94 MAMMALIA 



it to be due to rabbits. When I was in the Nelson district in 1872-3 there 

 were no rabbits on the eastern side of the Upper Wairau near Tarndale, 

 but they were abundant on the western side. Spaniards were abundant 

 on the eastern side, but almost destroyed on the western. The rabbits 

 seemed to burrow under the plant and then eat the root. 



Mr B.C. Aston, in ascending the highest point of the Kaimanawas 

 (5700 feet) on 31st December, 1914, found the physiognomy of the 

 sub-alpine scrub, which begins above the beech forest at an elevation 

 of 4200 feet, and consists of Senecio Btdzvillii, Veronica buxifolia, 

 Olearia nummular if olia, Coprosma cuneata and Phyllocladus alpinus, 

 mottled with the brown leaves of a dead shrub. On close investigation 

 this was found to be Panax Colensoi, and on still closer inspection 

 with a view to determining the cause of death, we found every bush 

 ring-barked. I have no doubt this was done by rabbits, which after 

 a heavy fall of snow would be driven down from the tussock land to 

 the scrub and forest zone. The scrub only occurs in the gullies, and 

 the beech forest usually has a bare floor with a few Panax trees 

 scattered through it. On examination of these we found the same 

 fate had overtaken them. Trees 10-20 feet high of Panax Colensoi 

 and P. Edgerleyi were found to be dead and ring-barked. 



A certain part of the destructive and exterminating work of rabbits 

 on the vegetation in mountain districts is particularly wrought at the 

 beginning of winter. In spring and early summer as the snows melt, 

 the rabbits follow up the mountain side, and are found during the 

 summer at all elevations. I saw them in abundance on the top of 

 Mt Tyndall — nearly 8000 feet — among the snow-beds. When the first 

 heavy snows come on about April, they are driven down in hordes 

 to the lower country, and, as has been told me by more than one 

 resident in the Wanaka district, "they are as thick as locusts, and 

 they eat the ground just as bare as those insects do." 



In a good many rabbit-infested districts, particularly in the North 

 Island, these animals have aided very materially in producing a certain 

 amount of erosion and washing down of alluvium, by burrowing 

 extensively in the banks of rivers and small streams. When floods 

 came down these undermined portions were commonly swept away 

 where the firmer banks resisted the impact of the water. Professor 

 Cotton of Wellington considers that some importance can be attached 

 to this agency as affecting the physiography of certain districts and 

 river systems. Cattle, sheep and goats no doubt assist in breaking 

 down such alluvial banks, but rabbits are probably the most active 

 agents in the work. Rev. A. Don writing me in 1901 said: 



the rabbits, by so stripping the ground of vegetation and burrowing into 

 the faces of the slopes are converting what were once nice green hill-sides 



