Portrack Marsh by Garry Sharples
Gary Sharples is a keen birder and visits Portrack Marsh perhaps more than anyone
else. He writes detailed annual reports on its birds. Here he reviews what is fast
becoming a rapidly emerging site on the edge of the Tees Estuary
If you were not familiar with Portrack Marsh before, you probably are now thanks
to the unexpected arrival of two little masked invaders earlier this year. However,
there is considerably more to this site than attractive rarities. Flanked by heavy
industry, retail parks, railway sidings, and a sewage works, Portrack Marsh affords
an oasis for a multiplicity of wildlife, from Common Blue to Common Newt. This 50-acre
Tees Valley Wildlife Trust reserve lies on the north bank of the River Tees sandwiched
between the Tees Barrage and the A19 flyover (OS grid reference NZ465195). Historically,
the marsh nestled within a meander in the river, which looped around its northern
fringe. In the early part of the 19th century, ships heading to Stockton had to
be dragged by horses around this section, hence the name “Port Rack”. Eventually
a cut was made in 1830 to exclude the bend and ease traffic congestion on the water.
The resulting artificial oxbow lake was partially filled in and the western part
of the loop, known as Portrack Lake, was finally lost during the 1970s.
Today, the marsh incorporates a mixture of shallow and deeper water pools, surrounded
by gradually expanding reedbeds (containing reedmace and phragmites) and grassland,
with mature hawthorn bushes to the west and a line of trees along the northern edge.
Saplings have been planted to the north and south of the main pool. Such an excellent
range of habitats makes this an enjoyable site to visit in any season, although
winter is best for birds. Wild flowers, butterflies and dragonflies provide additional
interest during the quieter summer months. Grey Seals gorge themselves on salmon
and sea trout and otters have been spotted in recent years. Typically, 90-100 bird
species visit annually, with a total of 153 species recorded overall. Those most
likely to be encountered are described below.
Winter: Jack Snipe are regular in small numbers and tend to favour the former settling
tanks next to the sewage works at the eastern edge of the reserve. Common Snipe
can number several hundred and Kingfisher, Grey Wagtail and Bullfinch are easy to
catch up with, offering a touch of colour to brighten up the short, dull days. Chiffchaffs
occasionally winter in the trees at the northern end and a couple of Stonechats
play hide and seek amongst the reeds. Siskins and Lesser Redpolls regularly adorn
the alder trees. The hawthorns along the western border formerly held roosting Long-eared
Owls and two were present this spring, although these were the first in 5 years.
Hunting Short-eared Owls are much more likely. Redshank and Lapwing are present
in good numbers; they feed on the river bank and take refuge on the marsh at high
tide. Shoveler, Mallard, Pochard, Tufted Duck and Teal frequent the pools, occasionally
joined by Goldeneye or Scaup. Coastal species are sometimes enticed upstream by
the large numbers of fish trapped below the Barrage. Red-throated Diver, Red-breasted
Merganser, Shag, Common Scoter and Guillemot have all been recorded. The five common
gull species are evident and a Yellow-legged Gull frequented the nearby Tees Barrage
from June 2004 to March 2006 and may yet make a return visit.
Spring: Sand Martins are often the first of the summer migrants to arrive and linger
to nest in the southern bank of the river at Maze Park. Regular spring passage visitors
include Wheatear and Whinchat. This is a reliable site for Grasshopper Warbler,
with 2-3 reeling into July. Other common warblers include Whitethroat, Willow Warbler,
Blackcap and Sedge Warbler. Singing Reed Warblers have been more evident in the
last two years. Water levels on the marsh are often high, so wader passage is mainly
restricted to Common Sandpiper and Ringed Plover. Common Terns arrive in the second
week of May and remain throughout the summer.
Summer: As expected, this is the quietest period for birds. Little Grebe, Coot,
Moorhen and Lapwing all breed, as do Mute Swan and Canada Goose, albeit more sporadically.
Little Ringed Plovers have bred in the past (2002) but have not been seen in the
last two years. Lesser Black-backed Gulls are numerous and Oystercatcher and Curlew
regularly fly over but rarely land. Common Terns resting on the main pool are sometimes
joined by one or two Sandwich Terns.
Autumn: By late summer significant amounts of mud can be exposed and waders such
as Dunlin, Black-tailed Godwit, Greenshank and Ruff show well. Green Sandpiper,
Wood Sandpiper, Curlew Sandpiper, Knot and Turnstone have also occurred but much
less frequently. Gadwall and Wigeon are at their commonest during this passage period.
Rarities are indeed rare but have included some exciting finds: Bluethroat (May
1995), Pectoral Sandpiper (September 1994), Spotted Crake (May 1996), Corncrake
(June 1998), Ring-billed Gull (February 2001 and March 2002), Great White Egret
(August 2001 and October 2002) and Penduline Tit (March-April 2006). Some commoner
bird species are surprisingly thin on the ground here. For instance, House Sparrow
has yet to be officially recorded within the marsh boundaries. Others due a first
visit include Barnacle Goose, Black-necked Grebe, Brambling, Coal Tit and Little
Egret, giving plenty of scope for new additions to the list.
Portrack Marsh can be accessed from Thornaby railway station (a 15-20 minute walk)
or by car from the A66; there is ample parking at the Talpore Travel Inn and on
both sides of the river at the barrage. The site is also accessible by bicycle as
part of the National Cycle Network (see: www.sustrans.org.uk and www.doitbycycle.com).
Further useful information can be found in ‘Where to Watch Birds – Northeast England’
by Britton and Day (ISBN 0-7136-6826-1).