Realized niche shift during a global biological invasion

Area of Science:

• Ecology
• Invasion Biology
• Evolutionary Biology

Background:

• Accurate biological invasion forecasts are vital for management.
• Niche shifts (fundamental and realized) complicate invasion prediction.
• Traditional methods focusing only on realized niches are insufficient.

Purpose of the Study:

• To differentiate between fundamental and realized niche shifts in invasive species.
• To investigate the invasion dynamics of the cane toad (Rhinella marina).
• To develop a novel approach combining mechanistic and correlative niche models.

Main Methods:

• Combined a physiologically mechanistic model of the fundamental niche with correlative models of the realized niche.
• Studied the global invasion patterns of the cane toad (Rhinella marina).
• Contrasted niche filling in native and invaded ranges.

Main Results:

• Cane toad success in Australia is linked to a realized niche shift, not evolutionary changes.
• Rhinella marina does not fully occupy its fundamental niche in South America, coinciding with hybridization.
• In Australia, cane toads occupy a larger portion of their fundamental niche due to the absence of coevolved species.

Conclusions:

• Biotic interactions, such as hybridization, significantly limit species' realized niches.
• The combined modeling approach provides insights into range limits and invasion success.
• Findings can inform invasive species management and assisted colonization strategies under climate change.