Ditching SUVs and breeding beefalos.

Have high oil prices of late really caused Americans to buy fewer SUVs, or is this just a myth?--Shane Wiener, Royal Oak, Michigan 

Is it indeed true that sales of sport utility vehicles (SUVs)--not to mention pickup trucks and vans--have plummeted in recent months in the U.S. Undoubtedly rising oil prices are playing a big role, and sales of the Ford Explorer, Lincoln Navigator, GMC Yukon and Hummer H2 are all down 50 percent or more. But U.S. automakers are quick to point out that sales have been dropping across all product lines and that attractive financing programs last year translated into record sales numbers. But General Motors (GM), the world's largest automaker, did report that overall sales in the U.S. sank in October 2005 by 22.7 percent compared to the previous year, while sales of SUVs, pickups and vans shrank by 30.3 percent. Ford experienced similar drops.

"We realize that gas prices are important to consumers and we're certainly not denying that there's an impact," says Paul Ballew of GM, who thinks the change in consumer preference is not as significant as it was following the world's first round of oil shocks three decades ago.

At the same time, Japanese competitors specializing in smaller cars have reported banner sales numbers in recent months. Toyota, maker of the industry-leading gas-electric hybrid Prius, beat its own October U.S. sales numbers from a year earlier by 5.2 percent, while Honda, which offers the world's most fuel-efficient traditional cars as well as hybrids, saw its U.S. sales rise four percent in October. Toyota's SUV and pickup sales slackened by four percent, while Honda's light truck sales stayed even.

One sign of flagging consumer demand for gas-hogging large SUVs is the recent development of so-called crossovers, which are SUV-type vehicles built on smaller, more fuel-efficient frames. Today almost half of all light trucks sold are considered crossovers. Another new development is the hybrid SUV, which uses both gasoline and electric engines to maximize fuel efficiency. Ford and Toyota lead the pack in hybrid SUV sales, but new models are on the way from GM. CONTACT: Ford Hybrid SUV, www.fordvehicles.com/escapehybrid/home; Toyota Highlander Hybrid SUV, www.toyota.com/vehides/minisite/hhy brid/index.html; U.S. Department of Energy, www.fuelecono my.gov.

What are the ramifications for wildlife of cross breeding species and creating animals such as tie "zone" (horse and zebra mix) and the "beefalo" (cow and buffalo)?--Kiernan Warble, San Francisco, CA

In 1986, a 14-foot long male false killer whale and a six-foot long female Atlantic bottlenose dolphin at Honolulu's Sea Life Park Hawaii became the proud parents of Kekaimalu, the first "wholphin" ever born in captivity. In the 19 years since, Kekaimalu, with a little help from male bottlenose dolphins, has given birth to three wholphins herself, each one three-quarters dolphin and one-quarter whale. Though rare, the interbreeding of different animal species does occur in nature. But mankind, in search of marketable traits or the next big zoo attraction, has long turned to controlled cross breeding.

The mule (horse/donkey mix) has been a beast of burden for centuries. The zorse, also bred for its work endurance, has been around since the late 1800s.

Beefalo meat was introduced in the 1960s to increasingly health-conscious consumers to provide a heart-healthier alternative to pure beef. And the Sierra Safari Zoo in Reno, Nevada now entertains visitors with a 1,200-pound "tiger" hybrid. It has the face and mane of his father, an African lion, and the body and striping of his mother, a Bengal tiger. Says the zoo's website, "He roars like a lion and swims like a tiger." But according to Science World magazine, such a pairing would probably not occur in the real world: "A tiger would probably not choose to visit a pride of lions; a raucous brawl--not romance--would be the more likely result." Indeed, unlike the wolphins at Sea Life Park, interspecies offspring are usually sterile.

Hybrid species would likely have many other survival challenges. Nature has evolved a number of unique traits within species enabling them to adapt to their unique environments. These traits may not pass down to hybrid creations. "I think it's important to maintain the integrity of species" says Susan Haig, a wildlife ecologist with the U.S. Geological Survey. CONTACT: Sea Life Park Hawaii, www.sealifeparkhawaii.com; Sierra Safari Zoo, www.sier rasafarizoo.com; U.S. Geological Survey's Haig Lab, fresc. usgs.gov/staff/haig.