Tail posture and motion as a possible indicator of emotional state in pigs

In the current study, the aim was to investigate whether tail posture and motion can be an indicator of the emotional state of pigs and if the tail posture of the pig is affected by social breeding value (SBV), coping style and/or housing. Emotional state can be defined in two dimensions: valence and arousal. Two batches of 96 finishing pigs were studied in a one generation selection experiment with a 2x2 set up and were housed in a barren or straw bedded pen. In each pen, 6 pigs (3 male, 3 female) were housed. A back-test was done to determine the coping style of the pigs with two categories; high resister and low resister pigs. When possible, each pen held 3 high resisters and 3 low resisters pigs. Furthermore, half of the pens contained pigs with low SBV and the other half contained high SBV pigs. Tail condition scores were determined weekly. A novel environment test (150 sec) with a small arena was performed at 3.5 weeks of age to test the fearfulness of the pigs. Behaviours and vocalisations were recorded together with the tail posture and motion. Four different tail posture and motion categories were recorded; curled tail, hanging tail, tail between legs and tail wagging. Furthermore, home pen observations were performed to link behaviours to a tail posture or motion. The most performed tail posture in the novel environment test and the home pen observations was a hanging tail posture (60%), while curled tail was performed 30% of the time and tail between the legs and tail wagging occurred both 5% of the time. A curled tail was linked with active behaviour (high arousal), whilst a hanging tail was linked with inactive behaviour (low arousal). No effect of SBV or coping style was found in the novel environment test on the tail postures and motion. In the home pen observations, low SBV pigs showed more tail between the legs than high SBV pigs (P<0.05). High resisters kept their tail curled more often than low resisters (P<0.01). Also, high resister pigs with a low SBV showed a curled tail more often than the other treatment groups (P<0.05). Tail between the legs occurred more often in barren housed pigs than in enriched housed pigs (P<0.05), which could link this tail posture to a negative emotional state. Housing had an effect on the tail condition score; barren housed pigs without straw had more tail damage than enriched pigs (P<0.0001). Positive correlations were found between eating/drinking and a curled tail, social behaviour and tail between legs, and negative social behaviour and manipulation with a wagging tail (P<0.0001). To conclude, a curled tail could be linked to a positive emotional state, with high arousal. A hanging tail may be linked to a neutral state, neither positive nor negative. Pigs with their tail between the legs may be associated with a negative emotional state and low to medium arousal. Tail wagging can be associated with a negative emotional state, with high arousal. However, conclusions should be made carefully, because still little is known about the link between emotional states and behaviour. Positive tests could be done to make the link between a positive emotional state and a certain tail posture more clear. Also, tests that elicit a more fearful response than the novel arena test could confirm results from the current study

Yellow sea mediated segregation between North East AsianDryophytesspecies

While comparatively few amphibian species have been described on the North East Asian mainland in the last decades, several species have been the subject of taxonomical debates in relation to the Yellow sea. Here, we sampledDryophytessp. treefrogs from the Republic of Korea, the Democratic People&apos;s Republic of Korea and the People&apos;s Republic of China to clarify the status of this clade around the Yellow sea and determine the impact of sea level change on treefrogs&apos; phylogenetic relationships. Based on genetics, call properties, adult morphology, tadpole morphology and niche modelling, we determined the segregated status species ofD.suweonensisandD.immaculatus. We then proceeded to describe a new treefrog species,D.flaviventrissp. nov., from the central lowlands of the Republic of Korea. The new species is geographically segregated fromD.suweonensisby the Chilgap mountain range and known to occur only in the area of Buyeo, Nonsan and Iksan in the Republic of Korea. While the Yellow sea is the principal element to the current isolation of the three clades, the paleorivers of the Yellow sea basin are likely to have been the major factor for the divergences within this clade. We recommend conducting rapid conservation assessments as these species are present on very narrow and declining ranges

Preference for natural borders in rice paddies by two treefrog species

In the Republic of Korea, one of the biggest threats to amphibians is habitat modification such as urbanisation and land conversion. With the loss of natural habitats, rice paddies play an important role as substitute habitats for amphibians that originally inhabited wetlands. However, since the 70’s, traditional rice agriculture has been modernised, leading to an increase in the number of concrete ditches and roads bordering rice paddies. This modernisation could have affected the distribution and density of amphibians. In this study, we investigated the preferred position, based on the advertisement calls for two treefrog species (Dryophytes japonicus and D. suweonensis), in relation to different types of borders such as natural ditch, concrete ditch, one-lane dirt road and vegetation. The results show that treefrogs seem to avoid rice paddies with concrete ditches, and with no ditch, which provided no resting microhabitat. The sides of the paddies preferred by the two treefrog species were the ones with vegetation of 30 cm wider or higher, while the two species seemed to avoid the side of paddies with roads. Our results are important for the conservation of anuran species in rice paddies in general as it highlights the need for vegetated areas, preferentially along natural ditches