| combinatory actions during object play in psittaciformes (diopsittaca nobilis, pionites melanocephala, cacatua goffini) and corvids (corvus corax, c. monedula, c. moneduloides). | the playful (i.e., not overtly functional) combination of objects is considered a potential ontogenetic and phylogenetic precursor of technical problem solving abilities, as it may lead to affordance learning and honing of mechanical skills. we compared such activities in 6 avian species: 3 psittaciforms (black-headed caiques, red-shouldered macaws, and goffin cockatoos) and 3 corvids (new caledonian crows, ravens, and jackdaws). differences in the type and frequency of object combinations were ... | 2015 | 25437492 |
| transfer of physical understanding in a non-tool-using parrot. | physical cognition has generally been assessed in tool-using species that possess a relatively large brain size, such as corvids and apes. parrots, like corvids and apes, also have large relative brain sizes, yet although parrots rarely use tools in the wild, growing evidence suggests comparable performances on physical cognition tasks. it is, however, unclear whether success on such tasks is facilitated by previous experience and training procedures. we therefore investigated physical comprehen ... | 2016 | 27639565 |
| mycobacteriosis in captive psittacines: a brief review and case series in common companion species (eclectus roratus, amazona oratrix, and pionites melanocephala). | in 2015, three psittacines were presented within 30 days, each with differing clinical signs and patient histories. a 13-yr-old male eclectus parrot (eclectus roratus) was presented for weakness, depression, and acute anorexia. on presentation it was determined to have a heart murmur, severely elevated white blood cell count (93.9 103/μl) with a left shift (2.8 103/μl bands), and anemia (30%). severe hepatomegaly was noted on radiographs, ultrasonography, and computed tomography. a cytological s ... | 2017 | 28920813 |
| mandibular squamous cell carcinoma in 2 psittacines. | a unilateral, malformed gnathotheca in a green-winged macaw (ara chloropterus) was managed for 16 mo with periodic beak trims. biopsy of the affected beak did not identify an underlying cause; however, at postmortem examination, a densely cellular neoplasm invaded the mandible from the beak, dissecting and effacing the cortex and trabecular bone and inciting periosteal proliferation. there was no evidence of metastasis. neoplastic cells were strongly immunopositive for cytokeratin ae1/ae3, consi ... | 2020 | 32081087 |
| serial reversal learning and cognitive flexibility in two species of neotropical parrots (diopsittaca nobilis and pionites melanocephala). | serial reversal learning of colour discriminations was assessed as an index of cognitive flexibility in two captive species of neotropical parrots. both species showed similar performances across serial reversals and no between species differences were observed. in a second task subjects' performances were assessed after they experienced either a low or high pre-reversal learning criterion. if reversal performances improve through processes of associative learning, a high pre-reversal criterion ... | 2018 | 29656091 |