Related Concept Videos

Conservation of Declining Populations 02:07

9.6K

Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.

Conservation efforts often utilize scientific approaches to identify the reasons, or the agents, causing the population to decline. This approach then devises steps to remove, oppose, or neutralize the agents.

Conservation efforts may also introduce a test group to determine the probable cause of the decline. The...

Survey Safety 01:28

25

Surveying near highways, rough terrain, or power lines involves significant risks. Working along highways is particularly dangerous and requires the use of warning signs and flagmen. It is safest to avoid working directly on roads and use offsets whenever possible. When highway work is unavoidable, it must follow all safety guidelines. Surveyors should wear bright clothing, such as orange reflective vests, to ensure visibility to motorists, coworkers, and hunters. In construction zones, wearing...

Types of Selection 01:46

40.4K

Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...

Keystone Species 01:39

21.6K

Measures of species biodiversity, such as richness (i.e., the number of species present) and evenness (i.e., their relative abundance), describe an ecological community’s structure. Many factors affect community structure, including abiotic factors (e.g., sunlight and nutrients), disturbances (e.g., fire or flood), species interactions (e.g., predation or competition), and chance events (e.g., foreign species invasion). Certain species—such as keystone species—also play a...

Optimal Foraging 00:48

12.0K

How animals obtain and eat their food is called foraging behavior. Foraging can include searching for plants and hunting for prey and depends on the species and environment.

Optimal foraging theory states that natural selection favors foraging strategies that balance the benefits of a particular food, such as energy and nutrients, with the costs of obtaining it, such as energy expenditure and the risk of predation. Optimal foraging maximizes benefits while minimizing costs.

For the Crows

Migration 00:53

7.9K

Migration is long-range, seasonal movement from one region or habitat to another. This common strategy, carried out by many different organisms around the world, is an adaptive response that typically corresponds to changes in an organism’s environment, like resource availability or climate. Migrations can involve huge groups of thousands of animals as well as single individuals traveling alone and can range from thousands of kilometers to just a few hundred meters.

Why Animals Migrate