Tolerance niche expansion and potential distribution prediction during
Asian openbill dispersal
Abstract
Aim: Understanding the tolerance niches of species plays an important
role in studying the mechanisms of species dispersal and invasion.
Taking the rapid dispersal bird, Asian openbill (Anastomus oscitans), as
a model species, we identified ecological niche changes in the process
of its dispersal, explored the potential distribution, and evaluated
population evolution trends. Location: East Asia, South Asia, Australia.
Methods: We used the ecological niche models Niche A and ecospat to
compare the spatiotemporal change in the observed niche of Asian
openbill, divided into original native, China, Malay Peninsula, and
present distributions. Moreover, several models were generated using a
biomod2 ensemble modeling framework to predict the trends and potential
distribution of species. Results: The observed niche of Asian openbill
was stable between the original native and present distributions. The
Malay Peninsula population represented significant niche conservatism
and propagable climate conditions. The rate of niche expansion reached
77.61% among the population in China, which was able to tolerate colder
temperatures than the native population. Models indicated that Asian
openbill dispersal was more suitable at low latitudes. According to the
best performing model, Random Forest, the distribution probabilities of
the China and Malay Peninsula populations were much higher than random
expectations. Main conclusions: We concluded that the novel tolerance
niche during northward dispersal exceeded the native observed niche,
which should not be neglected because of the cold temperature tolerance
for the evolution of the species in the future. In addition, northward
and southward dispersal corridors have opened and the possibility of
reproduction in the southward population was higher than the northward
population. Asian openbill dispersal behavior will continue both north
and south, but multiple factors affect dispersal rate and durability,
and the model results require more fundamental data on the source and
new southern populations.