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How to Design a Science Experiment for Red-Winged Blackbirds With Cattails

In a cattail marsh, male red-winged blackbirds might be a first sign of spring. They arrive from winter flocks well ahead of females and stake out territories to nest and mate. This is one of the most numerous species of birds, though their wetland habitats are somewhat threatened. It should be safe to manipulate a small marsh for one season --- preparing before the males arrive --- and learn how important the cattails are compared to other sorts of perches.

Things You'll Need

2 1/2 foot stake
6 foot length of rope or twine
Measuring tape
Scissors
Heavy mallet
Hedge shears
Substitute perches
Large sheet of paper
Colored pencils or highlighters
Binoculars
Lab notebook

Instructions

Test Territories
- 1
  Tie the rope to the stake, and trim it to a length of 5 feet from the stake. Pound the stake into the soil next to a standing cattail fruit. Walk the end of the rope around the stake as a pivot to mark out a 10-foot diameter area. Cut all vegetation with the hedge trimmers within the circle at a single height of about 2 feet, except the central cattail. Fill the experimental area as densely as possible with circles.
- 2
  Cut down the central cattails from several areas, scattered randomly across the experimental area. Install one substitute perch at the center of each of these test areas by hammering it into the soil at the same point and to the same height as the original cattail.
- 3
  Leave the central cattails standing in control circles for comparison to the experimental treatment(s). Cut the fruits off other cattails in the area, between the experimental and control circles.
- 4
  Draw a map of your experimental area, highlighting the circles with substitute perches in one way and those with natural perches (cattails) in another.
- 5
  Observe and record how often returning male red-winged blackbirds are seen on each of the substitute perches and each of the areas with natural cattails.
Nesting
- 6
  
  Female red-wings, who lack the males' trademark epaulets, nest on the ground.
  
  Observe and record the success of males in attracting females to each kind of area.
- 7
  
  Male red-winged blackbirds might help to tend and feed the young birds.
  
  Count the number of nests that are built within each circle in the experimental area. Mark them on your map. Record which nests have eggs laid in them, and how the eggs hatch and are tended by the parent birds.
- 8
  
  Outside of nesting season, red-wings join large mixed flocks with other blackbirds.
  
  Collect nests from both test and control circles, once the nestlings have fledged and the birds have moved off into flocks to feed and migrate. Record the materials used in nests from the two kinds of areas, paying particular attention to the leaves of cattail plants and their lengths.

Nature