Question

QUESTION: Please write a one paragraph lab report introduction based on the following experiment below:

Organisms must forage for food and other resources that are scattered around a heterogeneous environment. Food availability varies from site to site, but so do environmental conditions that foragers experience (e.g., temperature and wind) and the risks to which they are exposed. Foraging by any organism involves trading off the gains to be made by collecting food against the costs of doing so, including costs of energy spent moving and coping with stressful environments, and their exposure to injury or death from enemies.

Animals that venture out from relatively safe locations (e.g. trees and bushes) into more hazardous surroundings to find food are considered "central place foragers." Joel Brown, a behavioral evolutionary ecologist at UIC, reasoned that foragers might deplete patches more thoroughly in areas they consider safe, where they could spend a lot of time. In patches they perceive as more dangerous, they might give up earlier, leaving behind a higher density of remaining food. If food densities at various sites were initially similar before foraging occurred, the “Giving Up Density” (GUD) of food at a site after an animal quits foraging there might indicate how risky it considered that particular landscape position.

The study species for this lab is the Eastern Gray Squirrel (Sciurus carolinensis Gmelin), tree squirrels native to the Eastern and Midwestern United States. They are appropriate mammals to use in field studies on foraging behavior because they are diurnal and non-territorial with overlapping home ranges (so several animals have access to the same supply of food), social, and locally abundant.

In this lab, you will test predictions related to Brown's GUD hypothesis. Rather than measuring food densities after foraging, you will focus on the behavioral trade-offs squirrels make based on the riskiness of their environment, which we will assume is positively related to distance from cover. Specifically, you will test the hypothesis that Eastern Gray Squirrel foraging behavior occurs closer to cover than other types of behavior.

Methods

Each group will go outside and search the campus for Eastern Gray Squirrels. When you locate a squirrel, observe its behavior for a total of 20 minutes, recording the type of behavior it demonstrates each minute. You will categorize behaviors into one of five groups: foraging, grooming, vigilance, social, or other behavior. In order to not influence the squirrels' behaviors, be sure to stand at least 10 m (approximately 30 ft) away from the squirrel you are observing.

At each 1 minute interval (use your cell phone as a timer) you will record:

1. Whether the squirrel is searching, handling, or burying food items (foraging behavior, F), grooming itself (grooming behavior, G), scanning the environment (vigilance behavior, V), interacting with other squirrels or with other animals (humans, birds, dogs, etc; social behavior, S), or engaging in a behavior that does not fit into one of the other four groups (other behavior, O; include a brief description of what your group thinks this behavior is). Only ONE behavior should be recorded for each 1-minute interval.
   
2. A visual estimate of the distance (in meters, 1 m = 3.28 ft) to the nearest cover (tree or bush). If the squirrel is in cover for the majority of a minute of your observation, record the distance as 0 and continue to record its behavior.

Before you go outside and begin your search, make a data collection table in your lab notebook. The table should have 21 rows and four columns: one that identifies the squirrel, one that gives the time interval, one that identifies the behavior, and one that estimates the distance to the nearest tree (e.g., Table 1). If you observe more than one squirrel, you can add your second or subsequent squirrels to the same table OR you can create a new table for each new squirrel that you observe.

- Each group should attempt to record the behavior of at least two squirrels, but this number may change depending on timing and weather issues. We will pool the data for the whole class.

- Delegate jobs to various lab group members. One person should record the time and input data into the table, another student or 2 should check the squirrel’s behavior, and a third student should estimate the distance to the nearest tree from the squirrel being observed.

Answer 1

INTRODUCTION

Foraging by animals depends on availability of food and the barriers, like predators, temperature, geography etc that the animals have to encounter. In this research paper we present the foraging behavior of Eastern Gray squirrel, Sciurus carolinensis Gmelin, a species of tree squirrels native to Eastern and Midwestern United States. Animals that dare to forage in risky places are called ' central place foragers'.  Joel Brown, a behavioral evolutionary ecologist at UIC, proposed that animals forage more frequently in those places they consider safe and do not venture in those places which they consider unsafe, no matter how abundant the food is. This is termed as 'Giving Up Density' or GUD.

In this field work we test predictions related to Brown's GUD hypothesis. The research focuses on the behavioral trade-offs the squirrels make, based on the riskiness of their environment. Special attention is paid on the hypothesis that Eastern gray squirrel foraging behavior occurs closer to cover than other types of behavior.