Figure 1: Fact file about the red-necked and imperial amazon parrots
Figure 2: Changes in the numbers of individual imperial and red-necked amazon parrots
Using Figure 1, state one physical characteristic that may be used to differentiate these two species from each other in an identification key.
Award
- chest/underbelly colour (green v. grey/blue);
- head colour;
- neck/throat marking (red v. grey/blue);
- beak colour;
- foot colour;
Note: Do not accept only ‘colour is different'.
With reference to Figure 1, state the type of biotic interaction that occurs between the imperial amazon and the red-necked amazon parrots.
Award
- competition / inter-specific competition;
- competition for nesting sites/food (where their distributions/habitats overlap ie altitudes 600–800 m);
- resource partitioning;
Compare and contrast the realized niches of the two parrot species.
Award
- both species nest in holes in trees;
- both species eat fruit and nuts;
- the imperial amazon feeds only in dense forest, whereas the red-necked amazon feeds in forests and plantations/red-necked amazon also eats in banana and citrus plantations;
- the red-necked amazon lives between 0 and 800 m, whereas the imperial amazon lives between 600 and 1300 m/at higher elevations / both live between600 and 800 m;
Note: Must be evidence of comparison in the response: at least one compare and one contrast statement for full marks.
With reference to Figures 1 and 2, suggest two reasons why the red-necked amazon population has recovered more quickly than the imperial amazon population following Hurricane David in 1979.
Award
- Red necked amazon (RNA) more social so protection in numbers from predators, reducing mortality rates/increasing survival rates / imperial amazon (IA) lives singly so at greater risk of predation;
- RNA more social so greater breeding success/greater choice of potential mates / IA has reduced mating success due to solitary behaviour/may not breed again after the loss of a mate during the hurricane / IA may die if it loses its partner;
- RNA eat fruit from banana and citrus orchards/wider variety of food sources, so less competition for food / IA has a more limited food source so has greater competition for food;
- RNA less specialized/can adapt to a number of different habitats so less affected by hurricane damage to the forest;
- IA being outcompeted for nesting sites by the RNA;
- time taken for rainforest to recover after hurricane means delay in recovery of IA / humans replant orchards so food source for RNA recovers more quickly;
- initial population of RNA was higher in 1980;
