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Abstract Isospora bioccai (Cringoli and Quesada 1991) (Protozoa, Apicomplexa, Eimeriidae) is reported and described from captive canaries Serinus canaria forma domestica (Linnaeus 1758) in Mexico. The oöcysts are subspherical, 25.5 × 23.5 μm, with smooth, bilayered wall, ∼1.3 μm thick. Micropyle absent, oöcyst residuum absent, and polar granule present, 4–8 rice-grain-shaped. Sporocysts are ovoidal, 16.7 × 10.5 μm. Stieda body knob-like and substieda body trapezoidal of irregular base. Sporocyst residuum is composed of granules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. Gamogony was seen in the duodenum. In addition to new locality, this is the first description of I. bioccai from S. canaria. Graphical abstract Image 1 Highlights • The canary (Serinus canaria) as a new host for Isospora bioccai. • Gamogony was seen in the duodenum. • First record of I. bioccai in Fringillidae in Mexico. [ABSTRACT FROM AUTHOR]

Prosociality (behaviours that benefit to a recipient without necessarily involving a cost to the actor) has recently been shown to exist in various taxa, including birds. Studies on prosociality in primates found that prosocial tendencies of the subject could be related to sex and parental care, communication from the recipient, cognitive abilities and personality. To investigate the existence of such associations on birds, we conducted a Prosocial Choice Task with domestic canaries (Serinus canaria). In our experiment, the subject could choose between three options: a prosocial, a selfish, and a null option (with no cost for the subject). We also conducted a food sharing experiment and measured several personality traits. Our results highlighted high levels of prosociality and a tendency to reciprocity among reproductive mates. We found a higher propensity to be prosocial in nulliparous individuals than in individuals that have previously been parents, but better sharing abilities in parents than in nulliparous individuals. When they were recipient, parents also used communication more efficiently than nulliparous subjects. Data suggest that parental expertise could enhance subjects' skills in eliciting prosociality. We also highlighted some interaction between prosociality, learning abilities, and some personality traits, proactive individuals being fast learners and more prosocial, while reactive individuals being slow learners and more reciprocal. Our results suggest that prosociality and reciprocity could be linked to personality and cognitive abilities, and that it might be interesting to consider them as parts of individual's cognitive style. • Our results showed high prosociality in canaries among reproductive mates. • Parents exhibited better sharing abilities than nulliparous individuals. • As recipient, parents used communication more efficiently than nulliparous birds. • Proactive individuals were fast learners and were more prosocial. • Reactive individuals were slow learners and were more reciprocal. [ABSTRACT FROM AUTHOR]

Recent studies suggest that cognitive bias could constitute a novel and valid measure of animal welfare. Although interest for a link between personality and cognition is growing, no study to date investigated whether a cognitive bias might be related to the personality of the individuals. We trained 43 domestic canaries ( Serinus canaria ) to discriminate between two sides of a test cage, each side being associated with a different value (attractive or aversive food in a dish). During the test phase, the dish was placed at intermediate locations, representing ambiguous information. Results show evidence of an “optimistic” bias (flying faster to the dish at the ambiguous location) in birds housed in pairs, compared to birds housed singly, suggesting an influence of social context (living conditions) on canaries’ emotions when tested individually. We also studied six traits of individuals’ personality and found that aggressiveness, neophobia, one sociability index and obstinacy were repeatable across social context and/or day-light schedule, whereas the other sociability index, boldness and locomotion were not. No correlation between the birds’ optimism and any of their personality traits was found, suggesting that cognitive bias may be a matter of social context rather than of individual personality. [ABSTRACT FROM AUTHOR]

The emergence of bacterial resistance to antibiotic use in veterinary practice is considered a source of multidrug-resistant bacterial infections for humans. Although increasing incidence of antimicrobial resistance in small-animal practices has already been noted, limited information is available about the problem in domestic canaries ( Serinus canaria domestica ). This cross-sectional study describes the prevalence of Gram-negative bacteria among canaries exhibiting clinical disease signs and the antimicrobial sensitivity patterns of the bacterial isolates. During the breeding season, a bacteriological survey was carried out in 50 amateur breeding aviaries from the Messina Province (Sicily, South of Italy) to detect the prevalence of Gram-negative bacteria in sick birds. Fecal samples from breeder canaries were submitted for bacteriological examination. Of 50 breeding aviaries, 43 (86%) were positive for Gram-negative bacteria. Overall, 88 bacterial isolates, representing 12 genera of bacteria, were cultured. The most frequently recovered bacterial species was Escherichia coli (31/88 isolates, 35.2%). Other frequently isolated species were Enterobacter cloacae (9/88 isolates, 10.2%) and Proteus mirabilis (6/88 isolates, 6.8%). Potentially pathogenic species, including Salmonella Typhimurium ( n = 5 strains), Enterobacter sakazakii ( n = 4 strains), and Pseudomonas aeruginosa ( n = 6 strains), were also identified. The 88 isolates displayed significant frequencies of antibiotic resistance. These results confirm the potential presence of multidrug-resistant bacteria in canary facilities, suggesting that measures to educate the public about this risk are necessary. [ABSTRACT FROM AUTHOR]

Abstract: Carotenoids are pigments responsible for the red, orange and yellow coloration of plants and animals. They may be beneficial in two ways; they have a powerful antioxidant activity, and they can behave as an immunostimulant. Animals however cannot synthesize carotenoids de novo, they must obtain them through their diet. In our experiments on Canaries, we investigated how mothers transfer their dietary carotenoid-related benefits to their offspring; either through the egg, or through the diet (during chicks'' feeding). Female Canaries were allowed to access β-carotene enriched food during egg formation and/or chicks'' feeding. We sorted the chicks into four groups using the period when they assimilated the beta-carotene as a variable. The four groups were: (i) before hatching (from yolk), (ii) after hatching (from maternal feeding), (iii) before and after hatching, or (iv) never. Colorimetry and HPLC analysis from sub-samples of yolks confirmed the maternal transfer of dietary carotenoids to the yolk. Our results show that benefits from maternal dietary carotenoids are transferred to the chicks, but according to the period when they are assimilated by the chicks, the physiological effects are different. It was found that the chicks'' growth was enhanced when carotenoids were assimilated both before and after hatching. However an increase in cellular immunity efficiency only occurs when the assimilation takes place after hatching. [Copyright &y& Elsevier]

The steroid receptor coactivator SRC-1 modulates ligand-dependent transactivation of several nuclear receptors, including the receptors for sex steroid hormones. The distribution of SRC-1 transcripts was analyzed here by in situ hybridization in coronal sections through the brain of male and female canaries. A broad but heterogeneous distribution of SRC-1 transcripts was observed with high numbers of densely labeled cells being present in many steroid-sensitive areas including the medial preoptic nucleus, several hypothalamic nuclei, five song control nuclei (HVc, the lateral and medial portion of the magnocellular nucleus of the anterior neostriatum, area X and the nucleus uvaeformis) and several catecholaminergic areas (area ventralis of Tsai, substantia nigra, locus coeruleus). The volume of two song control nuclei, HVc and area X were reconstructed based on the boundaries of the cell groups exhibiting a denser SRC-1 expression as compared to the surrounding areas. Sex differences in the expression of SRC-1 were also detected in several song control nuclei. In particular, the volume of HVc based on the high density of SRC-1 expression was significantly larger in males than in females. The effect of steroids on the song control system could be, at least in part, indirect and result from a modulation by steroids of the catecholaminergic inputs to the song control nuclei. The presence of the steroid receptor coactivator SRC-1 in the telencephalic song control nuclei and in the catecholaminergic cell groups that innervate the song system supports the idea that SRC-1 expression could play an active role in the control of singing behavior by modulating estrogen and androgen receptor action at both locations. [Copyright &y& Elsevier]

• Fife Fancy Canaries show annual cycles in testicular activity and singing behaviour. • Song becomes plastic in the fall and crystallises again in the spring of each year. • Perineuronal nets (PNN) are present in high densities in song control nuclei. • In spring PNN are present in larger numbers in the nucleus robustus arcopallialis. • Changes in PNN could control annual variations in song plasticity. Songbirds learn their song during a sensitive period of development associated with enhanced neural plasticity. In addition, in open-ended learners such as canaries, a sensitive period for sensorimotor vocal learning reopens each year in the fall and leads to song modifications between successive breeding seasons. The variability observed in song production across seasons in adult canaries correlates with seasonal fluctuations of testosterone concentrations and with morphological changes in nuclei of the song control system (SCS). The sensitive periods for song learning during ontogeny and then again in adulthood could be controlled by the development of perineuronal nets (PNN) around parvalbumin-expressing interneurones (PV) which limits learning-induced neuroplasticity. However, this relationship has never been investigated in the context of adult vocal learning in adult songbirds. Here we explored PNN and PV expression in the SCS of adult male Fife Fancy canaries in relation to the seasonal variations of their singing behaviour. We found a clear pattern of seasonal variation in testosterone concentrations and song production. Furthermore, PNN expression was significantly higher in two specific song control nuclei, the robust nucleus of the arcopallium (RA) and the Area X of the basal ganglia, during the breeding season and during the later stages of sensorimotor song development compared to birds in an earlier stage of sensorimotor development during the fall. These data provide the first evidence that changes in PNN expression could represent a mechanism regulating the closing-reopening of sensitive periods for vocal learning across seasons in adult songbirds. [ABSTRACT FROM AUTHOR]