Mercury as an Indicator of Foraging Ecology but not the Breeding Hormone Prolactin in Seabirds

Marine predators are frequently exposed to contaminants through diet, and thus contaminants like mercury have the potential to be used as tracers of foraging ecology. Mercury’s neurotoxic and endocrine-disrupting effects can have far-ranging consequences for both individuals and populations, and thus mercury concentrations could also be indicative of wildlife health.

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Detection of Ultrafine Plastics Ingested by Seabirds using Tissue Digestion

This study provides the first quantification of ultrafine plastic in seabirds using chemical and biological digestion treatments to extract plastic items from seabird gizzards. The alkaline agent, potassium hydroxide, outperformed the enzyme corolase, based on cost and efficiency (e.g., digestion time). Ultrafine plastics were observed in 7.0% of Flesh-footed Shearwater (Ardenna carneipes) gizzards collected from Lord Howe Island,

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Seasonal Variation in Movements and Survival of Invasive Pacific Rats on Sub-tropical Henderson Island: Implications for Eradication

Invasive rodents are successful colonists of many ecosystems around the world, and can have very flexible foraging behaviours that lead to differences in spatial ranges and seasonal demography among individuals and islands. Understanding such spatial and temporal information is critical to plan rodent eradication operations, and a detailed examination of an island’s rat population can expand our knowledge about possible variation in behaviour and demography of invasive rats in general.

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Recovery of Introduced Pacific Rats following a Failed Eradication Attempt on Subtropical Henderson Island, South Pacific Ocean

Rodent eradications in tropical environments are often more challenging and less successful than those in temperate environments. Reduced seasonality and the lack of a defined annual resource pulse influence rodent population dynamics differently than the well-defined annual cycles on temperate islands, so an understanding of rodent ecology and population dynamics is important to maximise the chances of eradication success in the tropics.

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Bait Colour and Moisture Do Not Affect Bait Acceptance By Introduced Pacific Rats (Rattus exulans) at Henderson Island, Pitcairn Island

Changing bait colour may reduce mortality of Henderson crakes (Zapornia atra), an endemic globally threatened flightless bird on Henderson Island, Pitcairn Islands, South Pacific Ocean. Crakes had high non-target mortality in a failed 2011 rat eradication operation and consumed fewer blue than green cereal pellets

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Changes in technology and imperfect detection of nest contents impedes reliable estimates of population trends in burrowing seabirds

Burrow-nesting seabirds present many challenges for determining abundance reliably. We used burrow scopes to determine the population status of Flesh-footed Shearwaters on Lord Howe Island. Comparing two burrow scope models, we found >50% of burrow contents were classified differently. Our results highlight a need for regular surveys to quantify detection probability so that as video technology advances, previous estimates remain comparable.

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Trace Element Concentrations in Feathers of Seven Petrels

Gadfly petrels (Pterodroma spp.) are one of the most threatened and poorly studied seabird groups, and as marine predators, are exposed to biomagnified and bioaccumulated chemical pollutants from their prey. We quantified trace element concentrations in breast feathers of seven petrel species that breed in the southern hemisphere to quantify current concentrations.

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