Experimental and modeled thermoregulatory costs of repeated sublethal oil exposure in the Double-crested Cormorant, Phalacrocorax auritus.

To fully understand the impact of oil exposure, it is important to understand sublethal effects like how increased thermoregulatory costs may affect survival and reproduction. However, it is difficult and time-consuming to measure these effects in wild animals. We present a novel use of a bioenergetics model, Niche Mapper™, to estimate thermoregulatory impacts of oiling, using data from captive Double-crested Cormorants (Phalacrocorax auritus) experimentally exposed to oil.

Changes in white cell estimates and plasma chemistry measurements following oral or external dosing of double-crested cormorants, Phalacocorax auritus, with artificially weathered MC252 oil.

Scoping studies were designed whereby double-crested cormorants (Phalacocorax auritus) were dosed with artificially weathered Deepwater Horizon (DWH) oil either daily through oil injected feeder fish, or by application of oil directly to feathers every three days. Preening results in oil ingestion, and may be an effective means of orally dosing birds with toxicant to improve our understanding of the full range of physiological effects of oral oil ingestion on birds. Blood samples collected every 5-6 days were analyzed for a number of clinical endpoints including white blood cell (WBC) estimates and differential cell counts.

Organ weights and histopathology of double-crested cormorants (Phalacrocorax auritus) dosed orally or dermally with artificially weathered Mississippi Canyon 252 crude oil.

A series of toxicity tests were conducted to assess the effects of low to moderate exposure to artificially weathered Deepwater Horizon Mississippi Canyon 252 crude oil on representative avian species as part of the Natural Resource Damage Assessment. The present report summarizes effects of oral exposure (n=26) of double-crested cormorants (DCCO; Phalacrocorax auritus) to 5 or 10ml oil kg day for up to 21 days or dermal application (n=25) of 13ml oil to breast and back feathers every three days totaling 6 applications in 21 days on organ weights and histopathology. Absolute and relative kidney and liver weights were increased in birds exposed to oil.

Reprint of: Development of methods for avian oil toxicity studies using the double crested cormorant (Phalacrocorax auritus).

Oral and external dosing methods replicating field exposure were developed using the double crested cormorant (DCCO) to test the toxicity of artificially weathered Deepwater Horizon Mississippi Canyon 252 oil. The majority of previous oil dosing studies conducted on wild-caught birds used gavage methods to dose birds with oil and determine toxicity. However, rapid gut transit time of gavaged oil likely reduces oil absorption.

Development of methods for avian oil toxicity studies using the double crested cormorant (Phalacrocorax auritus).

Oral and external dosing methods replicating field exposure were developed using the double crested cormorant (DCCO) to test the toxicity of artificially weathered Deepwater Horizon Mississippi Canyon 252 oil. The majority of previous oil dosing studies conducted on wild-caught birds used gavage methods to dose birds with oil and determine toxicity. However, rapid gut transit time of gavaged oil likely reduces oil absorption.

Lead exposure and poisoning of songbirds using the Coeur d'Alene River Basin, Idaho, USA.

Previous studies have found widespread Pb poisoning of waterfowl in the Coeur d'Alene River Basin in northern Idaho, USA, which has been contaminated by mining and smelting activities. We studied the exposure of ground-feeding songbirds to Pb, sampling 204 American robins (Turdus migratorius), song sparrows (Melospiza melodia), and Swainson's thrushes (Catharus ustulatus) throughout the basin. These songbirds had mean blood Pb concentrations (mg/kg, dry weight) of less than 0.