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Simple Summary In this study, the environment of hand-raised budgerigars in captivity (people's homes) was simulated. We investigated the effect of coloured LED lights in addition to natural light on the behaviour of the birds. For birds raised by humans, the light in houses is significantly different from the lighting conditions in a bird's natural habitat. This may lead to behavioural and health problems in birds, adversely affecting their wellbeing. This study investigated how white, blue, yellow, and red LED lights applied at the beginning of the dark cycle of the photoperiod affected the behaviours of budgerigars. The results indicated that when offered the opportunity, the birds chose yellow light. The open field tests (OFT I and II) were used to assess the locomotion and exploratory behaviour of birds. The results of the OFT I test, which was performed with an unfamiliar object, indicated that the group experiencing yellow light was more self-confident. The birds in cages with blue light felt more comfortable and displayed more social behaviour. People will be able to use this new information to improve the living conditions of their pet budgerigars. This study examined the effects of exposure to coloured LED lights on some behavioural responses, food and water consumption, and live weight in budgerigars kept in captivity using behavioural tests to compare different lighting conditions. Budgerigars' feeding, comfort, social, fear, and resting behaviours and behavioural reactions to a new environment were studied. Twelve male birds were assigned to four groups, with three birds in each group. They were provided with food and water ad libitum in wire cages at 25 +/- 2 degrees C in a room. The study was conducted with 10 h of natural light, 6 h of LED light (white, blue, yellow, and red LED lights), and 8 h of darkness. Their behaviours in the cages were observed. Home cage avoidance (HCA) and two open field tests (OFT) were performed. No difference was observed in the LW and food consumption, but the blue and yellow groups consumed less water. The blue group displayed more comfort and social behaviours. In the HCA test, the red group demonstrated higher reactions. Furthermore, the birds in the yellow group stayed closer to the centre of the platform in the OFT I test, and they chose the compartment simulating their familiar environment in the OFT II test. Consequently, it was concluded that first yellow and then blue lights may be used to prevent stress-related problems for these birds. Our findings could be used to improve the hand-rearing conditions of captive budgerigars.

Outbreaks of avian trichomonosis are being reported worldwide; meanwhile, the genetic and virulence variations are under investigation. In this study, the occurrence and genetic variability of oral or faecal trichomonads among various avian species were investigated. Samples obtained from either the oropharyngeal cavity, crop/oesophagus, droppings/cloaca, or conjunctival swabs of avian species were inspected for flagellates. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples was performed to investigate the genetic diversity of the isolates. Investigation of 737 birds revealed an infection rate of 15.7% in the upper gastrointestinal tract, 7.3% in the faecal samples, and 0.7% involvement of the conjunctiva. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples, identified genotypes A and B of Trichomonas gallinae and genogroups A-C and E of Tetratrichomonas gallinarum. A novel ITS genotype of intestinal trichomonads was also detected in hooded crow (Corvus cornix) and common mynah (Acridotheres tristis). In the present study, in addition to Columbiformes and Falconiformes, trichomonads were detected in Passeriformes and Galliformes with the involvement of organs other than the gastrointestinal tract. Genotype A T. gallinae was detected in domestic pigeons (Columba livia domestica), a laughing dove (Spilopelia senegalensis), a common kestrel (Falco tinnunculus), a budgerigar (Melopsittacus undulates), and a canary (Serinus canaria). Distinct genotype B was detected in a common mynah and a budgerigar. Genogroups A-C of T. gallinarum were also demonstrated in Galliformes and Anseriformes. Furthermore, two novel trichomonad ITS genotypes were detected in hooded crows and a common mynah warranting detailed multi-locus molecular analysis.RESEARCH HIGHLIGHTSITS diversity of trichomonads was shown in various avian species.Diversity of the parasites' target organ and clinical manifestations was demonstrated.Two novel ITS genotype trichomonads from common mynah and hooded crow were identified.

Over a 4-mo period, a Michigan zoo had 32 budgerigars, Melopsittacus undulatus, from their flock die. Whole animals or formalin-fixed tissues were submitted to Michigan State University Veterinary Diagnostic Laboratory for diagnosis. Avian gastric yeast infection, Macrorhabdus ornithogaster, was diagnosed in seven birds. There was atrophy of breast musculature and no subcutaneous or coelomic fat stores in six necropsied birds. Only two birds had proventricular dilatation grossly. Histologic examination of the proventriculus of all seven birds revealed abundant 3 × 50-µm septate, parallel-walled, nonbranching yeast organisms morphologically consistent with Macrorhabdus ornithogaster. Mycobacteriosis was diagnosed in three budgerigars, two of which were necropsied. Both necropsied birds had hepatomegaly and one also had splenomegaly. No acid-fast bacilli were found in the livers of either bird but were found in splenic macrophages of the bird with splenomegaly and in the intestine of the other bird. Mycobacterium species were cultured from the enlarged spleen and identified by DNA sequence as Mycobacterium genavense. Pulmonary granulomas with acid-fast bacilli were found in the bird submitted as fixed tissues. None of the budgerigars had a dual infection. The remainder of the budgerigars died from hepatitis, nephrosis, oviductal prolapse, exclusion from food and water by flock mates, or tumors.

Insensible evaporative water loss at or below thermoneutrality is generally assumed to be a passive physical process. However, some arid zone mammals and a single arid-zone bird can control their insensible water loss, so we tested the hypothesis that the same is the case for two parrot species from a mesic habitat. We investigated red-rumped parrots (Psephotus haematonotus) and eastern rosellas (Platycercus eximius), measuring their evaporative water loss, and other physiological variables, at a range of relative humidities at ambient temperatures of 20 and 30°C (below and at thermoneutrality). We found that, despite a decrease in evaporative water loss with increasing relative humidity, rates of evaporative water loss were not fully accounted for by the water vapour deficit between the animal and its environment, indicating that the insensible evaporative water loss of both parrots was controlled. It is unlikely that this deviation from physical expectations was regulation with a primary role for water conservation because our mesic-habitat parrots had equivalent regulatory ability as the arid-habitat budgerigar (Melopsittacus undulatus). This, together with our observations of body temperature and metabolic rate, instead support the hypothesis that acute physiological control of insensible water loss serves a thermoregulatory purpose for endotherms. Modification of both cutaneous and respiratory avenues of evaporative may be involved, possibly via modification of expired air temperature and humidity, and surface resistance.

Despite their prevalent use amongst avian species, particularly in Budgerigars, the relationship between mirror use and social behaviors is in need of elucidation. After establishing social behavior measures (e.g., agonistic and pair-bond data) in a colony of Budgerigars, mirrors were introduced and subsequent use was documented. Results illustrated a significant relationship between mirror use and pair-bonds, such that mirror use increased with increasing pair-bond strength. The authors posit that individual differences in gregariousness may best account for the obtained results, with certain birds seeking more social stimulation than others, whether it be from a pair-bond or from its own reflected mirror image. Additionally, the trends observed within agonistic behaviors were consistent with previous avian literature such that those who initiated more encounters also won more encounters and that there was a preference to be closer to birds that win more encounters.

In Pakistan, Knemidocoptes pilae (scaly face mite) mite infestation is a frequently seen parasitic issue in budgerigars. This mite specifically causes extensive damage to featherless areas of cere and legs. This study was conducted to evaluate the topical efficacy of 1% ivermectin and 10% fipronil against two groups of Knemidocoptes pilae infested budgerigars. Fipronil and ivermectin spot on were topically administered on days 0, 7 and 14, on dorsal surface of neck in their respective group. It was concluded that ivermectin readily initiates the healing response after first application as compared to the fipronil and both drugs clear the Knemidocoptic infestation and lesions by 21 days following first treatment.

Some group-living animals show conciliatory tendencies towards specific group members after conflicts, referred to as post-conflict affiliation (PC-affiliation). PC-affiliation with a former opponent and a third-party bystander is classified as ‘reconciliation’ and ‘third-party affiliation’, respectively. PC-affiliation is assumed to be mediated by high-quality social relationships between individuals. Recently, studies assessing lifelong monogamous birds, such as corvids, have found PC-affiliation as a case of convergent evolution with regard to primates. Nevertheless, PC-affiliation divergence in birds is still poorly understood. Here, we report that pair-bonds of budgerigars, a lifelong-monogamous small parrot, engage in both reconciliation and third-party affiliation. We also found that males initiated both types of PC-affiliation more often than females. However, during reconciliation, this skewed affiliation pattern was unlikely specific to the PC-context but could also stem from sex differences in basic social-behavioural features (i.e., female dominance over males and males’ primary role in initiating affiliation with females), which are common outside the PC-context. Conversely, the third-party PC-affiliation pattern was significantly different from the basic affiliation pattern: affiliations were initiated more often by combatant winners, by bystander males toward defeated females, and less often by defeated males. These results suggest specific signal and stress reduction functions related to PC-affiliation among budgerigar pair-bonds. The present study supports the view that PC-affiliations, based on high-quality relationships, did not only evolve in mammals but also in birds, with species-specific forms associated with social behavioural tendencies.

The Blank Park Zoo began suffering mortalities in the spring of 2012 within a flock of 229 captive budgerigars (Melopsittacus undulatus) housed in an interactive public-feeding aviary. Clinical signs in affected birds included weakness, posterior paresis, inability to fly, or acute death. Gross and microscopic lesions were not initially apparent in acutely affected deceased birds. Many birds had evidence of trauma, which is now hypothesized to have been related to the birds' weakness. Investigation into the cause(s) of morbidity and mortality were complicated by the opening of a new interactive enclosure. For this reason, environmental conditions and husbandry protocols were heavily scrutinized. Microscopic examination of dead budgies later in the course of the investigation revealed mineralization of soft tissues consistent with hypervitaminosis D. Pooled serum analysis of deceased birds identified elevated vitamin D3 levels. Vitamin D3 analysis was performed on the feed sticks offered by the public and the formulated maintenance diet fed to the flock. This analysis detected elevated levels of vitamin D3 that were 22.5-times the manufacturer's labeled content in the formulated diet. These findings contributed to a manufacturer recall of more than 100 formulated diets fed to a wide variety of domestic and captive wild animal species throughout the United States and internationally. This case report discusses the complexities of determining the etiology of a toxic event in a zoologic institution.

The subgroup J avian leukosis virus favors the myelocytic series cells and causes myeloid leukosis (myeloblastosis and myelocytomatosis). Natural cases of myeloblastosis (myeloblastic myeloid leukosis) are uncommon and usually occur in adult chickens. This paper describes clinical signs and gross and histopathologic features of myeloblastosis in an adult female budgerigar (Melopsittacus undulatus) that was infected naturally. At necropsy, the spleen was greatly enlarged (enlarged seven or eight times normal) while the other visceral organs were normal. Histologic examination of the spleen indicated a massive intravascular and extravascular accumulation of myeloblasts with a variable proportion of promyelocytes and myelocytes in the red pulp of the spleen.

Parrots are renowned for their vocal learning abilities. Yet only few parrot species have been investigated and empirically proven to possess vocal learning abilities. The aim of this study was to investigate if short-term vocal learning may be a widespread phenomenon among Psittaciformes. Through an interactive experiment we compare the ability of four parrot species, the peach-fronted conure (Aratinga aurea), the cockatiel (Nymphicus hollandicus), the peach-faced lovebird (Agapornis roseicollis) and the budgerigar (Melopsittacus undulatus), to vocally match playback of contact calls. All four species made an overall change to their contact call in response to the playback, and they also varied the degree of similarity with the playback call throughout the playback experiment. The peach-fronted conure showed the biggest overall changes to their contact calls by vocally matching the playback call and the budgerigar showed the least change. The cockatiel and the peach-faced lovebird showed intermediary levels of change making their calls overall less similar to the playback call. The peach-fronted conure responded with highest similarity to familiar individuals and the cockatiel responded with an overall higher similarity to female playback stimuli. Cockatiel males and budgerigar males responded with a higher call rate to playback than female conspecifics. Peach-faced lovebirds responded fastest to unfamiliar males. Based on the results we conclude that short-term vocal learning is a widespread phenomenon among parrots. The way short-term vocal learning is used however, differs between species suggesting that short-term vocal learning have different functions in different species.

In many bird species, male song functions both to defend a territory against other males and to attract a female mate. Male budgerigars (Melopsittacus undulatus) produce a song-like vocal signal, the warble, that can be directed at either females or other males. Warble is a long, complex, low amplitude, and variable vocalization composed of different element types. While there is some evidence that warble can induce reproduction, the function of this signal is largely uncertain and it is unclear whether male- and female-directed warble differ in either function or structure. We recorded male budgerigars in the presence of either their mate or a familiar male to identify whether the warbles produced with different audiences differed in structure. We dissected each warble into specific element units, classified units into a limited number of types by rule-based visual classification and calculated the proportion of each element type, element diversity, and total duration for the male- and female-directed warbles of each male. We also examined the sequential organization of warble element types (syntax) using time-window lagged sequential analysis. We found no differences in the proportions of different elements used, element diversity or duration of warbles between male- and female-directed warble. The syntax of warbles is similar when directed at males or females. However, we found greater between-individual similarity in the sequential organization of warbles directed towards females than in those directed towards males. The greater syntactical consistency in female-directed warble suggests that females may prefer either specific types of element sequences, or consistency itself, and thus shape the organization of warbles.

Retinal ganglion cell (RGC) isodensity maps indicate important regions in an animal's visual field. These maps can also be combined with measures of focal length to estimate the theoretical visual acuity. Here we present the RGC isodensity maps and anatomical spatial resolving power in three budgerigars (Melopsittacus undulatus) and two Bourke's parrots (Neopsephotus bourkii). Because RGCs were stacked in several layers, we modified the Nissl staining procedure to assess the cell number in the whole-mounted and cross-sectioned tissue of the same retinal specimen. The retinal topography showed surprising variation; however, both parrot species had an area centralis without discernable fovea. Budgerigars also had a putative area nasalis never reported in birds before. The peak RGC density was 22,300-34,200 cells/mm(2) in budgerigars and 18,100-38,000 cells/mm(2) in Bourke's parrots. The maximum visual acuity based on RGCs and focal length was 6.9 cyc/deg in budgerigars and 9.2 cyc/deg in Bourke's parrots. These results are lower than earlier behavioural estimates. Our findings illustrate that retinal topography is not a very fixed trait and that theoretical visual acuity estimations based on RGC density can be lower than the behavioural performance of the bird.

The budgerigar (Melopsittacus undulatus) is a highly social species and serves as an excellent model of vocal learning and production. This species can be trained to vocalize as a conditioned response using an operant conditioning paradigm. In addition, the birds can be trained to produce different vocalizations in response to different visual signals. Budgerigars may be fairly unique in the capability for vocal production under operant control. Whether acoustic features of the bird’s natural social milieu can influence this conditioned vocal output is uncertain. The present study asked whether conditioned vocal behavior in budgerigars can be influenced by hearing vocalizations of other birds. The results show that birds vocalizing under operant control produced louder calls in the presence of vocalizations from other birds, than in pure tones or in quiet. The acoustic variation of the conditioned vocalization also increased when it in the context of hearing other bird’s calls. These results reveal a functional connection between the vocal production under operant control and the perceptual mechanisms subserving vocal production in the budgerigars’ natural social milieu.

The rabbit has various utilities and roles, mainly as a meat-producing animal, game species, companion animal, laboratory animal or pest. Among these roles, rabbit breeding for meat has traditionally prevailed in the Mediterranean countries. However, in recent decades the practice of keeping this species as a companion animal has been on the rise; a factor that could be changing public perception of the rabbit. A survey of 492 university students from Seville, Andalusia, Spain, was conducted to determine young people’s perceptions of the rabbit as livestock and as a companion species. The rabbit received the lowest score when regarded as livestock compared to the pig, cow, goat, sheep and hen. Regarding companion animals, young Spanish people preferred the dog and cat, respectively. The rabbit and the hamster were rated at the same level as a pet, while the budgerigar was rated lower than these two mammals by women and higher by men. The goldfish occupied the last position among the pet species in the women’s perceptions. With regard to the perception of various rabbit breeds and varieties when evaluated as pets, it was found that the pet Lop Dwarf, Netherland Dwarf, Angora and Lionhead breeds were rated higher than a typical meat breed (New Zealand White) and than the wild rabbit. The gender of the young people surveyed influenced their perception of the rabbit. Women rated the rabbit lower as livestock while they rated it higher as a pet, also rating the pet rabbit breeds higher than men did. It is proposed that, in keeping with the rabbit’s attributes related to its cuteness, conceptually linked with pets, young Andalusian people’s perception of the rabbit is ambivalent and this perception might partly be shifting from perceiving it as livestock to regarding it as a pet.

The budgerigar (Melopsittacus undulatus) is a small parrot native to Australia that is commonly held in zoos, laboratories, and private homes. Assessment of budgerigar stress levels would aid welfare monitoring and improve our understanding of their biology. Analyzing fecal glucocorticoid metabolites provides a noninvasive method to measure stress levels in birds. For this method to be reliable, the antibody to be used in an immunoassay must be carefully selected for each species, and validation must be performed. A common limitation in many existing assays is the inability to accurately detect variable fecal glucocorticoid metabolites in minute quantities of feces, requiring small samples to be combined. We have developed a double antibody radioimmunoassay protocol based on a commercially available 125I-corticosterone radioimmunoassay kit for use in detecting fecal glucocorticoid metabolites in small quantities (

Parrots housed in inadequate environments can show behavioural patterns that they do not show in their biologically natural context, such as repetitive and nonfunctional activities, potentially indicators of poor welfare. In intensive breeding facilities, birds such as budgerigars (Melopsittacus undulatus) are often pair-housed in cages of limited size for the reproductive period. In this study, the effects of spatial and social restrictions on the behaviour of 18 budgerigars housed in different conditions (pair-housed condition vs social-housed condition) were investigated. Our aim was to compare the presence of species-specific stereotyped behaviours (Oral, Locomotor and Object-Directed) and the time-budget of normal activities between the two experimental conditions. Data were recorded by using video-cameras and, subsequently, a focal sampling technique to score the behavioural repertoire of experimental subjects was adopted. Frequency and duration of stereotyped patterns were significantly higher in p...

Auditory memory is crucial for mate recognition in birds and for long-term maintenance of pair bonds in monogamous species. Parrots, unlike the majority of birds, can imitate sounds into adulthood. During pair bond formation, male budgerigars, Melopsittacus undulatus, which are monogamous parrots, imitate the calls of females. This imitation results in convergence of the two calls. We examined whether and how long the auditory memory of a mate’s call affects female behaviour in relation to pair bond maintenance in this vocally plastic species. Females were paired with a male and then separated, without auditory/visual stimulation from the mate. Females responded to the calls of their separated mates, which had been recorded prior to pair formation, significantly more than to a call from an unfamiliar male. These females continued to show a preference for their respective mates’ calls at 1 and 2 months after separation, demonstrating that the auditory memory of the mate’s call was retained for at least 1 month in the absence of stimulation from the mate. These results show that long-term auditory memory mediates the preferential response to a mate’s call in female budgerigars. However, females ceased to prefer their mates’ calls after 6 months of separation, indicating that the preference response of females is eventually extinguished. We discuss the possibility that the extinction of the preferential response may be explained by an underlying mechanism other than the decay of auditory memory.

We investigated the hypotheses that a bold-shy personality axis exists in the budgerigar (Melopsittacus undulatus) and that dietary docosahexaenoic acid (DHA) supplementation has a significant effect on budgerigar personality and immune responses. DHA is an integral component of the brain known to impact cognitive function, and its impact on budgerigar behaviour is previously unstudied. Adult budgerigars (14 females, 9 males) were housed in two home pens and received either a control diet or a diet supplemented with DHA. The birds were tested in seven experimental situations designed to gauge boldness. Behavioural responses within the categories of fear, feeding and activity were recorded as well as immune status. Our results suggest that dietary DHA supplementation had no effects on the behavioural and immune variables measured in this study. The results do suggest that budgerigars have bold-shy personality traits for their activity and feeding behaviours, as indicated by significant correlations between percent of locations in the central area of the open field with activity in the presence of the familiar flock in the tendency to flock test (rS = 0.754, N =9 ,P < 0.05), net distance travelled in the open field with activity in the presence of the unfamiliar flock in the tendency to flock test (rS = −0.812, N =8 ,P < 0.05), activity in the presence of the familiar flock and activity in the presence of the unfamiliar flock (rS = 0.838, N = 10, P < 0.05) and the number of seeds eaten alone and the number of seeds eaten in competition, both in the foraging and competition test (rS = 0.770, N = 11, P < 0.05). Additionally, significant correlations between open field activity variables and fear variables measuring latencies may indicate that activity and fear variables are related. Finally, although there were several significant correlations between immune parameters and behavioural variables, the results were inconsistent with the hypothesis that immune status and personality are related in the budgerigar. In summary, our results indicate that DHA at the levels used had no effects on budgerigar personality or immune status. However, the results do provide evidence to support the hypothesis that budgerigar personality occurs as a bold-shy axis since budgerigars behaved consistently with regard to activity levels and, for males, feeding behaviour. Females showed a higher innate immunity as measured by the bactericidal activity of whole blood, while in males, this parameter was related to feeding behaviour.

Olguyu karin bolgesinde yavas olarak devamli sekilde buyume gorulen sekiz yasli, disi muhabbet kusu olusturdu. Kus operasyon sirasinda oldu. Nekropside karin boslugunda vezikuler/kistik sabun kopugu gibi polipoid kitle goruldu. Karin boslugu bu kitle ile tamamen doluydu. Ovidukt bolgesinden koken alan kitle histopatolojik olarak adenokarsinom olarak tanimlandi. Diger organlarda metastazlar gozlenmedi. Muhabbet kusunda ovidukt adenokarsinomu Turkiye’de daha once rapor edilmemistir

In mammals, yawning is associated with social and physiological stress, as well as thermoregulation, but little is known about why yawning occurs in stressful contexts or how it is integrated with natural stressors. To investigate the stress sensitivity of yawning in birds, we exposed budgerigars (Melopsittacus undulatus) to a handling stressor that simulated a predatory encounter. Each bird was captured, gently held for 4 min, and then released and videotaped for 1 h (experimental). On a separate day (±24 h), the undisturbed animal was videotaped for 1 h (control). The relationship between handling-induced yawning and body temperature was assessed in a separate experiment, in which the underwing temperatures of the same birds were measured at 1 min intervals during a 4 min holding period. After handling stress, yawning frequency was initially suppressed, then sharply increased within 20 min. Underwing temperature increased during handling, and individuals’ final temperatures at minute 4 were negatively correlated with their latencies to yawn after handling. Thus, stress-induced hyperthermia may be responsible for associations between yawns and stress. These results indicate that yawning may offer a sensitive, noninvasive measure of stress in birds.

Parrots comprise one of the several taxa in which life-long learning of new vocal signals used in intraspecific communication is known to occur routinely. The functions and evolutionary bases of this ability are largely unknown. In the budgerigar (Melopsittacus undulatus), males typically imitate their partner’s contact call type during pair formation. However, a female’s initial choice among unfamiliar males is not based on their production of her call type, because birds without prior social contact rarely produce the same call type. Here, we demonstrate that female budgerigars prefer unfamiliar males with calls that are similar to their own, as measured by spectrogram cross-correlation, but which are not imitations. This was shown by training females via operant conditioning to control access to movies of courting males and by systematically varying the audio tracks of these movies. Females learned this task easily and interacted with virtual males as if they were real. This methodology will be useful for exploring functions and mechanisms of social communication, because it eliminates the confounding impact of short-term changes in a stimulus individual’s behavior on a test individual’s response. Our results suggest that the neuroplastic vocal abilities of budgerigars, and perhaps other parrots, have been shaped by sexual selection.

Five hypotheses about relationships between begging rates, feeding rates and other variables were investigated in captive budgerigar nestlings from 23 days post-hatch to fledge date (Period 4). Within families, nestlings that begged more frequently during Period 4 were fed more often by their parents, but there was no indication that nestling weight on day 23 was related to begging rates in the subsequent growth interval. Instead, last-hatched nestlings begged more than their older siblings. Last-hatched nestlings were not “undersized” at the beginning of Period 4 relative to their siblings, and they experienced less competition than their siblings had at comparable ages. Even so, last-hatched budgerigars begged more often, were fed more often and fledged at heavier weights than their older nestmates. Across families, there was a strong positive relationship between average Period 4 begging rate and average parental feeding rate, but this relationship was much weaker when brood sex ratio was taken into account: female-biased broods had much higher begging and feeding rates than male-biased broods. Brood size was related to begging, with higher ratios of begging to feeding rates for family members than for single nestlings. Taken together, these results suggest that relationships between feeding and begging behavior in budgerigars are more complex than theoretical models have suggested. More studies of avian begging and feeding patterns are required before we can generalize about the control of parental food allocations in birds.

Embryonic calls occur 1–3 d before hatching among precocial and some altricial birds. In precocial species, calls may synchronize hatching among siblings or, in semi-precocial species, elicit parental attention to, and often thermoregulation of, the hatching egg. Much less is known about the functional significance of calls in fully altricial species. In this study, naturalistic observations and laboratory experiments were used to document factors affecting calling and the parental responses to calls in one altricial species, the budgerigar Melopsittacus undulatus. Budgerigar chicks hatch asynchronously and vocalize 24–48 h before hatching. Embryonic calling rates increase at higher egg temperatures, and also as embryos near hatching. Parents easily locate a calling egg in their clutch, even among a large brood of much older, vocalizing nestlings. Furthermore, they actively assist in the last stages of hatching by helping to break the shell along the crack in the egg. Both observational and experimental evidence suggests that embryonic vocalizations are distinctive signals that increase parental attention and care, and may stimulate hatching assistance to a calling egg.

Male budgerigars may be limited in the time they have available to pursue extra-pair copulations because of conflicts with other reproductive behaviour. If males could selectively court only immediately fertilizable extra-pair females they should do so. The cere colour of a female budgerigar may be used as a cue to her reproductive readiness. We experimentally tested the hypothesis that males prefer females with dark ceres, which are indicative of developed ovaries, over females with light-coloured ceres, characteristic of birds with undeveloped ovaries. In a pairwise choice experiment between females that had their cere colour artificially manipulated, pair-bonded males were more likely to choose the female with the dark-coloured cere.

SUMMARY We have used behavioural tests to determine the intensity thresholds of colour vision in Bourke's parrots (Neopsephotus bourkii) and budgerigars (Melopsittacus undulatus). We have also examined the relationship between these thresholds and the optical sensitivities of single photoreceptors using morphological methods. Bourke's parrots lose colour vision in brighter light (0.4 cd m–2) than budgerigars (0.1 cd m–2) and both birds lose colour vision in brighter light(`end of civil twilight') than humans (0.02 cd m–2,`moonlight'). The optical sensitivities of single cones are similar in both birds (budgerigar 0.27 μm2 sr, Bourke's parrot 0.25μm2 sr) but Bourke's parrots have more (cone to rod ratio,1.2:1.0), thinner (2.8 μm) and longer rods (18.5 μm) than budgerigars(2.1:1.0, 3.4 μm, 13.3 μm). Bourke's parrots thus have an eye type that,with a flexible pooling mechanism, allows for high resolution or high absolute sensitivity depending on the light conditions. The results nicely agree with the activity patterns of the birds, Bourke's parrots being active during the day and in twilight while budgerigars are not normally active before sunrise and after sunset. However, Bourke's parrots have fewer cones than budgerigars,which implies that a smaller number of cones are pooled within each retinal integration area. That could explain why Bourke's parrots have a higher intensity threshold of colour vision than budgerigars. Furthermore, the study emphasises the need to expand the sensitivity measure so that photoreceptor integration units are used rather than single receptors.

Regular, non-aversive interaction with humans can reduce domestic and captive animals’ fear of them. This has management implications because it can sometimes beneficially affect the animals’ condition, reproduction and productivity, probably as a result of a reduction in chronic stress. We determined for domesticated budgerigars living in flocks whether regular visual contact with humans for six weeks affected body mass, condition and peripheral blood parameters that are thought to indicate chronic stress levels. Contact comprised 300–360 min of visual exposure weekly to an experimenter pacing slowly in front of the aviary; control flocks had no exposure, except briefly during husbandry. Body mass and condition and the blood parameters were measured at the start (Sampling time 1, ST1) and end (ST2) of the treatment period and again after a further six weeks in which all birds were isolated from humans (ST3). Mass, residual mass (i.e. condition) and blood haemoglobin concentration were greater at ST3 than at ST1 or ST2, the heterophil/lymphocyte ratio increased from 0.35 to 0.67 between ST1 and ST2 and haematocrit decreased from 59 to 54% during the experiment. Improved nutrition and adjustment to the new environment were possible factors influencing these temporal trends. The changes were similar in visually exposed and control birds, so regular visual contact with a human of the specific type and extent imposed had no effect on body mass, condition or the blood parameters. Possible reasons for the lack of an effect are discussed.

The neuroendocrine conditioning of reproduction in birds could perform a very important role in captive breeding, especially in endangered species. Whereas in domestic and wild mammals pharmacological reproductive conditioning is well developed, in birds an effective method is not available. The aim of this study was to test the influence of a new slow-release GnRH analogue (buserelin acetate) implant on the reproductive activity of the Budgerigar (Melopsittacus undulatus), used as model species for captive-bred endangered birds. The effects were assessed by looking at reproductive parameters (egg-laying rate, egg fertility rate) and measuring excreted sex steroid metabolite concentrations in male and female birds. Modification of reproductive parameters and steroid metabolites excretion patterns were observed among birds administered with a GnRH analogue implant and maintained under artificial photoperiod (group I; 16L:8D). Implanted birds showed higher rates of egg-laying, potentially a higher proportion of fertile eggs and higher excreted steroid metabolite concentrations than birds maintained under natural photoperiod (group II; 10L:14D) and birds maintained under artificial photoperiod (group III; 16L:8D). Thus, it is concluded that the new slow-release GnRH analogue implant may represent an innovative and practicable treatment to rapidly induce reproductive activity in the Budgerigar, and that excreted sex hormone metabolites detection permits to monitor male and female gonadal activity.

Yawning is a widespread behavioural response expressed in all classes of vertebrates. There is, however, little agreement on its biological significance. One current hypothesis states that yawning serves as a thermoregulatory mechanism that occurs in response to increases in brain and/or body temperature. The brain-cooling hypothesis further stipulates that, as ambient temperature increases and approaches (but does not exceed) body temperature, yawning should increase as a consequence. We tested this hypothesis in a sample of 20 budgerigars, Melopsittacus undulatus, through the manipulation of room temperature. Birds were exposed to three separate conditions (control temperature (22 °C), increasing temperature (22–34 °C), and high temperature (34–38 °C)) in a repeated measures design, with each condition lasting 21 min. The incidence of yawning differed significantly across conditions (4.20 ± 2.39 yawns per bird in the increasing temperature condition, compared to 2.05 ± 1.90 and 1.25 ± 0.72 yawns per bird, in the high temperature and control conditions, respectively). These findings are consistent with the hypothesis that yawning serves a thermoregulatory function.

The interrelationships between the currently recognised subtaxa of parrots (Psittaciformes) are poorly under- stood and even monophyly of some is not well established. A recent phylogenetic analysis of nuclear gene sequences strongl y supports a previously unrecognised clade including Agapornis (lovebirds), Melopsittacus (Budgerigar), Cyclopsittini (fig-parrots) and Loriini (lories). In the present study it is shown that these taxa also share a unique derived morphology of the hypotarsus, which further occurs in Loriculus (hanging-parrots) and Micropsitta (pygmy-parrots). It is hypothesised that Agapornis, Loriculus, Micropsitta, Cyclopsittini, Melopsittacus and Loriini form a clade for which the name Loricoloriinae is proposed. The presence of an ossified arcus parahyalis on the hyoid bone further suggests a clade including Cyclopsittini, Melopsittacus and Loriini, which also gained support from analysis of molecular data.

SUMMARYBased on aerodynamic considerations, the energy use–flight speed relationship of all airborne animals and aircraft should be U-shaped. However,measures of the metabolic rate–flight speed relationship in birds have been available since Tucker's pioneering experiments with budgerigars nearly forty years ago, but this classic work remains the only study to have found a clearly U-shaped metabolic power curve. The available data suggests that the energetic requirements for flight within this species are unique, yet the metabolic power curve of the budgerigar is widely considered representative of birds in general. Given these conflicting results and the observation that the budgerigar's mass is less than 50% of the next smallest species to have been studied, we asked whether large and small birds have metabolic power curves of different shapes. To address this question we measured the rates of oxygen uptake and wingbeat kinematics in budgerigars and cockatiels flying within a variable-speed wind tunnel. These species are close phylogenetic relatives,have similar flight styles, wingbeat kinematics, and are geometrically similar but have body masses that differ by a factor of two. In contrast to our expectations, we found the metabolic rate–flight speed relationship of both species to be acutely U-shaped. We also found that neither budgerigars nor cockatiels used their normal intermittent flight style while wearing a respirometric mask. We conclude that species size differences alone do not explain the previously unique metabolic power curve of the budgerigar;however, due to the absence of comparable data we cannot evaluate whether the mask-related kinematic response we document influences the metabolic rate–flight speed relationship of these parrots, or whether the energetics of flight differ between this and other avian clades.)

Humans communicate with one another not only face-to-face but also via modern telecommunication methods such as television and video conferencing. We readily detect the difference between people actively communicating with us and people merely acting via a broadcasting system. We developed an animal model of this novel communication method seen in humans to determine whether animals also make this distinction. We built a system for two animals to interact via audio-visual equipment in real-time, to compare behavioral differences between two conditions, an "interactive two-way condition" and a "non-interactive (one-way) condition." We measured birds' responses to stimuli which appeared in these two conditions. We used budgerigars, which are small, gregarious birds, and found that the frequency of vocal interaction with other individuals did not differ between the two conditions. However, body synchrony between the two birds was observed more often in the interactive condition, suggesting budgerigars recognized the difference between these interactive and non-interactive conditions on some level.

Primary and secondary cardiovascular diseases are not uncommon in birds. Although radiologic standards for heart width have been developed for mammals, they are still not available for many avian species. The purpose of this study was to establish normal reference values for cardiac size in budgerigar (Melopsittacus undulatus), one of the most popular pet bird species all over the world. After clinical and radiographic (lateral and ventrodorsal views) evaluations, 27 adult, clinically healthy budgerigars (10 females and 17 males) were included in this study. High-quality ventrodorsal and lateral radiographic projections were obtained. The cardiac and thoracic width, distance between third and fourth ribs, synsacrum width, coracoid width, and the distance between clavicle bones were measured on ventrodorsal radiographs. The ratio between cardiac width and other mentioned indices was calculated. Correlation of each anatomical index with the cardiac width was evaluated by linear regression model. Sex and weight were included in all models. Mean + SD of cardiac width was 10.8 +/- 0.6 mm, with lower and upper limits of 9.5 and 12.0 mm. The results showed a significant correlation between the cardiac width and the thoracic width (R2 = 0.28; P = 0.005). There were no significant associations between weight, sex, and the heart width. The values and ratios obtained in this study can be used as a reference of normal cardiac size of budgerigar in radiology for detection of cardiomegaly in this bird.

A trait typical of parrots, but rare in other groups of birds, is the acquisition of new learned calls (acquired by copying conspecifics) throughout an individual's lifetime. The significance of this distinctive psittacid trait is not understood. In budgerigars, females preferentially affiliate with unfamiliar males whose contact calls resemble their own during brief dyadic choice trials; also, in forced-pair situations, contact call similarity of members of pairs increases as a result of a male tendency to imitate his mate's call type. The functions of budgerigar call imitation and preference for pre-pairing similarity are currently unknown. Moreover, as budgerigar pair formation occurs over a span of days or weeks, it is important to determine whether birds in breeding colonies assort and proceed to breed on the basis of pre-pairing contact call similarity, and whether high levels of call similarity are maintained after pair formation is complete. To explore these questions, we recorded contact calls of male and female budgerigars before and after they were placed into an aviary equipped for breeding. As predicted, birds paired assortatively based on pre-pairing call similarity. Once birds had paired, their calls converged further in acoustic structure, as previous work had led us to expect. However, after eggs were laid and the males began to feed their mates, the calls of mated birds diverged, suggesting that there might be some cost to maintenance of shared calls. Male care-giving correlated with the degree to which his pre-pairing calls resembled those of his mate, but not with the similarity achieved through convergence. These results suggest that female budgerigars may use a male's pre-pairing call similarity as a predictor of paternal investment. The questions of why such similarity predicts male care-giving, and why calls converge following initial pairing activities, require further work.

Parrots are unusual among birds and animals in general in the extent of their ability to learn new vocalizations throughout life and irrespective of season. The budgerigar (Melopsittacus undulatus), a small parrot that is well suited for laboratory studies, has been the subject of numerous studies investigating the neurobiology of vocal learning. To date, few studies have focused on the function of vocal imitation by parrots. Previous work from our research group has shown that vocal imitation in budgerigars is sex-biased, as males paired with females learn vocalizations from their new mates, but not vice versa. This bias led us to hypothesize that vocal learning has a reproductive function. To test this hypothesis, we conducted two experiments. In the first experiment, we tutored males so that they could produce a call similar to one shared by a group of experimental females. The experimental females were then presented with one of the tutored males and another, equally unfamiliar, male that had not been tutored. We found that the females spent a greater proportion of time in proximity of, and made more affiliative displays toward, the tutored males. In the second experiment, seven males received small bilateral brain lesions that disrupt vocal learning. These males and an equal number of control males were then released into an aviary containing females and reproductive resources. We found that lesioned and control males were equally successful in obtaining social mates, but females mated to lesioned males were more likely to engage in extra-pair activities. These experiments indicate that a male's ability to imitate a female's call can influence the sexual behavior of the female even though lack of imitation ability does not appear to influence social pairing. We hypothesize that mate choice in budgerigars has multiple stages. Upon meeting a strange male, a female quickly assesses its ability for social acquisition of calls by the presence or absence of a call type similar to its own in its repertoire. As courtship proceeds into pair formation, the female assesses the ability of male to learn more directly by the extent of the male's perfection of imitation.

A longitudinal study was performed in order to investigate virus excretion and viraemia during a clinical outbreak of the psittacine beak and feather disease in budgerigars (Melopsittacus undulatus). Viral nucleic acid was detected in feathers, cloacal swabs and blood samples. Overall, beak and feather disease virus (BFDV) DNA was detected most commonly in feather samples, followed by cloacal swabs, and least frequently from blood samples. In most cases the viraemia was short lived and correlated with clinical signs, such as feather abnormalities. Sequence analysis of the polymerase chain reaction fragment amplified from the replication-associated gene (ORF V1) indicated a close relationship with other BFDV isolates. Overall the highest level of nucleotide identity was found with the ORF V1 of another budgerigar isolate. Our results suggest that feather samples and cloacal swabs should be taken for polymerase chain reaction diagnosis to determine the presence of BFDV in an aviary, but that detection in these samples may not correlate well with psittacine beak and feather disease.

Many parrots have plumage that either reflects strongly in the ultraviolet-A (UVA) waveband, between 315-400 nm, or exhibits UVA-induced fluorescence. Previous experimental work on budgerigars (Melopsittacus undulatus) suggests that UVA reflectance plays a role in mate choice, as in other diurnal birds, but evidence for fluorescent cues playing a role is unconvincing. Here we report two experiments on budgerigars, designed to determine whether fluorescent cues play a role in signalling when UVA reflectances are absent, an approach which separates removal of UVA reflectance from removal of fluorescence. First, we determined whether the choices of different females are correlated under these treatment conditions. Secondly, we investigated female preferences for fluorescing and non-fluorescing males when UVA reflections are absent, to determine whether the yellow emissions of fluorescence are playing a role in mate choice. Results from experiment 1 do not suggest that females agree on which males are attractive when UVA reflectances are absent, with only half of the subjects choosing the same male. Neither did different females make the same choices in experiment 2. This lack of agreement provides further evidence that UVA reflectances from males play an important role in female choice in this species. Experiment 2 provides no evidence to suggest that UVA-induced fluorescence plays a role in mate choice. Overall, our study supports previous findings showing that UVA reflectance plays a role in sexual signalling in this species, but provides no evidence to suggest the same for fluorescence when UVA reflectances are absent.

Hans Duncker (1881–1961) is among the first avian geneticists, but remains poorly known. He trained as a biologist, completing his PhD at the University of Gottingen in 1905 and then became a high-school teacher in Bremen where he remained for the rest of his life. In 1921 he met Karl Reich (1885–1970) who was the first person to make recordings of bird song and was well-known for creating a strain of canaries that sang Nightingale (Luscinia megarhynchos) songs. Duncker provided a novel Darwinian/Mendelian explanation for how Reich's canaries acquired their songs. In the early 1920s, a time during which the field of genetics was rapidly developing in the USA and Britain, but not Germany, Duncker and Reich conducted large-scale breeding experiments to establish the pattern of inheritance of variegation and other traits in canaries. In 1925 Duncker met Generalkonsul Carl Cremer (1858–1938), who provided the financial backing for a massive and comprehensive study of inheritance of colour patterns in Budgerigars (Melopsittacus undulates). At the same time Duncker also initiated a project to create a red canary by hybridising canaries with the Red Siskin (Carduelis cucullata). Duncker recognized that bird-keepers had much to offer professional scientists (and vice versa) and was keen to bridge the gap between them and to this end in 1927 began his own journal “Vogel ferner Lander”. His research on the genetics of the canary and budgerigar resulted in the publication of a large number of papers in ornithological journals and magazines and several books. Duncker was a eugenicist, and when the National Socialists came to power in 1933 he supported and promoted the notion of positive eugenics. He was later (in 1990) condemned for these activities and for having been a Nazi, but we show that Duncker joined the Party only reluctantly. After WWII Duncker restored and re-catalogued the bird collections at the Ubersee-Museum in Bremen. We discuss the possible reasons why Duncker's research, much of it very innovative, has been largely ignored internationally.

Budgerigars are well known for their ability to imitate sounds, but little is known about the functional contexts in which they use these imitations. Recently, we have shown that male budgerigars consistently imitate the contact calls of the females with whom they are paired. Here we investigate whether males produce these imitations more frequently when they are with their mates than when they are with other females. In one experiment, we established seven budgerigar pairs and then tested each male with his mate and with an unfamiliar female. In the second experiment, we allowed pairs to form freely in an aviary and then tested the males with their mate and with a familiar mated female. In both experiments, the males produced significantly more imitations of their mate's call (defined as calls that were more than 75% similar to the mate's predominant contact call) when they were with their mate than when they were recorded with another female. Under aviary conditions, this difference was due to both a general increase in the males' rate of calling and to an increase in the percentage of the males' calls that were imitations. These data show that male budgerigars modify their contact call rates and repertoires in an audience-specific manner. This audience effect is unusual because it involves a learned vocalization and is extremely specific to a particular audience, namely the mate. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.

Macrorhabdus ornithogaster is a newly described anamorphic ascomycetous yeast that has been reported to cause a chronic, debilitating disease in many species of birds, including poultry. Study of this organism is complicated by the limited ability to grow M. ornithogaster in vitro. In this study, we showed that the chicken can be used to amplify this organism and as a model to study its pathogenicity. An infection rate of 100% was achieved in day-old chicks orally inoculated with 105 M. ornithogaster derived from the budgerigar (Melopsittacus undulatus). The organism was also determined to increase in number by greater than 10-fold 14 days after oral inoculation in these chicks. Chickens infected with M. ornithogaster demonstrated no sign of illness but had decreased feed conversion efficiency and consistent and characteristic histopathologic lesions in the proventriculus and isthmus of the stomach, suggesting that M. ornithogaster may represent a potential threat to the poultry industry.

We investigated the effects of estradiol-treated females on the behavior of male budgerigars. In comparison to control females, females given implants of estradiol showed elevated nest behavior and darker cere color, which are characteristics of breeding females. After we confirmed the efficacy of estradiol treatment on behavior and morphology, each female was paired with a male mate. Males paired with estradiol-treated females showed more courtship behavior (auditory and visual display, and courtship feeding) to their mates than males paired with control females. These data indicate that budgerigar females with a high estrogen level enhance males' courtship behavior. Since males did not show response to estradiol-treated females soon after females were introduced, effects of estradiol-treated female budgerigars may be mediated by the endocrine system, rather than wholly by the nervous system, of males.

© 2015 Current Zoology. Studies in several songbird species have shown that treating females with the androgenic steroid hormone testosterone (T) can negatively affect female reproductive behaviors and breeding success. As the effects of T on females appear to be species-specific, it is not clear if similar effects of high T occur in non-songbird species. Here, we studied the effects of T supplementation on female reproductive behavior and oviposition in the budgerigar, Melopsittacus undulatus, a small monogamous parrot species with distinct sex differences in parental behavior. We experimentally increased T concentrations to male-like levels in T-treated females compared to controls and we allowed females to breed. We found no significant effects of treatment on the latency to enter the nestbox but T treatment significantly interfered with oviposition. Our results show that T-treated females were seven times less likely to produce a clutch than control females. As we found that T treatment had a strong inhibitory effect on oviposition, our results indicate that female budgerigars suffer fitness costs from male-like plasma T levels. Therefore, it may be possible that, also in non-songbird species, selection for higher T levels in males is constrained by a correlated response to selection which imposes fitness costs on females in terms of reproduction. Evaluating whether or not this is indeed the case requires further work combining different approaches to the study of the evolution of male and female testosterone levels. ispartof: Current Zoology vol:61 issue:4 pages:586-595 status: published

Ad hoc studies of the compositions of bird communities at dispersed sites and bird-banding data have failed to reveal the timing, destinations and movement patterns of most Australian migratory bird species. The analysis of national atlas and count data, on the other hand, has the potential to provide information on the species undertaking migratory movements, the timing of these movements, and their sources and destinations. This study examines atlas data of 407 species for evidence of movements by these species in eastern Australia. Atlas and bird-count data were brought together to form the most extensive collection of bird observations in Australia. Mathematical, statistical and graphical tools were used to examine these data for evidence of temporal changes in the spatial distributions of each species. Examples are provided of the application of these tools to four speices (Dollarbird, Eurystomus orientalis, Noisy Miner, Manorina melanocephala, Grey Fantail, Rhipidura fuliginosa and the Budgerigar, Melopsittacus undulatus) that exhibit varying movement patterns. A standardised analysis applying these indicators across 407 species found strong evidence of migratory movements for 101 of these species and suggestive evidence for a further 45 species. These results indicated 19 distinctive patterns of migration among the birds of eastern Australia.

An outbreak of reovirus infection with high mortality in two groups of recently imported psittacine birds is reported. The disease in the two species involved, African grey parrots (Psittacus erithacus erithacus) and Australian king parrots (Alisterus scapularis), had differences in clinical presentation and gross lesions. Reovirus particles were observed by electron microscopy and ultrastructural examination of tissues, and two viruses were isolated in cell culture, one from each bird species. Both isolates were studied by cross-neutralization with antisera against reference avian reoviruses isolated from chickens and parrots, and were found to have the greatest similarity to viruses isolated from a budgerigar and a southern screamer.

The budgerigar (Melopsittacus undulatus) is a promising model species for the study of adult vocal learning. To date, several studies have confirmed the existence of vocal plasticity and, more importantly, rapid imitation of contact calls by adult male budgerigars. Vocal learning has not been investigated in female budgerigars, however. Since one likely function of the contact call is to denote group affiliation, we tested the hypothesis that female budgerigars, when placed into groups, would develop a shared contact call. We recorded the contact call repertoires of eight adult female budgerigars that were unfamiliar with one another, then placed them into two groups. Each group was deprived of visual contact with other birds. Recording sessions continued for the subsequent 8 wks, and behavioral observations were also conducted during this time. Within 4-7 wks, females in both groups converged on a common call type. This rate of convergence is slower than that observed in prior experiments limited to male birds, and much slower than vocal imitation by male budgerigars paired with females. Therefore, while our study documents vocal plasticity in adult female budgerigars, it also suggests that female budgerigars learn new vocalizations more slowly than males do.

In their native Australia the budgerigar’s breeding season is very short and rapid nest establishment is crucial. To minimize the time required to locate and establish nesting sites, female budgerigars were predicted to use cues on nest site locations provided by other females in their colony. Experimental results from captive birds indicated that, while females can be attracted to nests that are occupied by other females, the social and breeding experience of individuals affects this use of conspecific cues. Females that have had altercations with other females that resulted in physical injuries showed an aversion to apparently occupied nestboxes. Females that had no such social experience prior to testing were attracted to apparently occupied nestboxes. Breeding experience, as well as social experience, may have an effect on the use of conspecifics as cues. Experienced breeding females were less likely to be attracted to apparently occupied nestboxes than were females that had never bred before.

The metabolism, excretory rates, and excretory patterns of carbon 14 (14C) radiolabeled estradiol (E2) and testosterone (T) were studied in female budgerigars (Melopsittacus undulatus) and orange-winged Amazon parrots (Amazona amazonica). Radiolabeled E2 and T were injected intramuscularly into six budgerigars and two orange-winged Amazon parrots. Serial fecal/urine samples were collected for 168 h post-radiolabel injection. Peak radiolabeled E2 excretion was observed at 4 h post-injection, and by 24 h, 93.3 ± 6.3 and 65.9% (range, 59.1–72.7%) of the injected radiolabel was recovered in the fecal/urine matter of budgerigars and orange-winged Amazon parrots, respectively. Similarly, peak radiolabeled T excretion was observed at 4 h post-injection with 92.7± 3.6 and 66.2% (range, 57.5–75.2%) of the injected radiolabel recovered in the fecal/urine matter by 24 h in the budgerigars and orange-winged Amazon parrots, respectively. High-performance liquid chromatography (HPLC) analysis of the fecal/urine material revealed that both parrot species excreted >80% of the radiolabel in the form of complex steroid conjugates. Immunoreactive E2 and T metabolites were detected using estrone (E1) and C-21/C-19 conjugate enzyme immunoassays, respectively. Hydrolysis of the E2 metabolites and HPLC analysis of the ether extracts revealed that E2 and E1 were the major steroid moieties. Hydrolysis of the T metabolites and HPLC analysis of the ether extracts revealed two and three major unconjugated peaks for the budgerigars and the orange-winged Amazon parrots, respectively. Zoo Biol 18:247–260, 1999. © 1999 Wiley-Liss, Inc.

Three carpometacarpi and a tarsometatarsus of a small parrot, recovered from the Early Pliocene-aged deposits at Rackham's Roost Site, Riversleigh, north-western Queensland, are indistinguishable f...

In a series of experiment to elucidate the rule of amino acid requirements in the fowls from small to large ones, the fractional synthesis rates (FSR) of protein were determined to collect basal data on protein and amino acid metabolism in budgerigars as a small bird. Twenty young adult budgerigars were injected with 0.1 ml/10 g body weight containing 40 microCi/100 mumol phenylalanine/ml in a wing vein, and killed at 2 and 10 min after the injection. The FSR in the whole body, liver, proventriculs and gizzard, intestine and breast muscle were determined. The FSR were not the same in all tissues, and estimated values were highest in the liver (104.7), and followed by the intestines (68.0), whole body (55.2), proventriculs + Gizzard (46.8), heart (35.8) and breast muscle (26.9%/day).

The response of neurons of the budgerigar (Melopsittacus undulatus) was obtained in Field L, which is a laminated auditory structure of the caudal neostriatum in the telencephalon. Warble song of this species is comprised of a number of sounds (elements). The influence of sequence and silent intervals between elements on neuronal response was investigated. First, neurons in Field L were examined to know if neuronal response to isolated elements differed from that to the same elements in warble song, a sequence of elements. Sixty-two percent of the neurons exhibited increases of spike activity in response to elements in isolation compared with that to elements in warble song. These neurons thus exhibited temporally suppressed response. We then examined neuronal activity using the stimulation with paired elements, separated by various silent intervals (delta t msec). The spike activity in response to a specified element decreased as the interval was shortened. The responses of most neurons were str...