Catherine Guyomarc'h

Ontogeny of the ultradian rhythm of activity in Japanese quail.

As soon as they hatch, gallinaceous chicks follow broody hens. This matriarchal unit presents a temporal organization of activity. The ontogeny of this ultradian rhythm of activity was followed in Japanese quail during their first 3 weeks of life. Under controlled laboratory conditions, 12 groups of four chicks were recorded using an activity monitoring system. They were observed between the ages of 2 and 17 days. Chicks in groups presented an ultradian rhythm of activity, with a period that increased significantly from 14.3 ± 1.4 minutes when chicks were 2 days old to 26.0 ± 1.9 minutes when they were 16 days old. The increase of ultradian periodicity was particularly pronounced during their first and third weeks of life. Finally, the ultradian period was correlated positively with body weight of the chicks. (Chronobiology International, 17(6), 767–776, 2000)

Stable Individual Profiles of Daily Timing of Migratory Restlessness in European Quail

Temporal characteristics of migratory behavior in birds are usually studied at the species and population levels, and rarely at the individual level. Variations among species and populations of the seasonal onset of migratory behavior have been widely investigated, but very little is known about its daily organization or whether birds are conservative in their behavior. The determination of intra‐ and inter‐individual variability is important for the study of genetic variations and can reveal the existence of different adaptation capacities within populations. This laboratory study analyzed intra‐ and inter‐individual variability of daily initiation and time course of nocturnal restlessness in partial‐migrant European quail (Coturnix coturnix coturnix). Thirty‐five quail were selected randomly from a captive stock, and their spring activity was recorded under natural daylenghs. Eighteen of the thirty‐five quail presented behavioral profiles of migrant birds. Migrant birds initiated their nocturnal activity punctually, and the time courses of the nocturnal activity of 88% of them revealed intra‐individual stability over six consecutive nights. All birds initiated their nocturnal activity after sunset and civil twilight, and they were more active at the beginning than the middle or end of the night, suggesting that their drive to migrate could be synchronized with particular skylight conditions. For the first time, stable individual profiles in the daily time course of migratory restlessness are shown. These results support previous findings concerning biological rhythms of quail and raise questions concerning the timing of migratory behavior.

Circadian rhythm of activity in Japanese quail in constant darkness : Variability of clarity and possibility of selection

In conditions of constant darkness, interindividual variability in the clarity of circadian rhythmicity was observed in sexually immature young quail, with birds classified as more or less rhythmic or arrhythmic. The relative clarity of this circadian rhythm was observed on the actograms by measurement of the autocorrelation coefficient ratio over 12 cycles. Autocorrelation coefficients were calculated from sequential series of total activity over 12-minute periods. Crosses of selected phenotypes with different clarities of rhythmicity were conducted in order to study the possibility of selection of this characteristic. From a random population (N = 42, twice), pairs of the most rhythmic birds (3 families), and pairs of arrhythmic birds (4 families) were reared. Autocorrelation coefficient ratios of F1 birds from rhythmic families (N = 54) were greater than those of F1 birds (N = 48) from arrhythmic families (t-test, p < .0001). These ratios in offspring were significantly correlated with that of the mean parent of each clutch of siblings (N = 102, r = .35, p = .0003). This result was maintained in a second generation (F2) of birds, for which significant differences in expressed rhythmicity were observed. That is, autocorrelation coefficient ratios of F2 birds from two rhythmic families (N = 30) were greater than those of F2 birds from arrhythmic families (N = 20) (t-test, p = .039). Comparison of F2 outbred and inbred birds from rhythmic pairs showed greater values of autocorrelation coefficient ratios in the case of inbred birds (N = 16) than for outbred birds (N = 30; t-test, p = .036). There was no difference between outbred (N = 20) and inbred birds (N = 15) from arrhythmic pairs. Therefore, selection of a rhythmic strain seems possible, whereas crosses between two arrhythmic birds may also give rise to rhythmic birds. Comparisons between rhythmic birds of different families did not show differences in the free-running period of the circadian rhythm, which is true also for rhythmic birds bred from two arrhythmic parents. Therefore, our selection procedure did not seem to be based on the characteristics of the pacemaker itself, but rather on a downstream event. Although the parents were not selected on the basis of quantity of activity per cycle or on the duration of the active phase, significant differences among the offspring of different families were shown.

Moulting cycles in European quail (Coturnix coturnix coturnix) under constant photoperiodic conditions

Abstract Male and female European quails (Coturnix coturnix coturnix) were studied whilst being maintained in LD 12:12, at 20° C, for four years from birth. The birds exhibited the following phases: end of the first phase of the post‐juvenile moult, fattening and a period of nocturnal activity. Then sexual development is observed up to complete maturation at the age of four months. The second part of post juvenile moulting occurs towards the age of 5 to 6 months. During the following 6 months an important phase of reproduction is observed, thus completing their first year of life. The same sequence is repeated during the following years: a moult which lasts for 6 months in two (sometimes three) partial phases separated by episodes of reproduction; then an important period of reproduction (6 months) without moulting. The birds are capable of reproducing at all times except during moulting. The sequence of moulting begins each year in the same months as those for natural French populations. It thus seems th...

DAILY TEMPORAL ORGANIZATION OF LAYING IN JAPANESE QUAIL: VARIABILITY AND HERITABILITY*

In birds, many behavioral and physiological processes that occur during reproduction show daily rhythms in response to environmental temporal constraints. In this study, the individual daily organization of laying and its genetic determinant in Japanese quail (Coturnix coturnix japonica) were analyzed. For this purpose, the oviposition time of 102 randomly chosen females, maintained in long-day photoperiodic conditions (LD 14h:10h) for 1 mon was observed and extreme phenotypes selected. Laying is characterized by two parameters: oviposition interval and laying hour. The birds showed a specific time of laying during 24 h. All eggs were laid in the afternoon between 6.5 and 14 h after lights on (HALO). Two laying profiles were determined: 20% of females with an oviposition interval greater than 24 h (24.7±0.2 h) (the “delayed” profile) laid progressively later each day until a pause day. The remaining 80% of the females laid at the same time each day, with few pause days and an oviposition interval close to 24 h (24.0±0.2 h) (the “stable” profile). Among the females, showing this last profile, an intra-individual stability and an inter-individual variability of laying hour was established. Two extreme laying phenotypes were then determined: the “early” phenotype (E) for females laying on average between 7.5 and 9.5 HALO and the “late” phenotype (L) for females laying between 12.5 and 14 HALO. In order to study the genetic basis of the laying hour, three females of each extreme phenotype were selected and crossed with two different males. The E and L females produced 57 F1E and 42 F1L daughters, respectively. F1 females displayed both laying profiles. However, the proportion of females displaying a “delayed” profile was higher in the L line (50%) than in the E line (29.8%). For the “stable” daughters, artificial selection induced an advance in laying hour of 4.7% for the E line and a delay of 4.7% for the L line. Realized heritability was estimated at 0.5. Moreover, the laying hour of the daughters was correlated positively to that of the mothers (N=61;r=0.45). These results support the notion of heritability of oviposition time in Japanese quail.

Ultradian Rhythm of Activity in Japanese Quail Groups under Semi-Natural Conditions during Ontogeny: Functional Aspects and Relation to Circadian Rhythm

The function of ultradian rhythms is not yet clearly elucidated. In particular, short-term rhythms are expressed during early ontogeny, especially in broods of precocial birds. We investigated the relationship between the clarity of the ultradian rhythm of the activity/rest cycle of a group of young Japanese quail (Coturnix japonica) and the level of social synchronisation and spatial cohesion between the birds within that group. The subjects were descended from two lines selected for either very pronounced rhythmic or arrhythmic circadian activity. We found a positive relationship between the clarity of the ultradian rhythm of the activity/rest cycle when birds were young and the clarity of the circadian rhythm of feeding activity when birds were older, but still immature. The temporal organisation of the behaviour of the chicks from these two lines was observed in outdoor aviaries, when they were 4, 8, 12 and 15 days old. The mean ultradian period expressed by groups of 12 chicks was variable, with a minimum of 6 minutes. The ultradian period lengthened regularly as chicks grew older, and reached approximately 40 min on day 15. The clarity of the ultradian rhythmicity of group activity was linked to the level of inter-individual social synchronisation and of spatial cohesion; the more pronounced the ultradian rhythms of a group, the greater the temporal and spatial cohesion of the chicks within the group. Moreover, these characteristics varied with the age of the chicks. Finally, chicks in the less rhythmic groups weighed less. These results stress the adaptive value of this temporal organisation strategy under natural conditions.

Circadian rhythms of oviposition and feeding activity in Japanese quail: effects of cyclic administration of melatonin.

The aim of these experiments was to test the effect of a cyclic administration of melatonin, by mimicking the daily rhythm of hormone levels, on the circadian organization of two distinct functions in quail: oviposition and feeding activity. Laying and feeding rhythms under photoperiodic conditions and constant darkness (DD) were investigated. Under DD, where the two rhythms were free running, a daily rhythm of melatonin was administered. In LD 14h:10h, two different individual profiles of laying were established, with stable females laying at the same time each day and delayed females laying progressively later each day. For feeding activity, all birds were clearly synchronized to the photoperiodic cycle. In DD, the laying birds showed a free-running rhythm of oviposition with a period longer than 24 h for both profiles but the delayed profile females had a longer period than stable profile females. In comparison, the free-running period of feeding rhythm of the same birds was shorter than 24 h. A cyclic administration of melatonin had no effect on laying rhythm, which continued to free-run in DD, whereas feeding activity was synchronized as soon as the first cycle of melatonin was administered. From these results, it seems that two different circadian systems drive each of the two types of behavior separately. Melatonin could be the main synchronizer for the temporal control of feeding behavior, but it does not play a part in the control of oviposition in Japanese quail.

Individual differences in sexual display behaviour in the male Japanese quail

In repeated tests we investigated the intra-individual stability and interindividual differences of courtship behaviour for 23 Japanese male quail, Coturnix c. japonica. A moving taxidermically prepared female model, and then a living female quail, were used as stimuli. Eight display units were recorded: sidedisplay, tiptoe-walking, body-shaking, nest-invitation ceremony, shoulder-featherssmoothing, up-down head movement, curtsey and flattening. During visual contact with the lure or direct encounter with a female, intra-individual stability of male courtship behaviour was noticed throughout the tests. Inter-individual differences were also observed at two levels: quantitative and qualitative. Depending on the individual, males were more or less active and/or expressed different behavioural units during courtship. Some males did not react to the lure but were clearly stimulated by the living female, whereas other ones displayed with both of the stimuli. Using correspondence analyses, several profiles of behaviour were shown and discussed in terms of personality traits.

Circadian rhythm of activity during the annual phases in the European quail, Coturnix coturnix

Migratory birds, such as the European quail, present an annual cycle with the following phases: moult, fattening, migration and reproduction. This study aimed at determining how variations in the circadian rhythm of feeding during the annual cycle took endogenous rhythmic characteristics into account. The birds (n = 8) were maintained under constant dim light from the age of 1 to 9 months. Feeding activity was recorded using infra-red detectors. The birds expressed all the phases, except migration. Activity was arrhythmic when they were moulting. A circadian rhythm of feeding activity appeared during the fattening phase. In males, the circadian period lengthened and the clarity of the rhythm increased during sexual development. These results appear to confirm the effects of physiological state on the temporal organisation of activity. Variations of the circadian rhythm could influence the ability to synchronize with exogenous cycles such as the alternation of day and night.

Synchronization of Ultradian Rhythms of Activity in Young Japanese Quail: Effect of Kin Relationships

Synchronization of activity cycles is common in coveys of gallinaceous birds, which usually include a dozen chicks at birth. To study this synchronization more precisely, we recorded the ultradian rhythms of activity of seven groups of young Japanese quail reared in the laboratory, without brooding females. Four groups included only kin-related birds (K1–K4), two mixed groups consisted of associated chicks from two families (M1 and M2 groups), and the seventh group (NK group) included only non-kin chicks. Numbers of chicks in a group varied from eight to 14, depending on the group. They were observed twice during their two first weeks of life (day 3 and day 10) and all activities were recorded by scan sampling. An ultradian rhythm of activity, with a period less than 20 minutes, was found. This period varied among quail families. All chick groups were globally synchronized, except group M2 on day 3. Inter-individual levels of synchronization were calculated. Spearman rank correlation coefficients of the non-kin chicks were significantly lower than those of kin-related chicks. This was especially clear on day 3. Survival of newborn quails is linked to their presence within a covey or a group. Their survival, as well that of their brothers and sisters, may be enhanced by an ability to synchronize with kin better than with non-kin chicks.