Coupling stable isotopes with bioenergetics to estimate interspecific interactions

Area of Science:

• Ecology
• Wildlife Biology
• Conservation Science

Background:

• Understanding interspecific interactions is crucial for wildlife management, especially for large vertebrates across vast ecosystems.
• Traditional methods often struggle to capture the complexity of these interactions at large spatial scales.

Purpose of the Study:

• To develop and validate a novel methodology for estimating interspecific interactions.
• To model the population dynamics and species interactions within a specific vertebrate community.

Main Methods:

• Combining stable isotope analysis with bioenergetics modeling.
• Applying the methodology to a suite of vertebrates on Santa Cruz Island, California, USA.
• Including endemic carnivores (island fox, island spotted skunk), an exotic herbivore (feral pig), and a predator (Golden Eagle).

Main Results:

• Sensitivity analyses indicated robust parameter estimates for the model.
• Natural history observations supported the model's accurate representation of species interactions.
• The integrated approach effectively captured community dynamics.

Conclusions:

• Stable isotopes, when integrated with bioenergetics and other approaches, are powerful tools for studying interspecific interactions.
• Further research on species-specific isotopic fractionation and diet breadth is necessary for refining isotope-based inferences.
• This methodology offers a robust framework for illuminating complex community dynamics in wildlife ecology.