... Daily energy expenditure of Purple Martins (Progne subis) during the breeding season: estimat... more ... Daily energy expenditure of Purple Martins (Progne subis) during the breeding season: estimates using D,O1* and ... Department of Animal Ecology, Ecology Building ... an adaptation for predator avoid-ance, and Lack (1968: 110), discussing heron species that only nest in colonies ...
Dr Michael B. Usher's account of the main parts of this multiple occasion-apart from the indicati... more Dr Michael B. Usher's account of the main parts of this multiple occasion-apart from the indication here of an additional 3 days of deliberations-we are pleased to publish here its Recommendations, since received with comments from its main organizer and 'moving spirit'.-Ed.
Abstract Tiger Herons (Tigrisoma) are little studied and generally characterized in the literatur... more Abstract Tiger Herons (Tigrisoma) are little studied and generally characterized in the literature as being relatively uncommon birds of forested streams and wetlands. Contrary to these expectations, we found Bare-throated Tiger Herons (Tigrisoma lineatum) on the Pearl Islands of the Gulf of Panama to be birds of open, wave-exposed rocky seashores. We also found them to be common birds, inhabiting most shoreline coves. They fed over much of the tidal cycle along beaches and rocky shores, especially on and near surf-washed rocks. They caught crabs and fish by standing and walking slowly and methodically. Feeding efficiency was low, averaging about one prey item per hour. Plumage coloration is highly cryptic against shore rocks; but, in contrast, the bird becomes quite obvious when it expands its bare yellow throat, especially when accentuating a distinctive stretch display used to claim shore-line territory and for within-pair interactions. Tiger herons in the Pearls nested high in trees on ocean-facing cliffs. The habitat choice and behavior of this population of tiger herons that we report extend understanding of the biological scope of the subfamily of tiger herons.
The status of seabirds and other colonial waterbirds along the Caribbean coast of Panama has neve... more The status of seabirds and other colonial waterbirds along the Caribbean coast of Panama has never been determined comprehensively. Surveying the entire Caribbean coast of Panama and Lago Bayano, we found six species of seabirds and other colonial waterbirds nesting at eight sites. Brown Boobies (Sula leucogaster) nested at five sites, while other seabirds along the coast nested at only one site each. Red-billed Tropicbirds (Phaethon aethereus) nested at Isla de los Pájaros and Audubon's Shearwaters (Puffinus lherminieri) at Cayos Tigre. Lago Bayano had two nesting sites of Cocoi Herons (Ardea cocoi) and Neotropic Cormorants (Phalacrocorax brasilianus) and one of Great Egrets (Ardea alba). More species and numbers of waterbirds occurred along the coast in April than in June. The Caribbean coast of Panama is clearly an important area for wintering colonial waterbirds. However, it supports limited nesting of seabirds. No nesting was found in coastal wetlands, despite there being extensive areas of apparently suitable habitat. Inland, Lago Bayano supports nesting herons and cormorants, and foraging sites for spoonbills, storks, and other herons. This study is the third in a series aiming to document the nesting status of seabirds and other colonial waterbirds in coastal Panama, allowing a comparison to be made of the two coasts. Colonial waterbird nesting populations on the Caribbean coast are only 2% of those of the Pacific coast, and more species of waterbirds nest on the Pacific. We suggest that differences are due to oceanographic factors and climatic conditions that differ between the two coasts.
The vestiary hypothesis proposes that hair reduction in humans, a characteristic of the species, ... more The vestiary hypothesis proposes that hair reduction in humans, a characteristic of the species, evolved coincident with a developing intellectual capacity that permitted the use of artificial insulation. Functional hairlessness permitted the elaboration of an extraordinarily ...
Ask any non-ornithologist to predict the prestige of the following journals, based on the name al... more Ask any non-ornithologist to predict the prestige of the following journals, based on the name alone:
The neotropical range of the American crocodile (Crocodylus acutus) extends from the north and we... more The neotropical range of the American crocodile (Crocodylus acutus) extends from the north and west coasts of South America to the coasts of Mexico, the Greater Antilles and south Florida. Potentially viable populations exist in Jamaica, Hispanola, Cuba and on the southern tip of the Florida peninsula. The status of these populations, each of which are in some way threatened with extinction, has long been of concern (Moore, 1953; Ogden, 1968; Klukas et al., 1979). The possibility that pesticides and heavy metals in waste products could represent a substantial threat to the continued existence of the south
Information on the energy used by birds from hatching through fledging is needed to estimate the ... more Information on the energy used by birds from hatching through fledging is needed to estimate the amount of food that parent birds must obtain from the environment (Ricklefs 1974) and, thus, to assess the energetic role of a species in an ecosystem (Kendeigh 1974a). Because it is technically difficult to estimate accurately the total energy used for the growth and maintenance of wild nestlings, such studies have often been conducted com-
Evidence from the attempt to preserve wading birds in Everglades National Park suggests that appl... more Evidence from the attempt to preserve wading birds in Everglades National Park suggests that application of biogeographic theory to design and management of continental wildlife reserves requires considerations additional to those previously proposed. Shape and areal extent alone are inadequate criteria for reserve design. Unlike islands, continental reserves are not necessarily self-contained ecosystems driven by endogenous processes. The isolation of a continental reserve may lead to a phenomenon of ecosystem degeneration, the extent and rapidity of which depends on the ecological condition of adjacent habitat. Management strategies to preserve maximum species richness are seldom totally acceptable and often inherently unattainable. Conflicts between species management and ecosystem management illustrate the need for instituting an array of management strategies on a regional basis for preservation of both endangered species and ecosystems.
Fish assemblage patterns were examined in 40 dry-season pools in a hydrologically variable river ... more Fish assemblage patterns were examined in 40 dry-season pools in a hydrologically variable river drainage in northeast Texas, to test the hypothesis that fish assemblage structure is correlated with environmental gradients of habitat characteristics. The study ...
... Daily energy expenditure of Purple Martins (Progne subis) during the breeding season: estimat... more ... Daily energy expenditure of Purple Martins (Progne subis) during the breeding season: estimates using D,O1* and ... Department of Animal Ecology, Ecology Building ... an adaptation for predator avoid-ance, and Lack (1968: 110), discussing heron species that only nest in colonies ...
Dr Michael B. Usher's account of the main parts of this multiple occasion-apart from the indicati... more Dr Michael B. Usher's account of the main parts of this multiple occasion-apart from the indication here of an additional 3 days of deliberations-we are pleased to publish here its Recommendations, since received with comments from its main organizer and 'moving spirit'.-Ed.
Abstract Tiger Herons (Tigrisoma) are little studied and generally characterized in the literatur... more Abstract Tiger Herons (Tigrisoma) are little studied and generally characterized in the literature as being relatively uncommon birds of forested streams and wetlands. Contrary to these expectations, we found Bare-throated Tiger Herons (Tigrisoma lineatum) on the Pearl Islands of the Gulf of Panama to be birds of open, wave-exposed rocky seashores. We also found them to be common birds, inhabiting most shoreline coves. They fed over much of the tidal cycle along beaches and rocky shores, especially on and near surf-washed rocks. They caught crabs and fish by standing and walking slowly and methodically. Feeding efficiency was low, averaging about one prey item per hour. Plumage coloration is highly cryptic against shore rocks; but, in contrast, the bird becomes quite obvious when it expands its bare yellow throat, especially when accentuating a distinctive stretch display used to claim shore-line territory and for within-pair interactions. Tiger herons in the Pearls nested high in trees on ocean-facing cliffs. The habitat choice and behavior of this population of tiger herons that we report extend understanding of the biological scope of the subfamily of tiger herons.
The status of seabirds and other colonial waterbirds along the Caribbean coast of Panama has neve... more The status of seabirds and other colonial waterbirds along the Caribbean coast of Panama has never been determined comprehensively. Surveying the entire Caribbean coast of Panama and Lago Bayano, we found six species of seabirds and other colonial waterbirds nesting at eight sites. Brown Boobies (Sula leucogaster) nested at five sites, while other seabirds along the coast nested at only one site each. Red-billed Tropicbirds (Phaethon aethereus) nested at Isla de los Pájaros and Audubon's Shearwaters (Puffinus lherminieri) at Cayos Tigre. Lago Bayano had two nesting sites of Cocoi Herons (Ardea cocoi) and Neotropic Cormorants (Phalacrocorax brasilianus) and one of Great Egrets (Ardea alba). More species and numbers of waterbirds occurred along the coast in April than in June. The Caribbean coast of Panama is clearly an important area for wintering colonial waterbirds. However, it supports limited nesting of seabirds. No nesting was found in coastal wetlands, despite there being extensive areas of apparently suitable habitat. Inland, Lago Bayano supports nesting herons and cormorants, and foraging sites for spoonbills, storks, and other herons. This study is the third in a series aiming to document the nesting status of seabirds and other colonial waterbirds in coastal Panama, allowing a comparison to be made of the two coasts. Colonial waterbird nesting populations on the Caribbean coast are only 2% of those of the Pacific coast, and more species of waterbirds nest on the Pacific. We suggest that differences are due to oceanographic factors and climatic conditions that differ between the two coasts.
The vestiary hypothesis proposes that hair reduction in humans, a characteristic of the species, ... more The vestiary hypothesis proposes that hair reduction in humans, a characteristic of the species, evolved coincident with a developing intellectual capacity that permitted the use of artificial insulation. Functional hairlessness permitted the elaboration of an extraordinarily ...
Ask any non-ornithologist to predict the prestige of the following journals, based on the name al... more Ask any non-ornithologist to predict the prestige of the following journals, based on the name alone:
The neotropical range of the American crocodile (Crocodylus acutus) extends from the north and we... more The neotropical range of the American crocodile (Crocodylus acutus) extends from the north and west coasts of South America to the coasts of Mexico, the Greater Antilles and south Florida. Potentially viable populations exist in Jamaica, Hispanola, Cuba and on the southern tip of the Florida peninsula. The status of these populations, each of which are in some way threatened with extinction, has long been of concern (Moore, 1953; Ogden, 1968; Klukas et al., 1979). The possibility that pesticides and heavy metals in waste products could represent a substantial threat to the continued existence of the south
Information on the energy used by birds from hatching through fledging is needed to estimate the ... more Information on the energy used by birds from hatching through fledging is needed to estimate the amount of food that parent birds must obtain from the environment (Ricklefs 1974) and, thus, to assess the energetic role of a species in an ecosystem (Kendeigh 1974a). Because it is technically difficult to estimate accurately the total energy used for the growth and maintenance of wild nestlings, such studies have often been conducted com-
Evidence from the attempt to preserve wading birds in Everglades National Park suggests that appl... more Evidence from the attempt to preserve wading birds in Everglades National Park suggests that application of biogeographic theory to design and management of continental wildlife reserves requires considerations additional to those previously proposed. Shape and areal extent alone are inadequate criteria for reserve design. Unlike islands, continental reserves are not necessarily self-contained ecosystems driven by endogenous processes. The isolation of a continental reserve may lead to a phenomenon of ecosystem degeneration, the extent and rapidity of which depends on the ecological condition of adjacent habitat. Management strategies to preserve maximum species richness are seldom totally acceptable and often inherently unattainable. Conflicts between species management and ecosystem management illustrate the need for instituting an array of management strategies on a regional basis for preservation of both endangered species and ecosystems.
Fish assemblage patterns were examined in 40 dry-season pools in a hydrologically variable river ... more Fish assemblage patterns were examined in 40 dry-season pools in a hydrologically variable river drainage in northeast Texas, to test the hypothesis that fish assemblage structure is correlated with environmental gradients of habitat characteristics. The study ...
Uploads
Papers by James Kushlan