Geology topics

J. S. Lamb

Publications and source records attributed to J. S. Lamb.

5 recordsLinked to original sources

USGS2021

Post-release survival of California brown pelicans (Pelecanus Occidentalis Californicus) following oiling and rehabilitation after the Refugio oil spill

Oil spills represent a continued threat to marine wildlife. Although the public expects, and the State of California, US requires, oiled animals to be rescued for rehabilitation and release, scientists have questioned the welfare and conservation value of capture and rehabilitation of oiled wildlife, based on poor postrelease survival documented in the few available studies. In May 2015, Plains Pipeline 901 spilled >100,000 gallons of oil near Refugio State Beach, California. Many California Brown Pelicans ( Pelecanus occidentalis californicus ) were oiled; capture and rehabilitation efforts began within 1 d. Ultimately, 65 live birds were captured, including 50 pelicans. Forty-six pelicans survived and were released. Of these, 12 adults (six male, six female) were fitted with solar-powered GPS satellite Platform Terminal Transmitters (PTT) and released in June 2015. In early July, we captured eight adult (three male, four female, one unknown), unoiled pelicans from the Ventura, California area. These control birds were similarly instrumented and released immediately. At 6 mo after release, PTTs from nine of 12 oiled pelicans and six of eight control pelicans were still transmitting; at 1 yr, those numbers decreased to two of 12 and two of eight, respectively. Survival analysis revealed no difference in survival between oiled and control birds. Although our sample size is limited, these data demonstrate that most oiled and rehabilitated pelicans can survive for 6 mo following release, and some individuals can survive over 1 yr.

California↗

USGS2020

Mercury, cadmium, copper, arsenic, and selenium measurements in the feathers of adult eastern brown pelicans (Pelecanus occidentalis carolinensis) and chicks in multiple breeding grounds in the northern Gulf of Mexico

The amounts of trace metals and metalloids that have been introduced into aquatic ecosystems due to anthropogenic activities have increased in recent decades. Some of these elements like mercury are easily transferred from one trophic level to another and can accumulate to toxic quantities in organisms at the top of aquatic food webs. For this reason, seabirds like the Eastern brown pelican (Pelecanus occidentalis carolinensis ) are susceptible to heavy metal and metalloid toxicity and may warrant periodic monitoring. Mercury, cadmium, copper, arsenic and selenium were measured in the feathers of adult brown pelicans and chicks in several breeding colonies (Shamrock Island, Chester Island, Marker 52 Island, North Deer Island, Raccoon Island, Felicity Island, Gaillard Island, Audubon Island, and Ten Palms Island) in the Northern Gulf of Mexico. Overall, most chicks and adults examined had mercury levels in feathers that were below the concentration range in which birds show symptoms of mercury toxicity. However, chicks in the Audubon Island and Ten Palms Island colonies displayed mercury levels that were 3 times higher than values observed in 5 other colonies. In addition, several adults and chicks displayed selenium concentrations that are above what is considered safe for birds. Cadmium quantities in feathers were below levels that trigger toxicity in birds. Similarly, arsenic measurements were at quantities below the average of what has been reported for birds living in contaminated sites. Finally, we identify pelican breeding colonies that may warrant monitoring due to elevated levels of contaminants.

Alabama, Florida, Louisiana,Texas↗

USGS2019

Seasonal variation in environmental and behavioural drivers of annual-cycle habitat selection in a nearshore seabird

Aim Conservation of highly mobile species often requires identifying locations or time periods of elevated vulnerability. Since both extrinsic habitat conditions and intrinsic behavioural and energetic requirements contribute to habitat use at the landscape scale, identifying spatial or temporal foci for conservation intervention requires understanding how habitat needs and distributions vary across the annual cycle. Nearshore marine birds inhabit highly dynamic systems and have widely varying habitat needs among breeding, moult and non-breeding seasons, making them a useful case study for testing the relative contributions of individual resource requirements and environmental conditions in driving annual variation in distribution patterns. Location Northern Gulf of Mexico (USA). Methods We tracked Brown Pelicans using bird-borne GPS transmitters and used a combination of Hidden Markov Models and multivariate selectivity analysis to compare the characteristics of preferred resident habitats used throughout the annual cycle. Results Habitat selection was driven by dynamic oceanographic variables during all stages of the annual cycle. Key habitat characteristics varied between seasons, with particularly strong selection on high productivity, low temperature and low salinity during the breeding and post-breeding moult periods. The post-breeding moult also corresponded to a time of limited availability of preferred habitats, resulting in extensive overlap between breeding populations from different administrative planning areas. Main conclusions By incorporating seasonal variation in individual behaviour and resource requirements into our habitat models, we were able to identify the post-breeding moult as a period of high selectivity and restricted availability of preferred habitats for Brown Pelicans. Locations meeting preferred habitat criteria during the post-breeding period, particularly estuarine habitats with high productivity and low salinity, would therefore be high-value targets for management and restoration. Our analysis demonstrates the importance of accounting for both intrinsic and extrinsic temporal variation in evaluating habitat selection.

Alabama, Florida, Louisiana, Mississippi, Texas↗

USGS2019

Tropical cyclones alter short-term activity patterns of a coastal seabird

Background Mobile organisms in marine environments are expected to modify their behavior in response to external stressors. Among environmental drivers of animal movement are long-term climatic indices influencing organism distribution and short-term meteorological events anticipated to alter acute movement behavior. However, few studies exist documenting the response of vagile species to meteorological anomalies in coastal and marine systems. Methods Here we examined the movements of Eastern brown pelicans ( Pelecanus occidentalis carolinensis ) in the South Atlantic Bight in response to the passage of three separate hurricane events in 2 years. Pelicans ( n = 32) were tracked with GPS satellite transmitters from four colonies in coastal South Carolina, USA, for the entirety of at least one storm event. An Expectation Maximization binary Clustering algorithm was used to discretize pelican behavioral states, which were pooled into ‘active’ versus ‘inactive’ states. Multinomial logistic regression was used to assess behavioral state probabilities in relation to changes in barometric pressure and wind velocity. Results Individual pelicans were more likely to remain inactive during tropical cyclone passage compared to baseline conditions generally, although responses varied by hurricane. When inactive, pelicans tended to seek shelter using local geomorphological features along the coastline such as barrier islands and estuarine systems. Conclusions Our telemetry data showed that large subtropical seabirds such as pelicans may mitigate risk associated with spatially-extensive meteorological events by decreasing daily movements. Sheltering may be related to changes in barometric pressure and wind velocity, and represents a strategy common to several other classes of marine vertebrate predators for increasing survival probabilities.

Florida, Georgia, North Carolina, South Carolina↗

USGS2018

Movement patterns of California brown pelicans (Pelecanus occidentalis californicus) following oiling and rehabilitation

Direct mortality of wildlife is generally used to quantify the damage caused by pollution events. However, free-ranging wildlife that survive initial exposure to pollutants may also experience long-term consequences. Individuals that are rehabilitated following oil exposure have a known history of oiling and provide a useful study population for understanding behavior following pollution events. We GPS-tracked 12 rehabilitated brown pelicans and compared their movements to those of eight non-oiled, non-rehabilitated controls over 87–707 (mean = 271) days. Rehabilitated pelicans traveled farther, spent more time in long-distance movements, and occupied more productive waters than controls. These differences were more apparent among females than males. Rehabilitated pelicans also visited breeding colonies and nest sites at lower rates than controls. Our results indicate that, although rehabilitated pelicans undertake long-distance movements, they may display increased dispersion and reduced breeding investment, particularly among females. Such behavioral changes could have long-term effects on populations.

Marine Pollution Bulletin↗