The Browers increasingly focused their research on what Lincoln calls the "coevolutionary arms race" between the monarchs and the milkweeds. The butterflies have been voraciously eating milkweed for millions of years, and the plants have been defending themselves by becoming more toxic, which the butterflies counter by evolving their ability to metabolize the new levels of cardiac glycosides without harm to themselves. In northern Florida, for instance, a species of milkweed is so toxic that about a third of the young caterpillars that eat it become cataleptic (in a state of suspended animation).

Both the milkweeds and the monarchs were originally Neotropical species, but in the Miocene epoch, 24 million years ago, the milkweed family experienced an "adaptive radiation." Some species evolved frost tolerance and expanded their range into North America. The monarchs followed, but they never developed the ability to withstand freezing temperatures, so each fall, as the milkweed dies back in North America, they have to fly down to the tropics and lie low for several months until the plant re-emerges and the temperature rises. The different areas east of the Rockies from Canada to Mexico that successive generations of the eastern monarchs occupy in the course of the summer are those of their food plant as it sprouts farther and farther north in the abandoned fields, roadsides, railroad beds, and other disturbed land that it prefers.

In 1970, the Browers split, and Jane left the field; she is now a New England antiques dealer. Four years later Lincoln and two colleagues discovered that you can "fmgerprint" a monarch by analyzing its cardiac glycosides. Each species of milkweed has its own cardiac-glycoside pattern and its own geographic range, so you can pinpoint where the butterfly fed as a caterpillar.

Lincoln Brower, now 68, was eager to find the eastern monarchs' winter colonies and "fingerprint" the butterflies in them. Hearing in 1973 that the Urquharts were getting close, Brower sent them a paper comparing the cardiac-glycoside content of various eastern populations, and Urquhart wrote him that "if we do fmd the areas of concentration we will certainly be able to arrange for specimens to be sent to you or, if you wish, give you exact locations and names of persons to contact."

Actually, Urquhart and Brower already had a long history of bad blood. Urquhart disagreed violently with Brower about the toxicity of milkweed, and he went as far as to reject the entire notion of Batesian mimicry. The early pioneers, he claimed, boiled and ate milkweed pods like snow peas,and in the 50s and early 60s the Urquharts staged a series of dramatic experiments in which they had people eating monarchs to show they weren't toxic. Their subjects reported that the insects tasted like dry toast. In 1962, Brower, reviewing Urquhart's book The Monarch Butterfly for the journal Ecology, took Urquhart to task for his stance, and the ideological gap between the two widened with the 1969 publication in Scientific American of the results of the Browers' celebrated "puking blue jay" experiments. Brower, then at Amherst College, fed blue jays palatable monarchs, which the birds gobbled up happily. Then he fed some different jays monarchs raised on the very toxic milkweed species Asclepias curassavica, which they promptly vomited. Thereafter the second group avoided further offerings of monarchs, including palatable ones, while the first group continued to eat them with gusto.

Urquhart would have none of it, and the bitterness between the rivals simmered. In 1973, Brower was asked by the National Science Foundation to do an outside peer review on a grant proposal from Urquhart. Brower recommended in the most glowing terms, he told me, the proposal, which asked for funds to continue the quest for the eastern monarchs' winter colonies, but the grant was rejected, according to Brower, because "Urquhart didn't know how to write a grant proposal." Urquhart, however, was convinced that Brower had sabotaged the grant, and he implied such in a letter three years later.

When the Urquharts announced the discovery of Cerro Pelon in the 1975 edition of their annual newsletter, Brower called Urquhart in order to take him up on his two-year-old offer. But Urquhart explained he couldn't reveal the locations until National Geographic published his article on the colonies. Mter the article appeared in August of the following year, Brower again wrote Urquhart, and received on December 3 a reply to the effect that he and the society's president and editorial staff had met and "agreed that the site should not be divulged since it was anticipated that many people, collectors, film makers, etc. would wish to visit and, as happened in other similar situations, destroy it. ...I would suggest to you, since the Mexican site is not available, that you examine the ...monarchs that pass along the. ..Gulf Coast during October and November. These monarchs will eventually reach Mexico and you would accomplish the same results as visiting the area."

Furious that his equally legitimate scientific motives were blown off, Brower set out to find the colonies on his own. The National Geographic article disguised the location, saying it was in the Sierra Madre, a rugged mountain range 250 miles to the northeast of the actual sites, but a brief announcement of the discovery by the Urquharts in the Journal of the Lepidopterists' Society was more helpful. The colony, they reported, was at 10,000 feet, "on the slope of a volcanic mountain situated in the northern part of the state of Michoacan." So Brower and his colleague WIlliam Calvert pored over a topographical map of Michoacan and circled everywhere above 10,000 feet. This narrowed the search to a few mountain ranges in the geologically recent province in central Mexico known as the Transverse Neovolcanic Belt, and on December 26, 1976, Calvert and three colleagues drove down to Mexico. Four days later they drove up to Angangueo and were taken by a local man, Alian Ariega, to the Chincua colony.

Hearing the news, Brower rushed to Chincua. "It was like walking into Chartres Cathedral and seeing light coming through the stained-glass windows," Brower recalled two years ago in an article for National Wildlife magazine. "This was the eighth wonder of the world."

As luck would have it, the Urquharts and the Bruggers were at that very moment tagging monarchs inside the colony. The Urquharts "were bewildered by our arrival and initially treated us rudely, then with hostility," Brower wrote in a 1995 article, this one for the Journal of the Lepidopterists' Society. He related the episode in more explicit detail to me: "I put my hand out. Urquhart barely took it, then he withdrew his hand and asked, 'How did you get here?' It was a moment." Brower's assistant managed to take a snapshot of Urquhart sitting on a log and fuming. It is a portrait of a man who is totally bummed out.

Brower published his own article about the site in the June-July 1977 issue of Natural History magazine. He estimated that it contained between 14 million and 100 million monarchs. There was no mention of the encounter with the Urquharts or the fact that the Urquharts and the Bruggers had gotten there first. The Urquharts and their loyal army of volunteers were outraged. That September, Urquhart wrote a special eight-page report to his research associates accusing Brower of having followed Brugger to the site and starting a fIre "to dislodge monarchs from their roosting trees to provide material for dramatic photographic shots." Brower vehemently denied both allegations in an article in The New York llmes.

"The Urquharts were devastated that we found the place," Brower told me. "We were interlopers." Mter the vicious attacks against him, Brower gave Urquhart no quarter, missing no opportunity to point out errors in Urquhart's subsequent monographs, while Urquhart snubbed Brower completely, never discussing or even citing his work.

Carlos Gottfried, who has worked with and is fond of both men, told me that Brower "is a passionate scientist and so is Urquhart, but Urquhart's science wasn't up to the same level as Brower's. In the 70s, Brower brushed off Urquhart as a rank amateur. He was very arrogant in those days. Now he's a nice guy. He has grown. It's been kind of beaten out of him."

This was my impression of Brower from the day I spent with him in Virginia. The rivalry, Brower admitted sadly, "polarized the small community of people who care about the monarch, and this impeded the conservation effort." 

Kurt Johnson, a lepidopterist and coauthor of the recently published Nabokovs Blues, explained the rivalry as largely generational: "I know both Lincoln and Fred. Both are great people, but rivalries -develop when you have institutions and people with the same research interests. The thing that's special about this case is something we call the clash between the old science and the new science. Brower received his training more recently, so he was simply able to bring to bear on monarch research more sophisticated methods than Urquhart had been trained in. That's something that all of us deal with in science: methods change so quickly and the level of sophistication changes so quickly."

The Urquharts soon had to retire from the scene; they weren't physically up to j working at the high altitude. Today, Urquhart is not involved, but his tagging pro~ gram continues, run by Orley "Chip" Tay: lor at the University of Kansas. It is now a computerized effort, and you can sign up to join it on the Monarch Watch Web site (www.MonarchWatch.com). 
 

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