Of Love and Dancing

The albatrosses began to return in late October.  One day I looked out from our cook tent and there were perhaps a half-dozen of the huge white birds standing serenely on the sand, looking both grave and comical with the stark, sharp beauty of sea-gray wings folded crisply across their backs.  They waddled uncertainly over the dunes to just the right spot, there, that's the nest, right there.  A few days later, there were hundreds, and a week later, thousands.  Their season on the tiny speck of sand in the middle of the Pacific had begun.

 Laysan albatrosse pair on Laysan Island.  Photo: J. A. Gervais, 1992

You can find Laysan Island on most world maps, although it is only about a mile and a half long, a mile wide, and cradles a large super salty lagoon.  Essentially it is nothing more than a large sand dune perched on a remnant volcano.  There isn't much else out in this part of the world, a thousand miles northwest of Honolulu, and Laysan is the second largest of the Northwestern Hawaiian Islands.  For a few years over a century ago, it was inhabited, briefly, by humans, who mined the guano, harvested the albatrosses' eggs, and killed the birds for their feathers.  It has belonged to the birds for many thousands of years.

Land is a rare commodity in the middle of the ocean, and all seabirds are tied to it for breeding.  The birds of Laysan do a time-share, where different species come in from the far reaches of their wanderings and breed at different seasons.  Winter belongs to the bonin petrels, the black-footed albatrosses, and Laysan albatrosses.

Blackfooted albatrosses dancing, Laysan Island.  Photo: J. A. Gervais, 1992.

The albatrosses were mostly quiet at first.  It must be very strange, to land on unyielding ground for the first time in nine months, and the newest arrivals seemed to suffer from the same "sea leg" syndrome that people do.  They wobbled around and studied the clumps of bunchgrass and their neighbors in silence.  But as the few birds swelled to thousands, the singing and dancing began in earnest.

Albatrosses dance.  These are spectacular dances, involving wild bows and snapping beaks, with some individuals becoming so excited they gape and scream, whipping their heads back and forth.  They whinny and moo and clap that huge beak.  Sometimes they throw themselves up on tiptoe and point skyward, with a soulful moan at the apex.  The black-footed albatrosses have a different dance than the Laysan albatrosses, but both dances are exotic, energetic, and incredibly noisy.  Living on a colony numbering tens of thousands of pairs is like being in the middle of a demented barnyard.

Laysan albatross skypointing.  Photo: J. A. Gervais, 1992.

We quickly learned that young albatrosses were so anxious to get going with their adult lives that they would throw themselves into a frenzied performance if we just waved two fingers back and forth in front of them, mimicking the first moves of the dance.  When we failed to deliver the correct response partway into the performance, they would retreat hastily, looking flustered.

I tried coaxing a few of the pairs who settled into spots right around my tent into a cross-species tango.  These birds' mates had already arrived, and after a few passionate rounds of dancing it seemed that old ties were renewed well enough to get down to the business of breeding.  Waving fingers in front of these birds elicited a sidelong look.  The albatross would draw in its chin, that huge, hooked beak held down along its neck, and waddle emphatically away.  Sometimes interspecies communication is shatteringly clear.

Every now and then, a Laysan albatross and a black-footed albatross mate, and raise a chick.  The chick, however, is doomed to be completely unlucky in love, because its dance is stuck halfway between the species.  Nobody seems to want a partner who can't do all the right moves.  The vast majority of birds belong to one species or the other, however.  Nearly all find a partner and stay together for many years, renewing the relationship each autumn with the ritual of the dance.

Blackfooted albatross dance on Laysan Island.  Photo: J. A. Gervais, 1992.

I worked on Laysan for a magical four months, picking away at invasive grass that provided shelter for none of the birds, but crowded out the native bunchgrass that nearly all of them need.  Although the work was far from special, sneaking by sea turtles and monk seals, admiring the antics of boobies and albatrosses, and watching tropicbirds and frigatebirds engage in aerial warfare made even plodding over sand dunes carrying backpack sprayers full of herbicide the best job I ever had.

I left Laysan Island on a November morning nearly twenty years ago, and I still dream sometimes of the intense color of the sea, the enormity of the sky, and the noise of all those birds.  It was an early love, one you don't forget, even if you go on to fall in love with many other places.

Road Kill

There are two more dead deer lying along the road that ends just a few miles from town.  One is a doe, probably pregnant, the other a young buck just out of rut.  Someone has stopped and sawn off the antlers of the buck but both carcasses remain in the ditch, apparently inaccessible to scavengers.  They are hardly visible from a car, and possible to overlook even from a bicycle, as the cold weather has prevented the usual tell-tale smell.

We think of roads as opportunities for our own rapid movement and convenience, if we think about them at all, not the ribbons of death that wind through the home ranges or migration routes of many animals.  Stand at a rest stop along a busy interstate and see how many seconds pass in which there are breaks in traffic from one side of the highway across all lanes to the other side.  Not surprisingly, research has shown that roads can be major obstacles to animal movement.

How much roads cut off movement depends on not only the traffic load but the animals themselves.  Some animals such as urban gray squirrels seem almost oblivious to the traffic despite the risk and frequent near-misses.  There are video clips of urban wildlife using crossroads and even apparently waiting for lights to change before they cross.  They include deer, gray squirrels, coyotes, and Japanese crows.  The crows, of course, can easily fly over the traffic, but it seems that some of them have figured out that if they drop nuts into the crosswalks, cars will run over them, and the cracked nuts can be retrieved when the light changes.  These animals have adapted to live in the new world we've created for them.

But the vast majority haven't adapted.  Desert bighorn sheep populations are already showing reduced genetic diversity in just four decades after interstate highways threaded among them, raising the risks of extinction for the now-isolated populations.  Cougars avoided two-lane paved roads although dirt roads did not deter them.  Both wolves and elk in the Canadian Rockies avoided roads and trails in national parks as their traffic increased, but elk were less repelled and actually used the areas near moderately busy trails as predator-free zones because the wolves appeared more sensitive to the disturbance.  There are gradients in responses, and consequences.

At the other end of the spectrum, freshwater turtles don't seem to recognize the danger.  Turtles moving between two wetlands in Florida were willing to attempt to clamber over a barrier made of plastic netting to cross the busy highway separating the wetlands; nearly all those that succeeded were killed.  Populations of turtles near roads have a sex ratio skewed towards males relative to populations away from roads. More dead  female turtles are found on roads than males because the females are driven to leave the safety of water to find nesting sites.

The biggest issue may not be just the body counts, as staggering as they may be (upwards of 350 million wildlife deaths per year in the United States).  The worst thing about road kill may be what it reveals about our own fundamental thoughtlessness.  We are the one species that seems able to contemplate killing in an abstract way, evaluating the moral and ethical consequences of taking another's life.  The vast majority of us would not describe ourselves as careless killers, and would claim to avoid causing senseless death when possible.  Then we get into our cars.

The speed limit on the road with the dead deer is fifty miles an hour.  Every branch of this winding road ends a few miles farther into the hills, serving an exurban bedroom-community development.  People claim to like living in the country because they enjoy nature, but nature had better not get in the way of easy access to town.  Of course, very few wildlife-vehicle collisions occur on purpose; after all, people are often also victims of severe injuries or death when large animals like moose are involved.  But nearly all animals that are hit die.

When animals die of natural causes besides predation, they tend to die in places where scavengers can get to them, so that the occasion of death is also an occasion for the continuation of other life.  One of the elements of roadkill is its wastefulness, because the traffic may prevent scavengers from at least cleaning up after our carelessness.  Worse, other animals may be attracted to the bounty then also die in traffic.  This is only one aspect of the particularly repugnant facets of road kill.  Another facet is its anonymity, with neither killer or victim aware of the other.  It is the ultimate in thoughtless take.

The vast majority of victims are not ever seen before being hit, especially if they are low to the ground and cryptic, like snakes, lizards, or salamanders.  It is easy to ignore the carnage if you never see it, easy to believe that you don't contribute to it, easy not to think about it at all.  What if we did think about it?  What if seeing a dead animal, even a snake or a slug, required a moment of reflection and grief?  We would have to slow down enough to see the corpses.  If we slowed down, there would be far fewer of them.  That would be one benefit.  The process of acknowledging the losses might have a far greater benefit, that of helping us recognize our own place in the scheme of life, the first critical step to salvaging our planetary home.

Swallows

The violet-green swallows are back, wheeling under lowering clouds threatening more winter rain, even though the pasture grass is greening up and the spring wildflowers are defiantly blooming.  These plants are not pollinated by honeybees, but rather by beetles, bumblebees, and other animals less prone to an unusually cold, late spring.

Violet-green swallow, Tachycineta thalassina. Photo by Tom Munson

The swallows are back.  Their internal drives told them to head north into the teeth of cold wind, rain, and hail.  The day I first saw them this year was hardly in the mid-40s, with a sharp-tongued wind laying bare the fragile promise of my jacket.  I wondered if there were any airborne insects for the birds, between the cold and that wind.

These birds spend the northern hemisphere winter in South America, a long way away. They make their way there and back again on those marvelous, fragile wings, guided by the shared hertitage twisted into the strands of their DNA.  We call it instinct, which means we don’t know how they know.  At leas, it doesn’t appear to be knowledge acquired only through the individual’s own experience.

Animal navigation has been the subject of a great deal of human curiosity and research, and we are slowly making headway in understanding the cues that animals use when traveling over vast differences.  Recent work with loggerhead sea turtle hatchlings suggest that the hatchlings use magnetic forces in the earth to find their way, both with respect to latitude, their north-south position, and longitude, their east-west position.  The magnetic field isn’t consistent particularly on the east-west gradient, but the variation through space may be sufficient for the hatchling turtles to recognize their position and make their huge circuit of the Sargasso Sea. 

Loggerhead sea turtle, Caretta caretta. Photo credit: NOAA

Birds also use magnetic cues to find their way.  However, their ability to navigate is also clearly influenced by their experience.  When a biologist captured and transported south-bound starlings en route from northern Europe in the Netherlands and released them in Switzerland, the adult birds compensated for the sideways shift, but the young birds did not.  Juvenile barn swallows responded to magnetic cues when skies were overcast, but didn't do so otherwise. Different birds use different methods of migration, a result of the behavior having evolved again and again. Landmarks and stars and the sun all are used to some extent.  Migrating birds travel enormous distances and risk death if they arrive in the wrong place.  No wonder they draw their navigational information from many sources.

The feat is perhaps all the more spectacular for braiding together multiple lines of evidence, experience, and instinct in a brain we are more likely to mock than admire.  However they do it, I’m glad the swallows found their way back to our pastures again.  Their astonishing flight seems more an aerial celebration than simply a means of survival.