The removal of dead limbs is usually done for aesthetic reasons, or risk management. Where carried out correctly, the removal of dead branches from trees will have little to no adverse impact on tree health.
The removal of dead branches from tree crowns is not always necessary. Cracks and hollows in decaying timber can provide valuable habitat to birds, lizards, spiders and insects. Dead branches provide perching sites for many bird species that would otherwise not visit the tree. Shortening large dead limbs that may fall is an effective way to reduce the likelihood of failure while maintaining habitat values.