DOUBLE-CRESTED CORMORANT

Double-crested Cormorant
Copyright © 2005 Eric Secker

Conservation Concern: NONE

Population Trend: Poorly Known
Credibility: Mod. Poor

The Double-crested Cormorant is an uncommon breeder in the CW Region. Breeding habitat includes lakes and ponds - often with dead trees or snags. This species was placed on the endangered species list in the late 1970's and was later delisted in 1999. This marshland species is poorly sampled by the BCN Census, but long term trends seem to show a sizeable yearly increase.

Trend Level

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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*:

-8%

31%

Technical Notes (1997-2004 Trend)

Sample Size (Indiv.): 108

Sample Size (Records): 50

AVG. YEARLY RATE OF CHANGE:
(including standard error)
-31 to 14

GOODNESS OF FIT:
Chi-square: 202.48, df 103, p 0
Likelihood Ratio: 198.61, df 103, p 0
AIC: -7.39
NOTE: (model fits if p values are above 0.05)

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