About natural hybridization different opinions exist among specialists.

Behavioural and ecological correlates of natural hybridization in birds.

The species is very difficult due to natural hybridization and is hard for both research and enforcement.

In eastern Myanmar there is some natural hybridization with Pycnonotus aurigaster.

The Lonicera fly is an example of a novel animal species that resulted from natural hybridization.

However, some observers consider such variations as evidence of natural hybridization with other species of grapes.

This is the highest rate of natural hybridization so far reported and is significantly greater than rates observed elsewhere in Europe.

The problem of its species status and placement in the genus is complicated by extensive natural hybridization with Tilia americana.

The species is highly variable, possibly a result of spontaneous mutation, natural hybridization, and autopolyploidy.

Study of natural hybridisation in some tropical plants using amplified fragment length polymorphism analysis.