MARB 403 Lab 1

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Lab Introduction

Lab Instructor

Sarah Piwetz

sarahpiwetz@hotmail.com

cell phone: (281) 686-1681 (call or text)

Policies

Be on time!
- Classroom will be unlocked early for reading, etc.
No makeup quizzes
- Quizzes at end of class time after discussions
- No exams!
No late work accepted
If you have problems or concerns please talk to me as soon as possible

Lab structure

Group presentation of reading material
Group leads discussion of reading material
Quiz on reading materials for the day

Reading materials should bea available on eLearning

Grading

Lab accounts for 40% of total course grade.

Daily quizzes: 10%
Group presentation and discussion: 20%
Independent written assignment: 10%
- Due to turnitin.com by Jan 12

Presentation

See "discussion questions" to guide presentation

Avoid summarizing entire paper (only include most important points

Use powerpoint or other slides

Group Organization

I am in group 2, presenting on Bottlenose Dolphins and Sociobiology Group Members:

Matthew Barry
Jessica Cade
Courtney Hughes
Megan Laney
Ashley Riley

Group Behavior

by Alejandro Acevedo-Gutiérrez

Group: A set of individuals of the same species which remain together and interact for a period of time (more common within group than with individuals outside of group.

Types of Groups

aggregation: non-social factors attract animals to same place; don't benefit from the presence of others
groups: form for mutual benefit of members; schools may last from minutes to hours; groups may last from months do decades

Defining a group

In Field studies, a group is defined by a distance rule

Usually

10-m chain rule: dolphins in a group must be within 10 meters of each other
100-m radius rule: dolphins that fit within a circle of radius 100 m are in a group

BUT—these definitions are less meaningful to cetaceans

Kin selection

One of the more common arguments for group formation

By helping your relatives, you indirectly influence your own genes.

Many interactions occur between relatives in low-spatial/low-dispersal

Alloparental care (babysitting)

Table 1: Benefits of Group Living

Sensory integration (reacting as a group): predator and prey detection
"Many Eyes": less vigilance time per individual; Following others to food
Dilution Effect: reduced probability of being selected as prey or parasitized
Social: Learning; Increased mating opportunities

Table 2: Costs of Group Living

Higher visibility: Easier for predators to find large groups; More attractive to predators
More Intraspecific Competition: for food, mates, and other limited resources; May increase travel time (in relation to foraging; have to travel farther for food)

In general, more benefits than costs.

Alliances

Long-term associations between male dolphins (Shark Bay Western Australia)

Several levels:

First-order are strongest and last for over 10 years
Second-order are possibly kin selection

Improved mating opportunities

Female Social Behavior

Females often stay near the area they were born (philopatry; allows for group formation through kin selection)

Alloparenting (babysitting)

Social Complexity and Culture

Social complexity is related to amount of material investment time

Baleen whales: < 1 yr w/ calves; Adult long-term associations are unclear
Toothed whales: Varies greatly betw. species; up to 11 years with calves; adult long-term associations are common

Females form "bands" or stronger groups

Grandmothers transmit and store cultural information

Foraging

Hypothesis: Group living increases foraging efficiency

transient killer whales are only clear example

Search for prey as group by combining sensory abilities
Forage communally by prey herding

Predation

Group size correlated with predation pressure and prey availability No conclusive evidence that group living in cetaceans decreases predation

Conclusion

Group living benefits foraging efficiency and reduced predation (though not proven)
Female social strategies influence social structure of larger population