Migration and Biodiversity Flashcards
1
Q
why migrate?
A
- Seasonal changes in the local environment
- Changing needs at different life stages
- Move to a suitable habitat for reproduction
2
Q
Hyperphagia
A
- Excessive appetite
- intense period of feeding prior to migration
- Fat is stored for the long journey
3
Q
Advantage of breeding in the arctic?
A
- Long daylight hours and very productive ecosystem
- Ample resources
- Space (reduces competition)
- Relatively few predators
4
Q
How do birds navigate?
A
- chiefly by sight (topographical landmarks)
- Earth’s magnetic field
- Sun and stars
5
Q
anadromous
A
running upwards (salmon) live in saltwater, swim to freshwater to spawn
6
Q
catadromous
A
running downwards (eel) live in freshwater, swim to saltwater to spawn
7
Q
How do fish naviate
A
sun
olfactory senses
8
Q
euryhaline
A
can live in both salt and fresh water.
catadromous and anadromous fish
9
Q
what are the 3 levels of biodiversity
A
genetic, species, ecological
10
Q
what are the types of extinction?
A
background rate of extinction
mass extinction
anthropogenic extinction
11
Q
threats to biodiversity
A
- Habitat Loss and Fragmentation
- Invasive Species
- Overexploitation
- Others (e.g. pollution, climate change…)
12
Q
how do invasive species threaten biodiversity?
A
- Cause disease
- Act as predators or parasites • Act as competitors
- Alter habitat
- Hybridize with local species
13
Q
Panmitic species
A
• all members of the species mate randomly and are considered to form one large population
