Northern Waterthrush (BBRC)

Northern Waterthrush Parkesia noveboracensis

Vagrant. North America.

Northern Waterthrush Gibraltar Point October 22nd 1988 (P. Davey)

There is one county record from Gibraltar Point on October 22nd-23rd 1988 which is by some way the most astonishing of the American landbirds to be found in the county. It was trapped and ringed in the East Dunes on October 22nd. This constituted the fourth British record at the time after records in 1958, 1968 and 1982 (all on the Isles of Scilly) and was the latest by nineteen days. Five of the seven records to 2019 have been on the Isles of Scilly, the other was at Portland, Dorset, Oct 1996.

So how did this bird arrive in Lincolnshire? The five records on the Isles of Scilly arrived between August 29th-October 3rd, that on Portland was later, October 14th. So the very late date for the Lincolnshire record compared to those on Scilly suggests an earlier arrival somewhere in Britain or even further north in Norway as most recently arrived American landbirds take significantly longer than Siberian birds to feed up and recover. When trapped it weighed 16.1g, and this is quite similar to quoted weights of this species wintering in Central America, northern South America and the Caribbean which suggests it had arrived earlier further north, made good weight gain and then drifted south down the east coast with regular Palaearctic migrants (The weather at the time in Lincolnshire caused large falls of thrushes, finches, buntings and Goldcrests, Regulus regulus). The true mechanism behind the arrival of this absolute gem may never be absolutely known but it was certainly a once-in-a-lifetime experience for those who saw it.

Northern Waterthrush at Gibraltar Point October 22nd-23rd 1988, first county record.

by Ian Hartley and Ken Winfield.

Note: this account is taken from the Lincolnshire Bird Report of 1988, together with some details from the original RC submission. The RC report for 1988 noted that this was the first since 1983 (one on Cape Clear Island, Co. Cork); previous British records were all in the Isles of Scilly, in 1958, 1968 and 1982. This is the latest arrival by 19 days.

Circumstances

October 1988 saw the arrival of some of the best falls of autumn migrants for many years on the east coast of Britain. Gibraltar Point Bird Observatory was one of many sites which saw mass arrivals of birds with 1600 Goldcrests, 800 Blackbirds, 100 Song Thrushes and 50 Robins being recorded on the 22nd. Over 650 birds were ringed that day, most of which were Goldcrests, thrushes, and Robins. At approximately 10.00 hr, a bird was mist-netted in the East Dunes, which could not immediately be identified by any of the observers present, although with the help of a suitable American field guide (Peterson and National Geographic), the bird was quickly identified as a Northern Waterthrush.

Description

General impression  - at once, the bird was seen to be something good - it was a small, Redwing-like bird with a large supercilium about the size of a plump pipit.

Upperparts - dark, chocolate brown from the tail to the top of the head with paler cream edges to the tertials, and a broad cream supercilium 2.5 mm. wide at the eye and extending from the nostril to 18mm behind the eye. Eye-stripe and cheeks as other upperparts. Tail short and square at the end. Upperwings the same uniform dark brown but with a pale edge to inner tertial.

Underparts - breast and belly creamy buff streaked dark brown, more heavily on the flanks. Throat cream with very fine brown flecking. Undertail coverts pale cream-buff, large central feathers grey-brown towards base, with a pale cream distal half.

Soft parts - Upper mandible dark horn with paler cutting edge. Lower mandible dark horn at tip, pinker at base. Eyes very dark brown. Legs pink with some dark horn scaling on the toes.

Biometrics - wing 76 mm; tail 51 mm; tarsus 21mm; hind claw 6mm; weight 16.1 g.

Wing formula -  (measurements in mm) from wing point (WP), or longest primary covert (PC); E = Emargination:

Ss      10      9        8        7        6        5        4(E)    3(E)    2        1

-191   -17     -15     -12.5  -10.5  -7      -3      -1      WP     -1.5    -9.5PC

The bird was later trapped two times on October 22nd but subsequent field sightings of the bird were infrequent, although it was seen skulking in the East Dunes in some bushes when it flew off along the net ride, on October 23rd. It was occasionally heard to give a distinctive “chink” call reminiscent of Great Spotted Woodpecker. Bobbing behaviour, similar to that of Common Sandpiper was also observed.

The Northern Waterthrush is a common summer migrant to much of North America and winters from Central America south to Peru. The only other species which could cause identification problems is Louisiana Waterthrush, which is a less common summer migrant to central America and has not been recorded on this side of the Atlantic. Northern Waterthrush is finely streaked on the throat and has a creamy supercilium, whereas Louisiana Waterthrush has a plain, white throat and supercilium.

This constituted the first record of Northern Waterthrush for the county and the 5th record for Britain and Ireland, the previous birds being seen on the Scillies (3) and in Ireland (1). The occurrence of North American passerines in Britain usually coincides with westerly winds. It seems strange therefore that this bird’s arrival coincided with a mass arrival of North European migrants from the east*. However, interestingly, two other North American species also turned up on the British east coast in the same two day period – an Indigo Bunting in Norfolk on 22nd and a Cliff Swallow in Cleveland on 23rd.

*see modern day theory, above.

Reference

Smith, J. (2010). Influence of Moisture and Food Supply on the Movement Dynamics of a Nonbreeding Migratory Bird (Parkesia noveboracensis) in a Seasonal Landscape. Ecology 91(10: 2874-2882

 (Account prepared October 2017; updated with reference to the new Birds of Lincolnshire (2021) January 2023)