Fisher and Other Trails

Compared to summer, winter can seem like a dull companion, especially in my corner of the globe. The buzzing of insects ceased months ago. The forest floor rests under one to three feet of snow. Trees, shrubs, invertebrates, amphibians, and fungi lie dormant. Ice insulates wetlands that were vibrating with life not long ago. Migrating birds vanished months ago. Then, there’s the dangers posed by cold weather. Numbed toes and fingers aren’t pleasant, nor are the perpetual threats of frostbite and hypothermia. All-in-all, I could convince myself that winter is a season to be endured rather than embraced. This would be a mistake, though. 

While I miss the sheer volume of aliveness that accompanies summertime, winter has many endearing qualities. It helps me appreciate the abundance of summer. Off-trail travel is often easier when wetlands are frozen and snow smooths the terrain. And few experiences are as peaceful as the immense quiet that accompanies a snowstorm in an isolated grove of trees.

But this post isn’t about falling snow. Rather, it’s about a story written in the snow. Instead of looking at the wintertime forest as lonesome and empty, snow allows me to better understand how the landscape is a fully inhabited place. 

Last Monday, I highlighted the travels of a fisher during More to Explore, a bi-weekly highlight show on explore.org cohosted by Brian Byrd and me.

In the interest of brevity for the show, I skipped some details of the fisher’s trail. Tracking is an art that I’m still learning and I argue that I’m a slow study, but a few clues revealed I was looking at a fisher’s trail rather than a fox, coyote, marten, or lynx, all of whom inhabit the area.

  • Claw marks registered in most of the prints that I examined carefully, effectively ruling out felines since their claws are retractable and don’t register reliably in tracks.
  • The clearest tracks had five toes—an important clue that rules out the canines such as foxes and coyotes. Porcupines, bears, skunks, hares, and rodents can make five-toed tracks too, but they have other features that make them distinctive.*
  • The tracks’ size were too large for other members of the weasel family who live here such as short- and long-tailed weasels, mink, and marten. I could rule out river otters too since there was no evidence that the animal slid across the snow (something otters routinely do) or sought liquid water. The trackway crossed a beaver-created swamp but the tracks did not lead to water as an otter would have.
  • The animal’s gait was a mostly loping in a 3 x 4 pattern, which is a common way for fishers to travel. The 3 x 4 lope is a method of travel where a fisher places a front and rear foot from one side of the body in the same place, while the feet on the other side do not overlap. This gives the impression of only three tracks instead of four. Fishers walk, lope in a 2 x 2 pattern, and gallop too, but in my experience they’ll use a 3 x 4 pattern much more often in firm snow than American martens.
A set of fisher tracks in the snow. Four tracks are visible. The fisher moved from left to right. The yellow notebook at bottom center is ~17 cm wide.
A clear set of fisher prints. Her five toes are perhaps easiest to see in the second track from left. Also note that the fisher created four prints here so she slightly deviated from her typical 3 x 4 lope.

A fisher trackway in snow. The yellow notebook at bottom left is ~17 cm wide. The fisher moves mostly in a 3 x 4 lope. It was headed from left to right in the photo. The tracks are shallow, maybe only a centimeter deep.
A trackway from the fisher. She was moving with a 3 x 4 lope across firm snow. My notebook is about 17 cm wide for scale.

Several other mammals were active that day as well. Snowshoe hares, red fox, red squirrels, mice, and voles all left tracks or scat to reveal their presence. I was only lucky enough to be chastised by a couple of squirrels and didn’t see any other mammals for the majority of the day but walking slowly and quietly gives one the opportunity to be surprised. In a moment of quiet contemplation, the kind you experience while gazing through trees pondering your next move, a glimmer of movement appeared in the corner of my eye. I turned my head to find a weasel bounding through the snow. I didn’t dare reach for my camera knowing I’d spook it into hiding, although I remember clearly my confusion upon seeing it. 

A long-tailed weasel changes its fur color from summer brown to winter white and back again with the seasons. In winter, they are nearly pure white except for the tip of their tail, which is black—a feature that seems to misdirect attacking predators away from the head. This weasel, however, appeared to have a dark tail and head. 

My brain needed to register a few more bounds by the weasel to clear the confusion. it wasn’t oddly colored. The weasel was carrying a vole or mouse in his mouth. As he disappeared in a thicket, I was offered a special opportunity to examine its prints for clues about that may help me better understand how small weasels move in snow when they are burdened by the weight of their prey. 

Long-tailed weasels and the smaller short-tailed weasel (ermine) travel most often in snow by using a 2 x 2 lope. When you see them traveling in this way, it looks almost like a long hop, with the front feet hitting the ground first. The front feet quickly lift into the air while the hind feet land in the same place. The weasel I watched used this method and he seemed to carry his rodent cargo with ease—an impressive display of relative strength. His prey, though, left an important clue. Each of the weasel’s bounds were accompanied by a slash in the snow, which must have been created by part of the dead rodent (a foot? a tail?) dragging in the snow with each leap of the weasel.

A single set of long-tailed weasel tracks. They make a single depression in snow in the center of the photo. A light slash is visible beneath the weasel prints. The width of the yellow notebook at bottom is about 15 cm.
A long-tailed weasel’s prints are underscored by a slash in the snow created by the rodent prey it carried.

Two sets of long-tailed weasel tracks. Each set makes a single depression in snow. A light slash is visible beneath the weasel prints. The width of the yellow notebook at bottom is about 17 cm.
Two sets of prints from a long-tailed weasel. Note the repeating slash next to each track. The weasel traveled from right to left.

As I discussed in the video segment above, the life of a fisher would be far more mysterious without the record it leaves in snow. I would have no real clue how much fishers leave scent marks or climb trees without reading their trackways. Likewise, if I’d not been in the right place at the right time or been looking in a different direction I would have missed the weasel and its meal completely. Had I stumbled upon its trail with the strange, repeating mark next to each print I’m not sure I’d reason it was from the weasel’s prey. But now, I’ll be looking for other examples like it.

I hope you have the opportunity to utilize snow to learn more about your neighbors. When the snow pack melts in spring, I welcome the change although I must admit that forest seems a bit lonelier when I don’t know who has been visiting. 

*Mammal Tracks and Sign: A Guide to North American Species by Mark Elbroch is an invaluable resource if you want to learn more.

Thirteen Mountain Months

Truly knowing a place might be a capacity only of the omniscient or for earthly beings, perhaps, something gained through multi-generational experience. Lacking omniscience, living in an area far from where I was raised, and having lived in my home only for a few years, I’m forced to make do as best I can. I’ll never know a place in its totality, but I’ve come to realize that I can get closer if I experience it in every season, which is how I found myself trekking to the top of Mount Chase, Maine during every month of the year. 

December 11, 2022 
The first trip in the journey and the most treacherous. Snow has yet to establish itself for the winter and ice covers many sections of trail. The summit is frosty. The hike down is much slower than the hike up.

A trail ascends through a thick forest. The trees are generally less than 6 inches in diameter and grow closely together. The trail is covered in ice like a steep stream that has frozen. About 30-40 feet of the trail is visible before it disappears at center.
Ice covers the Mount Chase Trail on Dec. 11, 2022.

View of forested landscape. Lightly frosted spruce and fir fill the foreground. A lake is visible at center in the lower elevation forest. A ridge of mountains forms the horizon at left center.
Looking west from the Mount Chase summit toward Upper Shin Pond, Sugarloaf Mountain, and Traveler Mountain.

January 8, 2023
With snow now covering the ice, the trip is far easier than last month and the snow is not yet thick enough that I have to ski to the trailhead. My trusty fat tire bike, Large Marge, gets me there. At the summit, visibility is exceptional and perhaps only limited on this day by the curvature of the Earth. On the way down, I hear a raspy-sounding chickadee. A boreal? Yes. I see it fluttering from branch to branch in the spruce-fir forest maybe 200 – 300 feet in elevation below the summit.

View from a mountain of a forested landscape. A ridge of large mountains form the horizon, although they appear small in the photo. Snow covered trees form the foreground just above windswept rock. Frozen ponds and forest sit in between the
The view to the west-southwest from the Mount Chase summit on Jan. 8, 2023. The mountains of Baxter State Park including Katahdin form the horizon.

A boreal chickadee perches in a frost covered dead spruce tree. The bird is at left center. It has a brown cap with is diagnostic of boreal chickadees.
A boreal chickadee perches in a dead spruce.

February 12
Peak winter. Minus 60˚ F wind chills during the week prior and low air temps approaching -30˚ F at home. I know arctic peoples cope with those temperatures routinely, but I’m too poorly prepared to survive those conditions. Thankfully, this day is warmer, so much so that snow fleas are active on the snow surface. I ski as far as I can up the trail. Eventually, I abandon my skis and walk the rest of the way when the trail steepness beyond my comfort level. The trail is also too narrow to ski down safely and I don’t own the the right style of skis or the skills to do that anyway. On the way up, though, I miss their floatation. The snow pack on the upper mountain must be at least 36 inches. I post-hole to my waist on two occasions.

View of mountain from a low elevation. The mountain is covered in trees that transition from deciduous to coniferous from low to high. The foreground is snow covered.
The destination: Mount Chase on Feb. 12, 2023.

View from a mountain of a forested landscape. Only a sliver of the lowlands are visible. Snow and trees fill the fore and middle ground. The trees are snow covered, especially on their left side.
The view looking south from the Mount Chase summit on Feb. 12, 2023.

March 11
The snow seems deeper than February, but maybe this will be the last deep snow trip of the year? Along an alternative route I like to take to the main trail, I find a set of lynx prints in the snow. Farther up the mountain I ditch my skis again at a point above the abandoned fire warden’s cabin where the slope gets too steep. A few snowmobiles have made the trip, though, and I continue with relative ease in their trackways.

A single lynx track. Photo is taken from directly above it. The notebook at bottom is about 7 inches long.
A single lynx track. The feline was traveling from right to left.
The 3x4 gait of a lynx in snow. Photo is taken from directly above tracks looking down. The tracks are several inches in width and length.
Although these lynx tracks aren’t well defined, the size and shape are distinctive. I find one set of these tracks per winter on average. Lynx are rare in Maine and have large territories.
Portrait view of forest. Spruce and fir trees fill the scene with spruce growing the tallest. A narrow trail is visible at bottom center.
The coniferous forest on the upper slopes of Mount Chase.

April 22
A difficult trip to the top and back (the hardest of them all, in hindsight). Mud season has fully enveloped the region. The dirt roads that approach the trailhead are slop. Large Marge gets me to the trailhead but not without extra effort from my legs. The trail remains almost wholly snow-covered above the abandoned fire warden’s cabin and the remaining snow is soft. Still, I’m thankful winter’s dormancy is broken. Near the trailhead, I hear wood frogs looking for love in a nearby a vernal pool. The calls of juncos, robins, and sapsuckers—birds that do not overwinter here—fill the deciduous forest nearby.

Two trails intersect at lower right. Both have water flowing on them. A sign at left points to the center of the photo. The sign is mounted on a post has a homemade look. It says "trail." An arrow points to the right toward the trail. Both "trail" and the arrow are outlined in permanent marker.
The official Mount Chase trailhead.

A derelict cabin in a forest. Wet, late season snow covered the bare area in front of the cabin. A mixed forest surround the cabin. The windows and door of the cabin is missing and the brick red lead paint is peeling from the outside.
The abandoned fire warden’s cabin on Mount Chase.
View from a mountain of a forested landscape. A ridge of large snow capped mountains form the horizon, although they appear small in the photo. Snow covered trees form the foreground just above windswept rock. Frozen ponds and forest fill the middle ground.
Looking west-southwest toward Katahdin and Baxter State Park from the Mount Chase summit on April 22, 2023.

May 17
I thought I’d be done with snow on the mountain by now. I was wrong. It falls on the way up and on the summit. Some small patches linger in the shadiest areas among the spruce and fir. Bud break might be advancing fast at lower elevations, but the plant phenology seems at least a week delayed on the mountain’s mid elevations and maybe two weeks behind in the summit area.

GIF of landscape view from a mountain top. Stunted spruce and fir fill the foreground. Forested lowlands fill the middle ground to the cloud obscured horizon. Snow flakes fall in the air.

Close up photo of flower in deciduous forest. The flower petals face the camera. The three petals are maroon.
Trillium erectum on the lower slopes of Mount Chase.

June 19 
A busy day on the trail with a whopping three cars at the trailhead! Large Marge, as usual, doesn’t have any other bicycles to keep her company. The forest has come to life. I note more than 20 plant species blooming. Biting insects are surprisingly few in contrast to home where the abundance of mosquitoes and black flies force me to don long sleeves, long pants, and a headnet almost anytime I intend to spend more than a few minutes outside. In the spruce-fir forest, I enjoy listening to the songs of blackpoll warbler. Sadly, they are categorized as a threatened species in the state.

A rocky trail disappears into a green forest. Trees with bright green leaves obscure the sky. The understory is also thick with green plants.
Late spring on the Mount Chase Trail.

This is the song of a blackpoll warbler recorded in the spruce-fir forest of Mount Chase. The song is a rapid series of high-pitched notes near the beginning of the track. The audio also captures part of the songs of Swainson’s thrush and winter wren.

July 21
The air feels and looks heavy due to high humidity and hazy, smoke-filled skies. This isn’t the first day of the summer with these conditions, and the past two summers had days like this too. Is the presence of smoke becoming the new normal for summertime Maine? I concentrate on observing the trees, which are in “peak green,” a phase in summer when the foliage has reached its max yet still retains some of the freshness of spring. Fledgling birds are the latest addition to the animal community. Golden-crowned kinglets and red-eyed vireos feed noisy babies. On the summit, hundreds of dragonflies zip between the stunted trees.

Portrait view of rocky trail through a green forest. The trail starts at lower right and disappears at center.Trees with bright green leaves obscure the sky. The understory is also thick with green plants.
Peak green on Mount Chase trail. July 21, 2023.

View of forested landscape from mountain summit. Bare rock covers the ground at bottom while spruce and fir trees slope off the mountain. The lowlands and horizon are obscured by haze in the air.
Looking west-southwest through smoky haze toward Katahdin and Baxter State Park from the Mount Chase summit on July 21, 2023.

Close up view of a dragonfly. The insect rests on rock speckled with small crusty lichens. It has a blue-spotted abdomen and holds its wings flat parallel with the rock.
A darner dragonfly of genus Aeshna rests on at the summit of Mount Chase. If you know what species it is, please identify it on iNaturalist.

August 20 
A quiet hike now that songbird nesting season is done. Only white-crowned sparrows sing in the summit area. The summer foliage has reached “tired green.” The work of photosynthesis as well as insect attacks have rendered the previously vibrant leaves a darker, less vibrant hue. I experienced a stressful week. Yet, I’m fortunate to have an escape for some brief solace.

View of forest that is a mix of young and old spruce and fir trees. Dead standing trees are among them. A large trunk is at left.
A section of old growth forest on upper Mount Chase.

View of forested landscape from mountain summit. Bare rock covers the ground at bottom while spruce and fir trees cover the near slopes. The skies are mostly cloudy. Forest fills the lowlands. A pond and mountains can be seen near the horizon at center left.
Looking west-southwest toward Katahdin and Baxter State Park from the Mount Chase summit on August 20, 2023.

September 24 
I discover (for myself) the remnants of a long abandoned cabin maybe 20 yards off the trail. It’s collapsed to its foundation. Still, I’m surprised by its presence. I walked by it many times previously without seeing it. The forest tends to make things disappear. Hazy conditions have returned to the area. A thick band of wildfire smoke clouds the north horizon and the mountains of Baxter State Park are mostly obscured. A few red-tailed hawks ride the thermals on the mountainside on their migration south. A raven family doesn’t tolerate their presence. They move to chase one of the soaring hawks. We’re approaching peak fall colors, although the colors are quite muted compared to normal.

A collapsed cabin rests in the forest. Vegetation has yet to grow over the structure but the wood at the base in the foreground is rotted and moss covered. The rest of the structure forms a pyramid shape.
The forest and weather will soon consume this collapsed cabin.

The Mount Chase Trail on Sept. 24, 2023.

View of forested landscape from mountain summit. Bare rock covers the ground at bottom while spruce and fir trees cover the slopes. A pond is visible at center left. Haze obscures the horizon. The low elevation forest is speckled with yellow foliage.
Looking west-northwest from the Mount Chase summit on Sept. 24, 2023.

October 18
The forest trends brown. A solid layer of newly fallen leaves cloaks the forest floor. I somehow sleepwalk most of the way to the summit, a habit I’ve been trying to break for years with greater mindfulness. I find myself stopping to focus on my breath and immediate surroundings. Something distracted me, probably precipitated by a media culture that profits from distraction and rage-inducing social networks. It is possible to walk through a forest and not see it at all.

Landscape view of rocky trail through a forest. The trail starts at bottom center and disappears at left of center. The canopy is mostly bare of leaves. The leaves that remain are mostly yellow. A larger tree bisects the image from top to bottom.
The Mount Chase Trail on October 18, 2023.

View of forested landscape from mountain summit. Bare rock covers the ground at bottom while spruce and fir trees cover the upper slopes. The lowland forest is mostly brown and bare of leaves. Tall mountains form the horizon although they look small due to the perspective. A pond is visible in the forest at center right.
Looking west-southwest toward Katahdin and Baxter State Park from the Mount Chase summit on October 18, 2023.

November 16
I begin at an alternative trailhead that I’ve used a few times this year. The route isn’t maintained. It’s nothing more than a decades-old skidder trail, but it is a quicker and more secluded course than the main trailhead. The year has been wetter than average, so water has consistently flowed over parts of the trail. Mid fall brought a prolonged stretch of dry weather though, and the trail is drier than it has been over the entire year. Winter will soon be here. The canopy is bare. Patchy snow sits in the shady areas of the mountain’s spruce-fir forest.

View of forest that is a mix of young and old spruce and fir trees. Dead standing trees are among them. A large trunk is at left. Tiny patches of snow sit on fallen tree trunks.
The old growth forest on upper Mount Chase on November 16, 2023.

View of forested landscape from mountain summit. Bare rock with some patchy snow covers the ground at bottom while spruce and fir trees cover the upper slopes. The lowland forest is bare of leaves. Tall mountains form the horizon although they look small due to the perspective. A pond is visible in the forest at center right.
Looking west-southwest toward Katahdin and Baxter State Park from the Mount Chase summit on November 16, 2023.

December 8, 2023
Winter is a time of dormancy for many life forms, although it brings vibrancy in other ways. None of the previous trips were as beautiful or as quiet. Several inches of snow coat the ground at low elevations and about 12 inches linger higher on the mountain. No human footprints are discernible on the trail. Snow and hoarfrost cover the conifers like cake icing. The landscape appears clean in a way that I don’t find in spring, summer, and fall.

A fat tire bicycle rests against a snow covered bank. Trees fill the background at top. The bike has a rear pannier and bar mitts.
Large Marge

view of snowy forest. The trees are mostly deciduous and bare of leaves. Snow covered the ground.
The Mount Chase Trail on December 8, 2023.
The final approach to the Mount Chase summit on December 8, 2023.

View of snowy conifer trees looking toward mountains on a far horizon. The trees are pyramidal in shape and their branches are covered in thick snow. The ground is fully snow covered. A blue sky fills the upper half of the photo.
Looking down the Mount Chase Trail near the summit on December 8, 2023.

View of forested landscape from mountain summit. Snow covers ground at bottom. A single set of human footprints cross them toward the perspective of the camera. Snow-covered spruce and fir trees cover the near slopes. Ice covered ponds and forest fill the lowlands. A line of mountains forms the horizon.
Looking west-southwest toward Katahdin and Baxter State Park from the Mount Chase summit on December 8, 2023.

Time spent in the forest is never wasted and every moment offers the potential to discover new perspectives. I’m no closer to profound insights after thirteen trips to the summit of Mount Chase, although I’ve walked away with a greater appreciation for the mountain’s rhythms. The experience is both the same and vastly different every time. 

2023 Fat Bear Week Endorsement

Think of a mama bear. What does that idea conjure in your mind? Perhaps it is fierceness, since mother bears are ornery and defensive when necessary. Maybe it is commitment, because mother bears dedicate years to raise a single litter. Perhaps it is sacrifice, since mother bears provide cubs with time and energy that could otherwise serve to promote her own physical health.

We’re fortunate to watch many different female bears at Brooks River in Katmai National Park. Yet there is one whose maternal efforts are legend. One who can fish successfully almost anywhere. One whose fearsome reputation is long-lived among other brown bears, including large adult males. Don’t get in her way. Don’t lurk near her fishing spot. Don’t look at her cubs. Do give 128 Grazer your 2023 Fat Bear Week vote.

Early and late summer photos of 128 Grazer. Photo on left is Grazer on July 8. She is facing left and walking through water. Photo on right is from September 14, 2023. She is facing left and standing in belly deep water. She is round.

Grazer | ɡrāzər |

  • (2005 – Present) A female brown bear documented to use Brooks River in Katmai National Park, Alaska. Also known as bear 128.
  • verb. [with object]
    The effort of a mother bear to maul or attack another bear with little provocation, especially in defense of her cubs: She grazered him.
  • Origin: Bear cam slang. Circa late 2010s and early 2020s.

Grazer is famous among people and (maybe) infamous among brown bears for her extraordinary defensiveness. When she arrived at Brooks River in 2016 with three cubs representing her first known litter, she would confront and attack other bears with little or no provocation. Sometimes it appeared that another bear only had to look in her family’s direction to draw her ire, as bear 83 knows well. 

Her behavior didn’t mellow when those first cubs grew into yearlings the following summer. Nor did she rethink her aggressiveness toward other bears when raising her second litter. While mother bears can change their parenting strategy as they gain skill and experience, Grazer continued on the path forged with her first litter—the best defense is a good offense.

Grazer separated from her most recent litter at the beginning of summer 2023. Since then, she’s lived a brown bear bachelorette’s life. Her pheromones attracted the attention of male bears during the mating season. They chased her tail, with varying degrees of success, right bear 164? After the mating season, and also during it, she focused on eating. A lot. Her waistline carries the weight of her success.

Grazer’s formidable reputation carried into this summer. She ranked high in the hierarchy among bears and was perhaps the river’s most dominant female. Notably, 151 Walker deferred to her frequently in early summer. Walker is a big dude and he’s not shy about displacing bears from preferred fishing spots. Bears have good memories, though. Maybe he had too many bad experiences with her in the past and didn’t want to risk more dangerous confrontations.

In this video, Walker is in full dominance mode as he works to displace another adult male at Brooks Falls. But watch his behavior when Grazer shows up on the boulders above.

And in case you need more examples of Grazer bulldozing bears, here you go. (Watch with sound on for the full effect.)

During my brief time at Brooks River early last summer, I watched bears fish largely without success because the expected salmon run was slow to arrive. Some of the big guys caught some fish. 747, for example, sat at Brooks Falls like he always does and let the fish come to him, but even he wasn’t catching many. Most other bears fared worse. They roamed from one place at the river to another, searching for the few early arriving salmon.

Grazer, though, has practiced—no, perfected—her fishing tactics in many different places. If fish are jumping Brooks Falls, she’ll catch them there. If there’s space in the waterfall’s far pool, she’ll catch them there. She’ll work the jacuzzi below the falls. She’ll fish in the middle of the night. She’ll use her strength and agility to chase down salmon. 

One evening last summer, I stood on the riffles platform watching her work the river in front of me. While the riffles provides brown bears with fishing opportunities, it is often a more challenging place for bears to catch salmon than the falls. The riffles doesn’t provide the same pinch points in topography as the falls and salmon have many escape routes. There aren’t many bears who can make the best of that situation consistently, especially when few salmon are in the water and bears are forced to run through the water to get them.

Grazer parks herself on the near bank upstream of me. She moves into the water after several minutes and spots a lone salmon. She lunges and misses. She chases. Another lunge, another miss. She continues running at full speed through the water while somehow keeping an eye on the salmon. With a final lunge, she fully submerges into a two to three-foot-deep pool and surfaces with the salmon in her jaws. I can see the fish gasping in the air as blood runs from deep puncture wounds in its body. Grazer eats all of it—tail to head—even the gill plates and mandibles.

In early summer when few bears were catching salmon, Grazer found success. She is perhaps the best angler at Brooks River. 

Brown bear standing in river. Water is flowing over boulders forming riffles. Bear is moving in direction of camera. Water drips off her fur. She holds a sockeye salmon in her mouth.
Bear 128 Grazer with a catch in the riffles on July 6, 2023.

Let’s not lose sight of Grazer’s goals either. She’s working to build the fat reserves necessary to sustain her survival during winter hibernation. She’s also building fat in case she gives birth in the den. Bear cubs are born mid winter while mother hibernates. Abundant fat reserves are necessary for mother bears to reproduce, so getting fat is vital to a bear’s reproductive success.

In a way, my 2023 Fat Bear Week endorsement is a recognition of Grazer’s full-bodied and fat-addled collection of work since 2016. When she is raising cubs Grazer is the archetypal mama bear. She’s formidable, strong, brave, skilled, and  successful. She deserves your vote in Fat Bear Week 2023.

Fat Bear Week bracket. Four bears (806 cub vs 428; 402 vs 901) in two first round matches on left. Two bears (32 and 480) are in bye round on left. Four bears (128 Grazer vs 151; 284 vs 164) in two first round matches on right. Two bears (747 and 435) are in bye round on right. Graphical cartoon bears fill the top and bottom center of the bracket.
My Fat Bear Week bracket predictions for 2023. Yes, yes, I know. I don’t predict that Grazer will win. There’s a difference between who I think should win and who I think will actually win, after all. Which bear’s corner are you in? Download your bracket from FatBearWeek.org.

A Turd of a Time

While every season has much to admire, I find springtime especially enthralling. Something new appears nearly every day. At first, maple sap runs heavy during March’s warm days and sub-freezing nights. Around then, a trickle of meltwater in a ditch and a bare patch of matted leaves on the edge of a snow bank promise room for other plants to break dormancy. Soon after, the first golden catkins appear on the hazelnut and gray alder. Rainy evenings bring amphibians out of hibernation. In a short time, the soon-to-flower ephemeral herbs emerge from the crust of leaves. By late April and early May, the forest canopy bursts to life again with bird song, the blossoms of red maple and quaking aspen, and finally the unfurling of leaves that will soon thoroughly shade the ground where I trod.

Each of these are little events that promise a lot more. I’m unsure if non-human animals contemplate these changes like I do. Yet, I’m certain they pay attention to them. Black bears, recently emerged from their dens, know the pattern and are eager to exploit the change of the season to their advantage. If I’m lucky, their efforts to find their first substantial meals of the year might allow me to investigate what they are up to.

A section of Katahdin Woods and Waters National Monument sits to the east of Sebois River. It’s a quiet area of the park since there are no campsites, less than a mile of developed hiking trails, and only a few maintained roads. Bicycling through it is fun and is made even more enjoyable when I afford myself the time to go slow and pay attention. It’s one of the best places in park that I’ve yet found to look for bear sign in the spring.

Riding the single lane spur that loops off and back to American Thread Road last weekend I came across many piles of bear scat, which I was hoping to see. Not because I particularly admire turds, but because bears are cryptic here. They are frequently hunted throughout northern Maine and consequently have a substantial fear of people. The thick forest also limits my ability to watch a bear if I happen to see one. The signs that bears leave behind—such as marking trees and scat—are like pages in a book. A single page may not reveal much but look at enough pages and you’ll get a good story

A large pile of dark colored, almost black, bear scat on gravel. The bear scat is framed by grass blades and wild strawberry leaves. The background is open forest.

In particular, scat can reveal how recently a bear was in the vicinity and what it was eating. Black bears are omnivores that are well adapted to survive on plants, and the vast majority of their annual calories come from plant foods. In north-central Maine, though, there are no calorie-rich berries to eat in the spring. Perhaps there are some leftover acorns, but oak trees are not common in the forests as this area is near the northern end of their range in the northeastern U.S. So other plant foods are a bear’s best springtime bet.

While a black bear’s digestive track remains essentially one of a carnivore, it utilizes adaptations such as an elongated gut and slightly flattened molars to extract nutrition from tough to digest plant foods. A bear also consumes plants when they are most nutritious and digestible. Newly emerged green vegetation like grass, sedge, and clover contains relatively high amounts of protein, for example. As those plants mature, protein content declines while indigestible fiber increases. Fiber helps keep the bear on a so-called regular schedule, but the bear is really after the protein. Even though hibernating bears maintain their muscle health without eating or exercise, if they’ve exhausted their fat reserves by springtime then their body is forced to tap into their lean tissue reserves. Young, tender veg helps bears stave off muscle loss and even build muscle before sugary, fat-building foods become available in mid to late summer.

All but one of the scat piles I found were filled with herbaceous plants. Although most looked older than a day–when bears eat green veg, the resulting scat quickly oxidizes when exposed to air to form a black surface crust–this was a promising sign. I knew that the lightly used roads are good travel corridors for bears and the sunlight reaching the road edges allows vegetation to green-up more quickly than the forest interior, which attracts bears to the roadsides. Perhaps I might see a bear if I pedaled slowly and remained observant.

The effort paid off near the crest of a hill when I spotted a dark mass of animal on the edge of the road. I stopped to watch.

The wind was at my back, which is a welcome push when cycling uphill but also carried my scent to the bear. Once it caught my scent, the bear only needed a couple of seconds to decide to run into the forest. Had the wind been blowing the other way, I probably could’ve watched it much longer with less chance of disturbing it unintentionally. Still, I was grateful for the moment and the small insights into its world.

Before widespread logging and, later, roadbuilding encroached on the area’s forests, grassy areas in northern Maine were likely much less common than today. Black bears always sought the first spring greens, but they had to look in other places—riverbanks, stream sides, and beaver meadows for example. They continue to go to those areas, of course, even as roadsides have opened another foraging opportunity. Roads are risky places that expose bears to people though. Bears weigh the risk along with the potential reward of a good meal.

I knew the bear I saw was eating well even as it still had a long way to go until it was fat enough to enter its winter den next fall. Its effort is a journey recorded in its scat—pages, if you will, in the Book of Turds.

Action Needed: Support a Permit System for Brooks River

Brooks River in Katmai National Park, Alaska is historically, culturally, and ecologically unique. The river corridor has harbored Alaska Native peoples for thousands of years, is one of the densest archeological sites in Alaska, and remains a place of profound significance for Alutiiq descendants of former Katmai residents. The underlying geology records stories of great volcanic and glacial change. Hundreds of thousands of sockeye salmon annually use the river for migration and spawning. And, during the last 40 years it has become especially famous for its brown bears and wildlife viewing opportunities. There’s no other place like it.

A mother bears swims through water in front of a grassy shoreline. Her two first year cubs ride on her back. She swims from right to left.
Bear 482 Brett searches for salmon in Brooks River while her two cubs hang on for the ride. July 14, 2021.

Brooks Camp is also experiencing more people than ever before. 

In the midst of skyrocketing visitation last year, Katmai National Park implemented a pilot permit program for Brooks River. The permit system didn’t change wildlife distance regulations at Brooks River or limit the overall number of people who could visit. Instead, it applied only to those who wish to physically enter the river or its banks outside of the designated trails, roadways, bridge, and platforms. No one needed to reserve a permit unless they planned to enter the river or walk off trail along the riverbanks (two activities that I suggest should be avoided to give bears the space they need).

The pilot program appeared to be successful. It provided National Park Service (NPS) staff with an additional opportunity to communicate the special circumstances, rules, and responsibilities that apply to Brooks River. The NPS could revoke the permit in instances where permit holders did not adhere to wildlife distance or fishing regulations, which effectively prohibited the person(s) from reentering the river. It allowed approved Brooks River Guides to continue to give their clients the mandatory bear-safety orientations. And finally, it did not restrict or interfere with subsistence fishing associated with the traditional redfish harvest.

Now, the NPS is looking for public comments about the permit system. If you have the time and care about the bears who make the river their summer home, then please support the plan with a comment on or before April 28. As the Katmai Conservancy suggests, say yes to the permit and ask the NPS to limit the number of permits on a daily or weekly basis.

Modified satellite map image showing permit area for Brooks River. Title text reads, "Brooks River Permit Corridor (Permit Needed Within 50 Yards of River). Areas highlighted in blue represent the permit corridor. The area outlined in red represents the area closed to people from June 15 to August 15.

Why are permits necessary? The relative ease and accessibility of the bear-viewing experience at Brooks Camp has attracted increasing numbers of people. More than 16,000 people visited in 2022—an all time record high—and almost double the visitation of 2008. Brooks River is a mere 1.5 miles (2.6 km) long, yet dozens of brown bears use it during the salmon migration and spawning seasons of summer and early fall. 

People who enter in the river directly occupy the habitat that bears need to fish for salmon. Numerous scientific studies (reviewed here) have documented that human recreation can displace bears in time and space. The presence of people can cause bears to switch from diurnal to crepuscular activities in response to bear-viewing, angling, hiking, and camping. Bears decrease in number and are present for shorter time spans when exposed to people, angling, and bear-viewing. Bears also spend less time fishing and have less fishing success when anglers and bear-viewers are present.

View of river surrounded by boreal forest looking downstream. Five bears are in the water. Nearby, a group of four people stand in the water photographing the bears.
Bears gather at Brooks River to fish for salmon. People in Brooks River risk displacing bears from important foraging areas in the river. This is especially true for bears who do not habituate to our presence. In these situations, we unwittingly become a competitor in the bear’s mind for space, and most of the time that bear won’t challenge us for it.

Studies specific to Katmai National Park have found that the presence of people can affect when bears fish (Olson et al. 1998) and cause bears to avoid or alter their use of foraging areas (Rode et al. 2007; Smith 2002; Turner and Hamon 2016). Therefore, even a small number of well-behaved and well-intentioned people in the wrong place (like in the river) can have a disproportionately negative effect on brown bears. Disturbance of wildlife can also result in decreased visitor satisfaction (Skibins et al. 2012) and create user conflicts between visitors who are recreating in different ways (bear watching from the platforms or online via webcams vs fishing or photographing bears in the river).

Importantly, and tucked away in the park’s newsletter about the permits, is this: “There is no limit established to the number of permits issued during the permit-required time frame currently, but this will be considered if public feedback to the plan supports a limitation or if conditions change within the Brooks River Corridor to warrant a limitation.” Therefore, I recommend that comments ask the NPS to go beyond merely requiring permits. Comments about the permits should encourage the NPS to establish limits to permits on a daily or weekly basis and perhaps even greater seasonal closures to Brooks River to adequately protect habitat for bears.

I didn’t visit Brooks River in person last year, but rangers and some people I know who had traveled there reported to me that the pilot permit system worked well. While it does not address over-crowding and congestion issues at Brooks Camp caused by record-high levels of visitation, it is certainly a big step in the right direction to ensure the river’s bears have access to the habitat they need to survive. None of the existing regulations would change at Brooks Camp. The permits only make it easier for the NPS to enforce them. But permits alone are not enough. Existing protections for bears can be made more effective if permits were limited in availability. Our national parks, and indeed Brooks Camp, cannot support unlimited numbers of people. The Brooks River corridor is a small area overall. It has limited space for bears and a limited carrying capacity for a high-quality bear-viewing or fishing experiences. Please let the NPS know you support their efforts to protect habitat for bears in the river through the permit system and that the number of permits should be limited on a daily or weekly basis when bears are actively fishing in the river.

Submit your comments here on or before April 28, 2023.

For additional information, please see the comments I wrote on behalf of the Katmai Conservancy, an example comment that you can use, and my Brooks River pledge. As always, when commenting please stay polite and respectful. The people who manage Katmai are intelligent and well-meaning. They do not deserve insults or personal attacks.

Book Talk at Veteran’s Memorial Library

Mark your calendars if you’re based in northern Maine. I’ll be giving a talk at the Veteran’s Memorial Library in Patten at 6 p.m. on February 28. While I’ll discuss some of the main storylines in my book, The Bears of Brooks Falls: Wildlife and Survival on Alaska’s Brooks River, I also talk about how those stories might provide lessons for our relationship with the Maine landscape.

This will be a new talk, so now it is time for me to stop procrastinating and get to work polishing the presentation. I hope to see you there.

Flyer for a book talk. Background image is a bear swimming through water with two cubs clinging to her back. Above the bears is a book cover with the title "The Bears of Brooks Falls." The descriptive text reads, "What can brown bears and Pacific salmon teach us in Maine? Join Mike Fitz as he discusses his book, The Bears of Brooks Falls: Wildlife and Survival on Alaska’s Brooks River, and how that landscape offers lessons for our relationship with Maine’s wild spaces. Date: Tuesday, February 28, 2023. Time: 6 p.m. Location: Veteran’s Memorial Library at the Patten Lumbermen’s Museum."

E.P.A. Vetoes Pebble Mine!

On January 31, the U.S. Environmental Protection Agency banned the disposal of mine waste associated with the Pebble deposit in southwest Alaska. The mine could have become one of the largest open pit mines in the world and would have imperiled Earth’s last great salmon run. The EPA’s decision is a great victory for the Bristol Bay region and its salmon.

Seventy-nine million salmon returned collectively to Bristol Bay in 2022, setting a new record high for the region. Bristol Bay’s wholly intact watersheds make this possible. Water flows freely from snowmelt-fed rivulets and springs high in the mountains through the chains of lakes that occupy glacially-carved basins and into the lower stems of rivers that empty into the Bering Sea. Adult salmon swim upstream without encountering human-made obstructions or water diversions. And, instead of being displaced by shore-line hardening structures to protect buildings or roads, such as it is throughout much of the U.S. west coast, billions of salmon fry in Bristol Bay find ample refuge in the slack-waters along stream margins, grassy marshes, and lakes. Vast numbers of salmon don’t even see a bridge during their entire lives. The diversity and health of the watersheds make Bristol Bay whole. 

Turbulent water filled with salmon. A red-colored salmon's tail fin breaks the surface at upper left. At center, a more silver-colored salmon's face breaks the surface.
salmon jumping at waterfall. salmon are jumping from bottom center to lip of falls on upper left.
GIF of underwater footage of salmon fry. Water is clear. Salmon swim in current facing right over pebbly bottom.

I was late to the Pebble fight, only learning about the proposed mine in 2007 during my first summer as a park ranger in Katmai National Park. But many people in the Bristol Bay region have been advocating against Pebble Mine for 20 years. I hope the fishing boat captains and their deck hands; Alaska Native Tribes, village councils, and coalitions; lodge owners, employees, and fishing guides; chefs; scientists; those who work for non-profit and conservation organizations; and many others have the opportunity to rest well for at least a few days now that the threat of the mine is no longer looming. I thank them for their work.

Landscape scene from mountaintop. Scree slope in foreground transitions to lowland area with, forests, some mountains, and large lakes. No human development can be seen.
GIF of underwater footage of sockeye salmon. Salmon are facing left over stream bottom covered in cobbled

Before I had the fortune of living in the Bristol Bay area, I did not understand—or even fathom—the importance of salmon to place and people. The calendar in Bristol Bay is centered on salmon. The region’s economy is centered on salmon. Its ecology is centered on salmon. And it works, beautifully.

I’ve said many times before that our world is wounded. Too much of humanity seems to have a unique desire and capability to consume land, habitats, material without considering the rights of other creatures or the value that future generations of people might place on those things. I wish I could take everyone to Bristol Bay at the height of the summertime salmon run to see the fishing fleet and processors, to stand on the edge of a river while tens of thousands of salmon swim upstream, to watch brown bears gorge on their most important and sought-after food, to see an ecosystem functioning at its fully realized potential. It just might change your perspective on what should be and what is possible for our world.

Ten Years of Bear Cam and Counting

Last summer, explore.org celebrated the 10th anniversary of the bear cams at Brooks River in Katmai National Park. These webcams offer an in-depth look at the behavior and ecology of a population of brown bears, allow us to observe the same individual bears over many years–giving us the chance to learn about their personalities and habits–and provide a platform for rangers and other experts to host live programs and commentary about the bears and their stories. It’s a wildlife watching experience like no other.

As part of the celebration, I chose to highlight some the moments that I thought were most memorable from the last ten years of bear cam. Some explore point-in-time events. Others celebrate the behavior of individual bears who have left their mark on Brooks River in ways we can’t forget or ignore. Each was unforgettable from my perspective. I hope you enjoy them.

Most Defensive Mother: 128 Grazer 

Grazer is an archetypal mother bear. Don’t get in her way and don’t approach her cubs.

Lefty Learns to Fish at Brooks Falls

Old bears can definitely learn new tricks. In July 2015, we watched a fully mature adult male brown bear figure out how to fish where he’d never fished before.

Otis Eats 42 Salmon in a Sitting

Be awed by the capacity of his stomach.

Death of 451’s Spring Cub

When a bear cub falls ill the world will watch.

503’s Saga

A lone yearling finds a new family.

Reign of 856

Few bears will ever experience the prolonged dominance and advantage earned by 856.

2020 Salmon Smorgasbord

What happens when bears have access to unlimited salmon? The 2020 salmon run gave us the answer.

History of Fat Bear Week

A goofy idea becomes a world famous internet sensation.

We are Family: 909, 910, and Cubs

Sister bears reunite while raising cubs to create an extended family.

If that’s not enough, the bear cam community complied links to all of our bear cam live events from 2022. Two stand out in my mind: 1. The impromptu Q&A about a fight between and mother bear and a dominant male, and 2. The bear cam 10th anniversary live chat.

We’ve seen a lot of special moments on the cams during the last ten summers–perhaps too many to recall–so these are only a small snippet of the larger story. What are your most memorable moments from the bear cams?

Little Bog of Horrors

I find the urge to explore bogs and boggy habitats difficult to resist. Other people avoid them, which gives me space to be alone. They’re mucky, which is often a fun and challenging substrate underfoot. They contain unique species, which I find fascinating. They are full of life. And they offer surprises.

On an unseasonably warm late October day, I found myself poking around the edges of Little Messer Pond, an approximately 27-acre pond in Katahdin Woods and Waters National Monument, Maine.

Photo of pond and surrounding vegetation. Pond is at lower right. Short shrubs and sedge at lower left. Pines, spruce, and large line pond.
Little Messer Pond
Photo of pond. Trees line the pond in the middle and background. Short shrubs form the pond's border in the foreground.
Little Messer Pond

While exploring the pond’s northern flank, on a shelf of sphagnum peat that cups the pond’s shore, I found several purple pitcher plants (Sarracenia purpurea), one of the most iconic bog species in this area. The purple pitcher lives an uncommon, carnivorous lifestyle for a photosynthesizing organism. Pitcher plants supplement their growth by capturing small animal prey, typically insects. Unlike Venus fly-traps, however, which ensnare prey using a trigger-like mechanism, pitcher plants use a passive, gravity-driven process. Their leaves form bell or cone-shaped bowls that fill with rainwater. The top of the each leaf has a flaring lip lined with nectar glands to attract insects. If a hapless insect falls inside, downward pointing hairs resist its escape attempts. 

Several pitcher plants growing out of reddish-colored sphagnum moss.
Purple Pitcher Plant

Pitcher plants can’t move, so they have unsurprisingly indiscriminate tastes. To cite just one example, a study from Newfoundland documented 12 insect orders serving as prey in pitcher plants. Prey eventually drowns in the pitcher’s water where enzymes as well as inquilines (microorganisms adapted to live in the pitchers such as midge larvae, nematodes, bacteria, protozoa, and rotifers among others) break down the trapped prey, releasing nitrogen and phosphorus for the plant. Purple pitcher plants, in particular, seem to be particularly rich in inquilines, hosting at least 165 different species across its range. Pitchers are habitats of their own making and their adaptations allow them to live in nutrient poor soils where competition from tall plants in minimal.

Looking at the pitchers on the edge of Little Messer, I found ants, beetles, flies, dragonflies, various bits of unidentified insects, and a sludge of the leftovers in their bowls.

They’d eat me if I were small enough. 

GIF from Little Shop of Horrors. Plant says "Feed Me!" while Seymour looks at it.

None of the prey was unusual or unexpected until I stumbled upon a curious sight—a spotted salamander inside a pitcher.

Spotted salamander floating in a pitcher plant's bowl.

I was taken aback by the sight. I had never seen something like this before, and I remember exclaiming “What the?” even though I was alone. Was this a big payday for the plant or was the salamander only a temporary resident?

Small vertebrates are exceedingly scarce as a prey item for purple pitcher plants. In the scientific literature, I couldn’t find much documentation of it. A study from Massachusetts documented red-spotted newts as a food source for pitcher plants. A more recent study from an Ontario bog found that spotted salamanders are a potentially rich prey for pitcher plants. (One of the researchers leading that study described his sighting of a salamander in a pitcher plant felt like a “WTF moment” so I guess I wasn’t alone in my surprise.) In August 2017, researchers at that study site searched the contents of 144 pitcher plants. They found, as expected, mostly insects but also several recently metamorphosed spotted salamanders. In August 2018, they investigated 58 plants and found three spotted salamanders. The physical condition of the salamanders varied. Some were in an advanced state of decay while others were lively and were able to swim to the bottom of the pitcher when disturbed.

Plenty of uncertainty surrounds pitcher plants and the importance of small vertebrate prey to them like salamanders and newts. No one has yet tested what might attract a salamander into a pitcher since a salamander has to climb up to get into one. If the salamander can escape, then pitchers could be a refuge for salamanders who have recently emerged from the water onto the land. Perhaps salamanders are attracted to the pitcher by small insects visiting to feed on the plant’s nectaries. Their apparent capture could be random too, although, dead salamanders apparently break down quickly inside pitcher plants so maybe their true rate of capture is greater than anyone realizes.

I wonder if it might happen only in places with the right combination of habitats. Purple pitcher plants typically (but not exclusively) grow in nutrient poor bogs, places that don’t always support breeding populations of spotted salamanders. Adult spotted salamanders migrate en masse during spring to vernal pools where they breed. They may also use permanent ponds for reproduction as long as those don’t contain fish, which eat salamander eggs and larval salamanders. Newts, in contrast, breed in a greater variety of wetlands including ponds and lakes that contain fish. 

At the Ontario study site, pitcher plants grow on bog islands in permanent and fish free ponds where spotted salamanders gather to breed every spring. This seems to provide a combination of habitats that increase the likelihood of pitcher plants capturing salamanders later in the year when the juvenile salamanders metamorphose and begin their terrestrial lives. Little Messer Pond, in contrast, is home to fish, snapping turtles, and presumably other salamander predators.

A salamander or newt, even a juvenile, is a significant catch for a pitcher plant. A newt of about 500 mg of dry mass contains about 5 mg of nitrogen, which is several orders of magnitude more than an ant, a pitcher’s most common prey. That’s enough nitrogen to increase the probability of the plant flowering the next summer. If the salamander I saw had indeed perished in the pitcher, maybe it’ll dignified in death by a marvelous pitcher plant flower next summer.

Pitcher plant flower. Petals are fleshy. Flower is radially symmetrical.
In my area, purple pitcher plants flowers appear in early summer.

Pitcher plants are wonderfully adapted to secure nutrients and survive in habitats that most plants cannot tolerate. If they’re lucky enough to capture something as large and nutrient rich as a salamander, then their physical structure can hinder escape. Their acidic water (often lower than pH 4 by mid summer) can weaken salamanders through electrolyte imbalance. And, the water within them might contain compounds that inebriate or paralyze small prey. 

The fate of the salamander that I found remains unknown. I returned a week later with the intention of relocating it, but I could not find it despite my best efforts. Although I can’t be sure, I think it is unlikely that I missed it since the boggy area with the pitcher plants isn’t large and the pitchers are easy to locate. If it were still alive, perhaps it fled to the bottom of the pitcher upon my approach. However, if it were still in the pitcher after seven days, then it should’ve been dead. Did it escape the trap that so many other victims of pitcher plants could not? I wish I knew the end of this story—a drama of uncertainty, survival, life, and death.

The Remarkable Hummingbird Tongue

In the northern third of Maine spring weather is fitful, and I sometimes wonder if winter will ever break its hold. Eventually, though, usually in mid March, snow cover begins to thin as the sun travels higher in the sky and daylight hours lengthen. Around this time, maple sap runs heavy. As April arrives the hazelnut, speckled alder, and aspen (or “popples” as they are locally called) break bud as the ground thaws in earnest. I might see my first dark-eyed junco of the year about that time, followed by flickers and sapsuckers who drum from the trees as they establish nesting territories. Wood frogs, spring peepers, and salamanders wake from hibernation and migrate to their breeding pools on rainy nights. The warblers return in May along with early ephemeral wildflowers and the first expanding tree leaves in the canopy.

Although I welcome these changes like a reunion with friends, there’s one event beyond any other (even the appearance of biting insects), that to me signals the full arrival of spring—the return of hummingbirds.

A male ruby-throated hummingbird.

On May 12, I was treated to the first hummingbirds of the year at my feeders. Only one hummingbird species, the ruby-throated, nests in the northeast U.S. and southeastern Canada. The ruby-throats that establish summer residency near me may have migrated from wintering areas in Central America, probably by flying over the Gulf of Mexico before making their way farther north.

With a heart that pounds at several hundred beats per minute and wings that buzz at a too-fast-to-see pace, an active hummingbird is a powerful metabolic furnace. While insects and spiders are important foods, the fat and protein the bird ingests from invertebrate prey goes only so far in its effort to sustain their exceptionally high metabolism and energy-intensive flight. An active hummingbird’s metabolism is so high that it must eat about half its body weight in sugar each day, and it digests sugar so rapidly that it essentially refuels in flight.

The energetic costs of this lifestyle are great, so if you are a tiny bird that weighs only a few grams then it pays to be as efficient in your nectar gathering as possible. For a hummingbird, the process begins with an ingenious adaptation of the tongue.

Scientists long assumed that hummingbirds utilized the passive work of capillary action to drink nectar—stick your tongue into a flower, contact nectar with it, and allow the liquid’s surface tension to coat the tongue. However, in a 2011 paper published in the Proceedings of the National Academy of Science,* Alejandro Rico-Guevara and Margaret Rubega discovered that that a hummingbird tongue works in a much more efficient manner.

A hummingbird’s tongue is forked, somewhat tubular, and supported by stiff rods. That anatomy has been known for quite some time, but Rico-Guevara and Rubega found that the tongue utilizes no capillary action. Instead it is a shape shifter, a fluid trap, and in the author’s words, “a dynamic liquid trapping device.”

As the bird sticks its tongue out the tips remain adhered together. At this point, it looks like a long pin. Once the tongue contacts nectar, though, the real magic of the tongue’s anatomy begins its work. First, the tongue splits as curved lamellae (parallel hair like structures) along the tongue tips unfurl in the liquid.

GIF of
In nectar, a hummingbird’s unrolled tongue tips substantially increase the surface area in contact with the nectar. Timestamp is in milliseconds. Movie SM01 from (2011) Rico-Guevara and Rubega.

As the bird retracts its tongue, the lamellae re-furl over the supporting rods and trap a tube of nectar inside each tongue tip.

A view of a hummingbird’s tongue re-furling as it is withdrawn from nectar. Air is on the left. Liquid is on the right. Timestamp is in milliseconds. Movie SM03 from (2011) Rico-Guevara and Rubega.
A closer view of the tongue re-furling. Air is on the left. Liquid is on the right. Timestamp is in milliseconds. Movie SM04 from (2011) Rico-Guevara and Rubega.

Amazingly, the tongue’s transformation and liquid trapping properties are driven not by muscles, but by fluid and gaseous forces acting directly on the tongue. The tongue’s structure is hydrophilic, so when the tongue contacts air the lamellae curl around the nectar and traps it inside. The bird releases the nectar by squeezing and slightly flattening the tongue as it is pulled into the bill.

Nectar can be a difficult to access food. Hummingbirds exploit it like no other bird because they can hover in flight and, as a group, have diverse beak lengths and curvatures to probe flowers of different sizes and shapes. They are also clever enough to trapline—that is, they’ll visit the same food sources like patches of flowers on a regular basis to minimize competition and maximize nectar availability.

But knowing how specialized the hummingbird’s tongue is, I’ll never look at a feeding hummingbird the same way. The hummingbird tongue, long thought to be a passive part of the process, is a superb adaption that plays no small role in helping these tiny birds live a large life.

*The paper is a fascinating bit of natural history and is open-access, so I encourage you to read if you want to learn more about this topic.