Bengalese Finches Research Articles

The role of sex steroid in two avian song behaviours differing in ontogenetic process

The male Bengalese finch,Lonchura striata, has two types of song behaviour (directed song, DS and undirected song, US). DS and US share a basically identical syllable repertoire, sequence pattern and tempo, but differ in the time course of appearance during the maturational process. In order to examine whether this results from a difference in testosterone (T) dependency, we studied developmental changes in the fecal T level and the amounts of DS and US during the 2–4 month period (N=7). DS appeared between 83 and 94 days of age, 4–16 days after a rise in the fecal T level. In contrast, US appeared earlier and at high frequency even when T was still at a very low level. These results suggest that DS is more dependent on the T level than US, and is not activated until the T level rises during the maturational process.

Functional recovery from the “aphasia” induced by unilateral lesion of song control nuclei (HVc and RA) in the bengalese finch

Functional recovery from the “aphasia” induced by unilateral lesion of song control nuclei (HVc and RA) in the bengalese finch

Left HVC dominance for song production and perception in bengalese finches

Left HVC dominance for song production and perception in bengalese finches

Visual and auditory cues in conspecific discrimination learning in Bengalese finches

Four Bengalese finches were trained to discriminate 2 conspecific individuals in an operant chamber. Still visual images and contact calls were simultaneously presented to the subjects and specific (“correct”) perching response was reinforced with food. After the birds acquired the discrimination, they received the first test in which visual cues alone, auditory cues alone and combination of the 2 modalities were presented. Visual cues dominantly controlled the discriminative behavior of all birds. Then the subjects received the second test in which mixtures of the visual image of 2 stimulus birds appeared under 3 different auditory conditions, namely, no call, calls of 1 bird and calls of the other bird. Two subjects used the auditory cues when the visual stimulus was a mixture of 2 stimulus birds. These results suggest that the birds used less dominant cues when the dominant cues gave ambiguous information.

Discription of video images of conspecific individuals in bengalese finches

Discription of video images of conspecific individuals in bengalese finches

Relations between song repertoire size and the volume of brain nuclei related to song: comparative evolutionary analyses amongst oscine birds

Song and brain structure are compared amongst 41 species of oscine birds by using the method of independent evolutionary contrasts. We find a significant correlation between the relative volume of the song control centre, the high vocal centre (HVC), and the number of song types typically found in the repertoire. Relative HVC volume is not correlated with the number of different syllable types per song bout. The relative volume of a second song nucleus, area X, is not significantly correlated with either measure. Relative HVC volume is uncorrelated with relative volume of the hippocampus, a brain area involved in other forms of memory. This is the first evidence for repeated independent evolution of an association between complexity of learned song and the relative volume of one of the song control nuclei though to be involved in song learning.

Discrimination of video images of conspecific individuals in bengalese finches

Discrimination of video images of conspecific individuals in bengalese finches

Acoustical variations in sexually dimorphic features of distance calls in domesticated zebra finches (Taeniopygia guttata castanotis)

Species-specific distance calls (DCs) were recorded from Zebra finches (Taeniopygia guttata castanotis) obtained from three different breeding stocks: Japanese breeders that use Bengalese finches as fostering parents, and Japanese and American breeders that let natural parents rear Zebra finches. These calls were analyzed for five acoustic parameters that were shown to be sexually dimorphic in wild Zebra finches. Male Zebra finches had DCs that were variable among breeding stocks and among individuals. Female DCs recorded from Bengalese-fostered birds were generally longer in duration and higher in pitch than those recorded from Zebra-finch-reared birds, males and females in each breeding stock differed in at least one acoustic parameter, but that parameter was unique in each of the breeding stocks. These results suggest that although sexual dimorphism in Zebra finch DCs has gradually disappeared during the process of domestication, at least one acoustic attribute which allows discrimination between the calls of the sexes has been preserved.

Acoustical and perceptual structures of sexually dimorphic distance calls in Bengalese finches (Lonchura striata domestica).

We characterized the physical structure of distance calls by Bengalese finch (Lonchura striata domestica) and its relation to perception. Distance calls were recorded from 12 female and 12 male Bengalese finches and analyzed; such acoustic parameters as length, bandwidth, and peak frequency were obtained, and differences between sexes on combinations of these parameters were tested and shown to be significant. To assess perceptual salience of acoustic parameters, discrimination of 4 female and 4 male calls was examined. The reaction time required to discriminate a pair of distance calls was used as a measure of similarity between the 2 calls and analyzed by a multidimensional scaling procedure to find the perceptual dimensions

Acoustical and perceptual structures of sexually dimorphic distance calls in Bengalese finches (Lonchura striata domestica).

Acoustical and perceptual structures of sexually dimorphic distance calls in Bengalese finches (Lonchura striata domestica).

Prolactin and gonadal steroids during the reproductive cycle of the Bengalese finch ( Lonchura striata var. domestica, Estrildidae), a nonseasonal breeder with biparental care

Plasma levels of prolactin (Prl), testosterone (T), and progesterone were determined throughout the breeding cycle in pairwise caged Bengalese finches ( Lonchura striata var. domestica, Estrildidae), a monogamous altricial passerine with nonseasonal breeding, in which parental behavior including incubation is equally shared between males and females. In both sexes, Prl titers increased 4- to 10-fold during incubation period compared to values during nestbuilding. Likewise, Prl levels after fledging of the young were significantly lower compared to titers during incubation. In males, T increased significantly (15-fold) during nestbuilding compared to all other stages of the breeding cycle. In females, T remained basal throughout the entire breeding cycle. Thus, T levels were elevated only during stages with low Prl titers and vice versa. Progesterone titers were elevated during egg-laying in females and fluctuated without any obvious pattern in males. These results suggest that (1) high levels of Prl are involved in the control of parental behavior of male and female Bengalese finches and (2) Prl secretion is controlled by proximate factors of the early reproductive cycle since reproduction is independent of seasonal factors in this species.

Consolidation and Modification of Sexual Preferences in Adult Male Zebra Finches

In a previous study (KRUIJT & MEEUWISSEN, 1991) we examined the sexual preference of cross-fostered zebra finch (= Z) males that were reared by Bengalese finch (= B) parents and then isolated until the adult stage. Males then given a choice between a Z and a B female, directed most courtship and song to B. After subsequent social experience with a Z female in a breeding situation, these males showed a shift in preference to Z, though still preferring B. If, instead, Z males had social experience with Z in a breeding situation without being put in choice tests before, the subsequent preference was for Z, so modification of preference was stronger, suggesting that prior exposure and courtship to B had consolidated the effects of early experience with foster parents and had reduced the possibility for modification. The present study concerns Z males reared by conspecific parents, with the aim of examining whether the results of the previous study were influenced by an own species bias. Again, males either obtained the opportunity to express their preference in choice tests before social experience in a breeding situation with a female of another species (B), or not. The results were similar to those of cross-fostered males in that: (1) prior exposure to a female of the rearing species during choice tests resulted in consolidation of preference for the rearing species; (2) social experience in a breeding situation with B resulted in a modification of preference in the direction of B, which was stronger without prior consolidation; (3) shifts of preference were not related to breeding success; (4) the effects of consolidation and modification remained present for over 1 year, although preferences gradually shifted in the direction of the rearing species; (5) the shifts of preferences due to both types of rearing condition mirrored each other, so, no evidence was obtained for an own species bias. From a similar study, BISCHOF & CLAYTON (1991) concluded that an own species bias is present in cross-fostered Z males. Their finding might be due to the presence of more siblings during the rearing of cross-fostered males than in our study, but this is uncertain without further experimentation.

Effect of tracheosyringeal nerve section on sexually dimorphic vocalizations in bengalese finches ( [formula omitted

Effect of tracheosyringeal nerve section on sexually dimorphic vocalizations in bengalese finches ( [formula omitted

Ontogeny of sexually dimorphic distance calls in bengalese finches (Lonchura domestica)

Adult Bengalcse finches emit sexually dimorphic distance calls which are used to locate each other when visually separated. Distance calls of adult females are amplitude modulated while those of adult males are not. We studied the ontogeny of sexual differentiation in these calls. Before 50 days of age, both males and females emitted amplitude modulated, female-type distance calls. After day 55, juvenile males began to emit adult-male type distance calls which were not amplitude modulated, whereas females continued to emit amplitude modulated distance calls. In males, the transitional period coincided with the onset of subsongs. These results suggest that the sexual dimorphism of the distance calls in Bengalese finches involves hormonal and developmental processes.

Influence of adult courtship experience on the development of sexual preferences in zebra finch males

Young zebra finch, Taeniopygia guttata castanotis, males were raised by Bengalese finch, Lonchura striata, foster parents until day 35, 40 or 50 of age, respectively. Following isolation until day 100, about half of the birds in each age group were tested for their preference for Bengalese or zebra finch females in two double-choice tests (pretests). After breeding experience with a conspecific female for 7 months, their sexual preferences were re-tested in two series of five double-choice tests (post-tests), one series 14 days after breeding experience, the other 7–12 months later. Preferences established during early development were changed by breeding experience. However, this change in preference was suppressed by preceding short phases of courtship experience with the foster parent species (during the pretests) after isolation. The same results were obtained by double-choice tests of the same birds 7–12 months later, demonstrating that the acquired preferences are quite stable. Large individual differences in the preferences of the birds may be caused by as yet unknown, subtle differences in rearing conditions. It is proposed that the preferences acquired during early development have to be stabilized by courtship experience. If the adequate object for courting is replaced by another one, a new preference may emerge. The extremely short time which is needed for consolidation may be explained by the high arousal level during pretests.

Sexual preferences of male zebra finches: effects of early and adult experience

Sexual preferences of male zebra finches develop under the influence of early social experience and are assumed to be stable in adults. The present study examines whether adult experience can modify effects of early experience. Male zebra finches, Taeniopygia guttata castanotis, were raised by Bengalese finch, Lonchura striata, foster parents for 40 days. As adults, males were given choice tests between a zebra finch and a Bengalese finch female. In a two by two design, the effects of breeding experience with a conspecific female and those of choice tests given prior to breeding were examined. Breeding experience shifted preferences in the direction of zebra finches, but much less so in previously tested males than in males that were not tested before the breeding experience. The shift was not completely stable. However, the difference between previously tested and untested males continued to exist for over 1 year. Breeding success and extent of shift were not related. Another group of males, which received no prior choice tests as adults and were exposed to a zebra finch female but were separated from her by wire, showed in subsequent choice tests a shift of preference to zebra finches that did not differ from males that were treated similarly but received breeding experience. The results suggest that short exposure to a preferred female leads to consolidation of earlier acquired preferences. However, much longer exposure to a non-preferred female either in a breeding situation, or through wire, leads to considerable modification of preferences of adult zebra finch males. The effects of both processes are maintained for at least 1 year. The results are discussed in relation to current views on imprinting.

Stabilization of Sexual Preferences By Sexual Experience in Male Zebra Finches Taeniopygia Guttata Castanotis

Abstract Male zebra finches, Taeniopygia guttata castanotis, were normally-raised by zebra finches or were cross-fostered to Bengalese finch, Lonchura striata, foster-parents until 40 days of age. Following isolation until day 100, half the birds in each group were housed with a zebra finch female for seven days, isolated for three days and then housed with a Bengalese finch female for seven days. The other birds were exposed to females in the reverse order. Subsequent double-choice tests showed that all the normally-raised birds preferred zebra finch females whereas the preferences of cross-fostered males depended on the order of exposure to the two females: those exposed first to a Bengalese finch female preferred Bengalese finch females whereas of those exposed first to a zebra finch female, some preferred zebra finches, some preferred Bengalese finches and some showed no marked preference for either female. In order to examine the question of why the latter group showed such marked individual variation in their sexual preferences, a further group of males were cross-fostered to Bengalese finches and exposed to a zebra finch female and then to a Bengalese finch female and their behaviours were observed from day 21 until day 40 and for the two, seven-day periods with the females. The results show that, when comparing brothers within clutches, the one that begs and is fed more by by its foster-parents develops a stronger preference for Bengalese finch females and that the more song phrases a male directs to the zebra finch female during the first seven-day period, the stronger the sexual preference for zebra finch females in the double-choice tests. Hence, our results confirm and extend those of IMMELMANN et al. (1991) and KRUIJT & MEEUWISSEN (1991) that sexual imprinting may be a two step process. As a first step, information about the parents is learnt during a sensitive period early in life. In a second step, this information has to be tested for its validity for the selection of a sexual partner during first courtship encounters. It is this second step where the previously stored information is stabilized in memory. Giving conflicting information during the first and the second step, one can show that interactions between the young male and its parents as well as with its first sexual partner influence the final preference it shows in subsequent double choice tests.

Crystallized songs of bengalese finches ( lonchura domestica) deteriorate rapidly after deafening

Crystallized songs of bengalese finches ( lonchura domestica) deteriorate rapidly after deafening

Drinking Mechanisms in the Zebra Finch and the Bengalese Finch

Drinking Mechanisms in the Zebra Finch and the Bengalese Finch

Variation in egg weight in the Bengalese finch (Lonchura striata var. domestica)

Variation in egg weight was examined in 29 clutches (155 eggs) from 14 pairs of captive Bengalese finches. For clutches of four and seven eggs, egg weight varied more within than among clutches. The opposite was true for clutches of five, six, and eight eggs and when all clutches of four to eight eggs were pooled. Egg weight increased linearly with laying sequence for clutches of four, five, and eight eggs, and for clutches of four to eight eggs combined. Egg weight also varied with clutch size: large clutches contained heavier eggs throughout the clutch than did small clutches. Egg weight was not correlated significantly with the amount of food eaten around the time of egg laying. Furthermore, food consumption did not increase linearly through the laying sequence as did egg weight. These patterns suggest that complex investment allocation decisions underlie egg weight variation in the Bengalese finch.