Saturday, November 7, 2009

Diamond Hills South HMA - White Pine Co., Nv.

Status UnKnown: Anyone?


The Diamond Hills South Herd Management Area (HMA) is located 25 miles to the northeast of Eureka,

Nevada. The HMA is part of a larger horse herd encompassing three Nevada BLM districts. It also lies

adjacent to the Buck and Bald HMA which lies to the east. Wild horses from all of these areas mix

freely with each other. The Diamond Hills South HMA is 10,500 acres in size, by far the smallest HMA

administered by the Ely Field Office. (Wilson Creek HMA is 689,135 acres.) The topography consists of

portions of Newark Valley on the east slope of the Diamond mountain range. The climate is arid to

semiarid. Annual average precipitation varies from 20 inches at the higher elevations to 8 inches or less

at the lower elevations. The bulk of the precipitation occurs through early spring rains and winter snows.

Temperatures range from summer maximums in excess of 90 degrees Fahrenheit to winter lows falling

well below zero. Springs, reservoirs, wells, and intermittent streams provide a water supply of generally

fair to good quality.

The area supports a variety of wildlife. This region provides year-round habitat for the Diamond

Mountains mule deer herd. Sage grouse are common in the area. Waterfowl are found in wetlands in

Newark Valley which borders the area to the southeast. Wet meadow riparian habitats are scattered

throughout. The perennial streams do not support fish. Amphibians, reptiles, mammals, rodents, raptors

and passerine bird species common to the Great Basin can be found in the area. Federally threatened

bald eagles winter here annually between November and April. Also, threatened peregrine falcons may

occur in the area. Other species being considered for threatened or endangered status and found in the

area are the ferruginous hawk (nesting sites in the area), and two fish species, the Newark Valley Tui

Chub and Relict Dace.

Diamond Hills South Herd Management Area

White Pine County, Nevada

Wild horses use the area on a yearlong basis. Their summer range encompasses the Diamond Mountains

and they winter on the eastern slope of the mountains adjacent to Newark Valley and Huntington Valley.

The horses prefer to graze the grasses and grass-like species found throughout the area, but they will

utilize shrubs and forbs when necessary.


There are two major ecosystems/plant communities in the area. They are the pinyon-juniper woodland in

the mountains and the Salt Desert Shrub communities in the valley. The salt desert shrub community is

composed of two major vegetative zones, the shadscale and the sagebrush. The pinyon-juniper zone is

scattered throughout the area, and generally occurs above 6,000 feet elevation on the east slope of the

Diamond Mountains. Stands of these pinyon pine and juniper trees vary in density from scattered to

closed (solid) stands. A few isolated aspen groves dot the higher elevations. This zone provides summer

range for wild horses.

The shadscale zone is found mostly in the valley bottoms. Plants in this zone have adapted to the very

arid saline soils of the valleys. Important plants in this zone are shadscale, winterfat, black sagebrush and

black greasewood. This zone serves as important winter range for wild horses, livestock, and a yeararound

population of pronghorn antelope.

The sagebrush zone is scattered throughout the area, occurring between 5,500 feet and 7,000 feet where

soils are less salty and more gravelly in nature. The big sagebrush zone provides an important source of

perennial grasses and forbs from which the wildlife of the area derive a majority of their nutrition.

Throughout each of these zones, small riparian areas (wet/green) occur with seeps and springs.

Vegetation found in these areas can be found no where else in the ecosystem due to the lack of water.

Plants include rushes, sedges, deciduous trees, wild rose bushes and willows. Riparian areas are the most

essential components to life in the cold deserts of Nevada, and every species that exists here, including

wild horses, are dependent on riparian habitat.

Herd Description

The Diamond Hills South HMA is managed for an Appropriate Management Level of 22 wild horses. In

order to maintain a thriving natural ecological balance, the Diamond Hills South HMA is gathered

periodically to reduce the number of wild horses roaming the management area. The Diamond Hills

South HMA was first gathered in February 1996. Between 1985 and 1999, a total of 337 wild horses

were removed from the Diamond Hills South HMA or the neighboring horse-free area. These horses

were placed into the BLM’s National Wild Horse and Burro Adoption program.

Wild horses in the area possess a variety of colors with variations from white to black and all shades in

between. The herd contains a preponderance of sorrels and bays, as well as a high percentage of

palominos. Grays, buckskins and roans can be readily seen throughout the HMA, and even an occasional

pinto can be observed. Light colored horses and at least one Curly stud were released by a local rancher

in the 1930s or 1940s. The effects of introducing this blood line can be seen today in the abundance of

lighter colored horses and some captured Curlies.

Wild horse foals are generally born in the spring when new green grass is plentiful. Wild horses are

sound, and healthy for the most part having been subjected to the rigors of natural selection which sorted

out only the toughest animals.

The wild horse herd is comprised of numerous smaller bands of horses ranging in size from one animal

(rare) to bands of more than twenty animals. Wild horses exhibit a fairly complex social structure. A

typical wild horse band will consist of one stallion and one to several mares with their offspring. Bands

are stable family units, and commonly reunite after a wild horse gather although they do interact and

change members occasionally. The stud horse (stallion) will vigorously defend his mares against other

studs through a complex series of gestures, body stances and physical combat. A young colt (a male) will

generally stay in its family band until it reaches two to three years of age. It may then be driven out of

the band by the dominant stud or will choose to leave the band to search for its own harem of mares.

Often young studs will form bachelor bands, which are very loose associations of young studs. These

bachelor bands are apparently formed to satisfy the need for social contact and mutual protection. Young

studs may remain in bachelor bands until they mature enough to gain control over their own mares.

Young studs will sometimes be tolerated by other bands, but have low social status. Young fillies

(females) will often stay in their family bands for longer periods of time than the young studs, but they will

eventually either wander off to seek a new band or be stolen by a different stud horse.

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