July 2018    
         
         
 
     
     
  Feathered friend or foe  
     
     
  Birds can recognize each other by their songs, even across species.  
     
     
   
 
     
  Splendid fairy-wren. (Photography by Allison Johnson, SM'13, PhD'16)  
     
 
     
     
  Cooperation among different bird species is common. Some birds build their nests near those of larger, more aggressive species to deter predators, and flocks of mixed species forage for food and defend territories in alliances that can last years. In most cases, these partnerships are not between specific individuals--any bird from the other species will do.  
     
     
  Now scientists from the University of Chicago and the University of Nebraska have shown that two types of Australian fairy-wrens not only recognize individuals from the other species but also form long-term partnerships.  
     
     
  Two small Australian songbird species, variegated and splendid fairy-wrens, both feed on insects, live in large family groups, and breed during the same time of year. They are also nonmigratory, occupying the same eucalyptus scrublands.  
     
     
  When their territories overlap, the two species interact. They forage together, travel together, and help defend their shared territory from rivals. But how deep does this relationship go?  
     
     
  Many songbirds can recognize familiar members, friendly or rival, of their own species by their unique songs. In the case of these fairy-wrens, investigators suspected that this recognition was happening across species.  
     
     
  At Brookfield Conservation Park in South Australia, UChicago ecologist Stephen Pruett-Jones; Allison Johnson, SM'13, PhD'16; and Christina Masco, SM'14, PhD'17, monitored both fairy-wren species before dawn and captured recordings of their signature songs.  
     
     
   
 
     
  Variegated fairy-wren. (Photography by Allison Johnson, SM'13, PhD'16)  
     
 
     
     
  After sunrise they broadcast the recordings, simulating an intrusion by a particular bird into a group's territory to see how territory owners reacted to the songs of familiar and unfamiliar members of the other species.  
     
     
  The researchers played songs of four different birds: a familiar fairy-wren from the same territory, a neighboring territory fairy-wren, a stranger fairy-wren from a distant territory, and a red-capped robin--a common, local, nonthreatening species--as a control.  
     
     
  Both splendid and variegated fairy-wrens could recognize songs from friendly birds despite the species difference.  
     
     
  Dominant males of both types responded aggressively to the intruding neighbor and stranger of the other species--their foes. They didn't respond to the familiar fairy-wren or the red-capped robin, suggesting they saw them as nonthreatening friends.  
     
     
  By forming and keeping these associations with another species, fairy-wrens can better defend their nests from predators and their territories from rivals. Cooperating rather than competing, these already social species create a larger, stronger group.--Matt Wood  
     
 
 
 
     
  Five more instances of fowl play  
     
     
 
     
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UChicago neurobiologist Clifton Ragsdale shows that "birdbrain" is a misnomer.
 
     
     
     
     
 
     
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Evolutionary biology and art history grad students use sooty old bird specimens to trace changes in air pollution.
 
     
     
     
     
 
     
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Real-world Big Bird shows that new species forming from hybridization isn't so rare.
 
     
     
     
     
 
     
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Young male zebra finches learn songs from tutors, and the lessons change their epigenetics.
 
     
     
     
     
 
     
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How did the ancestors of modern birds survive the asteroid that killed the dinosaurs? By keeping their feet on the ground.
 
     
 
     
 
         
         
    Spotlight    
         
         
 
     
     
  Home to roost  
     
     
   
 
     
  A monk parakeet begins working on a new nest in Hyde Park. (Photography by John W. Iwanski)  
     
 
     
     
  Several newsworthy nesters call Hyde Park home.  
     
     
  We've got "culture vultures" who lounge at the Logan Center for the Arts. Chicken hawks stalk the quad. Peregrine falcons photobomb freelancers. And for more than 40 years, Hyde Park hosted colonies of monk parakeets--protected in part by former Chicago mayor Harold Washington's love for the squat green parrot.  
     
     
  Over the past decade, the invasive South American species has largely fled Hyde Park--and no one knows why. Did the peregrines eat all the parakeets? "Absolutely not," says ecology professor Stephen Pruett-Jones. A parakeet could easily break a peregrine's leg with its sharp beak. The mystery isn't confined to Hyde Park--monk parakeet numbers have plummeted nationwide.  
     
 
 
     
  In case you missed it  
     
 
 
A course of spooky action: Quantum entanglement looms large.
 
 
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