Anti-predator behaviour of adult red-legged partridge (Alectoris rufa) tutors improves the defensive responses of farm-reared broods.

The aim of this work was to improve natural anti-predator behaviour of farm-reared gamebirds. We evaluated the anti-predator behaviour of reared red-legged partridge Alectoris rufa chicks kept in brooder houses in large groups (>350 chicks), trained and not trained by parent red-legged partridges acting as experienced tutors. The experiment consisted of two conditioned tests (a raptor model and a human) and two control tests, which were conducted during three consecutive phases of life (1-4, 15-17 and 30-32 d after hatching). The motor anti-predator behaviour, its duration, the intensity of response in chicks and alarm calls elicited by adults were recorded. Tutors elicited aerial alarm calls (76% of tests) and showed prolonged crouching (59% of tests) in response to the raptor model whereas uttering the ground alarm call (73% of tests) and showing vigilance behaviour (78% of tests) was the main pattern during the human test. Trained and not trained chicks showed similar motor behaviour in response to the raptor model (crouching) and the human test (escaping), but frequency of strong responses (all chicks responding) from chicks trained with tutors was double that of chicks trained without them, and chicks trained with tutors showed a higher frequency of long responses (41-60 s). This study indicates that anti-predator training programmes before release may improve behaviour of farm-reared partridges which may confer benefits to survival of birds.

Are parent-reared red-legged partridges (Alectoris rufa) better candidates for re-establishment purposes?

Aiming to produce game birds suitable for re-establishment purposes, we studied the survival and behavior of 31 adult red-legged partridges reared by their natural parents in captivity (parent-reared) and 67 wild red-legs (35 adults and 32 subadults). Birds were radio-tracked and released in a game estate where management targeting small game species was conducted and shooting was not allowed. Survival of parent-reared partridges was shorter (mean 108 d) than wild adults (mean 160 d), though no significant differences were found. Parent-reared birds showed a longer escape reaction (mean 11.7 sec) than wild adults (mean 0.4 sec) and were mainly predated by terrestrial predators (52%), whereas the most important source of predation in wild red-legs was raptors (49%). The home range of parent-reared (mean 23 ha) was not significantly lower than wild adults (mean 27 ha). Nineteen percent of parent-reared and 31.4% of wild adults paired successfully, and we recorded 6 pairs in which one bird was wild and the other parent-reared and one pair in which both birds were parent-reared. A small proportion of red-legs started incubation (parent-reared 12.9%, wild 20%), and the proportion completing incubation was similar among wild and parent-reared birds. Overall, parent-reared red-legs showed similar survival and behavior compared to wild red-legs and better than intensively reared, so parent-reared red-legs should be chosen for the re-establishment of wild populations.

Do pairing systems improve welfare of captive Red-Legged partridges (Alectoris rufa) in laying cages?

Although animal welfare has become an important premise in poultry, little attention has been paid to the effects of present-day rearing methods on the welfare of game birds, species released for hunting and re-establishment purposes. This work studied the effect of pairing methods on the welfare of the Red-Legged partridge kept in laying cages (4,500 cm2), a commonly hunted game species in Western Europe. Agonistic behavior and possible injuries caused by aggression were studied during the pairing and laying period in 2 types of couples: the forced type (n=24), 1 male and 1 female randomly chosen and placed in the same cage, and the free type (n=24), where the female had the opportunity to chose between 4 males, using the time spent by the female near each male as female choice parameter. Welfare of partridges was affected by pairing system, as aggressive behavior, divorces and injuries were observed in a higher rate in forced pairs (25% of pairs did not finish the productive cycle) than in free pairs (16.6%). In addition, more females were attacked in forced pairs, whereas in free pairs, the number of attacked males and mutual aggression was increased. Males tended to display more aggressive behavior than females, pecking mainly on the head and back of females. Although injuries were observed in a minor rate in free pairs, a higher mortality was reported in females compared with males from both free and forced pairs (6 females died in total). The poor welfare in a high percentage of laying pairs hampers the development of sustainable rearing methods for the species. Thus, farmers should consider avoiding forced pairing.

Does early antipredator training increase the suitability of captive red-legged partridges (Alectoris rufa) for releasing?

This study aimed to evaluate the postrelease survival and spatial distribution of farm-bred red-legged partridges (Alectoris rufa) that were subject to a prerelease training program based on exemplary behavior and alarm calls given by adults that acted as experienced demonstrators in simulated predator encounters (wooden raptor models and humans). Two groups of partridges were released in this study: trained (intensively reared birds accompanied by tutors) and control (chicks reared without tutors). Releases were conducted in the fall and winter-spring during 2 consecutive years using a total of 44 trained and 40 control radio-tagged partridges. Trained partridges showed statistically higher mean values of survival (72.7 d), home range (13.04 ha), and dispersion (549.58 m) compared with nontrained partridges, with most nontrained birds failing to survive more than 2 wk after release. Trained adult partridges showed the best survival results (105.2 d). Taking all birds into account, causes of death were attributed to terrestrial predators (45%), raptors (18.7%), hunting (11.3%), and unknown causes (25%). Although values of variables reported here were lower than those reported in wild counterparts, survival time and spatial behavior of trained birds were close to that of previous data of parent-reared partridges and higher than that of farm-bred birds. This study aimed to confirm the potential of prerelease training techniques in present-day rearing systems. Farm-bred game birds, which normally suffer from high predation rates after release, could highly benefit from the use of cost-effective training techniques based on learning from experienced adults.

Isolation from predators: a key factor in the failed release of farmed red-legged partridges (Alectoris rufa) to the wild?

1. The effects of predation isolation were studied in two lines of 10 month-old farmed red-legged partridges (Alectoris rufa). Birds came from bred generations in captivity (F) and directly from wild parents (W). 2. Releases were carried out in March for two consecutive years on private farmland with a stable population of wild red-legged partridge using 68 tagged birds (36 F, 32 W). 3. No statistical differences were found in survival time (mean 18 d) or home range values (mean 7·38 ha); 49% of mortality was attributable to raptors, 36% to wild canids and 15% had doubtful causes of death. F birds suffered more predation by raptors and W partridges more by mammalian carnivores. 4. A statistical difference was found in post-release dispersion: the means were 243·4 m in F and 593·3 m in W. 5. The result of predation isolation was similar in both groups, which confirms the adverse effects of current production systems on anti-predator behaviour. Farmers should consider the introduction of new rearing techniques with the aim of improving survival after release.

Study of survival, dispersal and home range of autumn-released red-legged partridges (Alectoris rufa).

1. On a private property with a stable population of wild red-legged partridge (Alectoris rufa) and an appropriate habitat for the survival of the species, reinforcement repopulations were carried out in the months of October and November for two consecutive years using 5- to 6-month-old birds reared on a commercial game farm. 2. Of the 36 released birds, none was still alive by the following spring's breeding period. Mean survival time was 9.4 d in the first year and 7.6 d in the second year. 3. Seventy-two per cent of mortality was attributable to predation, 11% to hunting and 17% to doubtful causes of death, accidents and starvation. 4. Post-release mean dispersion was 377.8 m in the first year and 526.3 m in the second. Mean home range was 7.1 ha in the first year and 5.4 ha in the second. 5. The production systems and handling practices of commercial game farms may have modified some anti-predator ethological patterns and strategies, which might make it more difficult for the birds to adapt and integrate into the wild, resulting in reduced survival due to premature mortality.

Use of radiotracking techniques to study a summer repopulation with Red-Legged partridge (Alectoris rufa) chicks.

On a private property with a stable population of wild Red-Legged partridge (Alectoris rufa) and an appropriate habitat for the survival of the species, reinforcement repopulations were carried out using 54 birds that were 2 to 3 mo old and reared on a commercial game farm. This study aimed to evaluate the effectiveness of repopulations, the behavior in the wild of released partridges, and the possible causes of success or failure of reinforcement population operations. The releases were carried out during August and September of 2 consecutive years. All birds were equipped with radio transmitter collars to determine their behavior after release. Two release methods were used in yr 1: an acclimatization cage (AC) method and a direct release method on the day of the birds arrival (DR). The aim of the release in yr 2 was to collect data to determine the influence of year conditions using the DR method. Of the 54 released birds, none remained alive by the time of the reproductive period in the following spring. The mean survival time was 16.79 d for the AC method and was 11.89 and 5 d for the DR method in yr 1 and 2, respectively. Of the recorded mortalities, we assigned 81.13% to predation, 7.55% to hunting, and 11.32% to unknown causes of death, accidents, or starvation. Repopulation was not successful at providing a long-term increase in partridge numbers, with most birds falling victim to predation within 1 mo of release. Dispersion is the maximum distance from the release point at which each bird was located. The postrelease mean dispersion was 437.65 m for the AC method and was 647.57 and 266.07 m for the DR method in yr 1 and 2, respectively.

Effects of housing type and breeding system on the reproductive capacity of the red-legged partridge (Alectoris rufa).

Current methods of intensive breeding of the red-legged partridge (Alectoris rufa) are based on "industrial" laying practices, including removal and artificial incubation of eggs. These procedures can alter the reproductive behavior and physiology of the birds and, therefore, may not be suitable for use in breeding programs designed to increase wild populations. This study aimed to determine the effects of intensive housing and breeding methods on the laying capacity and reproductive behavior of the red-legged partridge. In Experiment 1, 70 pairs from a commercial game farm were randomly allocated into three treatment groups and placed in differing designs of breeding cages: 8 m2 cages with solid sides (n = 30), 4 m2 cages with solid sides (n = 30), and 4 m2 cages with mesh sides (n = 10). The number of eggs laid was recorded each week. In Experiment 2, 30 pairs, placed in 30 closed 8 m2 cages, were used. Fifteen pairs were birds reared under the intensive system used on game farms, and the other 15 pairs were birds adopted by pairs of foster parents when they were less than 48 h old. The total number of eggs laid during the reproductive period was recorded. In Experiment 1, egg production was greater in pairs housed in 8 m2 cages. There were no differences in egg production between birds housed in closed or open 4 m2 cages. In Experiment 2, the rearing method did not affect egg production. In both experiments, regardless of rearing history or cage type, the numbers of eggs laid were considerably higher than published figures for wild red-legged partridges. This fact, together with the absence of incubation by 100% of the females, indicates the considerable physiological and behavioral modifications that red-legged partridges have undergone due to domestication.

Adaptive metabolic responses in females of the fighting breed submitted to different sequences of stress stimuli.

The objectives of this study were to evaluate the stress reaction and the metabolic adaptive effort in females of the fighting breed when submitted to different manipulation sequences. Nine 4- to 8-year-old bovine fighting breed females slaughtered to establish the basal levels of different blood parameters. A study was, then, conducted to examine the metabolic response in 30 2-year-old females, divided into 3 groups of 10 animals and submitted to different manipulations in each group: restraint- "open-field" -restraint, "open-field" -restraint, and transportation-restraint- "open-field" -restraint. The basal levels of the different blood parameters found were, in general, similar to the levels for cattle given in the literature. All the manipulations resulted in increases that were statistically different (p < 0.001) from basal levels, in terms of both cortisol plasma levels and the Specie Specific Experimental Response to Stress index (SSERTS). The stress of restraint (and the prior manipulations) seemed to mask the stress associated with the open-field and transport situations. In general, animals responded to 13 of the 15 parameters examined in the various experimental manipulations.

Embryonic development of the freshwater crayfish (Pacifastacus leniusculus Dana): a scanning electron microscopic study.

The egg development of the freshwater crayfish (Pacifastacus leniusculus Dana) under laboratory conditions is studied in this work from spawning to hatching. The sequence of its development is presented here, and the chronology of the different embryonic phases is established at one specific temperature (15.5 degrees +/- 1 degree C).