Trends in the Number of Animals Observed During
Wildlife Surveys on the Wakulla Springs River Boat Tour Route
from November 1992 through May 2013
by Bob Thompson, October 3, 2013
Plots of the number of animals recorded on wildlife surveys from November 1992 through May
2013 are presented in Attachment 1. The plots include linear regression lines and annual means of the
number of animals. Trends in the number of animals were identified based on a visual evaluation of the
plots, slope of linear regression lines, and amount of change of annual means of animal abundance.
A summary of results of this graphical analysis is presented in the table below. Strong trends
were identified as 'DECREASING' or 'INCREASING' for larger changes in the number of animals,
compared to weaker 'Decreasing' or 'Increasing' trends.
SUMMARY OF PLOTS OF NUMBER OF ANIMALS
* Plot
page #
Trends in changes in the number of animals over time
Decreasing
Stable
Increasing
Other
Animal
Mammals
Florida manatee
1
Reptiles
American alligator
1
DECREASING
Cooter turtle
2
Snakes
2
Herons & Egrets
Great egret
3
Green heron
3
Decrease
Little blue heron
4
Snowy egret
4
Recent Decrease
Tricolored heron
5
Yellow-crowned night heron
5
Ducks
American widgeon
6
DECREASING
Blue-winged teal
6
Decreasing
Hooded merganser
7
Lesser scaup
7
Woodduck
8
DECREASING
Gallinules
American coot
8
Common moorhen
9
DECREASING
Purple gallinule
9
Decreasing
Other Birds
Anhinga
10
DECREASING
Double-crested cormorant
10
Limpkin
11
DECREASING
Osprey
11
Pied-billed grebe
12
White ibis
12
* Plot page # are page numbers in Attachment 1
1
INCREASING
Stable
Stable
Stable
Stable
Cyclic
Stable
Stable
Stable
Stable
Cyclic
Stable
Stable
INCREASING
None identified
The following provides a grand summary of trends based the graphical analysis and the previous table:





Decreasing trends were identified for 10 animals;
Stable for 10 animals;
Increasing for 2 animals;
Cyclic for 2 animals; and
No Trend was identified for one animal.
The plots and previous descriptive text concisely present a lot of information. The following
five items provide details:
1. Plots were not made and trends not identified for the following animals counted on wildlife
surveys, because of the relatively few numbers of these animals observed: Bald eagle, barred
owl, belted kingfisher, black-crowned night heron, Florida softshell turtle, great blue heron,
killdeer, red-shouldered hawk, and spotted sandpiper.
2. Wildlife surveys were generally conducted monthly from November 1992 through October
2012 by park staff. Weekly surveys conducted, by trained volunteers, began in November 2012
and are ongoing, coordinated by the Wakulla Springs Alliance.
3. Annual means were calculated for each animal and used to assess trends. The monitoring data
began in November 1992 and ended in May 2013. Because the first and last years of data do
not span entire annual cycles and present the possibility of seasonal bias, no data from 1992 or
from 2013 were used in the calculation of the means presented on the following pages.
4. Legend for all plots:
5. Determination of useful regression results is presented on the last page of Appendix 1.
Regression lines were included in figures, if linear regression R2 >=0.15 and Significance of F
<0.05
The remainder of this page and Attachment 2 provide a more objective and defensible
statistical analysis intended to meet concerns of scientists. Ideally a statistical test for detection of
trends would have been applied to be more confident of the graphical analysis results, but no test
specifically for trends was identified that was within the scope of this report and also appropriate based
on the wildlife monitoring data meeting test assumptions.
Attachment 2 presents a statistical test of the wildlife monitoring data that is informative and
appropriate. Wildlife monitoring data was divided into two subsets of equal time duration for each
animal. The Mann-Whitney test was used to test for differences in medians of the number of animals
during the early and late time periods. If the medians were different, then the animals were from
different populations.
Results of the statistical analyses supported results of the graphical analysis for all but the
following four animals: Little blue heron, snowy egret, purple gallinule, and blue-winged teal.
Graphical analyses identified stable trends for the little blue and tricolored herons; statistical analyses
of early and late time periods identified a significant difference in medians (increasing) for the little
blue heron and a significant difference in medians (decreasing) for the tricolored heron. Graphical
analyses identified decreasing trends for blue-winged teal and purple gallinule; statistical analyses of
early and late time periods identified no change in medians.
2
ATTACHMENT 1 Plots Of The Number Of Animals Over Time
FLORIDA MANATEE
30
25
20
15
Annual mean in 2012 = 11.7 manatees
10
5
0
1992
Annual mean in 2003 = 0.3 manatees
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
Note: Manatees were first observed in the Wakulla Springs State Park by staff in 1997.The number of
Florida manatee was not recorded on wildlife surveys from 1992 through 2002, 2004, or 2006.
A STRONG INCREASING TREND IN THE NUMBER OF FLORIDA MANATEES WAS
IDENTIFIED
AMERICAN ALLIGATOR
80
70
60
Annual mean
in 1996 =
43.8 alligators
Annual mean
in 2012 =
13.7 alligators
50
40
30
20
10
5
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STRONG DECREASING TREND IN THE NUMBER OF AMERICAN ALLIGATORS WAS
IDENTIFIED The number of alligators decreased by 30.1 alligators from annual means of 43.8 to
13.7 alligators (a decrease by 69 percent) over 17 years, from 1996 to 2012.
Attachment 1 - 1
SUWANNEE COOTER TURTLE
80
70
60
50
40
30
20
10
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF SUWANNEE COOTER TURTLES WAS
IDENTIFIED. No regression line was plotted, because the regression results were not statistically significant.
SNAKES
30
25
20
15
10
5
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF SNAKES WAS IDENTIFIED. No regression line was
plotted, because the regression results were not statistically significant.
Attachment 1 - 2
GREAT EGRET
25
20
15
10
5
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF GREAT EGRETS WAS IDENTIFIED. No regression
line was plotted, because the regression results were not statistically significant.
GREEN HERON
18
16
14
12
Annual mean
In 1995 = 4.1
green herons
10
Annual mean
In 2012 = 0.8
green herons
8
6
4
2
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
Based on annual means , A DECREASING TREND IN THE NUMBER OF GREEN HERONS
WAS IDENTIFIED. The number of green herons decreased by 3.3 birds from annual means of 4.1 to
0.8 birds (a decrease by 80 percent) over 18 years, from 1995 to 2012
Attachment 1 - 3
LITTLE BLUE HERON
25
Annual mean
In 2012 = 4.4
little blue herons
20
15
10
Annual mean
In 1995 = 4.3
little blue herons
5
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF LITTLE BLUE HERONS WAS IDENTIFIED
SNOWY EGRET
18
Regression significant
for subset of data
From 2/28.05 to 5/18/2013
16
14
Annual mean
In 2005 = 3.7
Snowy egret
12
10
Annual mean
In 2012 = 0.7
Snowy egret
8
6
4
2
`
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
Based on annual means, TWO LONG TERM CYCLES IN THE NUMBER OF SNOWY
EGRETS WERE IDENTIFIED, from 1992 to 1999 and from 2000to 2012. A RECENT
DECREASING TREND IN THE NUMBER OF SNOWY EGRETS WAS IDENTIFIED of a
decrease by 3 birds from annual means of 3.7 to 0.7 birds (a decrease by 81 percent) over 8 years,
from 2005 to 2012. Regression was not statistically significant for the entire data set from 1992 through 2013, but was
statistically significant for a subset of the data from February 28, 2005 through May 18, 2013.
Attachment 1 - 4
TRICOLORED HERSON
30
25
20
15
10
5
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF TRICOLORED HERONS WAS IDENTIFIED. No
regression line was plotted, because the regression results were not statistically significant
YELLOW-CROWNED NIGHT HERON
40
35
30
25
20
15
10
5
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF YELLOW-CROWNED NIGHT HERONS WAS
IDENTIFIED. No regression was plotted, because the regression results were not statistically significant.
Attachment 1 - 5
AMERICAN WIDGEON
900
800
700
600
Annual mean
in 1993 = 153
American widgeons
500
Annual mean
In 2012 = 0.0
American widgeons
400
300
200
100
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STRONG DECREASING TREND IN THE NUMBER OF AMERICAN WIDGEONS WAS
IDENTIFIED The mean number of widgeons decreased by 153 birds from 153 to 0 birds (a decrease
by 100 percent) over 20 years, from 1993 to 2012.
BLUE-WINGED TEAL
60
50
40
Annual mean
In 2001 = 9.3
Blue-winged teal
30
Annual mean
In 2012 = 0.1
Blue-winged teal
20
10
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A DECREASING TREND IN THE NUMBER OF BLUE-WINGED TEAL WAS IDENTIFIED
The mean number of blue-winged teal decreased by 9.2 birds from 9.3 to 0.1 birds (a decrease by 99
percent) over 12 years, from 2001 to 2012.
Attachment 1 - 6
HOODED MERGANSER
100
90
80
70
60
50
40
30
20
10
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF HOODED MERGANSERS WAS IDENTIFIED. No
regression was plotted, because the regression results were not statistically significant.
LESSER SCAUP
120
100
80
60
40
20
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
A STABLE TREND IN THE NUMBER OF LESSER SCAUP WAS IDENTIFIED
Attachment 1 - 7
2014
WOODDUCK
60
Annual mean
In 2012 =
4.4 woodducks
50
Annual mean
in 1997 =
22.7 woodducks
40
30
20
10
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STRONG DECREASING TREND IN THE NUMBER OF WOODDUCKS WAS
IDENTIFIED The mean number of woodducks decreased by 18.3 birds from 22.7 to 4.4 birds (a
decrease by 81 percent) over 16 years, from 1997 to 2012.
AMERICAN COOT
600
500
400
300
200
100
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
TWO LONG TERM CYCLES OF INCREASES FOLLOWED BY DECREASES IN THE
NUMBER OF AMERICAN COOTS WERE IDENTIFIED, the first rise and fall in abundance
spanned the years 1992 through 2004 and the second spanned the years 2005 through 2012.
Attachment 1 - 8
COMMON MOORHEN
Annual mean
In 2012 = 63.9
Common moorhen
200
Annual mean
In 2000 = 119.2
Common moorhen
150
100
50
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STRONG DECREASING TREND IN THE NUMBER OF COMMON MOORHEN WAS
IDENTIFIED The number of common moorhen decreased by 55.3 birds from annual means of 119.2
to 63.9 birds (a decrease by 46 percent) over 13 years, from 2000 to 2012.
PURPLE GALLINULE
18
16
14
12
10
8
6
4
2
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A LONG TERM DECREASING TREND IN THE NUMBER OF PURPLE GALLINULES
WAS IDENTIFIED. This was identified despite the relatively few number of these birds and the high
variability in the data. With the exception of one monitoring date in 2004, consistently more purple
gallinules were observed from 1993 through 2002 compared to 2003 through 2012.
Attachment 1 - 9
ANHINGA
60
50
Annual mean
in 1993 =
29.4 Anhinga
40
Annual mean
In 2012 =
12.5 Anhinga
30
20
10
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STRONG DECREASING TREND IN THE NUMBER OF ANHINGAS WAS IDENTIFIED
The number of anhingas decreased by 16.9 birds from annual means of 29.4 to 12.5 birds (a decrease
by 57 percent) over 20 years, from 1993 to 2012.
DOUBLE-CRESTED CORMORANT
16
14
12
10
8
6
4
2
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF DOUBLE-CRESTED CORMORANTS WAS
IDENTIFIED. No regression was plotted, because the regression results were not statistically significant.
Attachment 1 - 10
LIMPKIN
20
Annual mean
in 1993 = 13.4
Limpkin
18
16
14
12
10
8
Annual mean
in 2012 = 0.0
Limpkin
6
4
2
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STRONG DECREASING TREND IN THE NUMBER OF LIMPKINS WAS IDENTIFIED
The number of limpkins decreased by 13.4 birds from annual means of 13.4 to 0.0 birds (a decrease by
100 percent) over 20 years, from 1993 to 2012.
OSPREY
10
9
8
7
6
5
4
3
2
1
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A STABLE TREND IN THE NUMBER OF OSPREYS WAS IDENTIFIED. No regression was
plotted, because the regression results were not statistically significant.
Attachment 1 - 11
PIED-BILLED GREBE
60
Regression significant for
subset of data from
1/27/03 to 5/1/8/13
50
Annual mean
In 2012 = 27.2
Pied-billed grebes
40
Annual mean
In 2003 = 7.1
Pied-billed grebes
30
20
10
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
A RECENT STRONG INCREASING TREND IN THE NUMBER OF PIED-BILLED GREBES
WAS IDENTIFIED The number of pied-billed grebes increased by 20.1 birds from annual means of
7.1 to 27.2 birds (an increase by 283 percent) over 10 years, from 2003 to 2012. Regression results were
not statistically significant for the entire data set from 1992 through 2013. Regression was statistically significant for a
subset of the data from 2003 through May 18, 2013.
WHITE IBIS
180
160
140
120
100
80
60
40
20
0
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
THE NUMBER OF WHITE IBISES WAS TOO VARIABLE TO IDENTIFY A TREND. No
regression was plotted, because the regression results were not statistically significant.
Attachment 1 - 12
DETERMINATION OF USEFUL REGRESSION RESULTS
R Square (=R2) The overall regression accuracy can be determined by R2. It identifies the proportion of
how well the regression line approximates the real data points. R2 values range from 0 to 100 %. An R2
value of 0 means no linear relationship exists in these linear regression models. An R2 value of 1
means the regression line perfectly fits the data. So the higher the R2 the more accurate the model.
Regression models for analysis of wildlife surveys results are sufficiently accurate if R2 values are
greater than or equal to 0.15. This means that at least 15% of the variation in the number of
animals is explained by the regression model.
Significance of F This statistic measures the probability (p) that the regression coefficients (slope and
intercept) equal zero; therefore, a small Significance of F confirms the validity of the model.
Regression models for this analysis of wildlife survey results are significant if p is less than 0.05
(p<0.05). This means that there is less than a 5% chance that the Regression output was merely a
chance occurrence.
Useful regressions are defined as results with R2 >= 0.15 and Signficance of F <0.05
Useful
Regression Animal

Florida manatee

Florida alligator
Suwannee cooter turtle
Snakes
Great egret

Green heron

Little blue heron

Snowy egret
Snowy egret for subset of 2005 to May, 2013

Tricolored heron
Yellow-crowned night heron

American widgeon

Blue-winged teal
Hooded merganser

Lesser scaup

Woodduck

American coot

Common moorhen

Purple gallinule

Anhinga
Double-crested cormorant

Limpkin
Osprey
Pied-billed grebe

Pied-billed grebe for subset of 2003 to May, 2013
White ibis
Attachment 1 - 13
Rsquare
0.483
0.514
0.063
0.068
0.111
0.304
0.181
0.162
0.575
0.174
0.148
0.293
0.198
0.069
0.188
0.229
0.178
0.284
0.261
0.545
0.104
0.604
0.000
0.163
0.520
0.168
Significance of F
< 0.001
< 0.001
0.335
0.300
0.089
< 0.001
0.005
0.013
< 0.001
0.008
0.024
< 0.001
0.002
0.303
0.005
< 0.001
0.006
< 0.001
< 0.001
< 0.001
0.110
< 0.001
0.998
0.013
<0.001
0.010
ATTACHMENT 2 - Analysis of Medians Using the Mann-Whitney Test
by Bob Thompson and Rick Copeland, revised August 23, 2013
INTRODUCTION
Conover (1999) stated that the Mann-Whitney (MW) test is an excellent statistical procedure to
test if two randomly obtained samples are from two different populations. That is, it tests the null
hypothesis that the two populations are identical versus the alternate hypothesis that the two
populations are different. If the sample sets consist of ordinal data (e.g. data sorted from lowest to
largest), then the MW test determines if there is a difference in the central location (e.g. the median or
the mean) of the two populations. Does one population tend to yield larger values than the other
population? Are the two medians (or the two means) equal?
In order to conduct the MW test, one must do the following. Combine the data from the two
samples into a single sorted sample. Keep track of which population each observation comes from.
Assign ranks to the values in the combined sample from smallest to the largest. Take the sum of all of
the ranks (lowest value equal one, second lowest value equals two and so on) assigned to those values,
from either one of the two samples.
If the sum of the ranks is too small (or too large) relative to a hypothetical value of the sum
(based on the size n of the selected sample), there is an indication that the values from the selected
population tend to be smaller (or larger) than the values form the other population. The assumptions
for the MW test are: (1) Both samples are obtained randomly from their respective populations, (2)
The samples are independent, and (3) The measurement scale is at least ordinal.
For the bird count surveys, it is assumed that the data in the two samples are obtained randomly
and independently of each other. By sorting the data, the third requirement is met.
A way to imagine what is happening in MW procedure is to think of two decks of cards. One
is red and one is blue. Assume that the two decks are perfectly shuffled and that the card on the
bottom is red, the second card is blue, the third is red, and so on. Suppose the cards in the shuffled
deck are each given a rank score based on the ascending order of the card in the shuffled deck. Thus
the blue card at the bottom is ranked one; the red card next to the bottom is ranked two; the blue (third)
card is ranked three, and so on. Likewise, the next to last card is red and is ranked 103. The last card
is red and is ranked 104. The median ranked value of the red deck is 52, while the median ranked
value of the blue deck is 53. A Minitab printout of MW test results are provided below for this
example of a shuffled deck of red and blue cards. Minitab is a commercial statistical software that
includes the MW test.
Red
Blue
N
52
52
Median
52.00
53.00
Point estimate for ETA1-ETA2 is -1.00
95.0 Percent CI for ETA1-ETA2 is (-13.01,11.01)
W = 2704.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.8683
The null hypothesis being tested is that the median of red deck is equal to the median of blue one. The
alternate hypothesis is that the two medians are not equal. The sample size for each deck of cards is
52. Minitab refers to the two medians as ETA1 and ETA2. The term “W” is the test statistic and
represents the sum of the ranks of the deck (red) with the lowest sum. At a confidence of 95%,
Minitab produces a confidence interval (CI) about the difference in the two medians (not needed for
our example) and the probability that for the decks of cards, the medians are the same. This
probability is referred to as the p-val. Another way of thinking about the p-val is that it is the
Attachment 2 - 1
probability that the null hypothesis is true, based on the information supplied in the two samples. The
p-val above indicates that there is an 86.83% probability that the null hypothesis is true.
Now imagine that the two decks are not shuffled at all. The red deck is at the bottom, while the
blue deck is on the top. Suppose the cards in the non-shuffled deck are again, given ranked values.
The bottom card is ranked one, the second is ranked two, and so on. The lowest rank for the red deck
is one, while the highest is ranked 52. For the blue deck, the lowest rank is 53, while the highest is
104. Under this scenario, the median ranked value of the red deck is 26.5. The median value of the
blue deck is 78.5 A Minitab printout of MW test results are provided below for this example of a nonshuffled deck of red and blue cards.
Red
Blue
N
52
52
Median
26.50
78.50
Point estimate for ETA1-ETA2 is -52.00
95.0 Percent CI for ETA1-ETA2 is (-58.00,-46.00)
W = 1378.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0000
The resulting p-value is 0.000. Based on the example, data from the two decks of cards, the
probability that the null hypothesis is true (the medians are equal) is less than 0.01%. This means that,
not only are their medians different, but so are their ranks and their distributions.
Most environmental data are not normally distributed. The MW test is a nonparametric - test,
meaning that it is designed to evaluate data where there is no assumption regarding the shape of the
distribution. Therefore, the MW test is desirable test for testing the equality of medians of
environmental data. It should be noted that another nonparametric test is often used in place of the
MW test. It is referred to the Wilcoxon Rank Sum test and it produces results that are identical to the
MW test. Either method can be used to test the equality of medians
WAKULLA SPRINGS WILDLIFE SURVEY MANN-WHITNEY RESULTS
The wildlife monitoring data is not normally distributed, so the nonparametric Man-Whitney
test was used to determine if the number of animal in two evenly divided time periods for each animal
are equal. The test used medians as the measure of central tendency. A median is the middle number in
a sorted list of numbers; they are less influenced by outliers than means.
If the changes in medians were statistically significant (p<0.05) they were identified in the table
below as 'DECREASING' or 'INCREASING'. Insignificant changes were not identified as
'Decreasing' or 'Increasing'. It is important to understand for interpretation of test results that are not
significant, that even though the medians are numerically different they are considered to be equal
based on the statistical test.
Animal
Florida Manatee
# of
Number of animals
Time periods surveys Range Median Change in medians/Significance
2003-2007
33
0-7
0 INCREASING
2008-2012
63
0 - 29
4 Significant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -3.000; 95.1 Percent CI for ETA1-ETA2 is (-6.001,0.000); W = 1047.5; Test of
ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0000; The test is significant at 0.0000 (adjusted for ties)
American alligator
1995-2003
2004-2012
90
109
1 - 68
2 - 49
33
17
DECREASING
Significant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 16.000; 95.0 Percent CI for ETA1-ETA2 is (13.000,19.998); W = 12357.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0000; The test is significant at 0.0000 (adjusted for ties)
(Continued on next page)
Attachment 2 - 2
Animal
Cooter turtle
# of
Number of animals
Time periods surveys Range Median Change in medians/Significance
1993-2002
92
0 - 55
17 Change in medians not
2003-2012
120
0 - 12
19 significantly different (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -1.000; 95.0 Percent CI for ETA1-ETA2 is (-3.999,3.002); W = 9658.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.7535; The test is significant at 0.7534 (adjusted for ties)
Snakes
1993-2002
2003-2012
92
120
0 - 10
0 - 28
0 No change in medians
0
0-7
0 - 24
2 No change in medians
2
The test was not conducted because the medians did not change.
Great egret
1993-2002
2003-2012
92
120
The test was not conducted because the medians did not change.
Green heron
1995-2003
2004-2012
90
109
0 - 17
0 - 11
3.5 DECREASING
2.0 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 1.000; 95.0 Percent CI for ETA1-ETA2 is (1.000,2.000); W = 10705.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0000; The test is significant at 0.0000 (adjusted for ties)
Little blue heron
1995-2002
2004-2012
90
109
0 - 12
0 - 23
3 INCREASING
5 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -1.000; 95.0 Percent CI for ETA1-ETA2 is (-2.001,-0.001); W = 7995.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0130; The test is significant at 0.0125 (adjusted for ties)
Snowy egret
2005-2008
2009-2012
44
52
0-7
0-5
2.5 DECREASING
0 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 2.000; 95.1 Percent CI for ETA1-ETA2 is (1.000,3.000); W = 2816.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0000; The test is significant at 0.0000 (adjusted for ties)
Tricolored heron
1993-2002
2003-2012
92
120
0 - 10
0 - 26
1.5 DECREASING
1.0 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 1.000; 95.0 Percent CI for ETA1-ETA2 is (-0.000,1.000); W = 10842.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0184; The test is significant at 0.0154 (adjusted for ties)
Yellow-crowned night heron
1993-2002
2003-2012
92
120
0 - 35
0 - 22
2.0 Change in medians not
1.0 significantly different (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -0.000; 95.0 Percent CI for ETA1-ETA2 is (0.000,1.000); W = 10609.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0669; The test is significant at 0.0604 (adjusted for ties)
American widgeon
1993-2002
2003-2012
92
120
0 - 841
0 - 500
1.0 DECREASING
0.0 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -0.00; 95.0 Percent CI for ETA1-ETA2 is (0.02,7.00); W = 11326.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0006; The test is significant at 0.0001 (adjusted for ties)
Blue winged teal
2001-2006
2007-2012
65
76
0 - 52
0 - 14
0 No change in medians
0
0 - 91
0 - 69
0 No change in medians
0
0 - 100
0-6
0.0 No change in medians
0.0
The test was not conducted because the medians did not change.
Hooded merganser
1993-2002
2003-2012
95
106
The test was not conducted, because the medians did not change.
Lesser scaup
1993-2002
2003-2012
80
120
The test was not conducted, because the medians did not change.
Woodduck
1997-2004
2005-2012
79
98
0 - 58
0 - 48
11.0 DECREASING
07.5 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 4.000; 95.0 Percent CI for ETA1-ETA2 is (0.001,8.000); W = 7891.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0112; The test is significant at 0.0109 (adjusted for ties)
(Continued on next page)
Attachment 2 - 3
Animal
American coot
# of
Number of animals
Time periods surveys Range Median Change in medians/Significance
1993-2002
80 0 - 214
14.5 Change in medians not
2003-2012
132 0 - 501
2.5 significantly different (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 0.00; 95.0 Percent CI for ETA1-ETA2 is (-0.00,2.01); W = 8927.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.3472; The test is significant at 0.3384 (adjusted for ties)
Common moorhen
2000-2006
2007-2012
77 18 - 197
76 30 - 177
85.0 DECREASING
65.6 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 14.00; 95.0 Percent CI for ETA1-ETA2 is (5.01,24.00); W = 6715.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0042; The test is significant at 0.0041 (adjusted for ties)
Purple gallinule
1993-2002
2003-2012
92
120
0-9
0 - 16
0 No change in medians
0
The test was not conducted, because the medians did not change.
Anhinga
1993-2002
2003-2012
80
132
0 - 53
0 - 34
24.5 DECREASING
12.0 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 12.000; 95.0 Percent CI for ETA1-ETA2 is (10.000,15.001); W = 11992.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0000; The test is significant at 0.0000 (adjusted for ties)
Double crested cormorant
1993-2002
2003-2012
92
120
0 - 14
0-9
2.0 Change in medians not
1.0 significantly different (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 0.000; 95.0 Percent CI for ETA1-ETA2 is (0.000,1.000); W = 10616.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0646; The test is significant at 0.0599 (adjusted for ties)
Limpkin
1993-2002
2003-2012
92
120
0 - 18
0-4
1.0 DECREASING
0.0 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is 1.000; 95.0 Percent CI for ETA1-ETA2 is (1.000,2.000); W = 12939.5
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0000; The test is significant at 0.0000 (adjusted for ties)
Osprey
1993-2002
2003-2012
92
120
0-9
0-9
0.5 Change in medians not
0.0 significantly different (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -0.0000; 95.0 Percent CI for ETA1-ETA2 is (-0.0001,-0.0002); W = 9970.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.6984; The test is significant at 0.6766 (adjusted for ties)
Pied billed grebe
2003-2007
2008-2012
56
64
0 - 28
0 - 54
58 INCREASING
17.5 Signficant (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -7.000; 95.1 Percent CI for ETA1-ETA2 is (-12.002,-3.002); W = 2714.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.0004; The test is significant at 0.0004 (adjusted for ties)
White ibis
1993-2002
2003-2012
90
120
0 - 114
0 - 169
7.0 Change in medians not
9.5 significantly different (p<0.05)
Test results: Point estimate for ETA1-ETA2 is -2.00; 95.0 Percent CI for ETA1-ETA2 is (-5.00,0.00); W = 9147.0
Test of ETA1 = ETA2 vs ETA1 not = ETA2 is significant at 0.1417; The test is significant at 0.1404 (adjusted for ties)
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Attachment 2 - 4