Nectar robbing

Nectar robbing is a foraging behavior utilized by some organisms that feed on floral nectar. "Nectar robbers" usually feed from holes bitten in flowers, rather than by entering through the flowers' natural openings. Often, nectar robbers avoid contact with the floral reproductive structures, and therefore do not facilitate plant reproduction via pollination. Because many species that act as pollinators also act as nectar robbers, nectar robbing is considered to be a form of exploitation of plant-pollinator mutualism.

Nectar robbers vary greatly in species diversity and include species of carpenter bees, bumblebees, stingless Trigona bees, solitary bees, wasps, ants, hummingbirds, passerine birds, and flowerpiercer birds (Diglossia spp.). Nectar robbing has also been observed in mammals, including a fruit bat species, the squirrel species Tamiops swinhoei hainanus, which robs nectar from flowers of the ginger plant Alpinia kwangsiensis.

Records of nectar robbing in nature date back at least to 1793 when German naturalist Christian Konrad Sprengel observed bumblebees perforating flowers.Charles Darwin observed bumblebees stealing nectar from flowers in 1859.

The term "nectar robbing" specifically pertains to the behavior of consuming nectar from a perforation (robbing hole) in the floral tissue rather than from the floral opening. There are two main types of nectar robbing: primary robbing, which requires that the nectar forager perforates the floral tissues itself, and secondary robbing, which is foraging from a robbing hole created by a primary robber. The term "floral larceny" has been proposed to include the entire suite of foraging behaviors for floral rewards that can potentially disrupt pollination. They include "nectar theft" (floral visits that remove nectar from the floral opening without pollinating the flower), and "base working" (removing nectar from in between petals, which generally bypasses floral reproductive structures).

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