Question 1
Multiple choiceMedium1 markA simplified density-index series for the documented Canadian lynx–snowshoe hare case is shown; higher values indicate greater population density. Which interpretation is supported by the data?
| Year | Hare density index (arbitrary units) | Lynx density index (arbitrary units) |
|---|---|---|
| 1 | 20 | 5 |
| 2 | 50 | 12 |
| 3 | 90 | 28 |
| 4 | 40 | 45 |
| 5 | 15 | 22 |
Show answer and explanation
Answer: C. The hare density index is highest in year 3 (90), while the lynx index is highest in year 4 (45). This lag is consistent with predator abundance responding to prey availability; predation can then contribute to a decline in hare density, a density-dependent effect.
A: reverses the timing of the two population peaks.
B: reads the peak timing correctly but misclassifies a predator response to prey density as density-independent.
D: treats the peaks as simultaneous, although the hare peak occurs one year earlier.
Remember: a delayed predator increase following a rise in prey density is consistent with density-dependent predator–prey control.