Finding Refuge

Sandhill Cranes over water KKeeler

Sandhill Cranes and other species find refuge at the Merced Wildlife Refuge in California. Photo credit Kirk Keeler

by Shauna Potocky

The morning is damp and cool—not cold, just wet and cool. A thick blanket of Central Valley tule fog keeps the Merced Wildlife Refuge in a dream like state of obscurity. In the gray mist the voices of thousands of birds rise in the morning air. Only a few Whitefaced Ibis, Pintail ducks, Cinnamon Teals, and Northern Shovelers are seen on the edge of the wetland as the fog begins to lift and the sun rises.

Pintail Ducks and more stand at the water line as the fog breaks.

Pintail Ducks and company preen in the emerging sunlight as the fog breaks. Photo credit Kirk Keeler

Today, what the fog is hiding is substantial. As California emerges from January with hardly any precipitation, it is clear that the historic drought that California is experiencing is set to continue into a fourth year. With it will come significant challenges—exacerbating last year’s remarkable issues. From critical and hard decisions regarding water allocations to agriculture, wildlife refuges, and rivers with native fish runs. To addressing tree mortality estimated at 40 percent in some areas of the state as well as having faced a prolonged fire season, with no shortage of extraordinary and fast moving wildfires.

Taking action, California is now employing significant steps to address the ongoing drought and provide for both human use and environmental needs. In November, California voters approved Proposition 1, which allocates $7.5 billion via a bond measure for water programs, projects and restoration. The proposition addresses seven key areas: Regional Water Reliability; Water Storage Capacity; Water Recycling; Groundwater Sustainability; Safe Drinking Water; Flood Management; Watershed Protection and Ecosystem Restoration.

Specifically, the proposition focuses on expanding and diversifying water resources and management options. It is clear that one method of water management cannot address the needs of the entire state. Thus, the goal is to diversify water collection and storage, protect and correct current water quality issues—primarily in disadvantaged communities where water pollution is a major issue. In addition, efforts will be made restore ecosystems and river functions and address both short and long-term water needs.

The importance of water has grabbed the attention of representatives, business owners, farmers, public land managers, and citizens. Collectively, the people of California are taking a forward-thinking, diverse approach to address another record-breaking dry year. Of course there may not be consensus on all the initiatives, yet it seems clear a diverse approach will offer more potential solutions than a narrow focus.

Faced with today’s water realities in California, a proactive forward-thinking approach is needed to address these challenges.

Habitat that received water despite overall reduced wildlife refuge water allocations.

Habitat that received water despite reduced water allocations. Photo credit Shauna Potocky

One example of proactive management includes the actions and planning of California’s Wildlife Refuge managers in addressing the dry conditions of this winter’s migratory season. Many planned for a large influx of migratory birds in December and January based on reports of a productive breeding season in the northern habitats of Alaska and Canada. With refuges situated along the Pacific Flyway, it was critical that managers provided habitat for migratory species, despite the drought conditions, which serve as resting and feeding grounds as the birds move through California.

Sandhill Cranes in flight at the Merced Wildlife Refuge in California

Sandhill Cranes in flight at the Merced Wildlife Refuge in California. Photo credit Kirk Keeler

Faced with reduced water resources, wildlife refuges have concentrated water in critical habitat.  Many California refuges received only a portion of their normal water allotments, making strategic management of the wetlands essential. In addition, visitor use activities have been limited including hunting and tours at various locations. Although difficult for bird enthusiasts, it is a good reminder that the refuges are for the birds. They represent only 5 percent of the remaining historical habitat in California’s Central Valley.

A Whitefaced Ibis forging on a mild winter day.

A Whitefaced Ibis forges on a mild winter day in California. Photo credit Kirk Keeler

As the fog lifts on this winter day, the Sandhill Cranes begin to dance for their partners. The Ross’ Snow Geese rise in great loud clouds of movement and the reeds that frame the wetlands shimmer with the flutter of Redwing Black Birds—their songs as sharp as their brilliant red and yellow shoulders. With the receding fog, we are reminded that as resources like water become scarce, we are all pressed to be wiser and more forward thinking in our planning, use and conservation.

The fourth year of California’s drought is the perfect time to examine how water is allotted, conserved, and protected. Although facing significant challenges, California is also perfectly poised to embrace responsible, innovative, and robust water planning and management. Its success is critical. Frankly put, citizens, wildlife and ecosystems are depending on it, as California seeks its own refuge during a paradigm-shifting drought.

A perched raptor watches quietly as the wildlife refuge comes to life as the morning breaks.

A perched raptor watches quietly as the refuge comes to life just after daybreak. Photo credit Shauna Potocky

Home on the Range, Where Antelope Still Play

By Maymie Higgins

The cheetah’s shoulders arched upward like a ready arrow in a fully drawn bow. With head low and eyes forward, he hoped the thick morning fog over the savanna would work in his favor. His last meal was a mere rodent and days ago. He studied the grazing herd, waiting for an individual to linger as the rest of the herd moved away. He and his brother’s coordination with one another would be crucial. Today, it was this cheetah’s turn to subdue the prey as his brother isolated it from the herd. Suddenly, his brother bolted and startled an isolated doe and her fawn. The fawn darted into the herd, reflexively lifting its tail, revealing a flash of white fur and releasing a scent that signaled the herd to flee swiftly and en masse. The doe darted too, keeping pace with the herd, albeit 50 yards behind as the cheetahs flanked her, accelerating to 60 mph to remain parallel. They drew in closer and the attacking cheetah leapt, his claws grazing the doe’s haunches, but failing to apply full weight and subdue her. Neither cheetah could again accelerate to the speed at which the doe ran. These hungry cheetahs were not African Cheetahs (Acinonyx) on the Serengeti but rather the now extinct American Cheetah (Miracinonyx) in the Pleistocene Great Basin. Their extinction may be due to losing participation in an evolutionary arms race for speed. The winner? The pronghorn (Antilocapra americana), who, in modern times, is the only extant member of the family Antilidocapridae; a family that originally had 12-13 members.
Gallery-antelope-fawn-712-X-480

The pronghorn story is a success story, with caveats. Fossil records for pronghorn go back to the Miocene. In the 1800s, there were 35 million pronghorn in North America. By 1924, they were near extinction with only an estimated 20,000 remaining due to expansion of the nation and its effects from events such as overhunting and erection of fencing (pronghorn actually don’t jump very well) for domestic livestock that interrupted migration patterns. Human development and drought continue to pose threats in their current range. Pronghorn occupy tall and short grass prairies and deserts.

Pronghorn Range Map (Redrawn from Burt and Grossenheider, 1976) obtained at http://www.ultimateungulate.com/Artiodactyla/Antilocapra_americana.html

Pronghorn Range Map (Redrawn from Burt and Grossenheider, 1976) obtained at http://www.ultimateungulate.com/Artiodactyla/Antilocapra_americana.html

Pronghorn are of ecological importance because they eat noxious weeds and invasive plants which help to protect the cattle, bison, sheep and horses with which they share range. They also fill a niche in the ecosystem between deer and sheep and promote growth of native vegetation by grazing on plants such as Adam’s tree (Fouquieria diguetti), brittlebush (Encelia spp.), elephant tree (Pachycormus discolor), spurge (Euphorbia leucophylla), cliff spurge (E. misera), desert hollyhock (Sphaeralcea ambigua), thorn bush (Lycium spp.), saltbush (Atriplex spp.), Aristida aristidoides, and Phaseolusfiliformis.

Besides the importance of pronghorn to the ecosystem, their mere existence is thrilling. It is exciting that there remains an ungulate in North America that is not only one of a kind, but who also has physical adaptations to outrun predators that have not existed for thousands of years! They are capable of incredible speed because of an oversized windpipe, large lungs and a large heart. Pronghorns run with their mouths open to foster intake of oxygen, of which they require three times more than other similarly sized animals. They have more mitochondria in their muscle cells for power and padded hooves to withstand terrain at high speeds. There are tales (perhaps of the tall variety) of pronghorn racing horses and trains for sport, with one report citing in excess of 80 mph. They are the fastest land mammal in the Western Hemisphere. They are the second fastest land mammal in the world behind……you guessed it…..the African cheetah.

herd running

There are now an estimated 700,000 pronghorn in the wild, with recovery achieved from establishment of hunting restrictions and habitat protection. But there are two subspecies of pronghorn, the sonoran pronghorn (Antilocapra americana sonoriensis) and the peninsular pronghorn (Antilocapra americana peninsularis), that have required cooperative recovery efforts to prevent extinction. Both of these subspecies have the assistance of U.S. zoos in propagation and technical assistance with herd management.

The sonoran pronghorn is now estimated to have a wild population of 200-800 between U.S. and Mexico, but their population had dwindled down to a mere 21 in 2002 following a severe drought. Mexican populations have been listed on the Endangered Species List since 1967, and are also listed on the IUCN CITES Appendix 1. In 2003, the U.S. Fish and Wildlife Service partnered with biologists in several zoos, including the Los Angeles Zoo and San Diego Zoo, and with the Mexican government to begin a captive breeding program. Seven sonoran pronghorn were captured for a captive-breeding program and a square mile of desert was set aside at Cabeza Prieta National Wildlife Refuge, just north of the Mexican border, to hold the captive animals. Water guzzlers and supplemental food was provided within the enclosure and the pronghorn were protected from predators such as coyotes and mountain lions. These pronghorn successfully reproduced and the captive population grew. In 2006, the refuge began releasing some of the young males. The captive-reared sonoran pronghorn were able to integrate well with the wild population. So far, 91 sonoran pronghorn have been released into the wild and as of December, 2012, the overall wild population of sonoran pronghorn is estimated to be at 160 animals and growing. Also since 2006, captive-bred sonoran pronghorn, some from U.S. zoo propagation programs, have been released into the wild across several different sites in the U.S. and Mexico, including Barry M. Goldwater National Wildlife Refuge, Organ Pipe Cactus National Monument and Kofa National Wildlife Refuge.

The peninsular pronghorn is one of the most endangered large mammals in Mexico today, with a wild population lingering around 200, and is listed as critically endangered by the IUCN. The Mexican government, the Los Angeles Zoo and a sponsorship by the Ford Motor Company have implemented an in situ recovery program within El Vizcaino Biosphere Reserve (VBR) on the Baja California Sur peninsula. In 1997, the estimated population of peninsular pronghorn was 170. From 1998 to 2003, a total of sixteen wild fawns, which were hand-reared, and nine wild adults were captured to form a founding captive herd. This herd is protected within an elaborate fenced area with outer measurements of 1,400 x 1,850 meters and inner features such as moveable fences. There were challenges but by 2003, there were 85 births and only 20 deaths in the captive herd. Today, there are 250 adults and 40 young pronghorn in the captive population. The captive peninsular pronghorn are used to supplement the wild peninsular pronghorn population and maintain wild population genetic diversity.

The pronghorn story is just one of many examples of how biologists, veterinarians, keepers and aquarists at zoos and aquariums throughout the world are collaborating with governmental organizations, non-governmental organizations and even corporations to conserve and preserve the natural world.

All photos are of sonoran pronghorn and obtained from the United States Fish and Wildlife Service website http://www.fws.gov/faq/imagefaq.html)