144
THE ESSEX NATURALIST.
There are no surprises to be found in these pellets—the interest
of them lies rather in the fact of their uniformity, which is
no weak evidence of the usefulness of this species to the farmer
and the gamekeeper.
The other owls represented are the Short-Eared and the
Tawny. In the pellets of both occur Geotrupes, the dor-beetle.
The means of identification of the three types of mammals
so universally devoured by birds of prey—shrews, voles and
mice—may be of interest. In all, the teeth are the distinguishing
mark of the type. Shrews have a complete series of teeth,
being insect eaters and not rodents. Their teeth are all con-
spicuously red brown at the tips, the front incisors in each jaw
are longer than the rest, those of the upper jaw being curved.
Voles and mice are readily distinguished by means of their molar
teeth. Being rodents, there is a wide, toothless gap between
the incisors and the molars. The latter in voles are composed
of alternating triangular prisms; in mice the crown of each tooth
has a series of tubercles, forming a pattern. Thus the Field
Vole is readily distinguished from the Field Mouse by the pattern
of the teeth. In the House Mouse the third molar in both jaws
is diminutive. The molars have roots in Rats and Mice—those
of the two commonest voles, the Field Vole and the Water Rat,
are rootless.
The hairs of the fur of these small mammals are interesting,
but do not give certain evidence in every case as to the identity of
their owners. Those of the mole and shrew invariably show a
twist-like extension—that of the mole being more pronounced than
in the shrew. No other hairs that I have examined show this
feature. The jointed hairs of bats are characteristic. I
could not distinguish between the hairs of a vole and of a mouse.
To pass on to the Heron. Of Mr. Christy's three birds, one
had fed on a shrew, on a very large number of small larva of
Dytiscus and on one Water-boatman. The second had within him
a fair-sized frog, and the third had dined on a mature Dytiscus
and on a frog.
The collection includes a mass of fish-bones which had
lined the nest of a kingfisher, according to the usual custom of
this bird.
Of the three members representing the Ducks and Geese
the Mallard had eaten a frog, the Goldeneye showed whole and