ROSE-BREASTED GROSBEAK

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Rose-breasted Grosbeak
Copyright © 2005 Eric Secker

 Conservation Concern: NONE

Population Trend: Increasing?
 Credibility: Mod. Good

The Rose-breasted Grosbeak is a fairly common statewide breeder.  Breeding habitat includes forest edges and open woodlands with shrubs.  A significant decrease in 2003 may be related to the spread of West Nile Virus, but more research is needed.  Short-term and long-term trends give conflicting results.  BBS trends show an estimated yearly increase of about 2.9% in Illinois.

Trend Level

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1997-2004 Trend
 Point Count Data		 1988-2004 Trend*
 All Observation Types

*Data gathered using a assortment of sampling methods  - for casual inferences only
  Avg. Yearly
Rate of Change:

The vertical axis numbers represent an index of the population change.

Note that the scales may vary between graphs.

 Avg. Yearly
Rate of Change*:		  
  23%   -4%  
   
   

 

 

Technical Notes (1997-2004 Trend)

Sample Size (Indiv.): 66

Sample Size (Records): 55

 

AVG. YEARLY RATE OF CHANGE:
(including standard error)
-11 to 58

  GOODNESS OF FIT:
Chi-square: 81.90, df 79, p 0.3895
Likelihood Ratio: 71.54, df 79, p 0.7121
AIC: -86.46
NOTE: (model fits if p values are above 0.05)

Download Table of All Observations

 
 

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Copyright © 2005 Audubon - Chicago Region & Bird Conservation Network

 
 
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