MALLARD

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Mallard
Copyright © 2005 Eric Secker

 Conservation Concern: NONE

Population Trend: Increasing
 Credibility: Good

The Mallard is a common to abundant breeder in the CW Region, slightly less common in more rural areas.  Breeding habitat includes lakes, ponds, marshes, and occasionally grassy areas.  Short-term trends show a moderate yearly increase, but conflict with long-term trends.  BBS data shows an annual increase of about 4.9% for Illinois between 1966 and 2000.

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*:		  
  6%   -2%  
   
   

 

 

Technical Notes (1997-2004 Trend)

Sample Size (Indiv.): 683

Sample Size (Records): 205

 

AVG. YEARLY RATE OF CHANGE:
(including standard error)
-8 to 20

  GOODNESS OF FIT:
Chi-square: 706.68, df 279, p 0
Likelihood Ratio: 710.30, df 279, p 0
AIC: 152.3
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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