RED-WINGED BLACKBIRD

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Red-winged Blackbird
Copyright © 2005 Eric Secker

 Conservation Concern: NONE

Population Trend: Substantial Increase
 Credibility: Very Good

The Red-winged Blackbird is an abundant, statewide breeder.  Breeding habitat is varied and includes cattail marshes, grasslands, and other fields.  This is fairly well monitored by the BCN Census.  Short-term trends show a substantial estimated annual increase of at least 5%. Long-term trends show an annual increase of 1%.

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*:		  
  9%   1%  
   
   

 

 

Technical Notes (1997-2004 Trend)

Sample Size (Indiv.): 6257

Sample Size (Records): 1034

 

AVG. YEARLY RATE OF CHANGE:
(including standard error)
5 to 13

  GOODNESS OF FIT:
Chi-square: 1644.27, df 718, p 0
Likelihood Ratio: 1685.00, df 718, p 0
AIC: 249
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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