I've been reading a lot about birds recently, from new imaginings of the fabulously plumed transition from terrestrial dinosaurs to our modern feathered friends to recent insights into the arms race between bird parents and brood parasites. Birds are marvelous little alien creatures. Who hasn't looked at a swallow or a hawk and dreamed of soaring, or smiled fondly at a little sparrow hopping about after crumbs, or marveled at the iridescence of a hummingbird? They may be evolutionarily distant from us – in fact they are still dinosaurs, Carl Zimmer tells us – but somehow they remain emotionally compelling, at least for me. I may not have feathers, wings, a beak, or an appetite for worms, but I feel I can put myself in a bird's 3-toed shoes with easier empathy than I can muster for many mammals with whom I share a closer evolutionary bond. (And of course for "empathize", you should feel free to read "anthropomorphize".)
Carl Zimmer in particular, has done some really great coverage of the most recent science on the origin of feathers in birds' saurian ancestors, which he encapsulates in this 3-minute animation. Not to be outdone, KrulwichWonders provides our daily recommended dose of Plumed Dino GeeWhiz. Naturally, Monday's XKCD comments on this topic as well.
Recently, several studies have caught my eye about the trying experience of being a mother bird, which I thought would be appropriate to share in honor of Mother's Day.
Many birds are born before they are fully developed (altricial species) and so bird parents must make a considerable investment in raising their young. After incubating their eggs for weeks, they still must care for the helpless hatchlings until they can fly, feed, and fend (whatever that involves) for themselves. Many songbird species also depend on their parents to tutor them in song. As with human children, it takes time and care to keep the little things alive and get them ready for the moment they can leave the nest and fend for themselves in the big world.
There is a bittersweetness to leaving the nest, however. Some mother birds, however, must wish their fledglings would get back in the next before they get themselves killed.
In one report, described recently in Nature News, fledgling South African Pied Babblers seem to exploit their parents' need to protect their progeny by putting themselves in danger. The researchers report that when hungry, the fledglings went out into the open and called for food, risking predation, but obtaining much more food from their parents than they would if they'd stayed in the trees. The researchers refer to this tactic as "blackmail" – implying that the fledglings are intentionally acting out to get more parental attention – but I wonder whether these young birds are simply beginning the process of fending for themselves. At some point they are going to start going out and foraging when they are hungry, and it may be that the behavior the researchers note is simply a result of early failed attempts at independence – calling for help when the fledgling birds get in over their beaks.
Another amazing story of parenting in the avian world is that of the Australian Fairy Wren, described by Ed Yong at NotExactlyRocketScience. Fairy Wrens, being such good mothers, are often targeted by cuckoos, who evade their own parental responsibilities by laying eggs in other birds' nests. The cuckoo eggs then hatch a little earlier than the native eggs, and the hatchlings will push their competition right out of the nest in order to dominate the poor bamboozled mother bird's attentions. The Fairy Wren, however, has developed an amazing security measure against such brood parasitism: she sings a "password" to her unborn eggs while she incubates them, which the unborn chicks learn and can repeat to their mother later on as hatchlings. Cuckoos, however, lay their eggs too late for the impostor chicks to learn the mother's password. When they hatch, they can't repeat the correct phrase, and the Fairy Wren mother simply abandons the nest as a lost cause. While not as impressive as developing a pre-natal password, other species have also developed creative solutions to avoid brood parasitism. For instance, some may avoid cuckoos by moving in with humans (since cuckoos tend to avoid settled areas) .
In other Mom news, Scientific American's PsySociety blog has a nice piece ruminating on the seminal work of Harry Harlowe and Mary Ainsworth in the 1960s demonstrating the importance of cuddling and parental care to filial attachment.
Finally, a few other tidbits from the webs:
• NeuroHacks' Tom Stafford discusses the recently discovered phenomenon of the "autonomous sensory meridian response," a sort of pleasurable meditation on mundane details, that most would describe as mindless dullness, but apparently many youtube viewers (and perhaps scientists?) find totally enthralling.
• Colonel Chris Hadfield, outgoing commander of the international space station, has been very busy sharing what it's like to live and work in space. I've enjoyed a number of his videos, but here's a convenient top-ten list, including his recent (amazing) zero-gravity cover of David Bowie's Space Oddity. By the way, I highly recommend starting with the top ranked video all the way at the bottom of the page, in which Colonel Hadfield poses the interesting riddle – what happens when you wring out a soaking wash cloth in zero-gravity?
• Dean Burnett has a delightful article at the Guardian mocking a certain breed of fear-mongering pseudo-science writing practiced with particular persistence by authors such as Susan Greenfield.
That's it for this week. Catch you on the web!