The Experts below are selected from a list of 23160 Experts worldwide ranked by ideXlab platform
Robert Heinsohn - One of the best experts on this subject based on the ideXlab platform.
-
Breeding biology of three large, sympatric rainforest Parrots in New Guinea: Palm Cockatoo, Pesquet’s Parrot and Eclectus Parrot
Emu, 2019Co-Authors: Paul Igag, Andrew L. Mack, Sarah Legge, Robert HeinsohnAbstract:In New Guinea Palm Cockatoos, Pesquet’s Parrots and Eclectus Parrots are potentially threatened by deforestation and hunting. In a 28-month study, we found 51 Palm Cockatoo, 34 Pesquet’s Parrot and 71 Eclectus Parrot nests. Eclectus Parrots used taller, larger, live trees. Palm Cockatoos preferred hollows in broken trunks having deeper hollows with larger entrances. Pesquet’s Parrots excavated their nest hollows in dead trees. Palm Cockatoos nested at lower density (0.008 nests/ha) than Pesquet’s (0.022 nests/ha) and Eclectus Parrots (0.069 nests/ha). Palm Cockatoos and Pesquet’s Parrots appeared to breed seasonally; Eclectus Parrots bred at higher frequency year-round. Palm Cockatoo clutch size was one; Pesquet’s and Eclectus Parrots clutches had one to two eggs. Eclectus Parrots had higher fledging success: 54%, compared with 40% of Palm Cockatoo and 17% of Pesquet’s Parrot eggs. Predation caused most nest failures for Palm Cockatoos and Eclectus Parrots; starvation caused most loss in Pesquet’s Parrots. Humans hunted Palm Cockatoos and Pesquet’s Parrots, not Eclectus Parrots. Higher nest tree density, breeding success, and more generalised feeding habits may make Eclectus Parrots the least vulnerable of the three species. Low population density and breeding frequency of Palm Cockatoos and Pesquet’s Parrots may make them more vulnerable.
-
breeding biology of three large sympatric rainforest Parrots in new guinea palm cockatoo pesquet s Parrot and eclectus Parrot
Emu, 2019Co-Authors: Paul Igag, Andrew L. Mack, Sarah Legge, Robert HeinsohnAbstract:In New Guinea Palm Cockatoos, Pesquet’s Parrots and Eclectus Parrots are potentially threatened by deforestation and hunting. In a 28-month study, we found 51 Palm Cockatoo, 34 Pesquet’s Parrot and 71 Eclectus Parrot nests. Eclectus Parrots used taller, larger, live trees. Palm Cockatoos preferred hollows in broken trunks having deeper hollows with larger entrances. Pesquet’s Parrots excavated their nest hollows in dead trees. Palm Cockatoos nested at lower density (0.008 nests/ha) than Pesquet’s (0.022 nests/ha) and Eclectus Parrots (0.069 nests/ha). Palm Cockatoos and Pesquet’s Parrots appeared to breed seasonally; Eclectus Parrots bred at higher frequency year-round. Palm Cockatoo clutch size was one; Pesquet’s and Eclectus Parrots clutches had one to two eggs. Eclectus Parrots had higher fledging success: 54%, compared with 40% of Palm Cockatoo and 17% of Pesquet’s Parrot eggs. Predation caused most nest failures for Palm Cockatoos and Eclectus Parrots; starvation caused most loss in Pesquet’s Parrots. Humans hunted Palm Cockatoos and Pesquet’s Parrots, not Eclectus Parrots. Higher nest tree density, breeding success, and more generalised feeding habits may make Eclectus Parrots the least vulnerable of the three species. Low population density and breeding frequency of Palm Cockatoos and Pesquet’s Parrots may make them more vulnerable.
-
Ecological and socio-economic factors affecting extinction risk in Parrots
Biodiversity and Conservation, 2016Co-Authors: George Olah, Stuart H. M. Butchart, Andy Symes, Iliana Medina Guzmán, Ross Cunningham, Donald J. Brightsmith, Robert HeinsohnAbstract:Parrots ( Psittaciformes ) are among the most threatened bird orders with 28 % (111 of 398) of extant species classified as threatened under IUCN criteria. We confirmed that Parrots have a lower Red List Index (higher aggregate extinction risk) than other comparable bird groups, and modeled the factors associated with extinction risk. Our analyses included intrinsic biological, life history and ecological attributes, external anthropogenic threats, and socio-economic variables associated with the countries where the Parrot species occur, while we controlled for phylogenetic dependence among species. We found that the likelihood of Parrot species being classified as threatened was less for species with larger historical distribution size, but was greater for species with high forest dependency, large body size, long generation time, and greater proportion of the human population living in urban areas in the countries encompassing the Parrots’ home ranges. The severity of extinction risk (from vulnerable to critically endangered) was positively related to the per capita gross domestic product (GDP) of the countries of occurrence, endemism to a single country, and lower for species used as pets. A disproportionate number of 16 extinct Parrot species were endemic to islands and single countries, and were large bodied, habitat specialists. Agriculture, hunting, trapping, and logging are the most frequent threats to Parrots worldwide, with variation in importance among regions. We use multiple methods to rank countries with disproportionately high numbers of threatened Parrot species. Our results promote understanding of global and regional factors associated with endangerment in this highly threatened taxonomic group, and will enhance the prioritization of conservation actions.
-
Overlap and competition for nest holes among eclectus Parrots, palm cockatoos and sulphur-crested cockatoos
Australian Journal of Zoology, 2003Co-Authors: Robert Heinsohn, Stephen A. Murphy, Sarah LeggeAbstract:We examined the extent of overlap in the characteristics of nest holes used by eclectus Parrots (Eclectus roratus), palm cockatoos (Probosciger aterrimus) and sulphur-crested cockatoos (Cacatua galerita) in patches of rainforest and woodland in and around Iron Range National Park, Cape York Peninsula, Australia. Eclectus Parrots nested only in rainforest and palm cockatoos nested mostly in eucalypt woodland adjacent to rainforest. Sulphur-crested cockatoos nested in both habitats. Nest holes of eclectus Parrots and rainforest sulphur-crested cockatoos were in trees of larger DBH (diameter at breast height) and higher off the ground than those of palm cockatoos and sulphur-crested cockatoos in woodland. Palm cockatoos differed from the other Parrots in their use of deeper holes with entrances that faced skywards rather than sideways. Both palm cockatoos and woodland sulphur-crested cockatoos used nests with smaller entrances than eclectus Parrots and rainforest sulphur-crested cockatoos. All species showed intraspecific competition for nest holes. Behavioural conflict was also common between sulphur-crested cockatoos and the other two species. Each year 9.7-25.8% of eclectus Parrot nests were taken over either permanently or temporarily by sulphur-crested cockatoos. Only one palm cockatoo nest was taken over by sulphur-crested cockatoos. Nest-holes were destroyed by natural causes at similar rates in rainforest (3.8% per annum over 174 nest-years) and woodland (5.4% per annum over 93 nest-years). Four nest trees fell over, and the floor of the nest collapsed at a further four holes. Three woodland nest trees burnt down during dry-season fires (August-October). New eclectus Parrot and rainforest sulphur-crested cockatoo holes originated from incipient hollows on the tree that were modified by the Parrots. We discuss the intense competition between these large Parrots in light of the apparent shortage of appropriate nest holes in Cape York rainforest and eucalypt woodland.
Amadi O. Ihunwo - One of the best experts on this subject based on the ideXlab platform.
-
Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot (Psittacus erithacus) and Timneh Grey Parrot (Psittacus timneh).
Frontiers in neuroanatomy, 2018Co-Authors: Pedzisai Mazengenya, Adhil Bhagwandin, Paul R. Manger, Amadi O. IhunwoAbstract:In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey Parrot (Psittacus erithacus) and Timneh grey Parrot (Psittacus timneh) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey Parrots, but minor differences were also observed. In both species of Parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey Parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey Parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL). The widespread distribution of PCNA and DCX in the brains of both Parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations. Key words: Doublecortin, proliferating cell nuclear antigen, old world Parrots, Congo African grey Parrot, Timneh grey Parrot, adult neurogenesis, cell proliferation, cell migration
-
Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot (Psittacus erithacus) and Timneh Grey Parrot (Psittacus timneh)
Frontiers Media S.A., 2018Co-Authors: Pedzisai Mazengenya, Adhil Bhagwandin, Paul R. Manger, Amadi O. IhunwoAbstract:In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey Parrot (Psittacus erithacus) and Timneh grey Parrot (Psittacus timneh) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey Parrots, but minor differences were also observed. In both species of Parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey Parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey Parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL). The widespread distribution of PCNA and DCX in the brains of both Parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations
David T Parkin - One of the best experts on this subject based on the ideXlab platform.
-
characterisation of 13 microsatellite loci for the moluccan cockatoo cacatua moluccensis and cuban amazon amazona leucocephala and their conservation and utility in other Parrot species psittaciformes
Conservation Genetics, 2007Co-Authors: Tiawanna D Taylor, David T ParkinAbstract:The Parrot family consists of approximately 330 species, many of which are endangered due to habitat destruction and illegal trade. Microsatellite markers can provide important tools for examining both conservation and forensic issues in this family, and the availability of additional markers will prove useful for studies of other species in the Parrot family. Parrots have proved a difficult family from which to develop microsatellites and cross-species amplification is generally lower than expected. This paper details 13 microsatellite loci isolated from the Moluccan Cockatoo and Cuban Amazon and their conservation in other species of Parrots.
-
characterization of 12 microsatellite primer pairs for the african grey Parrot psittacus erithacus and their conservation across the psittaciformes
Molecular Ecology Notes, 2006Co-Authors: Tiawanna D Taylor, David T ParkinAbstract:This study describes 12 microsatellite loci identified in the African grey Parrot Psittacus erithacus. Eleven were polymorphic, with observed heterozygosities 42–94% (average 68) and exclusion powers of PE1 = 0.996 and PE2 = 0.999. Microsatellites have previously been developed for a number of other Parrots but showed limited cross-species polymorphism. Here high levels of cross-species amplification were observed: 71% of 32 Psittacines (22 genera). At least seven loci, 58%, were polymorphic in other African Parrots as well as Neotropical and Australasian Parrots, which diverged from the African Parrots c30.6 and over 41.4 million years ago, respectively.
Tiawanna D Taylor - One of the best experts on this subject based on the ideXlab platform.
-
characterisation of 13 microsatellite loci for the moluccan cockatoo cacatua moluccensis and cuban amazon amazona leucocephala and their conservation and utility in other Parrot species psittaciformes
Conservation Genetics, 2007Co-Authors: Tiawanna D Taylor, David T ParkinAbstract:The Parrot family consists of approximately 330 species, many of which are endangered due to habitat destruction and illegal trade. Microsatellite markers can provide important tools for examining both conservation and forensic issues in this family, and the availability of additional markers will prove useful for studies of other species in the Parrot family. Parrots have proved a difficult family from which to develop microsatellites and cross-species amplification is generally lower than expected. This paper details 13 microsatellite loci isolated from the Moluccan Cockatoo and Cuban Amazon and their conservation in other species of Parrots.
-
characterization of 12 microsatellite primer pairs for the african grey Parrot psittacus erithacus and their conservation across the psittaciformes
Molecular Ecology Notes, 2006Co-Authors: Tiawanna D Taylor, David T ParkinAbstract:This study describes 12 microsatellite loci identified in the African grey Parrot Psittacus erithacus. Eleven were polymorphic, with observed heterozygosities 42–94% (average 68) and exclusion powers of PE1 = 0.996 and PE2 = 0.999. Microsatellites have previously been developed for a number of other Parrots but showed limited cross-species polymorphism. Here high levels of cross-species amplification were observed: 71% of 32 Psittacines (22 genera). At least seven loci, 58%, were polymorphic in other African Parrots as well as Neotropical and Australasian Parrots, which diverged from the African Parrots c30.6 and over 41.4 million years ago, respectively.
Pedzisai Mazengenya - One of the best experts on this subject based on the ideXlab platform.
-
Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot (Psittacus erithacus) and Timneh Grey Parrot (Psittacus timneh).
Frontiers in neuroanatomy, 2018Co-Authors: Pedzisai Mazengenya, Adhil Bhagwandin, Paul R. Manger, Amadi O. IhunwoAbstract:In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey Parrot (Psittacus erithacus) and Timneh grey Parrot (Psittacus timneh) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey Parrots, but minor differences were also observed. In both species of Parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey Parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey Parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL). The widespread distribution of PCNA and DCX in the brains of both Parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations. Key words: Doublecortin, proliferating cell nuclear antigen, old world Parrots, Congo African grey Parrot, Timneh grey Parrot, adult neurogenesis, cell proliferation, cell migration
-
Putative Adult Neurogenesis in Old World Parrots: The Congo African Grey Parrot (Psittacus erithacus) and Timneh Grey Parrot (Psittacus timneh)
Frontiers Media S.A., 2018Co-Authors: Pedzisai Mazengenya, Adhil Bhagwandin, Paul R. Manger, Amadi O. IhunwoAbstract:In the current study, we examined for the first time, the potential for adult neurogenesis throughout the brain of the Congo African grey Parrot (Psittacus erithacus) and Timneh grey Parrot (Psittacus timneh) using immunohistochemistry for the endogenous markers proliferating cell nuclear antigen (PCNA), which labels proliferating cells, and doublecortin (DCX), which stains immature and migrating neurons. A similar distribution of PCNA and DCX immunoreactivity was found throughout the brain of the Congo African grey and Timneh grey Parrots, but minor differences were also observed. In both species of Parrots, PCNA and DCX immunoreactivity was observed in the olfactory bulbs, subventricular zone of the lateral wall of the lateral ventricle, telencephalic subdivisions of the pallium and subpallium, diencephalon, mesencephalon and the rhombencephalon. The olfactory bulb and telencephalic subdivisions exhibited a higher density of both PCNA and DCX immunoreactive cells than any other brain region. DCX immunoreactive staining was stronger in the telencephalon than in the subtelencephalic structures. There was evidence of proliferative hot spots in the dorsal and ventral poles of the lateral ventricle in the Congo African grey Parrots at rostral levels, whereas only the dorsal accumulation of proliferating cells was observed in the Timneh grey Parrot. In most pallial regions the density of PCNA and DCX stained cells increased from rostral to caudal levels with the densest staining in the nidopallium caudolaterale (NCL). The widespread distribution of PCNA and DCX in the brains of both Parrot species suggest the importance of adult neurogenesis and neuronal plasticity during learning and adaptation to external environmental variations
