Question

life science ls1
where have all the creatures gone?
lesson 2 - what could be causing the trout population to change?

1. __________________ penguins were found far from their usual habitat in the northern hemisphere.
2. california red - legged frogs need ______________________ for breeding, but their habitats have been destroyed by farming and building.
3. the edge of the area on a mountain where trees can no longer grow is called the __________________________
4. a population can change when the __________________________ changes, like when the climate gets warmer.
5. scientists saw that the timberline in the alps was moving ________________________ each year.
6. humboldt penguins ended up in the northern hemisphere because of an interaction with ______________________
7. the california red - legged frog population decreased when new ______________________ like bullfrogs moved into their area.

Explanation:

1. Humboldt penguins are native to the Southern Hemisphere, so they are the species found stranded in the Northern Hemisphere.
2. California red-legged frogs rely on freshwater wetlands/marshes, shallow ponds, and slow-moving streams for breeding, which are destroyed by development.
3. The timberline (or tree line) is the elevation on mountains where trees stop growing.
4. Environmental conditions (like climate) directly drive population changes.
5. With global warming, the Alps timberline moves higher up the mountain as temperatures become suitable for trees at higher elevations.
6. Humboldt penguins are carried north by ocean currents (like the Humboldt Current shifting or El Niño events) outside their natural range.
7. Invasive species such as bullfrogs prey on red-legged frogs and compete for resources, reducing their population.

Answer:

1. Humboldt
2. freshwater wetlands (or shallow, slow-moving water/riparian habitats)
3. timberline (or tree line)
4. environment (or climate/habitat conditions)
5. higher up the mountain (or upward)
6. ocean currents (or shifting marine currents/El Niño events)
7. species (or invasive species/predatory species)