Tiger Shark and Albatross Fledgling Interactions

Quantifying predation and evaluating drivers of abundance

Every summer, tiger sharks (Galeocerdo cuvier) aggregate around island seabird colonies, where they prey on albatross fledglings as they transition from land to sea. While this interaction is widely observed, it has historically remained anecdotal and unquantified.

This project uses direct observations to quantify predation dynamics on Laysan (Phoebastria immutabilis) and black-footed albatross (Phoebastria nigripes) fledglings at Kure Atoll (Papahānaumokuākea Marine National Monument, Hawai‘i). Using a combination of observational data and statistical modelling, we examine how environmental conditions and temporal factors influence shark presence, behavior, and predation outcomes.

This work provides the first quantitative baseline of tiger shark–albatross interactions, contributing to a better understanding of predator–prey dynamics in pelagic–island ecosystems.

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Tiger sharks are currently listed as IUCN Near Threatened (Ferreira & Simpfendorfer, 2019), with populations expected to decline due to ongoing exploitation. As top predators, they play a key role in structuring marine ecosystems. Previous modelling studies have shown that their removal can trigger cascading effects, including short-term increases in seabird populations followed by longer-term declines in key fish species (Polovina, 1984, and Stevens et al., 2000). Quantifying their ecological role through direct predator–prey interactions is therefore critical for informed conservation and management.​

Specific aim of the project:

• Relate tiger shark arrival and abundance to albatross fledging abundance

• Investigate the environmental influences on abundance patterns

• Quantify tiger shark predation success on fledglings

• Examine the seasonal patterns of predation success