Predation pressure

Definition

Predation pressure refers to the impact that predation has on the population dynamics and behaviors of prey species within an ecosystem. It encompasses both the direct effects of predators on prey populations, such as mortality rates, and the indirect effects, including changes in prey behavior, reproduction, and distribution in response to the presence of predators. This term is particularly relevant when considering how invasive species can disrupt existing predator-prey relationships and alter ecological balances.

5 Must Know Facts For Your Next Test

1. Predation pressure can lead to evolutionary adaptations in prey species, such as developing better camouflage or increased vigilance.
2. Invasive predators can impose higher predation pressure on native prey populations, often leading to declines or extinctions of those species.
3. Changes in predation pressure can alter community composition and biodiversity, affecting ecosystem health and function.
4. The introduction of a new predator can create a 'new normal' in an ecosystem, resulting in shifts in behavior and habitat use among prey species.
5. Predation pressure influences not only the survival rates of prey but also their reproductive strategies and population dynamics.

Review Questions

• How does predation pressure influence the behavior and population dynamics of prey species?
  • Predation pressure significantly influences both the behavior and population dynamics of prey species. When prey are subjected to high predation pressure, they may develop adaptive behaviors such as increased wariness, changes in foraging patterns, or altered habitat use to avoid predators. These changes can lead to decreased reproductive success and overall population numbers if the pressure remains intense over time.
• Discuss how invasive predators alter predation pressure and its effects on native prey populations.
  • Invasive predators can drastically change predation pressure within an ecosystem by introducing new threats to native prey populations that may not have evolved defenses against them. This heightened predation pressure often leads to significant declines in native species as they struggle to cope with increased mortality rates. The balance of the ecosystem can shift dramatically, resulting in loss of biodiversity and potentially leading to ecological collapse.
• Evaluate the implications of changing predation pressure due to invasive species on ecosystem stability and resilience.
  • Changing predation pressure from invasive species poses serious implications for ecosystem stability and resilience. As invasive predators disrupt existing predator-prey dynamics, native species may face elevated risks of extinction, resulting in decreased biodiversity. This loss can diminish ecosystem functions, such as nutrient cycling and habitat provision. Furthermore, ecosystems with reduced resilience are less able to recover from disturbances, making them more vulnerable to future invasions or environmental changes.

Related terms

invasive species: Non-native organisms that are introduced to an ecosystem, which can outcompete native species and disrupt local ecosystems.

trophic cascade:

An ecological phenomenon where changes at the top of the food chain impact lower trophic levels, often triggered by changes in predator populations.

keystone species: Species that have a disproportionately large effect on their environment relative to their abundance, often maintaining the structure of an ecosystem.