The Eurasian Otter, the species found in the UK, has a Palaearctic and Oriental range extending southeast through Sumatra and into Java. In the UK it is well but unevenly spread across the country (Harris and Yalden, 2008).
The coat is medium to rich dark brown with long coarse guard hairs and a dense under fur which traps air to insulate the body. Body length is just over one metre and male Otters are usually larger in size and weight than females (Harris and Yalden, 2008).
Otter habitat is mainly standing and running waters from the coast to the uplands. They are able to exploit coastal waters as long as fresh water is present to wash salt from their coat in order to maintain its insulation. In the North East Otters have been found to use coastal streams in Northumberland around Druridge Bay (O’Hara, 2005) and the seaward Skelton and Kilton Becks in Cleveland. Wilkin (1979) postulates a route for Otters using the coast between the mouth of the Aln and the Coquet and that the route is still available today. In 2010 an Otter was seen attempting to catch a Razorbill Alca torda in Marsden Bay (Environmental Records Information Centre (ERIC)) and Otter presence was recorded on the Farne Islands in 2008 (Steel, 2009).
Movement throughout their linear range is usually along water courses but Otters are capable of overland migration across watersheds (Harris and Yalden, 2008). Cross-country routes may be traditional and Coult (1998) records Otters crossing watersheds between the Wear and Tees, Tynedale to Weardale, the South Tyne to the Tees, Derwentdale to Weardale and Weardale to Allendale via the Middlehope Burn. George Wall (pers. comm. to Terry Coult, 1989) recalls a former gamekeeper who maintained an Otter trapping station on the Middlehope Burn (with some success), believing it to be a traditional crossing route for Otters. Wilkin (1979) considers the Devils Water to be a route between the Tyne and the Derwent. Ritson Graham (1993) records Otters crossing the watershed between the North Tyne and the Irthing in Cumbria via the Chirdon Burn in the mid-20th century.
Diet consists primarily of the most available fish species but including seasonal exploitation of amphibians at breeding ponds, water birds, Water Voles and Rabbits. Crustaceans are taken including crayfish in fresh water and crabs in coastal waters. Coult (1998) analysed prey species from Otter spraint (faeces) on the central river Browney in County Durham where the prey species included salmonids, Bullhead Cottus gobio, Eel Anguilla anguilla, Stone Loach Noemacheilus barbatulus and Minnow Phoxinus phoxinus. Thom (1997) showed that salmonids formed a large proportion of fish prey in the upper Tyne catchment but that Minnows had an equal value during the summer and autumn. As Otters continue to recolonise populated areas there is a growing trend for them to exploit ornamental and non-native fish in artificial ponds and lakes.
Breeding can take place during every month of the year, with two to three cubs being the norm and exceptionally five (Harris and Yalden, 2008). O’Hara (2005) suggests that in Northumberland breeding occurs in late winter and early spring and the ERIC data for Durham indicates a similar, but not exclusive, preferential timing. Coult (2010) records two very young cubs, not yet water confident on 3 April 2009 at a holt (den) on the river Browney. Otter den sites may be an above-ground couch of vegetation or an underground holt of which there will be several throughout an Otter’s range. Holt sites may be natural, for example under tree root plates, in the burrows of other animals or in rock cavities, but Otters will also use artificial sites, such as disused drains. John Durkin (pers. comm. to Terry Coult, 2010) records a riparian Badger sett on the lower River Derwent in Gateshead which is also used on occasion by Otters. ERIC has a record of cubs in a flood debris stick pile on the river Wear near Durham City in 2007. In Northumberland O’Hara (2005) records breeding in a scrap yard adjacent to the river Tyne.
Otters occupy linear home ranges along water courses which may extend to take in adjacent standing waters. Female Otters have overlapping ranges and males exclusive ranges which overlap those of several females (Harris and Yalden, 2008). Spraint is deposited throughout an Otter’s range acting as a scent marker conveying information to other Otters on the utilisation of habitat resources and reducing aggressive encounters (Harris and Yalden, 2008).
An indigenous resident, Otter bones were found in conjunction with those of Brown Bear Ursus arctos and Lynx Felis lynx during the excavations of the Teesdale Caves (Simms, 1974). Mennell and Perkins (1864), suggest that “our region” can be “designated as the headquarters of this fine animal” claiming it to be “abundant in all the rivers and streams”. They quote an unnamed contributor to The Field who relates that Otters abounded on the north Northumberland and Berwickshire rivers particularly the Till, “where they were very numerous often as many as half a dozen lying on different parts of the river at the same time”. In his 1896 pamphlet William Turnbull of Bellingham who hunted the North Tyne describing how common Otters were, states “there is scarcely a spot which will not harbour them, from a town sewer, to a garden to a shed”. Mennell and Perkins (1864) also consider the North Tyne to be a good Otter river but the South Tyne, Wear and Derwent are described as “not much frequented by Otters, being only visited en passant by emigrants from the Tyne to the Tees. The reason given for the lack of Otters on these rivers is the great influx of lead-hush or wash from the mines in the west.” Further south again the Tees is considered to be a good river for Otter hunting and J.W. Fawcett (1889), the Satley naturalist, sums up in rhyme the difference between Durham’s rivers:
An Otter on the Wear,
You may see but once a year,
But an Otter on the Tees,
You may see when ‘er you please.
In contrast to this Apperley (1924) regularly found Otters to hunt on the Wear near Durham City in the late 19th century, although he does record a July 1894 hunt near Durham City, which was hampered by the river being stagnant and smelly. He also hunted Otters on the lake at Wynyard Park, Stockton.
In Cleveland, Howes (in Delaney, 1985) reports 19th century presence of Otter on the Tees (including a pre-1800 record from Middlesbrough docks), the Greta at Bowes and the Leven at Ingleby Greenhow. From the Cleveland Hills he records Otters present on Lockwood Beck Reservoir and at Kilton, Liverton and Staithes. Stephens (1957) records an historical record of Otters breeding in the town drains of Darlington, and the former Tubwell Row museum in Darlington had a preserved Otter cub, presented in 1927, which was killed in Darlington’s South Park.
Otters were also moved between catchments for hunting: Lomax (1910) records moving Otters between the Greta in Durham and the Calder in Yorkshire and buying in Otters for hunting from Ireland.
At the end of the 19th century Otters could be said to be abundant on the north Northumberland rivers as far south as the North Tyne, less well represented on the South Tyne, poorly represented on the Derwent and Wear and well represented on the Tees and its tributaries.
In 1957 The Otter Report was published (Stephens, 1957). The report summarises Otter status within discrete River Board Areas (RBAs). Northumberland and Tyneside RBA is reported as “definitely good numbers”, Wear and Tees RBA, “Very little information. Apparently Otters have been less plentiful on the upper Tees in recent years”. Possibly an early hint of the decline to come.
On 15 August 1964 T. Paisley, then the master of the Northern Counties Otter Hounds, made a much more telling observation on the status of local Otters, in a note in The Darlington and Stockton Times: “There seems to be a general scarcity of Otters in the areas hunted by the Northern Counties Otterhounds.”
The 1960s and 1970s saw the nadir in the decline of the Otter in Britain, caused by a cocktail of pollutants, principally organochlorine pesticides, combined with adverse riparian habitat management. Otters became virtually absent from Durham and Cleveland and much reduced in numbers and range in Northumberland. In response to the decline the Otter was given legal protection in 1978 and organochlorine pesticides were phased out over the 20 year period between 1962 and 1983.
The Mammal Society’s provisional distribution map for Otter, 1960-70 (Corbet, 1971) illustrates Otters being sparse in Northumberland with only the upper Tees showing records in Durham and Cleveland. One of the authors, Bob Wilkin, does recall finding spraint on the Wear and Tees in the 1970s, but it was very scarce.
In response to the Otter’s decline the first all-England survey, the Otter Survey of England 1977-79 (Lenton et al, 1980) was instituted. For the Northumbrian Water Authority area (Tweed to Tees) it found only 14 out of 168 survey sites showing Otter presence and these were on the north Northumberland rivers, nothing was found on the Durham rivers although reference is made to a small bitch Otter deliberately killed by cows at Ornella Farm, Egglesburn in 1974.
Subsequent surveys show a slow and steady increase in Otter distribution in the region as water quality and riparian habitats improve to the present day. Signs of Otter could be found sparsely on the central river Tees during the 1980s but it was conspicuous by its absence elsewhere in Durham and Cleveland. An early attempt at re-colonisation of the river Wear and tributaries occurred in March 1987 when tracks of a male Otter were found on the river Browney, and in the summer of 1988 a bitch Otter and cubs were drowned in an eel fisherman’s fyke net at Low Burn Hall on the river Wear (Tyrell Brockbank, pers. comm. to Terry Coult, 1991). By the mid-1990s Otter sign was more common on all catchments and by 2002 Otters were well distributed across Northumberland, Durham and Cleveland west of the major conurbations (Coult and O’Hara, 2002). The most recent all England survey the Fifth Otter survey of England 2009-10 (Crawford, 2010) found 135 out of 168 sites surveyed to be positive in the Northumbrian region. It describes the status of the Otter within the region as “Otters are now using all the available water courses” and “Otters appear to be using the whole of the coast in this region.”
O’ Hara (2005), describing the status of the Otter in Northumberland, writes “At this present time it is the opinion of the author that the Otter population in Northumberland is certainly at its highest since the 1950s” and “signs of Otter presence now occur on all catchments.”
Otters are recorded along the length of both the South and North Tyne including their tributaries, and in urban Newcastle they were recorded on the Ouseburn by Bob Wilkin, for the first time in over 40 years, in May 2000. In 2010 he recorded Otter sign on Willington Gut and the Wallsend Burn. They are present on the whole of the Derwent catchment including at Derwenthaugh where the Derwent joins the Tyne. On the Don they have been recorded through Boldon and down to Jarrow Slake.
On the Wear they are present on the main river and all tributaries and bred in Sunderland south dock in 2010. They are present along the whole of the Tees catchment, including the Skerne through Darlington with spraint locations suggesting a possible crossing from the upper Tees to the Eden catchment via the Maize Beck.
Otters are well established on the Leven and the lower Tees itself and have been seen around the Tees Barrage. North of the Tees Otters are now regularly recorded around the North Tees Marshes from Saltholme to Greatham Creek. They have been reported in Seaton Channel and on the beach at Seaton Snook, at the mouth of the River Tees. They have been found on the Billingham Beck as far as the Billingham Beck Ecology Park and up Claxton Beck as far as Cowpen Bewley Woodland Park (Ian Bond, pers. comm., 2012).
South of the Tees they have been recorded on almost every beck, including Marton West Beck in urban Middlesbrough and they are regularly seen at the mouth of the Kilton Beck where it flows into the sea at Skinningrove (Kenny Crooks, pers. comm., 2012).
At the beginning of the 21st century Otters have reclaimed their former territory and are well distributed across all North East river catchments including those rivers where mining and heavy industry had previously displaced them.
Written by Bob Wilkin and Terry Coult (last updated Nov 12)