorothy F. Boorse, Richard T. Wright
569 solutions
Study Finds Aardvarks Suffering as African Climate Heats Up
Little is known about Africa's elusive aardvarks, but new research says they are vulnerable to climate change like many other species.
Hotter temperatures are taking their toll on the aardvark, whose diet of ants and termites is becoming scarcer in some areas because of reduced rainfall.
Drought in the Kalahari Desert killed five out of six aardvarks that were being
monitored for a year, as well as 11 others in the area.
The aardvarks' body temperatures plummeted during the night because they were not getting enough energy from diminished food sources. They tried to conserve energy by looking for insects during the warmer daytime, but their efforts to adapt could not save them.
Researchers said some birds, reptiles, and other animals use aardvark burrows to escape extreme temperatures, reproduce, and hide from predators. They could have fewer refuges
available if aardvark populations shrink because of rising temperatures, they said.
The aardvark, which lives in many parts of sub-Saharan Africa, is identified as an animal of "least concern" on an international "red list" of threatened species. There are no indications that the population is changing significantly in southern Africa, though it is speculated that numbers may be declining elsewhere because of habitat destruction, the bushmeat trade, and other factors.
Which of the
following best identifies the author's claim?
Estuary provides refuge after dam removal for bull trout
Bull trout use a bewildering array of strategies to aid in their survival, from remaining in streams their whole lives, like rainbow trout, to spending part of their lives in the ocean before returning to streams to spawn, just as salmon do.
Bull trout are present in only one of two neighboring rivers in the Olympic peninsula, Washington state, and in
this one (the Elwha River), where two large dams were removed. Dam removal resulted in massive outflow of sediments, reducing the clarity of the water and also building up a large delta and expanding the size of the estuary at the mouth of the Elwha River.
Sampling for bull trout before, during, and after dam removal was used to detect whether bull trout changed their use of the Elwha River estuary or moved into the adjacent Salt Creek stream where they were formerly absent. Sampling revealed
no movement into Salt Creek, but numbers of bull trout in the Elwha River estuary increased greatly during and immediately after dam removal, coinciding with large sediment outflow, before returning to their original low levels. Thus, bull trout appear to have used the enlarged estuary as a refuge from the effects of dam removal, then returning to the river when the river water cleared up from the sediment.
Of additional interest is the long-term response of bull trout to the additional
habitat opened up above the former dams.
Which of the following best identifies the author's claim?
Very Large Dead Zone Forecast for the Gulf of Mexico
Scientists at the National Oceanic and Atmospheric Administration (NOAA)(NOAA) are forecasting this summer's Gulf of Mexico hypoxic zone or "dead zone"—an area of low to no oxygen that can kill fish and other marine life—to be approximately 7,8297,829 square miles, or roughly the size of Massachusetts.
The annual prediction is based on United States Geological Survey river flow and nutrient data.
The 2019 forecast is close to the record size of 8,7768,776 square miles set in 2017 and larger than the five-year average measured size of 5,7705,770 square miles.
The annually recurring Gulf of Mexico hypoxic zone is primarily caused by excess nutrient pollution from human activities, such as urbanization and agriculture, occurring throughout the Mississippi River watershed. Once the excess
nutrients reach the gulf, they stimulate an overgrowth of algae, which eventually die, then sink and decompose in the water. The resulting low oxygen levels near the bottom are insufficient to support most marine life and have long-term impacts on living marine resources that are unable to leave the area.
A major factor contributing to the large dead zone this year is the high amount of spring rainfall in many parts of he Mississippi River watershed, which led to record high river flows and
much larger nutrient loading to the Gulf of Mexico. This past May, discharge in the Mississippi and Atchafalaya rivers was about 6767 percent above the long-term average between 1980 and 2018. The latest National Climate Assessment predicts an increase in the frequency of very heavy precipitation events in the Midwest, Great Plains, and Southeast regions, which would impact nutrient input to the northern Gulf of Mexico and the size of the hypoxic zone."
Which of the following best identifies
the author's claim?