Using GIS Mapping to Examine Influence of Forest and Box Spacing on Bluebird Nesting Success

Abstract

In this project I was using GIS mapping to examine the effect of 2 environmental variables on the success of bluebird boxes on Wye Island. I monitored 50 boxes this year and used the mapping to see what effect forest proximity and box spacing had on bluebird nesting success.

In order to find a solution to this problem I had to do various things. One thing I had to do was I had to check the fifty bluebird boxes. This took the whole summer to do. I checked them at a pretty consistent rate, which was one time every three four weeks. I then used the GPS and plotted the location of all the fifty boxes and used ArcView to get all my data arranged on the maps.

Relationship to Forest

The successful and unsuccessful bird boxes all had a different relationship to the forest. In our background information it stated that a bird's ideal habitat would be in fields and orchards. From this information I hypothesized that boxes near the forest would be unsuccessful.

From the data collected I found most unsuccessful bird boxes were less than about 200 meters away from the forest. I also found that successful boxes were all over 200 meters away. Some reasons I think bird boxes closer than 200 meters were unsuccessful are there are many predators that live in the forest and less protection.

Relationship to Other Boxes

Territory size had large impact on the success of the boxes. My background information states that most bluebirds like their boxes to be at least 300 feet (91 meters) away. My background information also says that around breeding season the birds expect to have 2-3 acres to themselves and are very territorial which is a reason that successful bird boxes were so far away from each other. Therefore I hypothesized that boxes less than 300 feet would be unsuccessful.

From the data I collected I found that bird boxes that were successful were generally about 200 feet (60 meters) and farther from other boxes. Therefore my hypothesis was significantly close to the data gathered.

If I were to do this project again I would change some things. On thing I would change is instead of having a project I would control an experiment. I would put ten boxes near the forest and I would put ten boxes in an open field area. I would then see which group was more successful. I would also replace the missing boxes and put them in area that were successful this year.

Problem

1. Does the environment surrounding bluebird boxes effect how successful the boxes are? Specifically in this investigation does the distance from the forest affect the success of bluebird boxes?
2. Does the distance between bluebird boxes affect the success of bluebird boxes?

Background Information

The Bluebird that appears more often throughout the Eastern United States is the Eastern Bluebird. You may know them as Blue Robin, Blue Redbreast, American Bluebird or Red-Breasted Bluebird. It's all the same species.

Identification

An adult Eastern Bluebird can be about 16-21 centimeters long and weigh a total of 30 grams. Between the female and male no difference can be seen in the size. In order to tell the gender of the Bluebird you must observe a tint or shade of their colors. A male Eastern Bluebird has a bright blue upper-part of the body, while the female is a blue-gray in the upper-part. A male also has a rusty or reddish orange throat and a white belly, while the female has a subdued reddish orange belly. Though different in color, both female and male have short black beaks that are slightly arched. They also both have black legs and feet. You can also identify an Eastern Bluebird by its vocalization. An Eastern Bluebird song would sound something like turwy, cherwee, cherey-lew.

Nest Box Description

Now that I have explained how to observe and identify a bluebird I will inform you on their specific needs regarding boxes. Eastern bluebirds prefer their boxes to be at least 300 feet apart. Eastern Bluebirds are remarkably territorial and when it comes to breeding season they expect to have around 2-3 acres to themselves. The bottom of the box should be at least 3 feet above the ground: a box mounted 4-5 feet would be an ideal height. When putting up bluebird boxes it would be greatly appreciated by the birds that you face the entering hole away from prevailing winds and in the summer facing away from the blinding sun. Be ready for your visitors around February in the south and March in the north.