In the Happy Valley of central Pennsylvania, honeysuckle shrubs provide local birds with an abundance of berries on which to feed. The honeysuckle berries are so plentiful they have helped boost local bird numbers and diversity. Scientists estimate there are 3 to 4 times as many fruit-eating birds in the Happy Valley today as there were 30 years ago.
Such a scenario implies a vibrant natural community. But that's not precisely the case: there's little natural about the presence of honeysuckle in the Happy Valley. The shrub is in fact an alien intruder—an invasive species introduced by humans that has run riot through the community with the enthusiasm of a common weed.
Normally, invasive species spell disaster for the habitats they invade. They are notorious for outcompeting sensitive native species, reducing biodiversity and dismantling the delicate interactions of a pristine community. But in the case of honeysuckle in the Happy Valley, the downsides of the invasive shrub appear to be dwarfed by the upsides.
To understand the role of the invasive honeysuckle, scientists from Penn State University selected a plot of land in Happy Valley and measured the abundance of honeysuckle and native birds that occupied it. They found that where honeysuckle was plentiful, so were birds. Their study indicated that birds and honeysuckle enjoy a mutualistic relationship in which both parties thrive. The birds feed on honeysuckle berries and in return disperse honeysuckle seeds.
"Honeysuckle comprises more than half of all the fruits available in the landscape, and it benefits birds by providing them with a source of food in the fall," explained biologist Tomás Carlo of Penn State University in a recent press release.
"Birds benefit honeysuckle by dispersing the plant's seeds across a wider geographical area, helping the species to occupy more and more territory in areas already affected by human activities," Carlo said.
Tomás Carlo and coauthor Jason Gleditsch, a biology graduate student at Penn State University, also examined the effect of honeysuckle on a native plant, the American nightshade. They found that where honeysuckle was present, the native American nightshade fared better:
"The same birds that ate the honeysuckle also ate the American nightshade, dispersing the seeds of both plants. It's a win-win-win for all three: the birds, the honeysuckle, and the nightshades." Carlos said in a recent press release.
The results of this study shake the commonly held view that invasive species wield only hazards for the communities they invade. As illustrated by the Happy Valley data, there may be considerable upsides to communities altered by non-native species.
Such a scenario implies a vibrant natural community. But that's not precisely the case: there's little natural about the presence of honeysuckle in the Happy Valley. The shrub is in fact an alien intruder—an invasive species introduced by humans that has run riot through the community with the enthusiasm of a common weed.
Normally, invasive species spell disaster for the habitats they invade. They are notorious for outcompeting sensitive native species, reducing biodiversity and dismantling the delicate interactions of a pristine community. But in the case of honeysuckle in the Happy Valley, the downsides of the invasive shrub appear to be dwarfed by the upsides.
To understand the role of the invasive honeysuckle, scientists from Penn State University selected a plot of land in Happy Valley and measured the abundance of honeysuckle and native birds that occupied it. They found that where honeysuckle was plentiful, so were birds. Their study indicated that birds and honeysuckle enjoy a mutualistic relationship in which both parties thrive. The birds feed on honeysuckle berries and in return disperse honeysuckle seeds.
"Honeysuckle comprises more than half of all the fruits available in the landscape, and it benefits birds by providing them with a source of food in the fall," explained biologist Tomás Carlo of Penn State University in a recent press release.
"Birds benefit honeysuckle by dispersing the plant's seeds across a wider geographical area, helping the species to occupy more and more territory in areas already affected by human activities," Carlo said.
Tomás Carlo and coauthor Jason Gleditsch, a biology graduate student at Penn State University, also examined the effect of honeysuckle on a native plant, the American nightshade. They found that where honeysuckle was present, the native American nightshade fared better:
"The same birds that ate the honeysuckle also ate the American nightshade, dispersing the seeds of both plants. It's a win-win-win for all three: the birds, the honeysuckle, and the nightshades." Carlos said in a recent press release.
The results of this study shake the commonly held view that invasive species wield only hazards for the communities they invade. As illustrated by the Happy Valley data, there may be considerable upsides to communities altered by non-native species.
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