Optimal Foraging in Granivorous Herbivores

Introduction

Optimal foragers balance costs and benefits to maximize Energy per unit Time. In some cases the costs and benefits are in the same currency. For example, the energy it takes to acquire a food item, or the time it takes to find (search for) and handle a food item are costs that are weighed against the benefits of the food energy contained in the food item. Other costs are not in the same currency, such as exposure to predation risk.

Methods

In this lab we will examine the optimality, and deviations from optimality, of forest-dwelling granivores at the MSUM Regional Science Center. We have 4 types of seeds that produce different a priori predictions:

1: oilseed
2: shelled oilseed (i.e., with no shell)
3: safflower
4: white millet

We will set up 14feeding stations in two locations: within forest over (n= 7) and away (at least 4m) from overhead cover in the open meadow (n = 7).

We will record the number of seeds eaten per station of each seed type. We will analyze the data using a 2 x 4 factorial ANOVA.

Results

We will create a column graph that show:

  1. Number of seeds eaten as a function of station location (open and forest).
  2. Effect of seed type on number of seeds eaten (oilseed, oilseed kernel, safflower, millet).

Discussion

What were the main trends in the results? Did they conform to predictions? Why or why not? How do these results compare to other studies in the primary literature?

References

At least 3 (THREE) references from the primary literature. Use format convention of the journal Animal Behaviour.Example: Note use of bold, italics, and ampersand (&). Ampersand is also used when citing references in the text.

Mini Report Grading Rubric (15 points → reduced to a weigh of 3/3)

Introduction (2 points)

-What is optimal foraging? Cite an example of optimal foraging in birds (0.5point)

-What is risk-sensitive foraging? Cite an example in birds (0.5 point)

-What were the main questions under study? (1 point)

Methods (1 point)

-Where was the study conducted? (0.5 point)

-Where were the feeders positioned? What were the seed types used? (0.5 point)

Results (8 points)

-What was the effect of feeder location?

  • Justify statement with statistical inference (1 point)
  • Refer reader to the figure where the data are presented (1 point)

-What was the effect of seed type?

  • Justify statement with statistical inference (1 point)
  • Refer reader to the figure where the data are presented (1 point)

-Figure: uncluttered figure that is clear and easy to read, complete with axis labels and legend underneath

(4 points). The figure should look something like this:

Figure 1. Mean (± 1SE) number of seeds eaten of each seed type by granivores in
open areas and areas under cover of forest.

Discussion (2 points)

-Brief restatement of the main results of the study (1 point)

-How do your results compare to other studies published in the primary literature?

  • Cite the primary literature (1 point)

Literature cited (2 points)

-Use format used by the journal Animal Behaviour

-Have 3 or more references (1 point)

-Use correctAnimal Behaviour format (1 point)