Transcript Since 1993, have there been changes in Great Lakes Piping Plover

Is Climate Change Altering the Breeding Biology of
the Endangered Great Lakes Piping Plover?
ABSTRACT
As average global temperature rises, heterogeneous changes from region to region are
expected. Regional changes will most directly impact ecology and conservation efforts. These
impacts on ecosystems which must be taken into account when designing conservation
programs. In the Great Lakes region, among the ways climate change will manifest itself are
changes in temperature trends, seasonality and water levels.
Nebraska Game and Parks Commission
Amy Canavan
Francesca J. Cuthbert
Conservation Biology University of MN
Biosphere/Atmosphere Research & Training
(NSF/IGERT)
Professor and Interim Head Fisheries, Wildlife,
and Conservation Biology, University of MN
REPRODUCTIVE PHENOLOGY
I examined whether or not Great Lakes Piping Plovers have exhibited a trend towards earlier nesting by running a linear regression using R software
on average nest initiation date versus year (Figure 4). This data was obtained from the University of Minnesota Piping Plover database and Piping
Plover recovery reports as submitted to the Michigan Department of Natural Resources. I then looked at whether there was a correlation between
May temperature and nest initiation data (Figure 5). Finally, I examined nest initiation date as a function of population size. In light of piping plover
recovery, this could be a factor in earlier nest initiation that would be separate from any climatological factor (Figure 6).
The Great Lakes Piping Plover nests in shoreline habitat which is sensitive to climate-induced
events. By predicting scenarios of the effects of global climate change on the Piping Plover
and its habitat we can make informed management decisions. I have completed analyses on
available Piping Plover reproductive data. The Piping Plover is nesting earlier. Earlier mean
nest initiation correlates with fewer days in May with low temperature below 40°F. Also
examined were correlations between precipitation and reproductive success and correlations
between lake levels and reproductive success. These correlations are less clear, but may
become more important with future changes in amount of lake level fluctuation, overall water
level changes and changes in weather patterns.
C. Perez (USWFS)
THE PIPING PLOVER
The Piping Plover (Charadrius melodus) is a
small shorebird. Its cryptic coloring blends into
the open, sandy habitat on the beaches where it
feeds and nests.
Piping Plovers have historically been common in
the Great Lakes region (Figure 1). The estimated
historic Great Lakes population of Piping Plovers
is 500-800 pairs. Today there are significantly
fewer breeding pairs in the Great Lakes region
compared to early 1900s. The Great Lakes
Piping Plover is biologically significant as an
umbrella species as it co-occurs with other rare
coastal species. Thus, the endangered status of
the Piping Plover helps to protect the entire
Great Lakes coastal dune habitat.
Figure 4
Great Lakes Piping Plover
Historical Distribution
Great Lakes Piping Plover
1998-2006 Distribution
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of Minnesota)
60
58
51 50
1984:
13 recorded pairs
54
53
40
Breeding Pairs
Despite this recovery, the Piping Plover population is still
vulnerable to extinction. The plovers are vulnerable to
predation, continued beach development means further habitat
loss, and greater human presence means more wild and
domestic predators as well as human disturbance. The small
population is vulnerable to demographic and environmental
stochasticity.
Figure 3
RESEARCH QUESTIONS
REPRODUCTIVE SUCCESS AND CLIMATOLOGICAL CHANGES
I completed regression on reproductive success versus Lake Michigan/Huron lake level to determine whether Great Lakes Piping Plover reproductive
success changed since 1993 as a function of lake level. I also did regression on reproductive success versus overall June precipitation and number of
days in June with significant rainfall (mean precipitation of two weather stations is more than 0.10 inches during a 24-hour period), to determine
whether Great Lakes Piping Plover reproductive success has changed since 1993 as a function of precipitation in the region.
Figure 1
50
1986:
Listed endangered
32
30
20
19
13
16 16
18
14
10
17 16 18
19
21
23 23 24
30
Figure 6
RESULTS
Since 1993, Great Lakes Piping Plovers have initiated nesting 1 to 2 days earlier every 2 years. This is statistically significant (P-value = 0.03). The
rate of change is such that per one fewer day in May with a low temperature of 40F, the mean nest initiation date is approximately 1 day earlier. 44%
of the variation in nest initiation date can be explained by cold days. This is statistically significant (P-value = 0.01). If I remove the point for the year
2004 (the most deviant point), the rate of change remains similar, but 66% of the variation in nest initiation date can be explained by cold days.
Breeding Records
Non-breeding Records
(Univ.
PIPING PLOVER RECOVERY EFFORTS
The Great Lakes Piping Plover was listed as federally
endangered in 1986. Recovery efforts have resulted in 53
breeding pairs in 2006 (Figure 3).
•
Ontario
Breeding Records
Figure 5
32
2006:
53 pairs
12
RESULTS
At this time, there is no statistically significant correlation between
lake levels and reproductive success from 1993 to 2006 (Figure 6).
However, there seems to be some relationship. Lower lake levels
tend towards higher reproductive success. This may become
significant in the future as lake level fluctuations change or lake
levels change overall. Also, there is no statistically significant
correlation between overall June precipitation and reproductive
success from 1993 to 2006 (Figure 7). Again, in this case, there
seems to be some relationship. Lower precipitation in June seems
to tend towards higher reproductive success. There is a statistically
significant correlation between reproductive success and number of
days in June with precipitation totaling more than 0.1 inches (Figure
8). More days with precipitation events correlate with lower
reproductive success.
Figure 6
Figure 7
Figure 8
0
1985
1989
1993
1997
2001
2005
Year
Since 1993, have there been changes in Great Lakes Piping Plover
reproductive phenology?
Since 1993, have there been climate-induced changes in Great Lakes Piping
Plover reproductive success?
HOW MIGHT CLIMATE CHANGE AFFECT THE GREAT LAKES PIPING PLOVER?
Global warming has altered the distributions of organisms and changed the phenology of
flowering in plants and reproduction and migration in animals (Cotton 2003, Both and
Visser 2001). Heterogeneous regional changes will most directly impact ecology and
conservation (Walther and Post et al. 2002). Ultimately, changes in climate will alter
species distributions, abundance and behavior.
The Piping Plover nests on shoreline sensitive to climate-induced events. Climate change
may affect a number of habitat traits: temperature trends; seasonality; lake water levels;
winter lake ice coverage; and synoptic weather patterns (Kling et al. 2003). Reduction in
winter ice coverage may result in greater winter evaporation resulting in lower water levels.
Less ice would mean less shore scouring and possibly more vegetation, including invasive
species. Also, there could be differences between climate-induced changes in plovers’
wintering grounds versus breeding grounds.
Lauren Wemmer
CONCLUDING REMARKS
It is imperative to take climate change scenarios into account when designing conservation programs for the species, communities and ecosystems
that are most vulnerable to the impacts of climate change. Easterling et al. (2000) suggest that we can ameliorate large uncertainties in regional
climate change scenarios by creating more connections between ecology and climatology.
Given climate change predictions and current Piping Plover behavior, early nesting will likely continue. Management and conservation efforts will need
adjustment (e.g. field season will start earlier). We should continue to monitor Piping Plover phenology trends and incorporate phenology information
into conservation plans. Climate change that affects quantity and quality of shoreline habitat will also affect Piping Plovers. Lake levels and
precipitation will become more important to Piping Plover fledging success via changes in amount of lake level fluctuation, predicted overall water level
decreases (Kling et al. 2003) and changes in weather patterns. Other behavior (e.g. migration) may ultimately be affected.
FUTURE WORK
To further investigate the impact of climate change on the Great
Lakes Piping Plover, we could examine relationships between
fledging success and specific weather events: flooding, storms,
cold events and examine relationships between population
success and weather in the wintering grounds. We should
continue to analyze habitat: are nest sites changing in response to
climate conditions? Are there measurable trends in distribution of
nests? Are there significant changes in vegetation? It also might
be telling to analyze phenology of emergence of Piping Plover
food sources (e.g. midge and mayfly hatch dates).
ACKNOWLEDGEMENTS
Cathy Haffner, Jesse Kroese, Olivia LeDee,
Vanessa Pompei, Erin Roche, Jennifer Stucker,
Lauren Wemmer
DATA SOURCES AND CONTACT
INFORMATION
Plover data Great Lakes Piping Plover
Population Database, maintained by F.
Cuthbert and graduate students,
University of Minnesota
Biosphere/Atmosphere Research and Training,
NSF/IGERT
Lake level data United States Army
Corps of Engineers
University of Michigan Biological Station
Weather data Regional weather station
data (National Center Atmospheric
Research)
University of MN Conservation Biology Program
For extended citation list contact
Amy Canavan at [email protected]