When we turn to the causes of the outbreaks, we find that British period writers arrived independently at the same conclusions as had been deduced by observers during the French period. Within two months of his arrival on the island in August 1770, at the very time that the island was experiencing a plague, Governor Patterson (1770) espoused a cause very similar to that which Jean-Pierre Roma had worked out in more detail at Three Rivers during the French period. Patterson wrote: My opinion is it depends entirely upon the sort of Winter we have. As I am informed the last was an uncommon one. The snow falling before the Frost came on, by which means the ground was kept soft; and the Mice in place of being partly destroyed by the Frost, as is commonly the case, bred under the Snow. By contrast, John Stewart (1806), as had Joseph de La Roque and Louis Franquet during the French period, considered the outbreaks to be caused by the high production of beech mast in certain years, and accordingly, they thought that, with the decline of the beech woods with increasing settlement, so the outbreaks would cease: lt being well known their increase is owing to the great crops of beech mast, produced occasionally in certain districts, as a proof of which is observable, that in those parts that are remote from any quantity of that wood, no injury to the crops has ever been known to happen. Elsewhere, more specifically, Stewart said that the ’mice’ became "very plentiful the year after a great crop of beech mast”.3O Six years later Bishop Plessis of Quebec, while on a five-day episcopal visit to the island in 1812 added more detail to Stewart’s theory, which he must have learned from someone on the island: One recognizes that there will be mice in large numbers when there has been a lot of beech mast in the woods the year before, because they nourish themselves with this fruit, and multiply, to the misfortune of the farmers. Is there a shortage of beech mast? One thanks heaven for it, because the mice, deprived of this nourishment, he quotes one person as saying “all the species known in the country“ were abundant in the plague year; another person, that “the jumping mouse was also numerous"; and a third person, that in addition to the [meadow mouse], “a smaller kind appeared". 30 Stewart expended two paragraphs in defending what he viewed as a slur on the island's reputation, coming especially from Nova Scotians. that the island was subject to frequent mouse plagues: such outbreaks, he said, had happened only “two or three years" in his thirty on the island, and that even in those years there had been only the partial destruction of the crops, and that had happened in just some parts of the island. 242 die of hunger the following year and only a few of them survive.31 Other mice and voles — Sutherland (1861) knew of two species of ’field mice’, though he said that it was likely that a fuller investigation might discover one or two others. The first, as we have seen, he called the ”burrowing field mouse”, and this appears to have been the meadow vole (Microtus pennsy/vanicus). His second species, which he called the ”leaping field mouse”, given its ”long tail and strong hind legs”, is likely to have been the meadow jumping mouse (Zapus hudsonius), though Sutherland did not realize that there was another species of jumping mouse on the island, the woodland jumping mouse (Napaeozapus insignis) .32 The second recorder to distinguish between the native mice and voles was Bain (1890) who was aware of three native species: his "short-tailed Meadow Mouse” can only be the meadow vole, Microtus pennsy/vanicus, since his brief description fits this species: ”it lives on grain and grasses, and builds a nest of dry grass and makes long galleries under the snow in winter when it causes much destruction by barking young orchard trees”. His two other species, he said were "much less common”: his ”White—Footed Mouse” can only be the deer mouse, Peromyscus manicu/atus, while his ”Hamster Mouse” may be the red-backed vole, C/ethrionomys gapperi. He thus did not record either species of jumping mice. The first notice that I have come across in the written records of the presence of the European rat and mouse on the island (the brown rat, Rattus norvegicus, and the house mouse, Mus musculus) is that of Johnstone (1822) who said "there are rats and mice, the same as at home".33 Bain (1890) also recorded the presence of these 3‘ Plessis 1812. It is interesting that in the late nineteenth century Patterson (1886), having examined the anecdotal evidence for the 1815 outbreak in Nova Scotia, recorded the view of a contemporary of the plague that it was a combination of the two factors that was the most likely cause of that outbreak: i.e., there had been a year (1813) in which “mast, wild fruits and nuts were in unusual abundance" and this was followed by a winter in which the snow had covered the ground before it had frozen, with the ground remaining covered for the whole season. It was the occurrence of both factors in succession, he thought, that had led to the outbreak in 1815. 32 The woodland jumping mouse was first recorded on the island by Cameron (1958), 33 It is probable that Walsh’s (1803) reference to “rats and quantities of mice" also refers to the brown rat (Rattus noveg/cus).