U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
 
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Nest Dragging Protects Migratory Bird Nests 

by Fritz Prellwitz, Malta FO

Nest dragging. It’s a low-tech, cost effective and time efficient means of helping the BLM (and industry) minimize adverse impacts to migratory birds across public lands in north central Montana.
 
Nest dragging is not a new management tool for wildlife biologists. It normally involves the pulling of a long piece of cable with trailing loops of chain between two vehicles, with several people watching for birds flushed from their nests as the device passes over them. Nests are rarely damaged and almost none are missed.
 
Nest dragging allows a biologist to precisely locate the ground nests of a wide variety of birds and use that information in time sensitive land use decisions. Ground nesting birds include many grassland songbirds, waterfowl and upland nesting shorebirds.
     
The nesting season for most migratory birds in northern Montana runs from approximately April 15 to July 15, which is a busy time of the year on our public lands. Oil and gas development, reservoir and fence construction and various public uses just to name a few, could create negative impacts to birds trying to nest in grassland habitat.
 
The Malta Field Office began nest dragging during the 2004 nesting season when drilling for several natural gas wells was proposed in late April. Industry has been very supportive of this process and one of the gas companies has occasionally supplied a second person to assist Fritz Prellwitz, a BLM wildlife biologist in Malta, with nest dragging on proposed well pad sites prior to construction.
 
As nest dragging became a more common BLM management tool, Prellwitz began modifying/improving the device. He soon learned that a simple drag made of plastic pipe and rope and pulled by only one person was more practical.
 
The improved nest drag consists of three 10-foot pieces of 1½-inch plastic pipe that can be hauled in the back of a pickup truck and then connected with clips on-site to create a 30-foot wide drag. The drag is completed after loops of rope with trailing tin cans are connected to the plastic pipe. One person can easily pull the drag across native prairie with little or no sagebrush and flushed birds often fly toward and past the wildlife biologist, providing ample time for species identification.
 
The located nests are flagged with a small pin flag and the locations are provided to the gas company, helping them make decisions about avoiding the nest(s) or delaying construction. A 160-foot by 200-foot well pad can be dragged in about 10 minutes. The drag assembles in just a minute or two.
 
The gas companies have been very supportive of nest dragging as it helps them know when they can work on a site or when disturbance could lead to a violation of the Migratory Bird Treaty Act. This act strengthens migratory bird conservation by identifying and implementing strategies that promote conservation and minimize adverse impacts to migratory birds. Companies have installed pipelines and prepared well pads around nests, delayed construction until after nests have hatched, or moved to another well pad where nests weren’t a concern in order to comply with this act.
 
Four years of nest dragging in the Malta Field Office has located 18 nests on proposed well pads, along proposed pipeline routes, and along access roads. Fourteen of the 18 nests later hatched. Most or all would have been destroyed if construction activities had been allowed without nest dragging.
 
Eleven of the 18 located nests have been those of BLM Sensitive Species, including 10 chestnut-collared longspur nests and one Sprague’s pipit nest. Other species found nesting include lark bunting, gadwall, horned lark, blue-winged teal, American wigeon, and common nighthawk.
 
The Malta Field Office has increased the use of nest dragging as an efficient means of inventorying nesting migratory birds along proposed natural gas developments, pipe line routes to stock tanks, and areas proposed for prescribed burning.
           
birds in nest

This chestnut-collared langspur nest on a gas well pad would probably have been destroyed if not found by the nest drag.  The nest was protected during pad construction and the young eventually fledged. 

Operation of the nest dragger 

Fritz Prellwitz, wildlife biologist for the Malta Field Office, pulls a nest drag across a proposed natural gas well pad while searching for migratory bird nests that could be impacted by construction activities. 

the nest dragger

A simple but effect device helps protect migratory birds.


 
Last updated: 06-28-2012