week 5-6 Flashcards
What changes in social bonds do female and male lions experience throughout their lives?
Female connections to males are strongest in middle age, while connections to other females are strongest during their teenage years. Male connections to other males are lowest in midlife and strengthen with age, while connections to females are strongest in midlife.
How do stronger social bonds affect the lifespan and reproductive success of animals?
Stronger social bonds can lead to longer lifespans and more offspring.
Why do many animals choose to live in groups?
Animals live in groups for various reasons, including resource aggregation, improved foraging success, predator detection, and social information exchange.
What are some costs of living in groups for animals?
Costs include increased pathogen transmission, risks of cuckoldry, conspecific competition for resources, and higher chances of cannibalism and infanticide.
How does group size affect pathogen transmission in animals like Belding’s ground squirrels?
As the population size increases, so does the parasite burden; however, beyond a certain size, adding more individuals does not significantly increase the risk of infection.
What is cuckoldry, and how does it affect male animals?
Cuckoldry refers to the risk of raising offspring that are not one’s own, which primarily affects males due to female mating with multiple partners, leading to post-copulatory competition.
How does conspecific competition manifest in group-living animals?
Intense competition occurs among members of the same species (often the same sex) for food, breeding sites, and mates.
What are some benefits of aggregation in animal groups?
Benefits include shared resources (e.g., breeding sites), improved foraging efficiency, and increased predator detection.
How do animals in groups improve foraging success?
Groups enhance collective detection of food, reduce variance in foraging efficiency, and allow eavesdropping on successful foragers.
What role does group hunting play in predator species like hyenas and lions?
Group hunting allows these predators to take down larger prey more effectively and increases their foraging efficiency.
How does living in a group help with predator detection?
Many eyes increase vigilance, allowing for earlier detection of predators, and reducing the time each individual spends being vigilant.
What is the dilution effect in the context of group living?
The dilution effect refers to the reduced risk of individual predation in larger groups, as the likelihood of being targeted decreases.
What are some confusion strategies used by animals in groups to evade predators?
Strategies include the “dazzle” effect seen in zebras, where individuals move in different directions to confuse predators.
What is interspecific vigilance, and how does it benefit animals in mixed-species groups?
Interspecific vigilance occurs when animals of different species benefit from the vigilance of others; for example, zebras and wildebeest increase their safety when foraging near vigilant impalas or when dwarf mongooses forage alongside fork-tailed drongos.
How does social rank affect the pace of life in macaques when it comes to food?
Lower-ranked macaques rub food on their bodies before eating, only removing some grit, while middle-ranked macaques clean their food thoroughly, preserving their dental health and potentially living longer.
Why might some animals prefer to live in larger groups despite the risks?
The benefits of increased resource availability, improved foraging, and enhanced predator protection outweigh the costs associated with social living.
How does the dilution effect work in group living?
The dilution effect suggests that as group size increases, the chance of any individual being attacked decreases, provided the attack rate remains constant and the benefits of dilution outweigh detection costs.
In meerkats, what is the relationship between guards and foragers?
When foraging, meerkats focus on food underground and rely on guards who are closer to bolt holes, allowing guards to enter first and choose safer spots. Guards often do not need to eat while on duty, making their vigilance mostly selfish.
What is predator swamping, and how does it work in impalas?
Predator swamping occurs when a large number of young impala lambs are born simultaneously, making it difficult for predators to consume them all, as many are born within a short time frame, leading to collective defense strategies.
What trade-offs do individuals face in a group regarding competition and predation?
Individuals must balance the risk of predation, which is often higher on the periphery of a group, with competition for resources, which is typically more intense at the center, leading to a dynamic movement within the herd.
How do predators struggle with targeting individuals in large groups?
Predators find it difficult to focus on a single target in larger groups, leading to decreased attack success rates as they cannot easily identify and pursue one individual amidst many.
What are some communal defense strategies prey animals use?
Prey animals may engage in mobbing behavior to chase away predators, and some species, like musk oxen, form protective circles around their young when threatened by pack hunters.
How can inferior competitors benefit from group living?
Inferior competitors, like blue tangs in damselfish territory, can increase their food intake when part of a larger group, allowing them to access resources they might not get individually.
What thermal advantages do some species gain from living in groups?
Species like pallid bats and starlings benefit from roosting together to maintain body heat, especially in colder conditions.
What social benefits might animals experience from living in groups?
Animals may experience reduced harassment, lower rates of infanticide, increased vigilance, and stronger social bonds that provide immediate stress-reducing benefits.
How does optimal group size differ from stable group size in animal populations?
While larger groups can offer more benefits, they also bring increased costs, leading to stable groups that may not reflect the calculated optimal size, as individuals navigate factors like aggression and food competition.
What is the role of territory defense in group living among predators?
Group living allows predators like lions to defend their territory more effectively, deterring competitors and securing access to resources within their territory.
What defines a behavior as altruistic within a species?
A behavior is altruistic when it negatively impacts the reproductive success (RS) of the individual performing it (direct cost) while providing a net positive effect on the RS of the recipient (indirect benefit).
: What are the costs associated with grooming behavior in animals?
Grooming can involve time, energy, a reduced ability to remain vigilant, and increased exposure to parasites, yet it can be altruistic even if individuals hope for reciprocation.
What is the difference between symmetrical and asymmetrical social groups?
In symmetrical groups, all members give and receive equally, while in asymmetrical groups, dominant individuals receive more benefits while subordinates contribute more.
How does reproductive skew vary among solitary, colonial, cooperative, and eusocial species?
Solitary species allow any individual to breed, colonial species experience moderate skew, cooperative species have limited reproduction primarily among dominants, and eusocial species have extreme skew with most breeding done by a single individual.
