Who's Kenn? Simply put, Kenn is a national treasure. A renowned birder, author, and conservationist, Kenn Kaufman has spent his life dedicated to observing birds, reading about birds, writing about birds, and sharing the world of birds with others. With all that birdy knowledge in his brain, he also acts as the field editor for 约炮视频 magazine. So, whenever we have a bird question stumping us around the office, we just ask Kenn. And now you can, too! If you have a bird or birding question you'd like Kenn to answer, leave them in the comments below or on Facebook. Maybe next month you'll get the kind of thorough, thoughtful, and even humorous response from Kenn we've grown so fond of over the years. 鈥擳he Editors
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Q: What's the deal with digital binoculars? Are they any good, and do you expect them to replace standard binoculars, which have barely changed?
KK: In talking about these new digital bins, I think we should avoid the promotional language from some dealers who claim that basic optical binoculars have been 鈥渦nchanged for centuries.鈥 John James 约炮视频, pursuing birds 200 years ago, had no binoculars. Florence Merriam, writing 130 years ago, was among the first to promote using opera glasses to actually look at birds鈥攁nd those opera glasses were quite primitive in quality and power. Roger Tory Peterson, as a rabid boy birder 95 years ago, eventually got clunky 4x LeMaire field glasses, almost the best things available at the time. The high-end bins available today鈥攆rom brands like Swarovski, Zeiss, and Leica鈥攁re vastly superior to the very best optics that existed when I was a kid. We can get views of birds in the field that would have been totally unbelievable only a few decades ago.
I'd feel safe in betting a million bucks that birders won't abandon their high-end binoculars in favor of a product that combines merely average optical quality with a mid-resolution digital camera. We really want to see fine detail, and a 10X image on a 5-inch screen won't cut it. But I can see this being a possibly useful gadget for birders in some situations. For example, for a bird that鈥檚 hard to spot, we could aim the bins and then point to the LCD screen to show others where the bird is hiding.
In terms of embracing digital technology, of course birders are already doing that. When I'm out in the field and not carrying my good camera, I always carry a little superzoom (currently the Canon Powershot SX70 HS). Recently I was looking at a tern more than a quarter mile away, barely discernible in binoculars, and I didn't have my scope with me. By size comparison to nearby Laughing Gulls I was sure it was either a Caspian or Royal Tern, but binoculars wouldn't resolve that (and the new 10x digital binoculars wouldn't have helped either). But I zoomed the Canon out to 130x, took a few pixelated shots, blew them up on the viewing screen, and confirmed that it was a Royal Tern. That kind of thing鈥攕nap a digital pic of a distant or fast-flying bird, then immediately confirm the ID from the image鈥攊s now standard birding practice.
Q: Can birds just change their ranges, or where they live, suddenly and without any obvious reason?
KK: Sometimes an introduced bird can spread explosively in a new land if it鈥檚 an adaptable species like the European Starling or Eurasian Collared-Dove. Finding open niches in disturbed habitats free of the predators and competitors from their native lands, those birds marched right across North America in just decades, becoming common coast to coast.
But changes almost as dramatic are also known to occur with native birds. There are undoubtedly reasons for such changes, but the reasons may not be obvious. For example, in the early 1930s, the only Great-tailed Grackles in the U.S. were in southern Texas. In Arizona, where they鈥檙e now abundant, they first appeared in 1936. Now Great-tailed Grackles are common west to the California coast and north to Idaho and Iowa. We think humans probably helped by irrigating farmland and building ponds and towns in dry country, but that鈥檚 a weak explanation for their vast expansion.
Other remarkable expansions in recent decades have involved the Neotropic Cormorant, White-winged Dove, Cave Swallow, White-tailed Kite, Black-bellied Whistling-Duck, and various others, all spreading north. The Cave Swallow adapted to new nesting sites, but the others are harder to explain鈥攎aybe just responding to a warming climate?
At the same time, the Bewick's Wren and Loggerhead Shrike completely disappeared from large areas of the eastern U.S. in a matter of decades, and the reasons are hazy. The Bachman's Sparrow expanded far north into the Midwest by about 1920, following a period when forests were replaced by young second growth, and then they receded and disappeared, possibly because many of those areas became forest again.
Birders have a tendency to regard bird distribution as stable, and the current status as "normal." But in fact it's changing constantly, and at any given moment we just see a temporary snapshot. As climate change accelerates, we can expect changes in birds' ranges to become even more pronounced. So some of the seemingly more outlandish forecasts in 约炮视频鈥檚 climate models may not end up so preposterous after all.
Q: Are there any bird species where males do the majority of the chickcare?
KK: There are actually quite a few examples. Many of them involve shorebirds, and what's cool is that it's not just an on-off, yes-no switch; you can see different degrees of development of this behavior.
The three species of phalaropes are the most striking examples because females are more brightly colored and totally dominant, and males do all the work of incubating the eggs and caring for the young鈥攃ompletely subverting our assumptions about brood care. What鈥檚 more, after mating and laying eggs, the female may go off and mate with another male, leaving him also with a set of eggs to tend (sequential polyandry). In the Northern Jacana (also a shorebird but in a different family), females aren't more colorful, but they are larger and more aggressive, and the female may have up to four mates at once, each of those males tending a clutch of eggs that she has laid (simultaneous polyandry). And in the Spotted Sandpiper, females are a little larger than males and they may practice sequential polyandry, simultaneous polyandry, or monogamy. Talk about a 鈥淔ree Bird!鈥 In any case, the male winds up doing more of the incubation and tending the young, but the female's involvement varies from none to a fair percentage, partly depending on whether she has other mates, and how many.鈥ㄢ
Those are "classic" examples, but if you dig into shorebird life histories you find intermediate stages. In many sandpipers, for example, the male and female both take part in incubating the eggs but the male may do more of it, and the female departs after the eggs hatch, leaving the male to tend the young. This happens with Western Sandpiper, Red Knot, and several others.
Before we start congratulating all shorebirds on their fathering skills, though, there are exceptions: In species like the Buff-breasted Sandpiper, Pectoral Sandpiper, and Ruff, the females do all the incubating and the caring for young. That's not a jab at those males鈥攔emember there is no right or wrong in the bird world鈥揵ut merely a reminder that, when talking about shorebirds as models of progressive parenting, we have to be careful about which species we choose.