Amazona amazonica, popularly known as the mangrove parrot, belongs to the order Psittaciformes and is widely distributed across South America, occurring in all regions of Brazil. Although this species is commonly admitted to veterinary care, detailed hematological data are scarce. These data are crucial for guiding clinical interventions, monitoring specimens in human care environments, and providing research references. Hematological reference intervals were established for man-grove parrots kept in a fauna management establishment located in the Amazon biome in the state of Pará, Brazil. The study included 32 Amazona amazonica parrots. Average values for the analyzed analytes in the complete blood count (CBC) were: red blood cells (RBC) 2.42 million/µL; hemoglobin 15.92 g/dL; hematocrit 50.31%; MCV 205.47 fL; MCHC 31.7%; MCH 66.73 pg; white blood cells (WBC) 6,281.4 cells/µL; heterophils 2,671.1 cells/µL; lymphocytes 3,452.27 cells/µL; eosinophils 0 cells/µL; basophils 22.63 cells/µL; monocytes 106.41 cells/µL; thrombocytes 29.44; PPT 6.71 g/dL. Morphological characteristics of the cells were similar to those of other parrots. This research is pioneering in deter-mining hematological reference intervals for mangrove parrots under human care in a holding facility in the Amazon biome. These data can be used as a reference for animals of the species raised under similar conditions.

Most Neotropical Psittacidae have a diploid number of 2n=70, and a dichotomy in chromosome patterns. Long-tailed species have biarmed macrochromosomes, while short - tailed ones have telo/acrocentric macrochromosomes. However, the use of chromosome painting with chicken and white hawk probes has demonstrated that karyotype evolution in Psittacidae includes a high number of inter/intrachromosomal rearrangements. Hence, to determine the phylogeny of Long and Short-Tailed species, and to propose a putative ancestral karyotype for this group, we constructed homology maps of Pyrrhura frontalis (PFR) and Amazona aestiva (AAE) and compared them to other previously analyzed long-tailed species. Chromosomes were analyzed by conventional staining and fluorescent in situ hybridization (FISH) using whole chromosome paints of G. gallus (GGA) and L. albicollis (LAL). Conventional staining showed a karyotype with 2n=70 in both species, with biarmed macrochromosomes in Pyrrhura frontalis and telo/acrocentric chromosomes in Amazona aestiva. Comparison of the results with the putative avian ancestral karyotype (PAK) showed fusions in P. frontalis of PAK1p/PAK4q (PFR1) and PAK6/PAK7 (PFR6) with a paracentric inversion in PFR6. However, in A. aestiva there was only the fusion between PAK6/7 (AAE7) with a paracentric inversion. Hybridizations with LAL probes confirmed these results. The results indicate that PFR retained a more basal karyotype than Anodorhynchus hyacinthinus (AHY), Ara macao (AMA) and Ara chloropterus (ACH), because these three species show the fusion PAK8/PAK9 that is not seen in PFR. Hence, we suggest that the ancestral karyotype of species with biarmed chromosomes have the fusions PAK1p/PAK4 and PAK6/PAK7 and, additionally, a pericentric inversion of PAK6/PAK7, while the fusion PAK8/PAK9 would have appeared in the common ancestor of Anodorhynchus hyacinthinus, Ara macao and Ara chloropterus. However, the species A. aestiva shows a characteristic plesiomorphic trait, since PAK1p/PAK4q and PAK8/9 fusions are absent. Our results base on chromosome rearrangements suggest the classification following the criterium of tail length may no reflect the real phylogenetic history of Neotropical Psittacidae.