The Birds of Hertfordshire have been carefully observed, and the appearance of rare visitors has been duly recorded.  At a lecture delivered at St. Albans in 1902, Mr. Alan F. Crossman, F.L.S., F.Z.S., stated that 212 species had been known to visit the county, and mentioned, inter alia, that the kingfisher is more numerous in Hertfordshire than formerly, that the heron nested in the county for the first time in 1901, and that the appearance of the bearded titmouse had been noticed on but three occasions.  During the last forty years the following birds, among others, have been noticed as occasional visitants:  the storm-petrel (Procellaria pelagica), golden oriole (Oriolus galbula), whooper-swan (Cygnus musicus), snow-bunting (Plectrophanes nivalis), greater spotted woodpecker (Picus major), black tern (Hydrochelidon nigra), great northern diver (Colymbus glacialis), herring-gull (Larus argentatus), cormorant (Phalacrocorax carbo), tufted duck (Fuligula cristata), hoopoe (Upopa epops), crossbill (Loxia curvirostra), sheldrake (Tadorna cornuta), Guillemot[d] (Lornvia troile), Pallas’ sandgrouse (Syrrhaptes paradoxus), rock thrush (Monticola saxatilis), black redstart (Ruticilla titys), Dartford warbler (Silvia undata), grasshopper warbler (Locustella naevia)[d], waxwing (Ampelis garrulus), twite (Linota flavirostris), hen harrier (Circus cyaneus), buzzard (Buteo vulgaris), redshank (Totanus calidris), greenshank (Totanus cunescens) and the little auk (Mergulus alle).

The lapwing is thought to be increasing in numbers; the writer frequently observed considerable flocks during his recent rambles in the county.  Finches are perhaps as numerous in Hertfordshire as in any other county of equal size; the large flocks of hen chaffinches that haunt the farmyards in winter being quite a notable feature.  The goldfinch, it is to be feared, is rapidly becoming scarcer; as are also the jay, the woodcock and other birds much more numerous a few years back.  Fieldfares and redwings visit the county in great numbers from the N. during the winter; one morning in the winter of 1886 the writer saw many thousands of fieldfares pass over St. Albans from the direction of Luton.  The redwing, being largely insectivorous, is often picked up dead in the fields when the frost is unusually severe and food proportionally difficult to obtain.

The presence of many woods and small streams attracts a good proportion of the smaller English migrants; the nightingale and the cuckoo are heard almost throughout the county.  Moorhens, coots and dabchicks are abundant; the reed-sparrow is heard only in a few districts.  Titmice, great, blue and long-tailed, are well distributed.

V. POPULATION