The advent of spring brings a revival of the senses as the world around us rebounds from winter. Flowers burst forth like a slow-motion fireworks display. Bird songs and frog calls echo through the woods. And the American woodcock’s aerial dance paints figure-eights in the evening sky. All of these exhibitions-the visual, the acoustic, and the physical- have a common purpose: reproduction.
Flowers are nature’s flashy neon billboards. Calling seductively to pollinators like bees, butterflies, beetles, and hummingbirds, flowers advertise that there’s sweet, sugary nectar to be had. And all a pollinator has to do in return is carry a little bit of pollen from one flower to another. This “sugar for services rendered” system of payment has spawned a wide array of relationships between plants and pollinators: there are generalist relationships, in which flowers are accessible to many types of pollinators, and there are extreme specialists, where a flower is uniquely shaped to allow access to only one species of pollinator. The coevolutionary relationships between plants and pollinators produce astonishing diversity, but with apologies to the botanists out there, I will leave the plants behind in the rest of this post and turn my attention to the displays of animals. That said, if you want to learn more about the breadth of plant-pollinator relationships, a good starting point is In Defense of Plants, which has over fifteen podcasts on the subject.
As we turn our eyes and ears toward the exuberant displays of the animal world, we quickly find that nature has a ridiculous sense of humor. If you see an animal (or human) doing something absurd, it’s likely under the control of a mind-altering parasite (a real phenomenon I’ll cover in a later post), or under the control of mind-altering reproductive hormones. To highlight the latter, let’s begin with one of the ducks currently wintering in the waters off both coasts of North America: the red-breasted merganser.
Mergansers have long, narrow bills equipped with tooth-like serrations that facilitate the capture and retention of slippery fish. They also sport wild, punk-style ‘dos which I recently learned can be converted into one giant spike on a displaying male’s head. This new insight occurred on an overcast morning a few days ago. I got up around sunrise and made my way down to the shoreline, equipped with my camera and travel mug full of coffee. I settled in among the wave-tossed logs on the beach and began watching the activity out in the water. The omnipresent harlequin ducks were engaging in their never-ending series of chases and reprisals, and a few common loons and horned grebes were foraging in the nearshore waters. There was also a pair of red-breasted mergansers close by, and as I watched, it became apparent that the male was keenly interested in getting the attention of the female.
In his quest for love, the male merganser began exhibiting behavior I’ve never seen the likes of, and it consisted of more than just transforming the shape of the feathers on his head. He was engaging in something called a “multi-modal display,” which occurs when an animal uses multiple sensory modalities (like acoustic and visual cues) to impress a potential mate. And in the case of this merganser, his display incorporated three modalities: sound (if you listen carefully in the video you can hear him squeaking towards the end of the display), feather appearance (both the color and the composition of the feathers), and physical performance (watch the slowed down version to fully appreciate what he does with his body). This elaborate show is all supposed to convey information to the female about the male’s quality. There’s a huge body of research focused on mating displays, but the general idea is this: higher quality males have flashier displays, and females generally prefer the flashiest displays. Based off the level of interest (or rather, disinterest) the female merganser is showing here, I’m guessing this male may not have been the highest quality. Although to be fair, it’s also possible that the female was just not in the mood for love.
Multi-modal displays are actually quite common. The red-winged blackbird, which is calling across much of North America right now, combines song with a visual display of his bright red and yellow shoulder patches, and will often add a fluttering flight component. A group of birds that lives in Australia and New Guinea called the bowerbirds, build structures (bowers) that they decorate with flowers, shells, and other colorful items they find or steal from other bowerbirds. If a female arrives to inspect the bower, the male will add on with an array of visual and acoustic displays: this video from David Attenborough shows one such astonishing display, but there are 20 species of bowerbird, and each has a different style bower and display. A multi-modal display my wife and I were fortunate to eavesdrop on this week was that of the sooty grouse.
Sooty grouse are large chicken-like birds that inhabit mountainous conifer forests of the West. The males of this species produce a deep, bass-heavy booming call that can carry for over half a mile. Around Quadra Island, each mountain peak seems to come with a resident, vocalizing male sooty grouse. The booming call is paired with a visual display in which the male fans out his tail feathers and reveals bright yellow/orange bare patches of skin on the neck. These patches are composed of tubercles, and both they and the skin above the eyes (called “combs”) can rapidly change in color from yellow to orange and red during peak courtship.
We had been hearing the calls of the sooty grouse on our hiking outings for the past few weeks. This past Tuesday, we decided to hike up to the top of South Chinese Mountain for sunset. As we neared the summit, we could hear a male booming from the top and decided to attempt a covert mission to see him. The grouse’s call travels far, but localizing the source is quite challenging; the call is almost felt more than it is heard due to its low frequency. But as we crept around a corner of exposed rock near the summit, I happened to catch site of our quarry about 20 meters away. For 15 minutes we watched him boom out his calls, while strutting around on a moss-covered rock stage, tail fanned and neck wattles flashing. He knew we were there, spying on him, but whether he enjoyed the attention, or just didn’t feel threatened by us I don’t know. We didn’t want to push him too far (rock stars—you know), so we left him alone and retreated down the mountain in the lengthening shadows.
I want to close this week’s post with my all-time favorite bird: the American woodcock (aka the Timberdoodle). There are so many reasons this bird tops the list for me, but high on that list is the male woodcock’s multi-modal display. These birds are active and displaying throughout most of eastern North America right now, and I encourage everyone who lives east of the Rockies to get out one evening soon to experience the wonderful mating display of the noble Timberdoodle.
Woodcock watching instructions: First, find a nice grassy, open area (preferably a little wet/marshy) with some woods or shrubby habitat nearby. Then, park yourself there as dusk settles. Be sure you’re in a safe area, take a flashlight, and bring some warm clothes for when the temperature drops after sunset. Once you’re settled in your spot, sit back and listen. You’re listening for this: the mellifluous “meep” (or “peent” as others describe it) of the male. If you hear the “meep”, you may soon capture the magic of his display. The woodcock’s display includes a terrestrial component (we’ll call that the “warm-up” part--as seen here) where he meeps while facing in different directions. Once he’s sufficiently warmed up, he takes off, shedding his earthly shackles and initiating the majestic aerial dance. The woodcock may look like a football with some googly eyes and a long bill plastered on, but they’ve got some moves. The male woodcock flies upwards in a spiral, and as he climbs his wings make a twittering sound as the air passes over the flight feathers (reminiscent of the Anna’s hummingbird display covered in the Farewell Ladysmith post). When the male gets to a height of a few hundred feet, he adds a chirping vocal to his display. The show reaches its crescendo as he zig-zags back down to earth, the air abuzz with the twittering of his wings. It will all go silent for a few moments, and then the male will begin anew, filling the air with the meeping sound of love.
Next week: The marine mammals of Quadra Island.
The transition from one season to the next stirs a variety of emotions in people, but the passage of winter into spring is unrivaled in this capacity. Many have written about spring as a period of rebirth and renewal. For me, the journey towards spring is best encapsulated by one word: anticipation.
One of the great joys in life is anticipation; the days leading up to a vacation, the moment before biting into a piece of blueberry pie, and for birders, the weeks preceding Spring Migration. For the non-birders out there, spring migration is the period when birds that have traveled south for the winter make their journey back north to breed. (The same phenomenon occurs in the southern hemisphere for their spring, although generally it happens on a smaller scale.) Because birds are such vivid parts of the landscape, their absence and subsequent reappearance is tangible even for those who don’t know the difference between an eagle and a hummingbird. This is why there are festivals celebrating the return of birds in the spring; the swallows of San Juan Capistrano is a particularly well-known example, but now there are festivals all over the world celebrating spring migration: Ohio’s The biggest week in American birding; Ontario’s Festival of Birds; Alaska’s Copper River Delta Shorebird Festival; and Croatia's Stork Festival are just a few examples.
Migrating birds are not the only harbingers of spring, however, and I’m going to cover a few other examples from this past week here on Quadra Island. Before I jump into those, I want to acknowledge the incredible celestial event that transpired on Wednesday this week; the "worm" (or sap) supermoon that rose a few hours after the vernal equinox. The last time we had a supermoon on the spring equinox was 1905, and the next one will be in 2144. So I hope you got to see this one; if not, enjoy some of the photos taken from Rebecca Spit Provincial Park as the moon rose over the Coast Range mountains right around sunset.
The first two “signs of spring” examples I’ll present may come as a surprise to some, but they represent a wide-spread phenomenon: amphibians on the march in the cold. With ice still clinging to ponds, and patches of snow lurking in the shadows, the longer days have triggered the alarm clocks for many species of ectotherms (“cold-blooded” animals) to emerge from their winter refugia. So while most feathered spring migrants are still drinking cocktails in tropical or semi-tropical climes, and many furry inhabitants are still snoozing in their dens, lots of amphibians are out on the prowl. And they are on the hunt for love.
This past week we had a rain event followed by some warmer days which brought the rough-skinned newts (Taricha granulosa) onto the island’s trails and roads. These amphibians breed in ponds and slow-moving sections of streams, and they travel from their terrestrial winter burrows to water bodies to find other newts. If multiple males encounter a female at the same time, they form writhing masses of limbs and tails fondly referred to as “newt balls,” in which one male attempts to wrestle the female (generally in the center of the newt ball) away from the competition. The successful male will then deposit a spermatophore (sperm packet) on the substrate which the female picks up with her cloaca, and uses to fertilize her eggs. She deposits fertilized eggs onto submerged vegetation within a few weeks, and then leaves them to develop on their own. But the eggs, like the adults, are not defenseless; rough-skinned newts (and their eggs) contain a potent neurotoxin (tetrodotoxin—perhaps better known from the Fugu pufferfish) that protects them from most predators. It does not protect them from cars or hikers’ shoes, however, so if you’re active in areas where these slow-moving amphibians are found, keep an eye out for them.
The next early-spring riser is the Pacific tree frog, or Pacific chorus frog (Pseudacris regilla). These little frogs are incredibly hardy; I’ve heard individuals vocalizing from patches of vegetation or rocks when the temps were just above freezing. I should note that these “cree-eek” croaks (known as the “dry land call”) came out at half speed, and without much enthusiasm. Now that daytime temps are well above freezing, these frogs have ratcheted up their activity to a fever-pitch. They congregate around just about any body of water and males use their “advertisement calls” to attract females. They advertise their good genes with “rib-bit” calls, performed at a much faster rate than the “cree-eek” calls, and with much more enthusiasm, even if the temps drop down close to freezing. Most of this calling happens at night, but in these first few warm days of spring, the males have kept with their singing all day long. Soon the jelly-like egg masses will start appearing in the ponds and drainage ditches, and the next generation of tree frogs will be on the way.
Our final telltale sign of spring is an auditory signal, like the frog calls, and it takes us back to the birds: I’m talking about the reverberating drumming of the woodpecker. The spring hammering is distinct from the pecking used to find food, which is usually a relatively slow, methodical tapping as part of the excavation process. Here's video of a male pileated woodpecker excavating a dead tree in search of food at Rebecca Spit Provincial Park. (For a bit of fun, slow the video down to half speed and watch the woodpecker's tongue dart in and out.)
The spring drumming, by contrast, is a male woodpecker’s proclamation of vigor, and is used to stake out a territory and attract a mate. The louder and more reverberant the sound, the better. This explains why people sometimes find themselves on the inside of a woodpecker acoustic amplifier at 5am; metal roofs and flashing, vinyl siding, and other home materials with good resonance properties are magnets for woodpeckers looking to make a statement. And they love to make that statement early in the morning when sounds travel far through the cool, calm air.
But woodpeckers aren’t picky; they’ll happily use a hollow tree, lamppost, or metal gate, which is what seems to be the medium of choice for northern flickers on one stretch of the island. Here’s a short video I captured of a male drumming on a metal gate.
About 10 minutes later, and a half mile down the road, I came across another male flicker using a very similar metal gate as his amplifier. Apparently the word is out on Sutil Road; metal gates are great for drumming. And they won’t lead to angry, half-awake humans throwing rocks at you (or worse).
So with the season of anticipation fully upon us, I'll be watching for returning birds, emerging bulbs and amphibians, new growth on trees and bushes, and a host of other signs that spring is really here.
Next week: TBA. *Note—I said this week would feature sea lions running the narrows, but the onset of spring and associated events took precedence. We’ll get to the sea lions at some point!
Early the other morning, I was hiking at the nearby Rebecca Spit Provincial Park, when I came upon a scene that spoke quietly, but surely, of death. Clumps of golden and beige deer hair lay scattered about, and the surrounding moss-covered ground was scarred by the action of hooves and paws. But whose paws?
I looked for evidence of the predator and for signs of the prey’s body, but found nothing. Tara and I returned later that afternoon to scan for more clues, but other than a pair of ravens vocalizing in the woods, we left without any further hints regarding the deer’s fortune.
The few puzzle pieces left by the interaction between predator and prey both thrilled and disquieted me. I suspect my conflicted response harkens back to our mixed backgrounds as predators and prey. As humans, our predatory history is still quite evident (consider the amount of meat the average person consumes), but most of us in North America rarely find ourselves in situations where we are under the risk of predation. A few thousand years ago (and in some areas of the world today), however, we were still very much on the menu, and I think my sympathies for the deer may ultimately stem from that shared threat.
Even without clear evidence of the predator’s identity, I can easily narrow it down to two likely candidates; wolves, and mountain lions. Both occur on the island in good numbers and both rely heavily on deer. And while I am hopeful that I will encounter one or both of these predators at some point on this journey, for now I will have to be satisfied with the knowledge that they are here, hunting in the night, and that the island is healthy enough to support top predators. And in considering that fact, it has sparked in me a disjointed and meandering contemplation of trophic interactions in general, and some of the trophic interactions I’ve come across recently.
I think as a biologist and, especially as a photographer, I’m drawn to the flashy trophic (feeding) interactions associated with predator-prey encounters. The bear chasing the salmon, the otter foraging for crabs, and the red fox pouncing on the vole. But there are, of course, many other strategies by which organisms feed. If you remember back to your Intro Biology days (nope) or Intro Ecology (umm…..) you may recall that there are a few basic categories that fall within the producer-consumer dichotomy. There are the producers (plants, algae, hydrothermal vent bacteria), that convert the energy from the sun (or from hydrogen sulphide) into food via photosynthesis or chemosynthesis. And then there are the consumers. These can then be subdivided into a number of categories; those that eat plants (primary consumers), those that eat animals that eat plants (secondary consumers), and those that eat animals that eat animals (tertiary consumers). Phew, ok we got through that. Except we forgot the decomposers; the fungi and bacteria that break down dead plant and animal matter. And I would be remiss (and likely subjected to a berating from my disease ecologist wife) if I neglected to mention the parasites, which have a durable and intimate relationship with their living hosts, from whom they siphon off resources. (My wife would also like to remind you that at least 50% of species on this planet are likely parasitic). Perhaps a bit more detail than you recall, but relatively straight forward. When we begin poking our noses into the natural world, however, there are lots of interesting cases where it is not immediately clear what sort of interaction is occurring and whether it qualifies as a trophic strategy.
Let’s consider a case I’ve already presented in the blog before; the red-breasted sapsucker. To refresh your memory, this sharply dressed syrup baron makes a living out of drilling holes into trees and consuming the sap that oozes out. I think at first blush, most people would place the sapsucker into a primary consumer category; it’s eating a living plant product. But there are a few aspects of this relationship that merit further consideration. The sapsucker drills through the outer and inner bark of the tree, thereby tapping into, and consuming, the tree’s life blood (xylem and phloem) over a matter of weeks or months. This is remarkably similar to the way in which an intestinal parasite extracts resources from its host’s gut, or an ectoparasite draws blood from its host. So does that make the sapsucker a parasite? Is it really a giant feathered tree tick?
At this point I think it requires further assessment before making a final designation, but it’s always fun to consider seemingly simple relationships between organisms in a new light.
Another relationship that I’ve touched on a few times in these digital pages, and that defies simple categorization, is the one between thief and victim; kleptoparasitism. The most common exhibitor of kleptoparasitism I’ve discussed so far is the bald eagle, who I’ve seen stealing food from otters and gulls. But gulls themselves are notorious kleptos, and will steal from terns, other gulls, as well as unsuspecting beach-goers. In eagles and gulls, this stealing behavior is opportunistic. For frigatebirds and jaegers, however, thievery can be a way of life.
First the kleptoparasite locates a target, which is typically a seabird of some sort carrying a mouthful of freshly caught fish. The frigatebirds or jaegers then begin pursuing their intended victim, chasing and tormenting them into dropping whatever food item they are carrying, which the chasers snag out of the air and gulp down. These full-time thieves make a living out of extracting energy from pre-consumed food collected by others. So the question is, does kleptoparasitism qualify as a trophic strategy, and if so, what type of trophic category is it? Are they micropredators of their victims, stealing small allotments of energy? Are they parasites, like the sapsuckers? Perhaps they are competitors, although generally that involves procuring resources prior to acquisition by the competition, not after. In answer to the question I posed, I’m not sure how kleptoparasitism fits into the current paradigm, and suspect that it requires a new category all to itself. It may not be a common full-time strategy, but many different organisms (yeah I’m looking at you humans) exhibit this form of energy consumption at least occasionally, and I think it warrants more attention.
I’ll wrap up this week’s post with an unheralded, but critically important trophic interaction; decomposition. Generally this category is reserved for the fungi and bacteria that break down waste material and dead organic matter, and in the process, recycle those nutrients back into the system. But should we consider adding carrion eaters, or scavengers, to this category? They consume dead organic matter, digest it, and excrete nutrients that are taken up by plants, algae, fungi, and bacteria. Furthermore, we now know that much of the work of digesting the dead material is conducted by the animal’s gut bacterial flora; their microbiota. Including scavengers in the decomposer category doesn’t seem like such a long shot now that we know who’s actually doing the work here. Of course, it’s likely that every animal requires the help of its gut microbiota to digest its food, but I think we’ll leave the implications of that relationship alone for now.
Next week: Sea Lions Running The Narrows
It’s been one week since we packed up our place in Ladysmith and headed north to Quadra Island. Located in the Strait of Georgia, Quadra is the southernmost of the Discovery Islands, and home to about 2,500 year-round residents (that’s an average density of 20 people per square mile). The island comes equipped with mountains, lakes, log-studded coasts, dozens of miles of hiking trails, wolves, deer, mountain lions, and stunning vistas everywhere you turn. It was the wild nature of the island that first attracted us to it, and so far it has not disappointed. This post will be a fairly short introduction to the island, and some of its inhabitants.
To get here from Vancouver Island, we hopped a ferry in Campbell River and journeyed across the narrow Discovery Passage to Quathiaski Cove on Quadra. We then drove the short distance across the southern neck of the island to our new home. Our cottage is on the southeast portion of the island and is perched on the somewhat elevated plateau overlooking the water. Although we’re tucked into the forest, we can still see the ocean, Cortes Island, and the mainland’s snow-capped Coast Mountains. And the sunrises. Almost every morning I awake to a different flavor of sunrise. On relatively clear mornings we get “the Midas touch,” when the sun peers over the mountains and turns everything a golden hue. There’s “the classic” which occurs when cumulus clouds hang lazily on the mountains and turn into pink, yellow, and orange-dipped balls of cotton candy. One morning I looked out to an astonishing spectacle (we’ll call it “the holy cr*p!”); bands of stratus clouds had been converted into wide tangerine and yellow rivers extending north and south as far as I could see. And then there’s always "the Pacific Northwest special” when there is no sunrise because we’re socked in with clouds.
We share these sunrises with a handful of Columbian black-tailed deer. There appear to be anywhere from 3 to 6 of these deer in our neighborhood, and they typically emerge from the forest in mid-morning and late afternoon. They follow well-worn paths into and out of the woods, and visit us to graze on the short grasses and other plants at the margins of the yard. They are wary of me, but don’t seem overly concerned when I’m nearby; I suspect they have learned that the people in this area are generally just interested in watching them. But these deer have good reason to remain alert; we are in wolf and mountain lion territory, and while these predators are unlikely to make an appearance in our yard, they do hunt in the tracts of forest that surround us. I, of course, would be thrilled if they showed up at our cottage, but our best chances of seeing them are in the northern, more rugged parts of the island.
The wolves of the Pacific Northwest have broadened their diets to include foods from the intertidal zone, and some of the best wolf-viewing opportunities are when low tides coincide with the early morning or late evening hours. During these times, the wolves can be found nosing around the exposed tide-pools, flipping rocks, and searching for edible morsels. Morsels like the purple shore crab.
Purple shore crabs are commonly found under rocks in the intertidal, and during a recent low tide, I spent some time exploring the exposed shoreline near our place. In addition to crabs (green shore crabs, hermit crabs, and a lone kelp crab, along with the purples) I found a dozen or so nudibranchs, or sea slugs. The species I found (and pictured here) are called Monterey Sea Lemons (or False Sea Lemons) and they specialize on sponges. Nudibranchs (which translates to “naked gills”) are close relatives of snails, but have lost their protective shells. Some species of nudibranch eat sea anemones and steal the anemone’s stinging nematocyst defenses (essentially cells that shoot a venom-tipped harpoon when triggered). They are then able to transfer these stinging cells into special tentacle-like projections on their back and use them to defend against their own predators. Talk about taking full advantage of a resource. Our Monterey Sea Lemons don’t do that; rather, they produce a distasteful chemical substance that discourages predators. The bright yellow warning color (“aposematic” coloration) is derived from carotenoid pigments the sea slug acquires from the sponges it eats. Not quite as cool as stealing your prey’s defenses, but pretty neat nonetheless.
Another abundant island inhabitant is the bald eagle. We have a resident pair along the shoreline near the cottage, and they are very active. The breeding season has begun and this duo is constantly on the look-out for food. And while there aren’t river otters to steal from on our beach, the eagles keep a close eye on the activities of the other birds. In particular, they watch the activities of the glaucous-winged gulls. Devotees of the blog will recall the glaucous-winged gulls’ penchant for sea stars (Feb 21-Snowbirds on the Beach), but these birds will eat just about anything they can fit down their gullets. If a gull finds something that the eagles like the look of, like a fish or bit of carrion, the eagles will launch from their perch, and attempt to steal the item. The gull’s first choice is to rapidly gulp down whatever it has found, but it the food is too big, the gull typically drops it, and, along with all the other birds in the vicinity, high-tails it out of there. One of the eagles then plucks the food item from the water or the rocks, and enjoys the fruits of the gull’s labor.
The local eagles are also more than happy to take advantage of free food, even if it has passed its expiration date. During an exploration of the southeast point of the island (Francisco Point), we happened upon a Steller sea lion carcass that had washed up on the beach. The carcass was clearly a few weeks old, and had been mostly stripped of its meat. But there were still bald eagles and common ravens jostling for access to the remaining bits of tissue stuck to the bones. The birds were wary and wouldn’t let us approach more than 50 meters or so before they would retreat to the trees.
The next morning, I returned to the carcass before sunrise, hoping to hide myself before the eagles appeared so that I could get some good shots of them feeding. Unfortunately, the eagles arrived even earlier than me, and my attempts at camouflaging myself failed. It’s hard to remain unnoticed by an animal that can spot a six inch fish in the water from hundreds of meters away. I packed up and left the dozen or so eagles that were patiently waiting for me to vacate the area. Next time, I’ll have to try getting there while it’s still dark.
Next post: TDB!
About the author:
Loren grew up in the wilds of Boston, Massachusetts, and honed his natural history skills in the urban backyard. He attended Cornell University for his undergraduate degree in Natural Resources, and received his PhD in Ecology from the University of California, Santa Barbara. He has traveled extensively, and in the past few years has developed an affliction for wildlife photography.