To the untrained eye and neophyte ear, the brightly colored
insects buzzing excitedly about and flitting from flower to flower
at Pinnacles National Monument, about 55 miles south of Morgan Hill
in San Benito County, are just bees.
To the untrained eye and neophyte ear, the brightly colored insects buzzing excitedly about and flitting from flower to flower at Pinnacles National Monument, about 55 miles south of Morgan Hill in San Benito County, are just bees.
But for those in the know, they represent one of the largest collection of bee species per square-mile in the world, according to biologists.
Several years ago, a pair of biologists with Utah State University, funded by the United States Department of Agriculture, spent three years armed only with a net scooping up thousands of bees at Pinnacles and cataloging their findings.
And what they found were 398 different bee species in an approximately 25 square-mile radius – one of the highest diversity of bee species per unit area in the world, according to Pinnacles wildlife biologist Paul Johnson. By comparison, another area rife with bee activity in Clark County, Nev. has nearly 600 bee species, but Johnson said they are spread over about 7,000 square-miles.
“This region is one of the hot spots of bee diversity in the world,” Johnson said. “The Pinnacles has about one-thousandth of 1 percent of land mass of the contiguous United States, and we have 10 percent of U.S. bee species.”
A combination of temperate weather, a large number of flowers and a protected ecosystem has created a hot spot of diversity for bees in San Benito County’s national monument, said Utah State Biologist Terry Griswold. Griswold and his assistant, Olivia Messinger, who specialize in bee research, spent several seasons cataloging nearly 24,000 bees over a three-year period after Griswold accidentally stumbled upon the natural phenomenon in 1996, Messinger said.
Griswold had been doing work in and around the area and had a hunch Pinnacles might be a diverse area for bee species, Messinger said. After spending every day from mid-February to mid-June during the spring seasons of 1997 through 1999, they discovered between 15 and 20 types of bees that had never recorded before and learned Griswold’s hunch was right: The area is teeming with bee species.
Most of the species are native to the area and some are extremely rare, and Griswold and Messinger’s work put Pinnacles on the map for bee enthusiasts everywhere.
Large numbers of bee species call the Pinnacles home for a number of reasons, Messinger said. The area offers a diverse plant and flower makeup, has a long flowering season because of the weather, and has dry soil that many bees like to nest in, she said.
While the question of why so many species occupy the park is easy to answer, Messinger said how they got there is a little more difficult.
“You’d have to look a long ways back into history. Most of the bees there are residents – they live and stay there,” she said. “Except for the honeybee and one or two others, all the rest are native to the area and have been there for years.”
Honeybees, which are native to Europe, are one of the only species that live collectively at Pinnacles, Johnson said. Most of the bee species at the park are solitary bees and either nest in the soil or inside plant stalks or logs, he said.
Johnson said one interesting species, called “leaf cutter bees” will neatly cut small pieces out of leaves and fly the pieces back to their home – which could be inside a plant stalk or rotting log – and line the hollowed out portion to make their nest.
Another specie, which pollinates one specific type of plant that only grows after a burn, has to tip itself upside down to get inside the flower, Messinger said.
Such unique bees – called “specialist bees” – comprise most of the species in the park, Messinger said. The diversity of plants in the park leads to a large variety of bees with which they form a symbiotic relationship.
“A lot of bees are specialists on different flowers. A bee is using a smaller piece of a resource and leaving another piece for another species,” she said. “This creates a bigger resource base for the bees.”
Although Messinger and Griswold finished their research in 2003 and published an article in the California Native Plant Society’s journal the “Fremontia,” Messinger said there are most likely a few more species now living within the park’s parameters.
Even without a bee expert like Messinger or Griswold, any visitor can take a walk along the Old Pinnacles Trail and be delighted by the hosts of beautiful bees going about their business along the way, she said.
“You’re guaranteed to find something,” she said. “And they are some of the prettiest bees.”
The Pinnacles National Monument is located on Highway 146 in Paicines. Take U.S. 101 south to Highway 25 through Hollister and follow the signs. For more information, call (831) 389-4485.
