Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 3. (Budapest 1953)
Szunyoghy, J.: The harvest mouse in Hungary, I
I have observed the building of the nest in two kinds of habitats : in sedgy, and in grassy, but always wet biotops. In sedgy areas the frame of the nest was made of frayed sedge leaves, it is absolutely unestimable how much leaves the mouse uses for the construction of the external nest and how much for its support. There was a nest made of 6 leaves, and another one made of 18 leaves. Neither can it be said that it makes its outern case of sedge leaves only in a sedgy habitat, for if there are some Gramineae among the sedge, their leaves will also be used. As I have stated above the nest of the harvest mouse has always a loose, roughly interwoven, external case. If one tries to cautiously unwrap this outer case the inner nest core, woven more densely and usually of finer and different vegetable materials, appears. This can be separated and extricated from the rough outern wrapping (figs. 3., 6., 7.). The situation of the nest itself can be different : it is either supported (figs. 1., 4., 8.) or hanging (figs. 2., 5.). The supported nests are well propped up by leaves, while the hanging nests, owing either to the small numbers of leaves used in the construction of it or to the peculiar position of the leaves, seem to be hanging, in mid-air. The nest itself is held together by the loosely knitted external case. The leaves serving for this purpose are, in a sedgy habitat, drawn together like a tent from an average area of 1 m 2 . This loosely woven external case increases the elasticity of the nest, the easily bending leaves giving free vent to the play of the wind, and they do not get torn. The further fixation and safer support of the comparatively heavy nest is also enhanced by such reed or sedge stalks as grow through its material later. Reeds of the previous years may be built also as supporting, columns into the texture of the nest during construction. Tn sedgy habitats the length of the nests are 10,5—14 cm, their length 7—8,5 cm. They are built 70—80 cm above ground. In sedgy, areas the external case of the nest is predominantly made of the shredded leaves of Carex riparia, in some cases of Molinia caerulea : the internal core is of the webbing together of the leaves and stalks of Poa pratensis. The hollow of the nest is padded either by the panicles of Phragmites vulgaris or of chewed up and therefore unidentifiable leaf fragments of various grasses. I have received the other group of the nests of the harvest mouse from wet, grassy habitats. Their construction is exactly similar to the above ones. There is also here a loosely constructed external case and a finer, more compact, inner nest. Their measurements also equal those which are built upon sedges. They also are supported or hanging. As the vegetation is lower here, the grasses used for the construction of the nest are drawn together from a smaller area of about 25—35 cm 2 . The height of the nests above ground are 20—25 cm. To build its nest the harvest mouse uses 80—180 leaves of grass ; for its external case a kind of Graminea, possibly Festuca pratensis : for the inner nest probably Poa pratensis. I say probable only because the material of the examined nests were in a very desiccated stage and so their determination was not absolutely possible. 1 have to remark finally that literature mentions a summer and winter nest (M i 11 a i s 1905 ; E. Möhr 1950). I succeeded to get only summer nests sofar but no winter ones.
