Optimal Foraging Theory in Glaucous-Winged Gulls

The set of behaviors an animal uses to find and exploit resources, primarily food, but also includes things like finding nesting material or mates.

A type of foraging where the predator waits in a fixed location for prey to come to them. This method relies on camouflage and ambush strategies.

A foraging style involving actively searching for prey, often pursuing it over long distances. It emphasizes speed and endurance.

The amount of resources an animal can acquire using a particular foraging method. Sit-and-wait predators have a lower capture rate but expend less energy.

The amount of energy required for an animal to perform a given foraging behavior. Active foragers expend more energy due to movement.

The study of how animals make choices to optimize their foraging behavior, maximizing energy gain while minimizing effort. It uses an economic approach.

In optimal foraging theory, this refers to the benefits an animal gets from obtaining a resource, often measured in energy gain.

The costs associated with a particular foraging action, including the energy required to search for and handle prey.

The ratio of energy gained from consuming a prey item to the energy spent handling and digesting it.

The amount of energy an animal needs to find, capture, and consume a prey item. It includes time spent searching, chasing, and processing the food.

The overall benefit of a predator consuming a particular prey item, considering both the energy gained and the handling time involved.

The goal of maximizing energy gain in animals leads to increased efficiency in their use of time and resources, and ultimately, improved survival and reproductive success.

As the variety of prey a predator consumes increases, the time spent searching for food generally decreases. This is because the predator is more likely to find a prey item quickly when there are more options available. By having access to a more diversified food source, the predator's efficiency in acquiring food improves.

As the variety of prey a predator consumes increases, the average time spent handling each prey item tends to increase. This is because different types of prey may require different handling methods, such as breaking open shells or extracting meat.

The optimal prey type for a predator is determined by the intersection of the searching time and handling time curves. This point represents the prey type that provides the maximum energy gain per unit time, balancing the effort needed for searching and handling.

The profitability of a prey item is measured by the energy gained from consuming it (E) divided by the time it takes to handle it (Th). This ratio helps the predator decide whether eating a specific prey item is worth the effort.

When a predator encounters a less profitable prey item (P2) while searching for a more profitable one (P1), the predator must decide whether to eat the less profitable prey or continue searching for the more profitable one. This decision depends on the relative profitability of the two prey items and the time cost of searching for the more profitable one (Ts1).

The time cost of searching for a more profitable prey item (Ts1) plays a significant role in the 'to eat or not to eat' decision. If the searching time is long, the predator may be more inclined to eat the less profitable prey to avoid spending more time searching. However, if the searching time is short, the predator may be more likely to continue searching for the more profitable prey.

In feeding experiments, predators tend to show a preference for prey species that offer the highest energy gain per unit handling time. This preference is based on the profitability of each prey species.

The choice of a predator to consume or reject a prey item depends on the relative profitability of the two prey items and the time cost of searching for the more profitable one. This decision-making process highlights the dynamic nature of predator-prey relationships and the importance of balancing energy gain with time investment.

A mathematical model that predicts how animals choose to exploit patches of food in order to maximize their energy gain while minimizing effort.

The amount of food or other resources available in a particular area, influencing how long an animal will stay there.

The ability of an animal to choose the most profitable strategy for exploiting patches, based on the quality of each patch.

The ratio of benefits (energy gained) to costs (energy spent) in acquiring a resource.

The fundamental assumption of optimal foraging theory, suggesting that animals behave in ways to maximize their fitness, ultimately leading to successful reproduction.

The most profitable food option yields the highest energy gain per unit of time. It prioritizes efficiency over quantity, suggesting that the largest item isn't necessarily the best choice.

When a consumer consistently encounters high-value prey, they specialize on that food source, maximizing their energy gain by avoiding less valuable options.

When high-value prey is rare, consumers broaden their diet to include less valuable options to ensure consistent energy intake.

An animal shouldn't spend time handling or eating a food if there's a good chance of finding a more valuable item in that time.

As the environment becomes less productive (fewer high-value prey), animals broaden their diets to include less profitable options. This ensures enough food even in scarcity.

Animals in unproductive environments are generalists because the time spent searching for high-value prey doesn't outweigh the benefits of a broader diet.

Animals in productive environments are specialists because they can focus on high-value prey due to their frequent encounters.

The initial time spent traveling to a food patch, during which no energy is gained.

The time spent extracting resources (e.g., consuming prey) from a food patch.

The rate at which energy is gained while foraging in a food patch.

The point in time when the rate of energy gain begins to decline, reaching a point of diminishing returns.

A higher travel time to a food patch increases the time spent foraging in that patch.

A food patch with higher resources value (e.g., richer prey density) justifies spending more time foraging in that patch.

Animals tend to prefer foraging in patches with higher resource values. These richer patches attract more animals and they stay there longer.