Micro-Habitat Characteristics of Mountain Plover Nest Sites

Scientific Disciplines
Biological Sciences - Terrestrial
Keywords
Ecology
habitat
grazing
Soil sciences
Mountain plover
plovers
plover
plant height
soil surface
visual obstruction
Charadrius montanus
Colorado
Years
Authors
Volumes
Volume 18, No. 1-4

Micro-habitat characteristics of 
Mountain plover nest sites
Jody J. Javersak, Sitka, AK  99835
Daniel W. Uresk, USDA Forest Service, Rapid City, SD 57701
Milton Joe Trlica, Department of Forest and Rangeland Stewardship, Colorado State University,    
Fort Collins, CO 80523
Abstract
This study was conducted on shortgrass prairie in northeast Colorado to determine micro-habitat 
characteristics of nest sites for mountain plover (Charadrius montanus Townsend).  Vegetation 
and soil surface characteristics were sampled in the spring of 1996-97 at and near 16 nests to 
identify important micro-habitat characteristics for site selection.  We collected data on plant 
structure and canopy cover near nests in the spring during 2 years.  Mean bare ground  within a 
15 m radius of the nest was 24 percent and bare ground patch size was 29 cm2.  Mountain plovers 
selected nest sites that had short plant structure and a mean visual obstruction reading (VOR) 
of 0.6 cm. Plant structure (VOR) from 4 m to 15 m was significantly greater than structure at 
0 to 2 m from the nest.  
Key Words: mountain plover, grazing, habitat, plant height, soil surface, visual obstruction.
Introduction 
mountain plover as a threatened species was 
withdrawn May 12, 2011.  It was determined 
 
The mountain plover (Charardrius 
that the mountain plover was not threatened 
montanus) is found on level sites with 
or endangered throughout all or a significant 
sparse, short vegetation throughout most of 
portion of its range.  Though not listed as 
its range (Olson and Edge 1985).  Bradbury 
an endangered species the, mountain plover 
(1918, page 157) described a mountain 
should receive continued surveillance just 
plover nesting area 20 miles east of Denver 
to maintain existing populations.  The 
as cattle range “…covered with short-
purpose of this study was to determine nest 
cropped buffalo or grama grasses with 
selectivity of mountain plovers by assessing 
frequent bunches of dwarfed prickly pear, 
and describing vegetation and soil surface 
and an occasional cluster of stunted shrub 
characteristics at, and directly surrounding 
or weed…”.  Graul (1975) found most 
mountain plover nests in Colorado. 
mountain plover nest sites in Weld County, 
Colorado in shortgrass areas of blue grama 
(Bouteloua gracilis) and buffalograss 
Study area
(Buchloe dactyloides) with scattered clumps 
 
The study area was in northeastern 
of plains prickly pear (Opuntia polyacantha
Colorado near Keota in Weld County and 
and western wheatgrass (Pascopyrum 
within the Pawnee National Grassland., 
smithii). There is little information focusing 
The grassland encompasses 78,162 ha of 
specifically on the micro-site characteristic 
publicly owned tracts of and intermingled 
of mountain plover nest sites.  The mountain 
with privately owned farms and ranches.  
plover was originally proposed as threatened 
The area is classified as a shortgrass steppe; 
or endangered according to the Endangered 
blue grama, buffalograss, plains prickly 
Species Act of 1973 in 1999 (Federal 
pear, western wheatgrass, and sun sedge 
Register 2011)in 2002 but  was withdrawn 
(Carex inops) are the principal plant species 
from consideration in 2003.  In 2010, the 
(USDA NRCS 2004).  Other plant species 
mountain plover was again proposed as a 
present included woolly plantain (Plantago 
threatened species.  The proposal to list the 
patagonica Jacq.), rubber rabbitbrush 


(Ericameria  nauseosa [Pall. ex Pursh] G.L. 
additional sample stations at 2, 4, 6, and 8 
Nesom & Baird), sixweeks fescue (Vulpia 
m from the nest along the transects in 1997 
octoflora), and fourwing saltbush (Atriplex 
in an attempt to more precisely describe the 
canescens).  The soil type in the study area 
vegetation zone around the nest.
is an Ascalon-Vona sandy loam, a deep well-
Canopy cover by major plant species, total 
drained Ustollic Haplargid (Crabb 1982).
grasses, total forbs,  total plants and bare 
M
ground (Daubenmire 1959) and soil surface 
Ethods
characteristics (percent bare ground and bare 
Mountain plovers, in a preliminary search of 
ground patch size) were estimated within 20 
the study area, were most frequently found 
x 50 cm quadrats positioned at 1 m intervals 
on loamy plains range sites with less than 2 
along each of the four 15 m transects.  Bare 
percent slope and a southern to southwestern 
ground patch size within each quadrat was 
aspect in the study area.  We selected 8 
classified into 1 of 6 class codes (Table 1). 
sites with these attributes that were 1.6 to 
Mid points of class codes were used to 
15 kilometers apart and roughly 500 ha in 
estimate patch size (cm2) following methods 
size to search for plover nests.  Searching 
described by Daubenmire (1959).
for individual plovers began at sunrise and 
continued through sunset during the nesting 
Table 1.  Class codes (1-6) with 
period.  Once a plover was located, it was 
corresponding size of bare ground patches.  
observed until it settled on the nest.  The 
Mid points of patch size were used to 
nest was then located and data collected 
estimate area (cm2).
within a very short time.  We initially 
 
 
Bare ground 
 
searched the selected sites for mountain 
 
 
Patch Size  
 
plover nests in spring, 1996.  Because so 
  class codes 
(cm2)
few nests were found on the 8 study sites in 
the spring of 1996, we expanded the search 
 

0 -   3.2
in 1997 to include larger areas outside the 
 

3.3 - 12.6
original study sites that were potentially 
 

12.7 - 28.3
good mountain plover habitat.  
 

28.4 - 50.3
We measured vegetation height-density 
 

50.4 - 78.6
(density of leaf mass at various heights 
 6 
>78.6
determined by visual obstruction readings 
on a Robel pole) and cover along 15 m 
VOR data at the nest site and along the 
transects radiating outward in the 4 cardinal 
transects at various distances (meters) were 
directions from each nest during the nesting 
analyzed with a General Linear Model 
period.  We recorded the height-density 
repeated measures design (SPSS, 2003) 
or visual obstruction reading (VOR) 
for both years.  The Bonferroni pairwise 
of vegetation for each nest site using a 
comparisons test was used to determine 
modified Robel pole as described by Uresk 
significance differences between VORs at 
and Benzon (2007) and Uresk and Juntti 
the nest site and at distances from the nest.  
(2008).  The modified pole had alternating 
We used a two sample T-test to compare 
1.27 cm white and gray rings.  Bands were 
differences between years for canopy cover 
numbered beginning with 0 (white band) at 
variables and patch size at p = 0.10.
the bottom and the pole was placed on the 
soil surface.  A (VOR) was taken from a 
Results
distance of 4 m from the pole for each of the 
Sixteen nests were located during the 2 
four cardinal directions. The lowest visible 
years of sampling: 6 in 1996 and 10 in 1997. 
band was recorded.  Visual obstruction 
Mean VOR at time of nesting for 6 nest 
readings were recorded at the nest site 
sites in 1996 was 0.9 cm ± SE 0.3 and for 
and at points 10 and 15 m from the nest 
10 nest sites in 1997 VOR was 0.3 ± SE 0.2.  
along each of the four transects. Because 
Bare ground, bare ground patch size, and 
1996 data showed significant differences 
canopy cover of major plants and categories 
between the nest and 10 m station, we added 
within the 15 m radius of the nest is shown 
Micro-habitat Characteristics of Mountain Plover Nest Sites       27


in Table 2 for both years.  Differences (p = 
1976; Leachman and Osmundson 1990).  
0.10) were observed between years for blue 
Micro-site characteristics were important 
grama, total cover and total graminoids with 
to mountain plovers nesting on the Pawnee 
1996 providing greater canopy cover than 
National Grassland.  With a refinement 
in 1997.  Overall, bare ground was 24% ± 
of the sampling design in 1997, the zone 
SE 2%, bare ground patch size 29 cm2 ± SE 
of greatest influence was shown to be a 
3cm, total plant cover 69% ± SE 3%, total 
distance of about 2 m compared to distances 
graminoides 67% ± SE 3%  and total forbs 
from 4 through 15 m from the nest.  Once 
4% ± SE < 1%. 
an area had been selected for a breeding 
VOR was greater at stations away from 
territory, the vegetation structure, cover, 
the nest.  For combined years, mean VOR 
and amount of bare ground were important 
at the nest station (0.06 ± SE 0.2 cm) was 
characteristics of the actual nest site location 
significantly less than VOR at both 10 m 
by mountain plovers.  
(1.8 ± 0.3 cm) and 15 m stations (2.0 ± 0.3 
Visual obstruction readings at the nest 
cm) ) (p = 0.05).  In 1997, VOR’s estimated 
site were slightly greater (0.57 cm) in our 
at 10 nests sites and at 2 m away from 
study in Colorado compared to values 
the nest were similar (Fig. 1, p > 0.10).  
(0.13 cm) reported by Parrish et al. (1993) 
However, mean VOR at the 4 m station 
in Wyoming.  In Colorado on shortgrass 
and beyond to the 15 m were similar but 
prairie, plover nests were found in blue 
significantly greater than at or less than 2 m 
grama, buffalograss, and western wheatgrass 
of the nest p = 0.10 (Fig. 1).
grazed by cattle.  Nesting sites were located 
D
in areas with 24 percent bare ground 
Iscussion
distributed in an average patch size of 29 
Mountain plovers prefer areas that have 
cm2.  Olson and Edge (1985) reported 27 
been intensively grazed by livestock and 
% bare ground (erosion pavement) for nest 
avoid areas of vegetation greater than 0.5 
sites in Montana.  However, Parrish et al. 
cm high for nesting (Graul and Webster 
(1993) and Plumb et al. (2005) reported 
Table 2.  Vegetation and soil surface characteristics measured within a 15 m radius of 
Mountain Plover nests on the Pawnee National Grassland for years 1996-1997 and years 
combined for 16 nest sites.
 
Plant Species 
Mean ± Se 
Mean ± Se 
Mean ± Se
   
(n = 6) 
(n = 10) 
(n=16) 
 
  
1996 
1997 
1996-1997
  


%
Pascopyrum smithii  
8.0 ± 3.2a 
5.7 ± 2.4 
6.6 ± 1.9
Bouteloua gracilis  
23.0 ± 7.1 * 
41.5 ± 5.9 
34.6 ± 5.0
Buchloe dactyloides  
38.3 ± 3.6 
22.9 ± 7.9 
28.7 ± 5.4
Opuntia polyacantha 
6.5 ± 1.7 
8.7 ± 1.9 
7.9 ± 1.3
Total coverb 
76.8 ± 1.7 * 
63.7 ± 3.6 
68.6 ± 2.8
Total graminoids  
76.3 ± 1.6 * 
53.1 ± 6.7 
67.2 ± 2.8
Total forbs  
4.3 ± 1.3 
3.8 ± 0.3 
4.0 ± 0.5
Bare ground  
21.8 ± 2.4 
26.0 ± 2.7 
24.4 ± 2.0
Bare ground patch size (cm2) 
25.7 ± 3.8 
30.6 ± 3.9 
28.8 ± 2.8
a Standard error
b Two dimensional cover that does not include the sum of individual species.
* Significantly dif erent between years at p = 0.10
28          Javersak et al.


Fig. 1.  Visual obstruction readings (VOR) at different distances away from 
mountain plover nests (n = 10) in Colorado for 1997. Different letters above the bars 
represent differences among the distances (m) at p = 0.10 with standard errors. 
nesting at areas of 72% and 47% bare 
homogeneous vegetation structure.  To 
ground, respectively, on grasslands in 
create or maintain optimal mountain 
Wyoming.  
plover habitat, grazing intensity should be 
Livestock grazing has been used as a tool 
heavy during fall, winter and early spring.  
for wildlife habitat management (Severson 
Livestock grazing provides managers with 
1990).  Grazing management can be an 
some control for creating favored plover 
important and perhaps less expensive tool 
habitat.  Creating vegetation areas with 
than mowing or prescribed fire for creating 
VORs with a mean of 0.6 + SE 0.2 cm with 
or maintaining mountain plover nesting 
livestock grazing could provide conditions 
habitat.  Prairie dog colonies are important 
of height-density structure and patchiness 
for plover nesting and should receive a high 
for attracting plovers. 
management priority: however, managing 
Mountain plovers use grasslands with low 
and maintaining prairie dog colonies is 
canopy cover, high percentage of bare 
difficult with continued outbreaks of plague 
ground and low visual obstruction near 
and rodenticide poisoning on the plains 
nests.  Target conditions for optimal nesting 
(Miller et al. 2007).  Grazing management 
habitat for mountain plovers include less 
plans related to the amount of herbage 
than 70 percent total vegetation canopy 
remaining after livestock grazing are 
cover , bare ground of 24 percent or greater 
generally designed for optimal livestock 
and visual obstruction readings of vegetation 
or plant production and often result in 
with averages ranging from 0.3 to 0.9 cm.  
Micro-habitat Characteristics of Mountain Plover Nest Sites       29


Prairie dog colonies and heavy livestock 
Miller, B. J, R. P. Reading, D. E. Biggins, 
grazing in late fall, winter or early spring 
J. K. Detling, S. C. Forrest, J. L. 
provide preferable mountain plover habitat.  
Hoogland, J. Javersak, S. D. Miller, J. 
These guidelines should be beneficial and 
Proctor, J. Truett, and D. W. Uresk. 2007. 
effective in keeping the mountain plover 
Prairie dogs: an ecological review and 
from being proposed as a threatened or 
current biopolitics. Journal of Wildlife 
endangered species 
Management 71:2801-2810.
Olson, S. L. and W. D. Edge. 1985. Nest 
Acknowledgments
site selection by Mountain Plovers in 
 
We thank Steve Denison, Hank Henry, 
north-central Montana.  Journal of Range 
Lakhdar Benkobi, Mark Ball, and Mary 
Management 38:278-280.
Ashby for their assistance on this project.  
Parrish, T. L., S. H. Anderson, and W. R. 
Jeffrey Baumberger assisted with data 
Oelkluas. 1993.  Mountain Plover habitat 
collection.  The research was in cooperation 
selection in the Powder River Basin, 
with Colorado State University Agricultural 
Wyoming. Prairie Naturalist 25:219-226.
Experiment Station, Cooperative Agreement 
Plumb, R. E., S. H. Anderson, and F. L. 
No. 28-C5-884.
Knopf.  2005. Habitat and nesting 
biology of Mountain   Plovers in 
Literature cited
Wyoming. Western North American 
Bradubury, W. C. 1918. Notes on the nesting of 
Naturalist 65:223-228.
the Mountain Plover.  Condor 20:157-163.
Severson, K. E. 1990. Can livestock be used 
Crabb, J. A. 1982. Soil Survey of Weld 
as a tool to enhance wildlife habitat?  
County, Colorado, Northern Part.  
43rd Annual meeting of the Society for 
USDA, Soil Conservation Service. 
Range management, Reno, Nevada, 
13 February 1990.  K. E. Severson, 
Daubenmire, R. 1959. A canopy-coverage 
Technical Coordinator.  USDA, Forest 
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[SPSS] Statistical Procedures for Social 
Federal Register 2011. Endangered 
Science.  2003. SPSS 12.0 for Windows. 
and threatened wildlife and plants; 
SPSS, Inc. Chicago, Illinois, USA.
withdrawal of the proposed rule to list 
the mountain plover as threatened; 
Uresk, D. W. and T. A. Benzon. 2007. 
proposed rule.  Part II Department of the 
Monitoring with a modified Robel pole 
Interior, Fish and Wildlife Service. 50 
on meadows in the central Black Hills of 
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South Dakota.  Western North American 
2011. 
Naturalist 67:46-50.
Graul, W. D. 1975. Breeding biology of 
Uresk, D.W. and T.M. Juntti.  2008. 
the Mountain Plover.  Wilson Bulletin 
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Graul, W. D. and L. E. Webster. 1976. 
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literature review. Unpub. Man. Prepared 
for the U.S. Fish and Wildlife Serv., 
Golden, Colo. 82 pp.
Received August 2. 2012 
Accepted October 25, 2012

30          Javersak et al.