Food selection by adult red foxes Vulpes vulpes was studied in a mountainous environment characterised by fluctuating populations of water voles. According to optimal foraging theory, the diets of adults and cubs should be similar during vole highs, with voles as staple prey. On the other hand, a difference should occur when water voles become scarce. Adults should then bring larger alternative prey to their cubs, and consume smaller prey at the capture site. Adult and cub scats were collected around breeding dens during a 6‐year period, from the peak to a near‐extinction phase of the water vole population, and analysed. As predicted by the optimal foraging theory, no significant difference was found between the diets of cubs and adults when voles were abundant. Furthermore, cubs consumed a higher proportion of large alternative prey, i.e. lagomorphs, than adults in the first year of low vole density. Unexpectedly, this difference did not persist the following years despite the water vole scarcity. The consumption of large alternative prey at the den decreased significantly, whereas the consumption of small alternative prey, i.e. invertebrates, increased. Consequently, the composition of prey brought to the den was similar to that consumed at the capture site. Food selection was probably affected by the unpredictability of large prey availability and accessibility. It is suggested that if small alternative prey proves less profitable to the cubs than large prey, a long‐lasting shortage of water voles could possibly become a factor regulating fox numbers in the area studied.

The objective of this study was to evaluate the effects of a 6, 12, 18, 24, or 30h transport period on the physiology and reproductive success of breeding age gilts, simulating transport of breeding gilts from one farm to a commercial breeding herd. Fifty gilts were allocated to one of five transport (TRANS) treatment groups; transported for 6, 12, 18, 24, or 30h. Fifteen gilts were allocated to one of five control (CON) treatments; gilts remained in their home pen for 6, 12, 18, 24, or 30h. Every 6h, gilts from one TRANS treatment were removed from the trailer. Blood samples were collected from gilts and their respective controls before and after transport. Gilts were then bred after puberty. The granulocyte to lymphocyte ratio (P<0.05) and cortisol concentrations (P<0.07) were greater in TRANS compared with CON gilts after a 6 and 12h transport period. Albumin concentrations were greater (P<0.001) in transported gilts after an 18 and 30h transport period compared with CON gilts. Blood urea nitrogen, glucose, and total protein concentrations were greater (P<0.05) in transported gilts compared with controls, regardless of the transport period. Reproductive performance measures did not differ (P>0.05) among treatments regardless of the length of transport duration. These data indicate that gilts transported for a period of up to 30h experienced initial acute stress during the first 6 to 12h and changes in water homeostasis throughout the 30h journey due to dehydration, food deprivation, and transport, however reproductive measures suggest that the long-term homeostasis of the gilts in this study were not significantly compromised. Transport of breeding gilts induced acute, transient stress but did not negatively impact reproductive performance. Interestingly, gilts were more at risk of physiological perturbations when transported 6h or less than 12 to 30h.

Cestodes found in water voles (Arvicola terrestris L., 1758) trapped over six breeding seasons in the same local habitats included the following species: Arvicolepis transfuga (Spassky et Merkuscheva 1967), Paranoplacepala blanchardi (Moniez 1891), P. omphalodes (Hermann 1783), Parandria feodorovi (Gulyaev et Chetchulin 1996), Aprostatandrya dentate (Galli-Valerio 1905), and Arostrilepis microtis (Gulyaev et Chetchulin 2005). The dependence of cestode maturation on interannual variation in the food supply, territorial status, and morphofunctional characters of the hosts was analyzed in the two most abundant species, A. transfuga and P. feodorovi. The results showed that differences in host sex and food supply had no significant effect on cestode maturation. Judging from the proportion of gravid helminths of either species, the rate of their maturation was higher in nonresident than in resident voles. This proportion negatively correlated with body weight of male or female voles. It also negatively correlated with male fecal testosterone level, whereas correlations with fecal protein and progesterone levels were positive. The observed relationships do not explain why the occurrence frequency of gravid cestodes was higher in nonresident water voles, because they either did not differ from residents in parameters relevant to cestode maturation (body weight, fecal protein and testosterone levels) or the difference was opposite in direction (fecal progesterone was higher in resident voles). Nevertheless, an increase in the proportion of gravid cestodes in nonresident water voles may provide for more effective dispersal of these parasites.

This study investigated the feasibility of using an invasive snail, Pomacea canaliculata, as a food source and water purifier for the commercial breeding of the loach Misgurnus anguillicaudatus. The predatory potential of M. anguillicaudatus (3.5–5.5 g) against hatchling snails was evaluated in aquaria and simulated paddy fields. Some hatchling snails left the water to avoid being preyed upon by the loaches, and approximately 10 hatchlings died per day in the presence of five loaches in aquaria, whereas a weaker snail control effect was observed in the simulated paddy fields. The growth of rice seedlings (Oryza sativa) was not reduced by the presence of hatchling snails alone, but the shoot biomass of seedlings coexisting with snails was promoted after introducing the loaches. Additionally, the presence of P. canaliculata adults improved the aquatic environment in the short term for loach breeding by decreasing the turbidity of the water. Importantly, M. anguillicaudatus (12–18 g) mortality decreased and its weight increased in the presence of adult snails.