"You see the cardinal at the feeder, and now you're going to know that the red colour in the feathers have carotenoids in them and that's signalling the male's health," says Bridget Stutchbury, an internationally renowned ornithologist, of the kind of knowledge she hopes readers gain from her new book, The Bird Detective.
The male cardinal's crimson signal is intended for possible female mates and prospective male competitors. In a way they're for humans, too, because we factor into the complex lives of birds. Perhaps it's time we paid closer attention. In The Bird Detective, the York University professor focuses on a different aspect of bird social and sexual behaviour. Stutchbury wrote the book to illustrate the complexity of birds' interior lives and how they're expressed externally through plumage, song and activity. She hopes this knowledge will motivate readers to step up conservation efforts by reducing energy consumption and supporting sustainable food production, which also benefits birds.
In 2007's The Silence of the Songbirds, Stutchbury documents her own and others' research showing the steep decline in North American songbird populations---some 50 percent of species in the last 40 years due to varied causes: pesticide usage; habitat destruction; climate change, to name a few.
Back to the cardinal. The Museum of Natural History's Birds of Nova Scotia site describes it as a "rare resident" here, sighted regularly in southwestern counties and in the Halifax area, and occasionally elsewhere.
"In places like Ottawa and Toronto [cardinals] used to be far less common," says Stutchbury. "It is partly climate change and partly the culture of birdfeeding that's moved them north and east."
Stutchbury's specialization in migratory songbirds has taken her north and south (field research in Panama features prominently in The Bird Detective). She hasn't visited the Maritimes in a long time and says her visit will be a learning experience. The Ecology Action Centre's Bird Issues Group is partnering with the Nova Scotia Bird Society and other organizations to host the author.
"I'm a birder from way back," says Mark Butler, EAC's policy director. For years, Butler has visited Brier Island with friends and fellow birders to watch warblers, flycatchers and tanagers arrive. "It was just like waves coming through," he recalls.
Cardinal sightings have occurred on Brier Island, according to the Natural History website. Butler doesn't mention seeing them, but agrees, "There's a story of a bird that's increasing its distribution."
One begins to see an ominous shade to the cardinal's presence here, and other shifts in populations. Butler mentions the decline in the black-throated blue warbler and chimney swift populations, the decrease in barn swallows reported by the province's farmers and the absence of nighthawks---and their yip-yip call---overhead in Halifax.
People often misunderstand birdsong, says Stutchbury. At public appearances, some attendees admitted they thought birds sing because they're happy. In The Bird Detective, Stutchbury shows there's more going on. "If you live in a busy city area and you hear song sparrows singing you'll start to wonder, 'Gee, I wonder if they're using a higher pitch because of all the traffic noise,'" she says. "We can hear the same frequencies that the birds can but they can hear a level of detail we can't hear."