The conservation of bees: a global perspective

Open Access

Table I

Causes of bee decline. The geographic and taxonomic impact of various factors as reviewed in this special issue of Apidologie (2009, vol. 40, issue 3). × : a strong effect; ?: a suspected effect.

	Solitary bees				Bumble bees	Honey bees
	Australia	Central and	Europe, Mediterranean	Sub-Saharan Africa	Worldwide	Asia	Europe	Africa
		South America	and North Africa	and Madagascar

Habitat loss,
fragmentation	×	×	×	×	×	×	×	×
degradation
Invasive species^a	?	×			×	×	× ^d
Parasites and disease^b			?		×	×	×	×
Exploitation						×		×
Extinction cascades^c	?	?	?	?	?
Climate change	?	?	?		?	?	?	?

Includes plants and animals but excludes parasites and pathogens;

Includes native and invasive parasites and pathogens;

e.g., the extinction of a plant species may have knock-on effects for a specialist pollinator. Difficult to separate from, and embedded within, habitat loss/degradation;

Hybridisation with non-native subspecies.