NOTES ON MARSH HARRIERS
When the young are fledging and for some time after they can fly, it is usually possible to find one or other of the adults, generally the female, perching somewhere at hand. Time after time I have found the same dead bough of an oak occupied by the same bird, which is ready to take off after a crow or other possible predator. At this stage I have known a male still bring food for the female. This occurred in 1956. The female ignored the cock as he flew past her oak tree perch carrying prey ; after several runs he dropped it and went down to it. The young at this time were Aying strongly. I mentioned earlier that I usually watch from a distance. I do so because most Marsh Harrier sites are accessible to the curious and because one inevitably leaves a track through the reed bed which invites others to follow. Where the visitors can be limited by whole-time Wardens, no disturbance need result. But it is obvious that on unpatrolled marshes it is unwise to Start the ball, shall we say snowball, rolling. A fine week-end might easily spell the end of a promising nest. Also, there are still those who will try for the eggs despite the penalties under the new act. I very much hope that these notes will not send anyone out into the reed-beds. There is fine entertainment to be had from afar. G.
B. G .
NOTE ON A TAPEWORM FROM A YELLOWNECKED FIELD-MOUSE B y STEPHEN
Department of Zoology, British Museum (Natural
The writer has been afforded the opportunity of examining a tapeworm from a yellow-necked fieldmouse (Apodemus flavicollis) collected by Dr. Grace Griffith at Bures, Suffolk. The tapeworm appears to be an example of the species Catenotaenia lobata Baer, 1925, a form recorded hitherto from A. flavicollis only in Russia. The occurrence of C. lobata in this host in Britain is, however, not surprising, since the parasite has been collected on many occasions from the intestine of the wood-mouse (Apodemus sylvaticus) near Oxford * and more recently from the same host species in West Wales **. Moreover, the present writer has found it in the bank-vole (Clethrionomys glareolus) in Berkshire. * Baylis, H. A., 1927. Ann. Mag. Nat. Hist. (9) xix p. 434. ** James, P. M., 1954. J. Helminthol., xxviii, p. 183.
TAPEWORM FROM YELLOW-NECKED FIELD MOUSE
Catenotaenia lobata has a fairly wide geographical distribution in various murine hosts. It extends eastwards from the western coasts of Europe to the Russian Transcaucasia and southwards through Africa to the Belgian Congo, and possibly into South Africa. There is at present some disagreement among taxonomists as to the systematic position of Catenotaenia in the Classification of the Cestoda. T h e genus possesses certain morphological features which provide arguments for its inclusion in any one of three well-defined families of cestodes. On purely morphological grounds, the strengest argument appears to support the view that Catenotaenia belongs to the family Anoplocephalidae, the basic systematic characters of which are the absence of a rostellum and the possession of an unarmed scolex (head). With regard to the life-cycle of the anoplocephalids, the family is, so far as we know, the only group of tapeworms which employs mites naturally as intermediate hosts. But only the soil-dwelling or oribatid mites are known to be involved. Although the lifehistory of Catenotaenia lobata has not yet been elucidated, in a closely-related form, C. pusilla (Goeze, 1782)—also a parasite of murines—it has been found that in laboratory conditions the adult and deutonymph stages of the tyroglyphid mite Glyäphagus domesticus are capable of acting as intermediate hosts. A further point of interest concerns the larva of Catenotaenia. Usually, the various types of late larval stages occurring among cestodes all bear a scolex identical with that of the adult worm. In Catenotaenia, however, the head of the larva has a large functional apical sucker, which disappears in the adult worm and is replaced by four well-developed lateral suckers. Finally, the anoplocephalid larva is of the cysticercoid type, while that of Catenotaenia resembles a plerocercoid. T h e differences in the structure of the larva, as well as the different group of mites involved in the life-cycle, have apparently induced some recent workers to disregard Catenotaenia as a member of the Anoplocephalidae and raise it to family rank—the Catenotaeniidae. T h e Y e l l o w Necked M o u s e (Apodemus flavicollis) has been reported by D r . Grace G r i f f i t h , trapped in a garden w i t h many sylvaticus at Bures. —Ed.