1. DIFFERENCES IN RED-LEGGED PARTRIDGES (Alectoris rufa) BEHAVIOUR DEPENDING ON THE PAIRING METHOD ALONSO, M.E.; PRIETO, R. PÉREZ, J.A.; DÍEZ, C.; GAUDIOSO, V. Dpto. Producción Animal II, Facultad de Veterinaria de León. 24071. España. E.mail: dp2mav@unileon.es XXXVIII International Congress of the ISAE (HELSINKI, FINLANDIA)dp2mav@unileon.es INTRODUCTION Handling and production systems in intensive red-legged partridge farms are very different from birds wild behaviour in natural conditions. One of the aspects to consider in the management is the type of pairing, since scientific evidence exist on the positive correlation between parameters of reproductive success, as fertility, broods size and chicks survival, and the possibilities of freely choosing a partner. OBJETIVES This study aimed to evaluate the differences in the behaviour of forced and free choice pairs of red-legged partridges. MATERIAL AND METHODS 48 birds hatched in May of the previous year on a commercial game farm that used an intensive breeding method were used. 12 pairs of free choice formed following the methodology described by PRIETO (2003) (Photo 1) and 12 forced pairs formed randomly were housed individually in metal mesh cages of 4 m 2 (2 m long x 2 m wide x 1 m high) (Photo 2) placed such that neighbouring pairs of birds could not see each other. Video recordings were made daily throughout the first week during 4 hours in the early morning (Photo 3). Frequency and duration of 22 behavioural parameters described by PINTOS et al. (1985) have been analysed using a computer program developed for this purpose. Data were analysed by one-way ANOVA to assess the significance of differences between pairing method using the computer program statistical SPSs© (version 10.0) for WINDOWS©. RESULST AND DISCUSION The free choice birds showed a significantly higher frequency of “alert pattern” (43,50±20,1 versus 18,19±9,6), and also shows more behaviours related to the nourishment and cohesive behaviours as "pecking" (82,69±28,5 versus 49,56±14,3), “come to peck " (6,00±3,9 versus 1,94±1,8), "pecking the two at the same time" (23,13±12,3 versus 10,75±4,4), and "follow the other" (8,00±5,7 versus 3,63±2,2) (Graphs 1 and 2 and Table 1). In the free pairs the male showed alert and feeding patterns more frequently than in the forced pairs and this could increase his own possibilities of survival as well as the female ones. At the same time, when the female is choosing a more vigilant male she is also increasing her time to feed and improving her body condition, having more chances to store reserves to use in eggs production and incubation, maximising reproductive success. Our result are in accordance with HAMILTON and ZUK (1982), DAHLGREN (1990), BEANI and DESSÌ-FULGHERI (1995) and FUSANI et al. (1997). BIBLIOGRAPHY BEANI, L.; DESSÌ-FULGHERI, F. (1995). Mate choice in the grey partridge, Perdix perdix: role of physical and behavioural male traits. Anim. Behav. 49: 347-356. DALHGREN, J. (1990). Females choose vigilant males: an experiment with the monogamous grey partridge, Perdix perdix. Anim. Behav. 39: 646-651. FUSANI, L.; BEANI, L.; LUPO, C.; DESSÌ-FULGHERI (1997). Sexually selected vigilance behaviour of the grey partridge is affected by plasma androgen levels. HAMILTON, W.D.; ZUK, M. (1982). Heritable true fitness and bright birds: a role for parasites?. Science 218: 384-387. PINTOS, R.; BRAZA, F.; ALVAREZ, F. (1985). Etograma de la perdiz roja (Alectoris rufa) en libertad. Doñana, Acta Vertebrata, 12 (2): 231- 250. PINTOS, R.; BRAZA, F.; ALVAREZ, F. (1985). Etograma de la perdiz roja (Alectoris rufa) en libertad. Doñana, Acta Vertebrata, 12 (2): 231- 250. PRIETO, R. (2003). Emparejamiento libre y forzado en perdiz roja (Alectoris rufa). Tesina de licenciatura PRIETO, R. (2003). Emparejamiento libre y forzado en perdiz roja (Alectoris rufa). Tesina de licenciatura. Univ. de León. 128 pp. 100 cm 50 cm Drinking point Male 1 Cereals (barley and wheal) Male 2 Male 3 Male 4 Female Photo 1: Free choice pairing system cages. Photo 2: Pairs cages. Nest Bush selther Drinking point 2 m Pair cage Video camara Photo 3: Daily viedo recording.