The Ship Rat’s Rattus rattus more common name of Black Rat can be misleading as it may be brown in colour, while the Common (or Brown) Rat Rattus norvegicus can on occasion be black. The two species are similar in appearance but the Ship Rat has proportionately larger ears and eyes and a longer, thinner tail than the Common Rat, with the effect that the differences in general appearance are similar to that between the Wood Mouse Apodemus sylvaticus and the House Mouse Mus domesticus.
It is much more agile than the Common Rat and in the period when both species could regularly be found together in buildings, the Ship Rat was typically found in attics and roofs, leading to its third common name, the Roof Rat, whereas the Common Rat was found in basements and sewers (Buckland, 1858). It should of course be borne in mind that it was the only rat in Britain until the introduction of the Common Rat in the 17th century.
Originally from the Deccan Peninsula in India the Ship Rat is more suited to warmer climates than that of much of Britain, and in this country it has been confined almost exclusively to buildings with the exceptions of colonies on the islands of Lundy and the Shiants (Twigg, 1993).
It was thought that the species had been introduced into Britain during the Crusades but it is now known to have been present since the early Roman period (Yalden, 1999). Its history in the North East is equally long: excavation of a Roman granary in South Shields found that Ship Rats made up as much as 10% of the individuals of the small mammal fauna associated with the location of the granary (Younger, 1994).
There is some evidence that it died out in Britain, or at least became rare and localised, in Anglo-Saxon times, though it was back by medieval times and widespread enough to be the vector for the Black Death in the late 1340s (Yalden, 1999). Its subsequent history in the North East appears to have been only patchily recorded. There are medieval records from the monastery at Jarrow, though its bones were found to co-occur with those of Common Rats, which leaves some question as to the stratographic integrity of the deposits. Its bones have also been found in drain deposits dating to the 15th century from the Great Hall at Barnard Castle, and later, in the 17th century from a pit in Blackgate in Newcastle (Stallibrass, 1995).
In a paper in the Transactions of the Natural History Society of Northumbria, Dr Embleton (1854) compared the anatomy of the two species of rat, obtaining his specimens from Stockton “which is, as far as I know, the only locality in our district where the black rat is yet to be found.” To this, Mennell and Perkins (1964) add: “where, as in many other places in our district, the species still lingers, though in constantly diminishing numbers.” From various references at the time, it would seem that the species’ distribution was somewhere between that of one location and many places. Middleton (1879) states: “The animal lingers in one old building at Stockton-on-Tees (NZ/41) and there is clearly a possibility of it being re-introduced in many seaport towns through the agency of ships.” Likewise, Clarke and Roebuck (1881) describe it as: “Extremely local, appearing to occur only at Stockton-on-Tees (NZ/41), where it is not unfrequent [sic] in one or two old buildings”. Faber (1879) on the other hand states “Last year  I caught two in my own house and a neighbour caught three in his stables … I also (Last year or the year before [1878 or 1876]) saw a man carrying one in a trap …. and which I heard had been caught in a warehouse in the town. Mus rattus is certainly not confined to “one old building at Stockton-on-Tees (NZ41).”
Black Rats were also to be found, at least sporadically, on Tyneside, about which Embleton (1884) states “Mr Gurney’s specimen therein noticed must have been from Gateshead, though it is quite probable that it had migrated from Newcastle, or escaped from some ship. The Black Rat has not been recorded from this town [Newcastle] because probably it has not been sought for … We know the Black Rat exists in some old premises in the Close, a narrow street in Newcastle-upon-Tyne, by the river side, above the bridge, where it appears to have been for some time, and that it has been seen at times on board ships laying at the Quay.” A few decades later it was still being encountered, with T. Russell Goddard (1926) reporting “In December 1925, Mr J. Alaric Richardson sent up to the Museum a wire cage trap containing four rats caught the previous night in a warehouse at Elswick Leather Works. Three of them were the typical form of the Black Rat, Rattus rattus rattus and the fourth Rattus rattus frugivorous.”
This same pattern, of Ship Rats being confined to relatively small numbers in ports along the North East coast, continued throughout the 20th century. In 1939, Colin Matheson published the results of his investigations into the numbers of Black Rats killed on ships entering seaports in England and Wales and within docks, quays, wharves and warehouses in those seaports from 1925 to 1937. This was based on a questionnaire sent to the Medical Officer of Health of the Port Health Area of each “approved port” in Great Britain and Ireland. Of the 22 replies received, two were from Middlesbrough and Sunderland. In Middlesbrough around 10 to 20 Ship Rats were killed on ships each year from 1929-1937. In the adjacent docks 216-456 were killed each year from 1934–1937 though in the preceding six years numbers killed were generally in single figures. In Sunderland the average number killed on ships was slightly higher, though the number killed in the docks was less than 20 per annum.
Some 20 years later another questionnaire, sent to every local authority in the UK by Bentley, looked at the status of Black Rats in 1951 compared to 1956. It found that most authorities reported a complete absence of Ship Rats. Nevertheless in 1951 it was still the case that Ship Rats were regarded as “always present somewhere in … Newcastle; South Shields; Hartlepool and Middlesbrough” (Bentley, 1959). By contrast, in Stockton and Sunderland, more than five infestations had been recorded but the species was not thought to be permanently established, whilst both Eston and Thornaby had seen fewer than five infestations. Only in Middlesbrough and Hartlepool was the Black Rat present outside of the immediate port area but in those cases its status was thought to be precarious. By 1956 the species’ hold in the North East had diminished to the extent that it was absent from Stockton and there were fewer than five infestations at South Shields, whilst at Hartlepool it could still be found at the docks but no longer outside of them.
Further work by Bentley (1964) found that the Black Rat’s toehold on the North East had become even more precarious and in 1961 there were no infestations from either Newcastle or Hartlepool and just a single Black Rat reported from Middlesbrough. However a later questionnaire by Twigg (1992) found that there had been an increase in records for the period 1985-89 with Black Rats being occasionally found and exterminated on ships on Teesside and West Hartlepool, and while not usually found on shore, two rats were found in a cargo of bananas that had reached a market in Gateshead.
Also around this time, Mr Graham Wood, Director of Tyne Port Health Authority (pers. comm. to T. Coult, 1989) claimed that typically two ships a year with Ship Rats would be dealt with, mostly Russian factory ships. In 1988 some 55 Ship Rats were killed. One of the authors received six Ship Rats (mostly of the brown form) that had come from a batch of 25 that had been killed on a Japanese ship, which had docked in Teesport in June 1992. The ship’s last port of call had been Burma.
In 2011 one of the authors contacted North East Local Authority pest control officers to see if any of them had encountered Ship Rats in their area. Responses were received from the boroughs of Redcar and Cleveland, Middlesbrough, Hartlepool, Sunderland, South Tyneside, North Tyneside, Newcastle and also the Port of Tyne. While the period of search was not stated and probably just related to the length of time individual officers had been in post, none had come across Ship Rats. However the pest control officer working for South Tyneside Council knew of a problem with Ship Rats at Seaham Docks about five years previously and another comparatively recent occurrence at Sunderland Docks, though both instances were dealt with by private contractors and both were thought to originate from incoming ships.
All of the above documented references to Black Rats in the North East, and others not cited in this account, relate to its presence in ports or port towns. The only inland place in the North East where it appears to have been recorded is Durham City. Canon Tristram knew of a colony in the vicinity of Durham Cathedral when he was at school in Durham in the 1830s, which had been there “since time immemorial”. The last specimen was supposedly taken in 1879 but a Mr J. Cullingford reported that one was taken near the town in the 1890s (Page, 1905). However James Rackham (pers. comm. to T. Coult, 1988) was brought a mummified Ship Rat carcass that had been found on an internal ledge within the Cathedral, which he considered to be unlikely to have been any older than a few decades. He also recalled a rat which had been found in Dun Cow Lane as being of this species, though he was not prepared to state this as an authoritative identification. Around 1960, when he was a student at Durham University and waiting for a date outside what was then the Regal Cinema, Gerry White found a Ship Rat dead in the gutter. Uncharacteristically unprepared for scraping up dead rats, he had to leave it there but nevertheless was absolutely certain of the identity of what is possibly the last North East Black Rat record outside of a port town.
Written by Ian Bond, Colin Howes and Terry Coult (last updated Nov 12)