350 TUTIRA 



Experts can calculate the quantity of bumble-bees required to "set" 

 300 acres of tall cow - grass ; in any case, it would be immensely 

 greater than the district could produce. As a matter of fact, the 

 number of bumble-bees was insignificant in 1909, nor are their numbers 

 likely to increase. This alien, like others, cannot quite adapt itself to 

 the peculiar climatic conditions ; any large increase is checked by the 

 deluges that from time to time pass over the run. 



A second northern centre of dispersion from which aliens have 

 reached Tutira has been Wairoa. From there have arrived the green 

 frog, of Australian origin, and, I believe, the " opossum," also from 

 Australia. Frogs reached Tutira in '94, being reported almost simul- 

 taneously on the east and west of the run. They are great climbers ; 

 I have got them not only on hill-tops up which they might have 

 been tempted by a gradual rise, but on steep cones like the " Natural 

 Hill "and the "Dome." 1 



They have never become plentiful on Tutira. About shallow 

 lagoons and surface water-holes harrier hawks take them ; in deeper 

 waters, I believe, they are devoured by eels. 



Opossum were turned out in the Waikaremoana forest reserve 

 in 1900 ; we believe, though they were never actually seen on Tutira, 

 that they passed southwards five years later ribbon- wood saplings 

 were peeled and succulent willow shoots barked bare, the hard cores 

 of both showing the tooth-marks of a large rodent. Our willows and 

 ribbon-wood had never before been thus peeled, and they have never 

 been touched in that way again. 



1 Mr J. N. Williams tells me that frogs, liberated at a dam on Edenham, "almost at once " 

 reached the top of the highest hill on the station. 



