String can cause Problems 
     
    
   
   
    
     BY GARY SCHNEIDER . 
     
    
   
   
    
     In the July—August issue of the Island Naturalist I asked if anyone 
     
     had any information on birds getting trapped in the string used by silvi— 
     
     culture contractors, forestry technicians and treeplanting assessors to 
     
     measure areas. A contractor that I work with had told me that he had 
     
     found several dead birds trapped in the string in 1986, and I wanted to 
     
     see if it was a common occurence. One response that I received was totally 
     
     unthought of — a woman riding next to a clearcut area said that her horse 
     
     got its legs caught up in the string and started to balk. Luckily the 
     
     horse was easy to calm down. 
     
    

    
     Another response came from Martin K. McNicholl of the Long Point Bird 
     
     Observatory on Lake Erie. He sent the following article by J. Derek John- 
     
     son, Editor of the Alberta Naturalist, entitled "An Unintentional Bird 
     
     Snare": 
     
    

    
     The research project I am currently involved in with the Canadian 
     
     Forestry Service is a study of the potential of drainage to improve tree 
     
     growth on certain peatlands in Alberta. One of our three study sites is a 
     
     treed fen located along a tributary of Wolf Creek, 16 km south of Highway 
     
     16, along the Wolf Lake Road, southeast of Edson. 
     
    

    
     In our work we have occasion to make considerable use of a thread 
     
     land measurer, known as a "Topofil chaix." The apparatus uses a lightweight 
     
     but strong white polyester thread. We have used it to measure distances 
     
     between points as well as to mark the boundaries of our sample plots. After 
     
     use the thread is usually severed from the measurer and left on the ground. 
     
    

    
     Unbeknown to us our work was creating a death trap for some of the 
     
     local avifauna. During the field season of 1985 we encountered birds en- 
     
     tangled in the thread on three separate occasions. One was a Black—capped 
     
     Chickadee; another was a Gray Jay. Both were mature birds and both were 
     
     found dead. The third appeared to be an immature Northern Flicker and it 
     
     was found alive. This bird was successfully untangled and released, how- 
     
     ever, we do not know if it survived. All the birds had caught the thread 
     
     with either a leg or a wing and in their struggles to free themselves had 
     
     only succeeded in entangling themselves more. 
     
    

    
     We were surprised that our work would be a hazard to the 
     
     local wildlife in this way, but once we realized there was a 
     
     problem we were much more careful when using the thread, 
     
     wither rolling as much of it up as we could after use and 
     
     disposing of it, or if it had to remain in place, making sure 
     
     it was as close to the ground as possible. During the 1986 
     
     field season no casualties were encountered, despite an 
     
     even greater use of the thread to mark plot boundaries. 
     
    

    
     At our other two study sites, Goose River southeast 
     
     of Valleyview, and Kimiwan Lake north of McLennan, we 
     
     have not encountered any entrapped birds. Whether or 
     
     not this is due to habitat differences and hence 
     
     differences in the local avifauna, or just blind 
     
     luck, we do not know. 
     
    

    
     As a final comment, personal observation has V - 
     
     shown the thread to be totally ineffective in restraining moose." (Spring 87) 
     
    

    
     On Prince Edward Island, as in Alberta, awareness of a potential pro— 
     
     blem can go a long ways towards solving it. Using the thread as little as 
     
     possible, leaving less on site and perhaps using a cotton thread that woul 
     
     break down more rapidly would all be a help. Thanks again to Martin for the 
     
     information. The Alberta Naturalist is available through the Northern Forest- 
     
     ry Centre, 5320-122 St., Edmonton, Alberta T6H 355. ' 
     
    
   
   
    
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