Northern Prairie Wildlife Research Center
|Fig. 13. The natural appearance of large bales make them attractive Canada goose nesting sites. (I. Rostad)|
One shortcoming in using large bales for goose nests is that they may be usable only a few years. Some, however, last as long as five years under favorable circumstances, especially if they are reinforced with woven wire. In general, high quality, tightly wrapped bales will last the longest.
Bale nest sites are more accessible to raccoons and other predators, although studies indicate a low rate of predation. Bales are also more likely to be damaged by abnormal rises in water levels than the other types of homemade nest sites discussed. A nesting bale is relatively easy to install since it can be transported onto the ice during the winter. The nest bale, in some circumstances, may be the most economical of all the homemade nest sites discussed.
Bales are a good choice for wildlife club projects because of their availability and general lack of maintenance. In addition, geese generally will begin nesting on the bales almost immediately. Other structures, such as fiberglass tubs, may require more time to develop consistent use by geese.
Although the technique is relatively new and not yet perfected, the results have been excellent. To date most bales placed are for nesting Canada geese. However, ducks, especially mallards, also nest on the bales. Large round bales also provide excellent loafing sites and are used extensively by ducks and geese throughout the spring and summer.
Bale Flax straw, coarse grass, straw or marsh hay Wire mesh 4 x 16 1/2-foot pieces of wire mesh
The ideal size of the round bales is about 5 feet high by 5 feet in diameter. These bales can weigh up to 1500 pounds.
The bales should be tight and securely tied. They will last longer if additional plastic twine is applied to them during the baling operation. Some individuals have wrapped the bales with plastic strapping similar to that used to bind crates or lumber in order to increase bale life.
Large round nesting bales will also last longer if the bales are wrapped with wire mesh or woven wire. If wire is used, the bales are wrapped so that a minimum of three-quarters of a bale is covered with wire mesh (Figure 14). Bales should be wrapped with wire mesh prior to handling and transporting. A disadvantage of the wire wrapping is that it will remain to clutter up the wetland after the bale has deteriorated unless removed.
|Fig. 14. Wrapping of bale with wire will greatly increase its longevity.|
Flax straw is the best material for a nest bale because of its coarse nature and resistance to rotting. If flax is not available, other straw or grasses may be used but they will not last long. Coarse grass or marsh hay is probably better than fine grass or straw. Alfalfa is very crumbly and should not be used to make a nesting bale.
Although bale nest sites are not completely predator proof, they offer a Canada goose protection from predators such as fox, coyote, and skunk, and a determined pair can frequently defend a bale against raccoons. Proper placement in a marsh will also reduce the chances of predation.
The best time to place large round bales on a wetland is in early winter when the ice is strong enough to support a vehicle and before snow has accumulated (Figure 15). When placing bales by driving a vehicle on the ice, be sure to enter the pond from the shore opposite the site. Vehicle tracks through emergent vegetation last for a number of years, creating an excellent predator travel lane. Entering the pond directly by a bale will draw attention to the bales and at the same time make it more accessible to mammalian predators.
|Fig. 15. Large round bales may be placed in wetland during the winter using standard farm trucks equipped with hoists. (I. Rostad)|
The bales can be placed in a variety of wetland sites. It is best to locate them in or near stands of bulrush, cattail or other vegetation. If possible, place on the leeward side of the wetland where they are somewhat protected from winds and ice action. Bales placed on small wetlands will probably last longer than bales on lakes because of reduced wave action in the summer and less ice action in the spring.
No more than two bales should be placed on sloughs or wetlands of less than five acres in size. Bales should not be located closer than 100 yards apart on any wetland. This spacing will avoid or reduce conflict between nesting pairs. It is also advisable to avoid placing bales close to well-traveled roads where human disturbance may occur.
Bales are less likely to be visited by predators if they are located at least 150 feet from the shoreline. This distance might be less in cases where the bale is partially concealed by emergent vegetation so it cannot be seen from shore by raccoons or other predators. Bales should not be placed in deep water or river systems where they will drift or float away. Water depth of 1 to 2 feet and no deeper than onehalf the height of the bale are ideal. Generally, the deeper the water, the shorter the bale's life span.
Bales placed on the ice sometimes tip over when the ice melts unevenly. Tipped bales are of little value as nesting sites. To avoid tipping, set the bale into a hole cut into the ice. A circular hole the size of the end of the bale can be cut in the ice with a chain saw and the chunks of ice removed with an ice tong. The bale is then laid on its side next to the hole, tipped up, and set into the hole so an end goes down through the hole settling on the marsh bottom. Experience has shown that if the distance from the surface of the ice to the marsh bottom is a foot or less, the bales can be set on end on the ice without much risk of it tipping.
Tipped bales that cannot be uprighted can be made usable for nesting geese. To do so, a small depression and loose straw must be provided on the top side of the bale. This can be done simply by cutting or chopping into the bale until enough loose material is available to form a nest bowl.
Bales should not be placed in pasture wetlands which dry up during the summer and fall. There are very few things that could destroy a nesting bale faster than livestock having free access to one.
Finally, extra straw can be placed on top of the bales to make them more attractive to Canada geese.
It is important to check the bales each year in late winter or early spring to determine if any need to be replaced. In some cases it may be desirable to add more bales to a wetland to replace usable but rapidly deteriorating bales or to accommodate an expanding breeding population.