Hypobaric hypoxia at high elevation represents an important physiological stressor for montane or... more Hypobaric hypoxia at high elevation represents an important physiological stressor for montane organisms, but optimal physiological strategies to cope with hypoxia may vary among species with different life histories. Montane birds exhibit a range of migration patterns; elevational migrants breed at high elevations but winter at low elevations or migrate further south, while high-elevation residents inhabit the same elevation throughout the year. Optimal physiological strategies to cope with hypoxia might therefore differ between species that exhibit these two migratory patterns, because they differ in the amount time spent at high elevation. We examined physiological parameters associated with blood-oxygen transport (haemoglobin concentration and haematocrit, i.e. the proportion of red blood cells in blood) in nine species of elevational migrants and six species of high-elevation residents that were sampled along a 2200 m (1000–3200 m) eleva-tional gradient. Haemoglobin concentration increased with elevation within species regardless of migratory strategy, but it was only significantly correlated with haematocrit in elevational migrants. Surprisingly, haemoglobin concentration was not correlated with haematocrit in high-elevation residents, and these species exhibited higher mean cellular haemoglobin concentration than elevational migrants. Thus, alternative physiological strategies to regulate haemoglobin concentration and blood O 2 carrying capacity appear to differ among birds with different annual elevational movement patterns.
Food availability is known to influence parental care and mating systems in passerine birds. Altr... more Food availability is known to influence parental care and mating systems in passerine birds. Altricial chicks make uni-parental care particularly demanding for passerines and parental investment is known to increase with decreasing food availability. We expect this to limit uni-parental passerines to habitats with the most consistent food availability. In passerine birds, species having uni-parental care are primarily female-only parental care (female-only care) and most passerine birds with female-only care are frugivores. We predict that frugivo-rous passerines with female-only care should be restricted to the most stable habitats characterized by longer fruiting season length. At a global scale, female-only care frugivores were distributed in areas with significantly longer fruiting seasons than non-female-only care frugivores. Female-only care species richness had a stronger spatial relationship with longer fruiting season than non-female-only care species richness. Verifying the lack of a phylogenetic signal driving this pattern, our findings indicate that the geographic distribution of female-only care, a geographically and phylogenetically widespread parental care system , is restricted by an extrinsic factor: fruiting season length. This reinstates the importance of food availability on the evolution and maintenance of parental care systems in passerine birds.
Page 1. Page 2. Responses shown by bird communities to teak plantations in Sagar Forest Division,... more Page 1. Page 2. Responses shown by bird communities to teak plantations in Sagar Forest Division,Karnataka Dissertation Submitted to University of Saurashtra, Rajkot In partial fulfilment of Master's Degree in Wildlife Science By SAHAS S. BARVE Under the Supervision of ...
A unique aspect of montane birds is the el-evational stratification they show in their distributi... more A unique aspect of montane birds is the el-evational stratification they show in their distribution, but in the Himalayas, a subset of the species show el-evational migration, making bird communities on these mountains especially dynamic. Thus, understanding the elevational distribution and movement of species across seasons is important to fully understand broad-scale community patterns. In this study, we compile a comprehensive checklist of birds along a 2,300 m Hima-layan elevational gradient in the Amrutganga Valley, Kedarnath Wildlife Division, Uttarakhand, India. We recorded 244 species including 34 species new for the area and two new species for the state. Most importantly, we describe the elevational distribution of more than a 200 species and the dates of first sighting for several summer migrants in the season. We also studied changes in species richness and turnover at multiple elevations across seasons. We hope that this study provides a base-line for future research on elevational distribution of birds in the Western Himalayas.
The ecology of cavity nesting in passerine birds has been studied extensively, yet there are no p... more The ecology of cavity nesting in passerine birds has been studied extensively, yet there are no phylogenetic comparative studies that quantify differences in life history traits between cavity- and open-nesting birds within a passerine family. We test existing hypotheses regarding the evolutionary significance of cavity nesting in the Old World flycatchers (Muscicapidae). We used a multi-locus phylogeny of 252 species to reconstruct the evolutionary history of cavity nesting and to quantify correlations between nest types and life history traits. Within a phylogenetic generalized linear model framework, we found that cavity-nesting species are larger than open-nesting species and that maximum clutch sizes are larger in cavity-nesting lineages. In addition to differences in life history traits between nest types, species that breed at higher latitudes have larger average and maximum clutch sizes and begin to breed later in the year. Gains and losses of migratory behaviour have occurred far more often in cavity-nesting lineages than in open-nesting taxa, suggesting that cavity nesting may have played a crucial role in the evolution of migratory behaviour. These findings identify important macro-evolutionary links between the evolution of cavity nesting, clutch size, interspecific competition and migratory behaviour in a large clade of Old World songbirds.
Hypobaric hypoxia at high elevation represents an important physiological stressor for montane or... more Hypobaric hypoxia at high elevation represents an important physiological stressor for montane organisms, but optimal physiological strategies to cope with hypoxia may vary among species with different life histories. Montane birds exhibit a range of migration patterns; elevational migrants breed at high elevations but winter at low elevations or migrate further south, while high-elevation residents inhabit the same elevation throughout the year. Optimal physiological strategies to cope with hypoxia might therefore differ between species that exhibit these two migratory patterns, because they differ in the amount time spent at high elevation. We examined physiological parameters associated with blood-oxygen transport (haemoglobin concentration and haematocrit, i.e. the proportion of red blood cells in blood) in nine species of elevational migrants and six species of high-elevation residents that were sampled along a 2200 m (1000–3200 m) eleva-tional gradient. Haemoglobin concentration increased with elevation within species regardless of migratory strategy, but it was only significantly correlated with haematocrit in elevational migrants. Surprisingly, haemoglobin concentration was not correlated with haematocrit in high-elevation residents, and these species exhibited higher mean cellular haemoglobin concentration than elevational migrants. Thus, alternative physiological strategies to regulate haemoglobin concentration and blood O 2 carrying capacity appear to differ among birds with different annual elevational movement patterns.
Food availability is known to influence parental care and mating systems in passerine birds. Altr... more Food availability is known to influence parental care and mating systems in passerine birds. Altricial chicks make uni-parental care particularly demanding for passerines and parental investment is known to increase with decreasing food availability. We expect this to limit uni-parental passerines to habitats with the most consistent food availability. In passerine birds, species having uni-parental care are primarily female-only parental care (female-only care) and most passerine birds with female-only care are frugivores. We predict that frugivo-rous passerines with female-only care should be restricted to the most stable habitats characterized by longer fruiting season length. At a global scale, female-only care frugivores were distributed in areas with significantly longer fruiting seasons than non-female-only care frugivores. Female-only care species richness had a stronger spatial relationship with longer fruiting season than non-female-only care species richness. Verifying the lack of a phylogenetic signal driving this pattern, our findings indicate that the geographic distribution of female-only care, a geographically and phylogenetically widespread parental care system , is restricted by an extrinsic factor: fruiting season length. This reinstates the importance of food availability on the evolution and maintenance of parental care systems in passerine birds.
Page 1. Page 2. Responses shown by bird communities to teak plantations in Sagar Forest Division,... more Page 1. Page 2. Responses shown by bird communities to teak plantations in Sagar Forest Division,Karnataka Dissertation Submitted to University of Saurashtra, Rajkot In partial fulfilment of Master's Degree in Wildlife Science By SAHAS S. BARVE Under the Supervision of ...
A unique aspect of montane birds is the el-evational stratification they show in their distributi... more A unique aspect of montane birds is the el-evational stratification they show in their distribution, but in the Himalayas, a subset of the species show el-evational migration, making bird communities on these mountains especially dynamic. Thus, understanding the elevational distribution and movement of species across seasons is important to fully understand broad-scale community patterns. In this study, we compile a comprehensive checklist of birds along a 2,300 m Hima-layan elevational gradient in the Amrutganga Valley, Kedarnath Wildlife Division, Uttarakhand, India. We recorded 244 species including 34 species new for the area and two new species for the state. Most importantly, we describe the elevational distribution of more than a 200 species and the dates of first sighting for several summer migrants in the season. We also studied changes in species richness and turnover at multiple elevations across seasons. We hope that this study provides a base-line for future research on elevational distribution of birds in the Western Himalayas.
The ecology of cavity nesting in passerine birds has been studied extensively, yet there are no p... more The ecology of cavity nesting in passerine birds has been studied extensively, yet there are no phylogenetic comparative studies that quantify differences in life history traits between cavity- and open-nesting birds within a passerine family. We test existing hypotheses regarding the evolutionary significance of cavity nesting in the Old World flycatchers (Muscicapidae). We used a multi-locus phylogeny of 252 species to reconstruct the evolutionary history of cavity nesting and to quantify correlations between nest types and life history traits. Within a phylogenetic generalized linear model framework, we found that cavity-nesting species are larger than open-nesting species and that maximum clutch sizes are larger in cavity-nesting lineages. In addition to differences in life history traits between nest types, species that breed at higher latitudes have larger average and maximum clutch sizes and begin to breed later in the year. Gains and losses of migratory behaviour have occurred far more often in cavity-nesting lineages than in open-nesting taxa, suggesting that cavity nesting may have played a crucial role in the evolution of migratory behaviour. These findings identify important macro-evolutionary links between the evolution of cavity nesting, clutch size, interspecific competition and migratory behaviour in a large clade of Old World songbirds.
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