BIRDS OF THE THAMES VALLEY (ESSEX ONLY). 161
Sand Martin (Riparia r. riparia (L.)). A colony in a large
pit at Mucking, birds entering holes, 18/7/26. Last dates,
12/9/26 and 2/10/27, only one being seen on the latter date.
Kingfisher (Alcedo atthis ispida L.). East Tilbury, two on
a fleet, 11/9/27 ; East Haven Creek, one, 27/11/27.
Little Owl (Athene noctua vidalii A. E. Brehm). Vange,
24/10/26; Mucking, 11/9/27 ; Fobbing, 6/11/27 and 19/2/28.
Short-eared Owl (Asio f. flammeus ((Pontopp.)). Fobbing
Marsh, two, 6/11/27. Both birds were seen in the air together
and were vigorously mobbed by gulls and crows.
Sparrow Hawk (Accipiter n. nisus (L.)). Canvey Island,
one, 21/8/27; Bowers Marsh, one, flushed from a reed-bed,
13/11/27.
Common Heron (Ardea c. cinerea L.). Identified during all
months of visits except March, but never in any numbers,
single birds usually being seen. No seasonal variation observed
White-fronted Goose (Anser albifrons (Scop.)). A flock
of over 150 was seen on Corringham Marsh on January 15, 1928.
I have never had better views of geese, which generally are very
wild and difficult to approach, but this skein allowed me to
get so near that I thought they must be domesticated birds.
They were very busy feeding on the grass and I was given plenty
of time to put up my telescope and examine and count them
individually. There were among the flock one or two other
geese, probably Pink-footed. After completing my examin-
ation I put up the birds, when they broke into two characteris-
tic "V" shaped flights. I was afterwards informed that the geese
stayed on the marsh for about a week.
Sheld-Duck (Tadorna tadorna (L.)). Identified in all months of
visits except July and November. Localities, Mucking Flats,
Canvey Island, Corringham Marsh, East Tilbury and New Eng-
land Island, but the first named was the favoured haunt of the
Shelduck, and it was here only that the species was seen in any
numbers. In this locality, 30 were seen on 13/3/27; 44, all im-
mature, 11/9/27 ; 100 in mixed flock of 200 with Mallards,
2/10/27 ; and a flock of 166, 15/1/28. This flock, the largest I
have seen in Essex, was probably the result of the previous
severe weather. A pair with four young was seen on May 15,
1927 on Shelford Creek.
Mallard (Anas p. platyrhynca L.). Identified during all