Dark-eyed Junco (Junco hyemalis)
   
 
Narrative and Science Lens
 

   

 Juncos from different areas differ in appearance. The form found in the eastern U.S., where Audubon painted, was apt to have a dark grey hood and wings, while the form found in Oregon (and here) has a blackish hood and rusty wings. In fact, this bird was formerly considered four separate species, and when clumped into one, was named for the darkness of its eyes, a seemingly small point of commonality. Despite their plumage variation, these small sparrows all flick their tails, flashing white outer tail feathers, a trait that catches our attention and makes them easy to spot.
You are likely to readily see these birdson campus--even without binoculars. They are often on or near the ground and should be noticable as they fly up to low perches if your approach startles them. Also, their vocalizations are louder than their size would suggest.

Mostly, though, there are just a lot of them to see. It wasn’t always that way here on campus: In 1990 they nested--and only rarely--no closer than the county's flatlands. Since then, they’ve expanded from the Santa Cruz Mountains into the lowlands, becoming numerous. Over its two-year lifespan a typical male fledges a little over six young, although only about 10 percent will survive long enough to breed.

Why is such a numerous bird so short-lived and unlikely to produce offspring that make it to reproductive age? Indeed, might being so short-lived and producing so many young that fail to survive, key to their their large numbers, as is often the case among insects? The main causes of junco death are cold-related starvation and nest predation, not running out of resources and coping with a degraded the habitat. In fact, these birds have a reputation for adapability. An 88-minute documentary by researchers at Indiana University discusses this rapidly evolving bird and its adaptability, see Science, below.
 
  Campus Locations
Uncommon and local summer resident, fairly common and more widespread during migration and in winter. Breeding birds on main campus nest almost exclusively in dense mats of ivy and other vines planted around buildings and courtyards, although the choice of nesting cover may be more diverse in woodland and scrub habitats near the Dish and in the faculty housing area. From fall through spring, flocks (sometimes fairly large in the Arboretum) occur virtually throughout campus.
  Sustainability
  These increasingly numerous birds may be out-competing other small woodland species at feeders: They have been observered, for example, dominating Chestnut-backed Chickadees.Since these birds feed on insects during breeding season, the competition may be limited.
  What you can do
  1. Find out if the campus population size (at least in some areas) differs seasonally and annually.
  2. Find out about the effects of climate change on these birds.
  3. Find out what effects their apparent increase in number is having on other campus woodland birds, like chickadees.
  4. Watch Indiana University's 88-minute movie "Ordinary Extraordinary Junco," and look into hosting a free screening of it--or parts of it--to those new to avian biology.
 


  Science
       Essays from The Birder’s Handbook:
            Eye Color; Walking vs. Hopping; Dominance Hierarchies; Taxonomy and Nomenclature
       References: Balph, 1979; Ketterson and Nolan, 1982; Smith and Andersen, 1982.
       Videos:"Ordinary Extraordinary Junco" 88-minute coverage by Indiana University
  Art
       Photos:
            T (p )
       Drawings and Paintings:
 

          DW drawing after Audubon
  To add reports or images please submit them via the Art at Exits home page