Increasing use of exotic forestry tree species as
refuges from nest predation by the Critically
Endangered Mauritius fody Foudia rubra

The population of the Critically Endangered       
Mauritius fody Foudia rubra fell by 55% over 1975–1993       
because of habitat destruction and predation. The species    
was believed to be dependent on a small grove of intro-      
duced, non-invasive Cryptomeria japonica trees that of-      
fered protection from nest predation. We investigated the    
current population size and distribution of the fody and     
compared nesting success in forestry plantations to that of  
a released population on an offshore island. The popula-      
tion size on the mainland has remained stable over the past  
10 years, with increases in pine Pinus spp. plantations, but 
continues to decline in areas of predominantly native vege-  
tation. Only 16% of pairs found were estimated to nest in    
native tree species. Up to 81% of nest failures on the main- 
land were attributed to predation but nesting success in     
C. japonica and pine trees was similar to that of a released 
population on a predator-free offshore island. The main-     
land population is increasingly dependent on plantations     
for survival and we predict this will continue. Management   
and protection of non-invasive exotic species, together      
with creation of native habitat refuges on the mainland and  
offshore islands can be used to increase numbers of threat-  
ened birds in areas where predator control is not feasible.