The records of one pack of Otter Hounds hunting in southwest England are examined for the prriod 1907 to 197 1 as well as the records of all packs active in Britain between 1950 and 1976. The hunting success per unit effort varies from year to year depending o n changes in hunting conditions but longer term changes can also be identified. The hunting success of the Culmstock Otter Hounds (hunting in parts of south-west England) increased steadily from 1907 to 1956 but in most of England and south Wales the success rate of the hunts declined rapidly after 1957. There was also a tlrcline in success in northern England and southern Scotland but to a lesser extent, while in north Walra and Eire, there is no evidence for a decline.'fhese changes are considered to reflect changes in otter populations but the extent of the decline in hunting success (to between 37% and 55% of previous levels in the southern hunts) is probably less than the actual decline in otter numbers. There are no signs of a recovery in the population but indications o f a continuing decline up to 1976.The reason for the increasing population in the first half of the century in south-west England is p~-obably the decrease in persecution since the nineteenth century. A variety of causes for the crash in thr late 1950s are considered and the factor most likely to be responsible is the introduction of the dieldrin group of insecticides in 1956. Use of these compounds has been increasingly restricted since 11163 and the possible reasons for the failul'e of the otter population to recover are listed but no firm conclusions can be drawn as yet.

Over the past 150 years the badger is believed to have undergone major changes in status, and possibly also in distribution. In the last century persecution by gamekeepers in particular had an impact on badger numbers, especially in East Anglia. More recent changes in badger numbers and the need for a quantified base line survey against which to monitor future population changcs provided the stimulus for a quantified national badger survey. This was achieved in the mid-1980s by a stratified survey in which prc-selected one kilometre squares used in the Institute of'l'errestrial Ecology land classification system were surveyed for badgers. A total of 2455 squares (1.05%) of the land area of Britain) was surveyed, and this provided a means to (a) assess the current distribution and status of the badger, (b) assess the current levels of persecution of badgers and (c) monitor future badger population changes. Currently there are approximately 43 000 badger social groups in Britain. Sett blocking and badger digging were found to he widespread, and their effects on the badger population are discussed, as are the cfferts of the current 'I'B control opcrations in south-wcst Britain. Future patterns of land use, particularly in response to rhangrs in farming practicc, could have significant rffrcts on badger numbers. 'I'hese are discussed in relation to potential changes in the Common Agricultural Policy. T h e effects of an expansion of forestry and the spread of urban areas on badger numbers are also estimated.

Craniometric variation between otters Lutra lutra (L.) from Ireland, Scotland, Shetland, Norway, and Czechoslovakia was examined using multivariate statistical analyses. Significant sexual dimorphism in cranial size and shape occurred in all samples, although the degree of dimorphism varied between samples, with the Irish sample exhibiting the most. Morphological differences were also observed across samples. Three groups were observed; Irish, Scottish, (Mainland and Shetland), and Mainland European, though within the two composite groups the samples were still differentiable. There was a good agreement between the patterns of variation between male and female samples, but morphological differentiation was not significantly correlated with geographic separation. These results are discussed in the light of our current knowledge of the ecology of the species in Europe. It is argued that, while there is morphological evidence for subspecific status of the Irish otter (as L. l. roensis), further investigations of morphological and genetic variation across Eurasia are clearly required.

Evidence from many sources indicates that, in several parasite–vector systems, flight ability, fecundity or gonotrophic concordance of vectors, are affected by parasites (including bacteria, rickettsia and viruses) and in some cases parasites cause well-documented pathogenic effects (see reviews, for example, by Lavoipierre (1958a) and Hawking & Worms (1961) on filaria; Molyneux (1977, 1983) for trypanosomatids; Killick-Kendrick (1979) for Leishmania).

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