This paper reports observations of flocking behavior of birds in a well-protected secondary forest in Tai Po Kau Nature Reserve, Hong Kong Special Administrative Region, China. A total of 1025 flocks including 5255 bi...This paper reports observations of flocking behavior of birds in a well-protected secondary forest in Tai Po Kau Nature Reserve, Hong Kong Special Administrative Region, China. A total of 1025 flocks including 5255 birds and 48 species were observed between October 2002 and November 2003. Most flocks consisted of only one species. The observed flocks averaged 1.79 +/- 0.05 (SE) species and 5.13 +/- 0.18 (SE) birds. The Japanese White-eye was the most numerous species and was present in 21.6% of the observed flocks. Seasonal trends in both flock size and number of species were similar to those in overall bird density and species richness in the study area reported in a previous study.展开更多
Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two for...Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two forest types in and around the Important Bird Area of Chitwan National Park in Nepal,between 150 and 800 m a.s.l.,to provide a first description of the composition of MSFs in this area.We also aimed to understand which species should be considered‘nuclear species',important to forming MSFs or leading them forward.Results:In total,we collected records on 222 MSFs that included 100 species,and 6097 individuals.The MSFs were similar to worldwide patterns in being dominated by leaf-gleaning,non-terrestrial insectivores.However,the MSFs were more dominated by canopy species than usual,and did not have a clear gregarious,understory leading species.Rather drongos(Family Dicruridae)and minivets(Family Campephagidae,Genus Pericrocotus)acted as leaders,and a cluster analysis of composition showed one group of large body size MSFs particularly characterized by the presence of the Greater Racket-tailed Drongo(Dicrurus paradiseus).Conclusions:Drongos are known to provide both costs and benefits to other flock participants:they are aggressive birds that can steal food,and manipulate other species with their vocalizations,but at the same time they are‘sentinel species'that produce information about predation risk other species can use.This study demonstrates that drongos can be considered nuclear species for some types of MSFs,despite the potential costs of their presence.MSFs led by sentinel species thus may form in Asia,as well as in the Neotropics.展开更多
Background:Ecological functions and processes in urban ecosystems are governed by various human activities.City-adapted and city-exploiting animal species are expected to present certain specific behavioral and physio...Background:Ecological functions and processes in urban ecosystems are governed by various human activities.City-adapted and city-exploiting animal species are expected to present certain specific behavioral and physiological traits in comparison to city-avoiders or conspecific individual frequenting less urbanized or rural environments.A trait of high importance,the plumage color polymorphism has been selected as the main study model and was correlated with different morphological and physiological parameters to highlight its importance in determining the possible health status of urban Feral Pigeons(Columba livia)in North African urban habitats.Methods:Different body morphometrics,hematological and hemoparasitic parameters were quantified on freeliving Feral Pigeons in urban environments of northern Algeria.Moreover,plumage melanin-based coloration(MBC)was measured and the data collected at the individual scale was correlated with the previous parameters using linear and non-linear modeling approaches.Results:Plumage MBC scores of the sampled Feral Pigeons ranged between 0.3%and 74.8%.Among the 12 morphological traits measured,body weight,tail length and total length were deemed to be positively correlated with MBC.Darker morphs appeared to have more hemoparasites compared to lighter pigeons.Quite the same observation goes with the immunity but with non-linear trends.The number of monocytes and granulocytes increased with the increase in MBC levels in lighter morphs,while pigeons with high MBC scores exhibited negative relationships between MBC levels and the number of white blood cells.Conclusions:Despite the existence of a number of studies demonstrating phenotypic directional selection,further studies are undoubtedly necessary to understand in detail the underlying mechanisms in species life-history strategies between differently colored individuals.Findings of this correlative study open exciting perspectives revealing that MBC can be considered a good indicator of and health status and adaptation strategies to changes in urban environments.展开更多
According to an official announcement by the CAS Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), a piece of critical evidence for the origin and early evolution of feathers has been described from a...According to an official announcement by the CAS Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), a piece of critical evidence for the origin and early evolution of feathers has been described from a Mesozoic bird fossil newly discovered by two IVPP paleontologists, Profs. Zhang Fucheng and展开更多
We investigated the levels of nickel in the feathers of the Western Reef Heron (Egretta gularis) and Siberian Gull (Larus heuglini) from the Hara Biosphere Reserve in southern Iran from November to December 2010. Anal...We investigated the levels of nickel in the feathers of the Western Reef Heron (Egretta gularis) and Siberian Gull (Larus heuglini) from the Hara Biosphere Reserve in southern Iran from November to December 2010. Analysis of variance shows that no significant differences in nickel levels were found between gender and age groups in either species, but it should be pointed out that the number of samples was small. Student t tests show that the amount of nickel in the feathers of the Siberian Gull was higher than in the Western Reef Heron. The level of nickel concentration in the Western Reef Heron was higher in females than in males; on the other hand, this level of concentration in the Siberian Gull was higher in males.展开更多
Psittacine beak and feather disease virus (PBFDV) and avian polyomavirus (APV) are the most common viral diseases in psittacine birds, both affecting feathers and physical appearance of birds. Between 2005 and 2009, a...Psittacine beak and feather disease virus (PBFDV) and avian polyomavirus (APV) are the most common viral diseases in psittacine birds, both affecting feathers and physical appearance of birds. Between 2005 and 2009, a total of 269 samples were collected from birds presented at veterinary clinics, shelters and rescue centers of wildlife in Costa Rica. They belonged to 19 species of psittacine birds. The most representative species in the sample were Ara macao (157), Ara ambigua (37), Amazona autumnalis (24), Amazon ochrocephala (21) and Ara ararauna (8). A prevalence of 19.7% (53/269) for PBFDV and 4.8% (13/269) for APV was determined using Polymerase Chain Reaction (PCR). In 3.3% (9/269) of the birds mixed infections were detected. Statistical analysis determined that psittacines living in shelters and rescue centers had a greater risk to be positive to PBFDV and APV than birds that were presented at veterinary clinics, while only for PBFDV it was determined, that it is more likely to detect it in feathers than in blood. Finally, birds infected with PBFDV had 6.24 times more probability to become infected with APV, than non-infected birds. This is the first report of prevalence of PBFDV and APV in captive psittacines from Costa Rica.展开更多
文摘This paper reports observations of flocking behavior of birds in a well-protected secondary forest in Tai Po Kau Nature Reserve, Hong Kong Special Administrative Region, China. A total of 1025 flocks including 5255 birds and 48 species were observed between October 2002 and November 2003. Most flocks consisted of only one species. The observed flocks averaged 1.79 +/- 0.05 (SE) species and 5.13 +/- 0.18 (SE) birds. The Japanese White-eye was the most numerous species and was present in 21.6% of the observed flocks. Seasonal trends in both flock size and number of species were similar to those in overall bird density and species richness in the study area reported in a previous study.
基金supported by a Special Talent Recruitment grant from Guangxi University to EGa Chinese Government Scholarship to KRG。
文摘Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two forest types in and around the Important Bird Area of Chitwan National Park in Nepal,between 150 and 800 m a.s.l.,to provide a first description of the composition of MSFs in this area.We also aimed to understand which species should be considered‘nuclear species',important to forming MSFs or leading them forward.Results:In total,we collected records on 222 MSFs that included 100 species,and 6097 individuals.The MSFs were similar to worldwide patterns in being dominated by leaf-gleaning,non-terrestrial insectivores.However,the MSFs were more dominated by canopy species than usual,and did not have a clear gregarious,understory leading species.Rather drongos(Family Dicruridae)and minivets(Family Campephagidae,Genus Pericrocotus)acted as leaders,and a cluster analysis of composition showed one group of large body size MSFs particularly characterized by the presence of the Greater Racket-tailed Drongo(Dicrurus paradiseus).Conclusions:Drongos are known to provide both costs and benefits to other flock participants:they are aggressive birds that can steal food,and manipulate other species with their vocalizations,but at the same time they are‘sentinel species'that produce information about predation risk other species can use.This study demonstrates that drongos can be considered nuclear species for some types of MSFs,despite the potential costs of their presence.MSFs led by sentinel species thus may form in Asia,as well as in the Neotropics.
基金supported by the DGRSDT and MESRS(Ministry of Higher Education and Scientific Research of Algeria)。
文摘Background:Ecological functions and processes in urban ecosystems are governed by various human activities.City-adapted and city-exploiting animal species are expected to present certain specific behavioral and physiological traits in comparison to city-avoiders or conspecific individual frequenting less urbanized or rural environments.A trait of high importance,the plumage color polymorphism has been selected as the main study model and was correlated with different morphological and physiological parameters to highlight its importance in determining the possible health status of urban Feral Pigeons(Columba livia)in North African urban habitats.Methods:Different body morphometrics,hematological and hemoparasitic parameters were quantified on freeliving Feral Pigeons in urban environments of northern Algeria.Moreover,plumage melanin-based coloration(MBC)was measured and the data collected at the individual scale was correlated with the previous parameters using linear and non-linear modeling approaches.Results:Plumage MBC scores of the sampled Feral Pigeons ranged between 0.3%and 74.8%.Among the 12 morphological traits measured,body weight,tail length and total length were deemed to be positively correlated with MBC.Darker morphs appeared to have more hemoparasites compared to lighter pigeons.Quite the same observation goes with the immunity but with non-linear trends.The number of monocytes and granulocytes increased with the increase in MBC levels in lighter morphs,while pigeons with high MBC scores exhibited negative relationships between MBC levels and the number of white blood cells.Conclusions:Despite the existence of a number of studies demonstrating phenotypic directional selection,further studies are undoubtedly necessary to understand in detail the underlying mechanisms in species life-history strategies between differently colored individuals.Findings of this correlative study open exciting perspectives revealing that MBC can be considered a good indicator of and health status and adaptation strategies to changes in urban environments.
文摘According to an official announcement by the CAS Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), a piece of critical evidence for the origin and early evolution of feathers has been described from a Mesozoic bird fossil newly discovered by two IVPP paleontologists, Profs. Zhang Fucheng and
基金Dr. Pourkhabbaz, Mr. Nowrouzi and Mr. Salehi for their help throughout the project
文摘We investigated the levels of nickel in the feathers of the Western Reef Heron (Egretta gularis) and Siberian Gull (Larus heuglini) from the Hara Biosphere Reserve in southern Iran from November to December 2010. Analysis of variance shows that no significant differences in nickel levels were found between gender and age groups in either species, but it should be pointed out that the number of samples was small. Student t tests show that the amount of nickel in the feathers of the Siberian Gull was higher than in the Western Reef Heron. The level of nickel concentration in the Western Reef Heron was higher in females than in males; on the other hand, this level of concentration in the Siberian Gull was higher in males.
基金the German Service of Academic Exchange(DAAD)for the scholarship awarded to Jessica Sheleby-Elias.
文摘Psittacine beak and feather disease virus (PBFDV) and avian polyomavirus (APV) are the most common viral diseases in psittacine birds, both affecting feathers and physical appearance of birds. Between 2005 and 2009, a total of 269 samples were collected from birds presented at veterinary clinics, shelters and rescue centers of wildlife in Costa Rica. They belonged to 19 species of psittacine birds. The most representative species in the sample were Ara macao (157), Ara ambigua (37), Amazona autumnalis (24), Amazon ochrocephala (21) and Ara ararauna (8). A prevalence of 19.7% (53/269) for PBFDV and 4.8% (13/269) for APV was determined using Polymerase Chain Reaction (PCR). In 3.3% (9/269) of the birds mixed infections were detected. Statistical analysis determined that psittacines living in shelters and rescue centers had a greater risk to be positive to PBFDV and APV than birds that were presented at veterinary clinics, while only for PBFDV it was determined, that it is more likely to detect it in feathers than in blood. Finally, birds infected with PBFDV had 6.24 times more probability to become infected with APV, than non-infected birds. This is the first report of prevalence of PBFDV and APV in captive psittacines from Costa Rica.
