The mountain plover is a medium-sized bird found in the grasslands and shrub-steppe regions of western North America. This unique bird has seen a dramatic population decline over the past few decades due to loss of habitat and is currently considered a species of conservation concern.
What is the mountain plover?
The mountain plover (Charadrius montanus) is a medium-sized shorebird that belongs to the plover family Charadriidae. It is pale brown in color with a white underside. The mountain plover has long legs, a medium-length black bill, and brown patches on either side of its breast.
Some key facts about the mountain plover:
- Length: 9-11 inches
- Wingspan: 20-26 inches
- Weight: 3.2-5.3 oz
- Lifespan: Up to 12 years
- Diet: Insects, spiders, worms, centipedes
- Range: Western North America from Canada to Mexico
- Habitat: Shortgrass prairies, shrub-steppe, fallow fields
- Nest: Shallow depression on bare ground lined with grasses and feathers
The mountain plover is highly adapted to living in open, arid environments. Its pale brown plumage provides great camouflage against dry grasslands. During the breeding season, the black patches on the breast become more pronounced. The mountain plover is sometimes confused with the killdeer, another type of plover, although the mountain plover lacks the killdeer’s distinctive double breast bands.
Where are mountain plovers found?
Mountain plovers are found in the western half of North America, ranging from southern Alberta and Saskatchewan down through the western United States to northern Mexico.
Within this range, mountain plovers are restricted to open habitats dominated by shortgrass prairie and shrub-steppe vegetation. Their breeding range centers around the Great Plains region, spanning across Montana, Wyoming, Colorado, New Mexico, and parts of surrounding states and provinces.
Some of the key breeding areas for mountain plovers include:
- Shortgrass prairie regions of Montana, Wyoming, Colorado, and New Mexico
- Shrub-steppe regions of Montana, Wyoming, Colorado, and Utah
- Grasslands and agricultural areas of Alberta and Saskatchewan
During the winter months, most mountain plovers migrate south to their wintering grounds, primarily in California, Arizona, New Mexico, and Mexico. A smaller number overwinter in parts of the southern Great Plains and Texas.
Why are mountain plover populations declining?
Populations of the mountain plover have seen sharp declines over the past several decades. The primary causes of the reductions in mountain plover numbers are:
Habitat loss: Large areas of native shortgrass prairie and shrub-steppe habitat have been converted to cropland agriculture. This removes vital nesting and foraging habitat for plovers. Between 1980-2010, an estimated 29% of U.S. shrub-steppe habitat was lost.
Intensive grazing: Overgrazing by livestock reduces vegetation cover needed by mountain plovers for nesting and raising chicks. Heavy grazing also degrades soil quality over time.
Conversion to non-native grasses: Introduced non-native grasses, often used for hay production or cattle forage, crowd out native grasses and alter local conditions so they become less suitable for plovers.
Predators: Higher numbers of predators, including foxes, coyotes, raccoons, and skunks drawn to farms and ranches, leads to increased nest predation.
Drought conditions: Periodic droughts in the Great Plains further degrade nesting habitat quality and dry up insect food sources.
How many mountain plovers are there?
Due to their remote grassland and prairie habitats, accurately surveying mountain plover populations poses challenges. The total global population is estimated to be between 11,000 – 14,000 adult birds based on data from annual breeding ground surveys.
According to the most recent mountain plover surveys by the US Fish and Wildlife Service, the total breeding population in 2016 was estimated at approximately 8,600 adults.
This represents a >60% decline since the late 1960s and early 1970s, when the breeding population was estimated at around 25,000 adults.
Below is a table summarizing the known mountain plover population numbers and trends over the past few decades:
Year | Breeding Population Estimate |
---|---|
Late 1960s to early 1970s | ~25,000 adults |
1999 | 10,000-14,000 adults (first-time global estimate) |
2003 | 16,000-32,000 adults (revised global estimate) |
2008 | 14,000 adults (revised global estimate) |
2016 | 8,600 adults (latest USFWS breeding survey) |
These figures paint a bleak picture for the mountain plover, which has lost well over half of its population in the past 40-50 years. While a partial rebound was observed in surveys from 1999-2003, the overall long-term trend remains a decline towards dangerously low numbers.
Why is the mountain plover declining more steeply in some areas?
The declines in mountain plover numbers have not affected their full range equally. Populations in certain core habitat areas have been hit especially hard.
For example, in Alberta and Saskatchewan, breeding plover numbers dropped by a staggering 98% between 1966-1992 as native prairie was plowed under for agriculture. Some sharp regional declines include:
- Montana: 85% decline from 1965-1999
- Wyoming: 68% decline from 1968-1993
- Colorado: 71% decline from 1966-2007
These severe regional declines are linked to high rates of habitat loss driven by land use changes. Expanding cropland agriculture and energy development displaced grassland nesting habitat.
Meanwhile, grazing pressure and changing livestock management shifted remaining native prairie towards vegetation compositions less optimal for mountain plovers. Converting native habitat to introduced forage grasses caused local habitat conditions to deteriorate.
In areas where substantial tracts of high-quality habitat remain intact, such as New Mexico’s shortgrass prairie, mountain plover declines have been less steep. But overall, habitat loss and incompatible land use changes are squeezing mountain plovers out of large portions of their ancestral breeding range.
What conservation actions are being taken?
In response to shrinking mountain plover numbers, several conservation actions have been implemented or proposed:
- Habitat protection: Securing legal designation and preservation of remaining intact grassland and shrub-steppe ecosystems.
- Managed livestock grazing: Developing rotational grazing approaches that provide periods of rest for vegetation and do not disrupt nesting.
- Prescribed burning: Using controlled burns to mimic natural fires cycles and improve habitat quality.
- Invasive plant control: Removing introduced grasses and woody shrubs invading open plover habitat.
- Predator management: Excluding, relocating, or controlling overabundant nest predators like skunks and raccoons.
- Population monitoring: Continuing annual surveys to detect population trends.
- Listing under ESA: Gaining threatened/endangered species protections to preserve habitat.
Partners in mountain plover conservation include government agencies like the Bureau of Land Management, U.S. Fish & Wildlife Service, state wildlife departments, and NGOs such as The Nature Conservancy.
Recovery actions focus on protected areas with high plover densities, including Montana’s Phillips County, Pawnee National Grassland in Colorado, and Comanche National Grassland in Colorado.
Could the mountain plover become extinct?
The steep population decline over the past 40-50 years raises real concerns about the mountain plover’s future extinction risk if current trends continue.
The mountain plover is already listed as threatened, endangered, or a species of concern in many states across its range. It is currently under review for possible listing under the federal Endangered Species Act.
As few as 8,600 breeding adults remaining makes the mountain plover vulnerable to any environmental fluctuations, habitat pressures, or mass mortality events. With so few individuals left, loss of genetic diversity also becomes a threat.
On the IUCN Red List of Threatened Species, the mountain plover is listed as Near Threatened. While not in immediate risk of extinction, the IUCN warns the plover is close to qualifying for Vulnerable status if habitat loss and population declines persist.
Preventing the mountain plover from going extinct will depend on preserving sufficient habitat and reversing negative population trends. More aggressive conservation action may be needed to ensure the survival of this unique bird of the prairies.
Conclusion
In summary, mountain plover numbers have plummeted over 60% in the past 40-50 years due to widespread habitat loss. The global population is now estimated to be as low as 8,600 breeding adults.
The mountain plover’s specialized shortgrass prairie and shrub-steppe habitat continues to decline across its range, putting the species at risk of extinction if trends are not reversed.
Targeted conservation action to protect crucial intact habitat areas, manage land use changes, and restore degraded ecosystems may help stabilize and slowly recover mountain plover populations. Annual surveys also provide valuable data to monitor the health of remaining populations.
The outlook for the mountain plover remains uncertain. But this charismatic bird of the grasslands is a reminder of the importance of conserving North America’s imperiled native prairie ecosystems and wildlife. With care and persistence, there is still hope of preserving the mountain plover as a part of our natural heritage.