Nectar Robbing - Evolutionary Implications

Evolutionary Implications

Pollination systems are known to cause coevolution. The close relationships between figs and fig wasps as well as yuccas and yucca moths are probably the most clear and well-known examples of this phenomenon. If nectar robbers have an effect (direct or indirect) on a plant or pollinator fitness, they are part of the coevolution process, as well. In the case where nectar robbing is detrimental to the plant, it is conceivable that a plant species might evolve to minimize the traits that attract the robbers or develop some type of protective mechanism to hinder them. Another option is to try to neutralize negative effects of nectar robbers. Nectar robbers also show adaptations for more efficient nectar robbing. Many hummingbirds and Diglossa bird species have serrated bills that are thought to aid them in incising flower tissue for nectar robbing.

Nectar robbing has been suggested to occur in two ways. The first is that the nectar robbing animal can only get food in illegitimate ways because of the mismatch between the morphologies of their mouthparts and the floral structure. The second is that nectar robbing is a relatively more efficient and more energy-saving way for animals to get nectar from flowers.

It is not completely clear how pollination mutualisms are able to persist in the presence of cheating nectar robbers. Nevertheless, as exploitation is not always harmful for the plant, the relationship may be able to endure some cheating. Also, in many cases mutualism simply confers a higher payoff than exploitative behaviours would.