next message in archive
no next message in thread
previous message in archive
Index of Subjects
> This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --Boundary_(ID_udR66eXQlGFLr/5uHos8VA) Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Globe and Mail, Thurs., Dec. 28, 2006 -- on-line Globe? [not in newspaper] Red squirrels time babies to big crops Larger litters are born when evergreens produce extra seeds, scientists discover STEVE LILLEBUEN Canadian Press EDMONTON -- In the eat-or-be-eaten animal kingdom, red squirrels have found a way to stay one step ahead of their food source. Biologists have discovered that the furry critters can anticipate when evergreens will produce bumper crops of seeds, and they respond with larger than usual litters. It's no coincidence, according to an article published in the latest edition of the journal Science. Rather, it's perfectly timed behaviour. "We usually predict that animals will just track resources and respond at a later date, so this is very surprising," lead author Stan Boutin, a University of Alberta biologist, said yesterday. "It's quite a story in the scientific world because we haven't seen this before, and more importantly, we hadn't even thought to look." Typically, spruce and pine trees use a boom-and-bust strategy in their seed production to counter a squirrel's big appetite. In lean years, Prof. Boutin said, trees starve squirrels so that when larger seed crops are produced randomly, there are fewer squirrels around to eat their future seedlings. Monitoring red squirrels near Kluane National Park in the Yukon, however, led to surprising results. Months before a big cone season started, squirrels went into a reproductive frenzy. The pattern repeated itself in 1993, 1998 and 2005. "Lots of animals breed well ahead of the spring flush when babies are born, and they can do that each year because temperature and daylight changes are such good predictors of upcoming changes," Prof. Boutin said. "It's a little bit tougher when things are unpredictable like seed production years, but the squirrels obviously figured out a cue." Squirrels also take quite a chance, he said, because they end up having their offspring during seasons with no resources in order to outwit the trees' swamp-and-starve mechanism. There's no danger that the squirrels will wipe the trees out, he said. Lots of seed still escapes to produce young seedlings. The same patterns were observed by scientists in Europe, where Eurasian red squirrels cranked up their reproduction so that their young could feast on a burst of seeds from oak and beech trees. Exactly how the squirrels have become smart enough to predict the future availability of seeds is not yet known. Prof. Boutin figures the animals may be aware of some as-yet-unseen cue. It takes roughly 18 months for a tree to produce a cone, he said. Cones start off as either reproductive or vegetative buds. The reproductive buds sit dormant over winter, giving the squirrels something to feed on until spring arrives. The reproductive buds may somehow give the squirrels a trigger to know that a big crop is on its way. It could be simply a matter of observing the abundance of reproductive buds, or plant hormones could be tapping into some kind of reproductive trigger in the squirrels' physiology. --Boundary_(ID_udR66eXQlGFLr/5uHos8VA) Content-type: text/html; charset=US-ASCII Content-transfer-encoding: 7BIT <HTML> <HEAD> <TITLE>FW: Red squirrels time babies to big crops -- Larger litters are born when evergreens produce extra seeds, scientists discover -- Globe and Mail, Thurs., Dec. 28, 2006</TITLE> </HEAD> <BODY> <FONT SIZE="2"><FONT FACE="Arial">Globe and Mail, Thurs., Dec. 28, 2006 -- on-line Globe? [not in newspaper]<BR> </FONT></FONT> <BR> <H2>Red squirrels time babies to big crops<BR> </H2><H3>Larger litters are born when evergreens produce extra seeds, scientists discover<BR> </H3>STEVE LILLEBUEN <BR> <BR> Canadian Press<BR> EDMONTON -- In the eat-or-be-eaten animal kingdom, red squirrels have found a way to stay one step ahead of their food source. <BR> <BR> Biologists have discovered that the furry critters can anticipate when evergreens will produce bumper crops of seeds, and they respond with larger than usual litters. <BR> <BR> It's no coincidence, according to an article published in the latest edition of the journal Science. Rather, it's perfectly timed behaviour. <BR> <BR> "We usually predict that animals will just track resources and respond at a later date, so this is very surprising," lead author Stan Boutin, a University of Alberta biologist, said yesterday. <BR> "It's quite a story in the scientific world because we haven't seen this before, and more importantly, we hadn't even thought to look."<BR> Typically, spruce and pine trees use a boom-and-bust strategy in their seed production to counter a squirrel's big appetite. <BR> <BR> In lean years, Prof. Boutin said, trees starve squirrels so that when larger seed crops are produced randomly, there are fewer squirrels around to eat their future seedlings. <BR> <BR> Monitoring red squirrels near Kluane National Park in the Yukon, however, led to surprising results. <BR> <BR> Months before a big cone season started, squirrels went into a reproductive frenzy. The pattern repeated itself in 1993, 1998 and 2005. <BR> <BR> "Lots of animals breed well ahead of the spring flush when babies are born, and they can do that each year because temperature and daylight changes are such good predictors of upcoming changes," Prof. Boutin said. <BR> <BR> "It's a little bit tougher when things are unpredictable like seed production years, but the squirrels obviously figured out a cue." <BR> <BR> Squirrels also take quite a chance, he said, because they end up having their offspring during seasons with no resources in order to outwit the trees' swamp-and-starve mechanism. <BR> <BR> There's no danger that the squirrels will wipe the trees out, he said. Lots of seed still escapes to produce young seedlings. <BR> <BR> The same patterns were observed by scientists in Europe, where Eurasian red squirrels cranked up their reproduction so that their young could feast on a burst of seeds from oak and beech trees. <BR> <BR> Exactly how the squirrels have become smart enough to predict the future availability of seeds is not yet known. <BR> <BR> Prof. Boutin figures the animals may be aware of some as-yet-unseen cue. <BR> <BR> It takes roughly 18 months for a tree to produce a cone, he said. Cones start off as either reproductive or vegetative buds. The reproductive buds sit dormant over winter, giving the squirrels something to feed on until spring arrives. <BR> <BR> The reproductive buds may somehow give the squirrels a trigger to know that a big crop is on its way. <BR> <BR> It could be simply a matter of observing the abundance of reproductive buds, or plant hormones could be tapping into some kind of reproductive trigger in the squirrels' physiology.<BR> <BR> </BODY> </HTML> --Boundary_(ID_udR66eXQlGFLr/5uHos8VA)--
next message in archive
no next message in thread
previous message in archive
Index of Subjects