Pollinator Pulling Power (Teacher Support)

Introduction

For pollinators to thrive they need good quality nectar and pollen supplies from flowering plants. On these counts, insect pollinated plants are not all equal. Some attract far more pollinators than others. Why might this be the case? This experiment attempts to get inside the heads of insects and birds to find out what might attract them to a flower. It is also about quality observations and making inferences from them.

Relates to: student's Pollinator Pulling Power Experiment

Pollinator Pulling Power Experiment Sheet

Answers (more detailed than expected from students)

1. Answers will vary, but flowers like kōwhai, camelia, dahlias and clematis have bright showy flowers.
2. Strong scent examples: roses, jasmine, boronia, honeysuckle, kohuhu (Pittosporum tenuifolium). Lots of pollen examples: canola, dandelion, apple, willow, sunflower. Lots of nectar examples: fruit trees e.g. cherry and apple, primrose, hellebore.
3. It doesn't need to put its energy into growing large showy petals because the scent attracts the pollinators.
4. Because producing all the different types of enticements is very costly for a plant in terms of energy and nutrients used.
5. Pollinators obtain food — pollen is rich in protein and vitamins, while nectar is rich in sugars and other food substances, e.g. amino acids.
6. By attracting pollinators, plants gain pollination services, whereby pollen is transferred from one flower to another of the same species. This transfer, called pollination, is required for fertilisation and seed formation. Without the pollination services of animals such as insects, birds and bats, a huge number of plant species would become extinct.
   
   

Discussion, critiquing and research

1. No, bees use compound eyes to see the visible light that we do, plus ultraviolet and polarised light.
2. No, some pollinators don't, for example honey bees and flies use their antennae to detect scent released by flowers. Honey bees are said to be 100 times more sensitive to smell than we are. On the other hand, birds use nostrils to smell things in a similar way to us, although many don't seem to rely on their sense of smell very much. Others like kiwi and vultures do.
3. No, there is no way we can truly know what aspects of flowers most attract pollinators. We can only infer what might be most attractive to them.
4. Answers will vary. Compare with seeds typically found in a commercial packet sold at a garden shop: borage, Phacelia, linseed, buckwheat, sunflower, bean, lupin and clover.