weather and competition with other species may play a role, but as these 
     
     have always been in force seem unlikely explanations in themselves. In 
     
     Ontario, loss of thorny pastures and roadside hawthorns have long been im- 
     
     plicated, a suggestion that is at least partially supported by its curren 
     
     stronghold along the southern edge of the shield, where oldfield habitat 
     
     with hedgerows and hawthorns can still be found. 
     
    

    
     As some areas of apparently suitable habitatt lack shrikes, habitat 
     
     loss does not provide a complete explanation for shrike decliens. Bent 
     
     (1950), commenting on the food of one of the races, noted that "Migrant 
     
     Shrikes" are more insectivorous than the Northern epecies, a factor that 
     
     could make it more susceptible to chemical insecticides, and as herbicides 
     
     are used frequently to clear roadside vegetation attractive to this species, 
     
     these chemicals may also produce undesirable side effects. A study in Il- 
     
     linois indicated an inverse relationship between eggshell thickness in 
     
     this species and levels of DDT. ' 
     
    

    
     Shortly after automobiles came into relatively common usage, Logger— 
     
     head Shrikes were found to be susceptible to being killed by them, and this 
     
     appears to be an important factor currently in parts of Canada. 
     
    

    
     Clearly, this shrike has declined dramatically in Canada and over most 
     
     of its range. Studies documenting its current range and investigating pos- 
     
     sible reasons for its decline are needed urgently if its slide into Threat- 
     
     ened status is to be halted before the Endangered stage is reached. 
     
    
   
   
    
     (The above report is number three in a continuing series of Profiles 
     
    
   
   
    
     on Risk Status of Canadian Birds. prepared by Mr. McNicholl of the Long 
     
     Point Bird Observatory.) 
     
    
   
   
    
       
     
    
   
   
    
     Envaronmental Calendar 
     
    
   
   
    
     .-DECEMBER 2: The Island Nature Trust will be featured on "A Tip of the Hat" 
     
     . on Lorne Greene's New Wilderness. ‘ 
     
     DECEMBER 2: The Natural History Society's December meeting will be held 
     
     in Meeting Room #2 in the Provincial Health Building at 8 p.m. 
     
     Diane Griffin and Dan McAskill will speak on Wildlife '87. 
     
     DECEMBER 6: The Island Nature Trust's First Annual Bird Seed Sale (see de- 
     
     tails on page 10). Do something doubly good for the birds: feed 
     
     them and help the Trust to buy habitat for them. 
     
     JANUARY 6: The first meeting of 1987 for the NHS will feature Winston John— 
     
     ston as guest speaker. Winston will talk on Wildlife on Stamps. 
     
     If the location of the meeting does change, it will be announced 
     
     at the December meeting and over the radio. 
     
     JANUARY 15: The Island Nature Trust will hold a public meeting at 7:30 p.m. 
     
     at the Farm Centre. Dan McAskill will speak on "Wildlife '87" 
     
     and Art Smith will speak on "The Provincial Conservation Stra- 
     
    
   
   
    
     tegy".