Animal Behavior Screencasts

Males compete for females in a variety of ways: competitive mate searching, various mechanisms of sperm competition, and overt conflict. This screencast portrays each of these with a variety of examples.

The Darwinian concept of sexual selection, explored through examples of sexual dimorphism, how females can benefit by being choosy when selecting a mate, what cues females might use to assess potential mates.

Pheromones are semiochemicals that typically communicate within a species for such purposes as territory marking and sexual behavior. Occasionally, they might operate between species, as we'll see in this screencast.

Allelochemics are semiochemicals (i.e., chemicals that have either communicative value or anti-predator benefits) that communicate between different species. Three subclasses of allelochemics are allomones (that benefit the sender), kairomones (that benefit the receiver), and synomones (that benefit both the sender and receiver). Examples are shown of each of these substances.

The reproductive behavior of ring doves has been investigated thoroughly beginning with the pioneering studies by Daniel S. Lehrman and his associates. His work, which is described here, nicely illustrates how external environmental factors cause the release of hormones, which, in turn, triggers behaviors, which, in turn cause the release of other hormones that affect all aspects of reproduction (courtship, incubation, parenting).

An examination of how how hormones have an immediate (activation) effect and how they have a longer-term (organizational) effect on behavior.

What happens to animals during the domestication process? Is their behavioral altered in a way that renders them “abnormal,” or are any observed behavioral changes due to the context in which domestic animals are maintained? The Russian geneticist Dimitri Belyaev investigated behavioral and physical changes in foxes, and more recent studies have examined behavioral changes in ducks.

Domestication is viewed as one of several social processes involving a "guest" as the exploiting species and a "host" as the exploiting species. Other processes include symbiosis, scavenging, robbing, social parasitism, and taming. Each of these are presented with examples.

The process of domestication as analogous to natural selection, examples of domesticated animals, including an historical perspective leading back to Darwin. Also, experimental studies of artificial selection, and the steps necessary to create domestic breeds.

An examination of changes in timing of developmental events over evolutionary time—a phenomenon known as "heterochrony," which covers both accelerated development across evolution as well as neoteny, a slowing down of developmental events.

Ways in which cultural evolution can occur and numerous examples in a birds, nonhuman primates, and whales.

Here, we explore whether every behavior has necessarily been selected for its current role, or if they were originally selected for a different role. The term “exaptation” helps to distinguish between these alternatives, as we consider a number of examples.

Numerous examples of animal adaptation among a wide variety of species, including the relationship between adaptation and speciation illustrated by Darwin's Finches.

Examples of ecological speciation, ecological character displacement, and geographic isolation, as mechanisms by which speciation can occur.

Is the rate of evolutionary change gradual or rapid? This screencast explores the Darwinian rate of gradualism vs. salvationism, or punctuated equilibrium. The two are not mutually exclusive.