Black Storm-Petrel
At a Glance
             This is the largest of the dark storm-petrels found off the west coast, and the one most likely to be seen from shore in southern California. It has a buoyant flight with deep wingbeats, low over the waves. The Black Storm-Petrel nests mainly on islands off western Mexico. The first breeding record for the United States was in 1976 on a rock near Santa Barbara Island, and a few may nest elsewhere in the Channel Islands. 
          
          
             All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved. 
          
        
        Category      
      
        Gull-like Birds, Storm-Petrels
      
    
        IUCN Status      
      
        Least Concern
      
    
        Habitat      
      
        Open Ocean
      
    
        Region      
      
        California
      
    
        Behavior      
      
        Flap/Glide, Hovering, Swimming
      
    
        Population      
      
        600.000
      
    Range & Identification
Migration & Range Maps
     After nesting, moves north regularly as far as central California. Common on Monterey Bay in late summer and fall during years of high water temperature. Most disappear after October, wintering south to waters off Panama and northwestern South America. 
  
  
Description
     9" (23 cm). The largest western storm-petrel. All black; tail rather long, forked. Flies with relatively slow, deep wingbeats. 
  
  
        Size      
      
        About the size of a Robin
      
    
        Color      
      
        Black, Gray
      
    
        Wing Shape      
      
        Long, Pointed, Tapered
      
    
        Tail Shape      
      
        Forked, Notched
      
    Songs and Calls
     A loud tuck-a-roo, given at nesting colonies. 
  
  
        Call Pattern      
      
        Flat
      
    
        Call Type      
      
        Rattle, Raucous, Scream, Trill
      
    Habitat
     Open sea. Favors warm ocean waters; off central California, fewer appear during years of colder water temperatures. Generally far offshore, but in southern California and Mexico, may occur regularly within a few miles of the mainland coast. Nests on rocky islands. 
  
  
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    Behavior
Eggs
     One. White, sometimes with small reddish-brown spots around larger end. Incubation probably by both sexes. 
  
  
Young
     Probably fed by both parents. 
  
  
Feeding Behavior
     Forages mostly by hovering or fluttering low over water and taking items from surface. 
  
  
Diet
     Includes crustaceans, small fish. Diet poorly known. May eat many small fish at times, and has been reported feeding on larval form of the spiny lobster. May also eat small squid. Scavenges floating fat from dead animals at sea. 
  
  
Nesting
     Breeding behavior poorly known. Nests on islands, often in small colonies. Both members of pair may rest in nesting burrow for nearly 3 months before egg-laying. Active around colonies only at night. Adults give staccato calls while flying around colonies, changing to a musical trill when inside the nest. Nest:  Site is in small opening among boulders, in crevice in cliff, or in burrow (especially abandoned burrow of Cassin's Auklet). Usually no nest built, sometimes a few bits of plant material. 
  
  
Conservation
Conservation Status
     Numbers probably stable. Vulnerable to introduction of predators (such as rats and cats) to nesting islands. 
  
  
 
       
       
      