Category Archives: Science

Abundance. From Abundance : Spawning Herring

The First Fish

After winter’s thaw and before salmon return to their natal rivers an important, silver fish appears by the millions along the northwest coast of North America. Spawning Pacific Herring provide a kickstart to the bounty of Southeast Alaska. Their oily flesh provides critical protein for migrating seabirds and returning whales and their eggs provide needed food to migrating shorebirds which have flown thousands of miles from their winter grounds. When herring spawn in abundance they attract abundance.

Herring, Kelp, Herring Eggs, Rockweed
A spawned-out herring lies among the rockweed in an estuary of SE Alaska.
Humpback Whale, Spawning, Herring, Alaska
This Humpback Whale is feeding on thousands of herring gathered in the mouth of an estuary.

The Morning As It Happened

I didn’t set out with a group of friends at 4:15AM on a clear day in Alaska in pursuit of herring. Actually, it was for birds. The “Global Big Day” is an opportunity for birders around the world to submit what they see over 24 hours to a global database which tracks and counts birds. Even if you are not a birder, you probably know that early mornings have the highest bird activity – have you ever had them wake you up?

Sunrise, old growth, tongass
We arrived at our destination right as the sun broke over the horizon and streamed through the old growth of the Tongass.

We arrived at our destination, stepped from our cars, and began to walk down a local trail. The sun burst on the horizon and its warmth only inflamed the calls of the birds. Townsend’s Warblers, thrushes, juncos, hummingbirds, and so many more! As we reached the tide flats about 20 minutes later we saw a large collection of the symbol of United States – the Bald Eagle. As it is unusual to see them in such large numbers I was curious to know why they gathered. With camera in hand I shifted my focus to that group of birds which were nearly a mile away on the coastline

Eagle, Herring, Alaska
This was only one group of the many eagles that congregated on the beach. There were four groups equally as large as this one spread across the coastline.

The walk was longer than it looked! It took 20 minutes to get closer to the eagles and as our path wound down an estuary river we began to see what the fuss was all about : flashing herring were spawning in the rockweed. Other pieces of the puzzle started to fall into place. Looking out at the ocean a large pack of Stellar’s Sealions patrolled the water, twelve harbor seals floated nearby, gulls passed over head continuously, a flock of Least Sandpipers flew by squeaking and squawking, and a Humpback Whale glided through the water only a few feet from the shore. They were here for one reason only – the abundant food.

Herring As Food

Herring, tide, trapped
These herring were trapped by the receding tide. Eagles, gulls, and ravens were able to scoop up as many as their bellies could hold.

There are about 290 calories per fillet (143g) of herring and 26% of your daily intake of fat. For wildlife they are nutrient powerhouses worth working for. Diving seabirds specialize in capturing them and Humpback Whales have perfected scooping them up in their huge mouth. However, very little effort was needed to catch herring this day. Some of the herring were trapped by the receding tide and flopped on the rockweed. All around us were torn and mangled bodies of fish had been eaten by the swarms of eagles, gulls, and ravens through the night. The Humpback Whale lunge-fed dozens of times on the spawning herring as we watched.

Abundance. From Abundance.

The film below showcases what we saw that morning. I hope it gives you a sense of place and a connection to the importance of herring and the necessity of keeping them abundant. The images below show off just a small slice of the wildlife frenzy around the herring that morning.

Abundance is created from abundance. I was so fortunate to watch these sites unfold before my eyes. It caused me to reflect on the importance of a healthy herring population. Healthy herring populations create thriving fishing industries, maintain bustling eco-tourism opportunities through whale watching and other marine activities, provide food for wildlife, and provide the continuation of the cultural practices of coastal people that have relied on them since time immemorial. As the base of the food chain a healthy herring population is critical for a thriving ecosystem that provides for people and wildlife. Here’s the catch – not all herring populations are healthy.

Herring need your help – they need you to care about them. They are in decline due to overfishing and changes in the ocean. Particularly harmful is the sac roe fisheries which net up herring right before spawning when they are the most vulnerable. The sac roe fishery is highly profitable and creates a luxury food item – herring roe – for mainly Asian markets. Herring fisheries have a history of collapsing under industrial fishing pressure. With marked declines in SE Alaska and Canadian herring population occurring, that knowledge alone makes it impossible for me to support an industry that creates a luxury item and supports only a small portion of the fishing fleet. I do not believe the cost (loss of other fishing industries, marine mammal reduction, seabird die offs) are nearly worth the benefit (a luxury item). I encourage you to do your research on this topic, but believe we need to err on the side of caution and halt fisheries that harvest at the bottom of the food chain. If you believe what I am saying rings true then please consider advocating to your representative or joining your voice to Herring Advocacy Groups.

The Secret Lives of Bears Revealed (?)

Last summer I built a camera trap with one goal in mind – photograph bears in their environments without people. I’m fascinated the insights you can gain into the animals and initially imagined all sorts of dramatic, National Geographic worthy photography. In short, I was convinced that “EPIC!” imagery was a guarantee. While I’m not there yet, I did manage to capture some dramatic moments, some fun ones, and learned a little about managing a camera trap along the way.

Brown Bear, Camera Trap, Alaska
This enormous and scarred Coastal Brown Bear was photographed strolling up river right at dusk. While I love the moodiness of the image created by the fog and the muted colors of the evening, it didn’t take long to realize that I needed to include a dehumidifier inside the camera trap box. Once I installed that I no longer dealt with fog building up on the inside of the camera housing during morning and evening hours.

Fishing Holes

For humans there is a lot of ways to “skin a cat”, for bears there is a lot of ways to catch a salmon. Throughout my images I saw bears perch above to look down in pools, snorkel in pools, and charge up pools. I’m sure each of these techniques had their strengths and their weakness.

Brown Bear, Camera Trap, Alaska
Like a gymnast this coastal brown bear balanced on a log and peered down into the pool where salmon were swimming below.
Brown Bear, Camera Trap, Alaska
This bear decided that the best way to catch a salmon was to go “snorkeling”. I have seen this behavior a lot from afar and find it is used a lot later in the season when carcasses abound on the bottom of the river.
Brown Bear, Camera Trap, Alaska
Charging up river and herding salmon into a corner is a favorite way of bears to catch salmon. This bear is doing just that.
Brown Bear, Camera Trap, Alaska
Bears and salmon both love logs. This bear is likely feeling under the log hoping to catch an unsuspecting salmon.

Family Time

Family interactions was something I hoped to gather more of. These two cubs with their mother were a special treat with an extra story. I deployed this camera and then walked back to my vehicle along the river and watched with my telephoto lens. About 10 minutes later this mother and cubs strolled down the river and then got spooked by something in the woods – likely a larger bear. They sprinted down river a ways and remarkably went right past my camera trap. Apparently the sow was not too concerned with the larger bear as she permitted her cub to capture a fish.

Brown Bear, Camera Trap, Alaska

Bears are very active at dusk and dawn. Next year I’ll be operating a camera with a flash to better capture these bears in the low-light hours. I learned quickly to program my motion trigger to only take images during the daylight hours as to avoid wasting battery on night shots. I do like the context and silhouette of this bear as it strolls in the evening, however

Brown Bear, Camera Trap, Alaska

Close Encounters

Bears are curious animals and I knew that could pose a risk to my camera. I housed my camera in an ammo can and that sufficed to keep the bears from wrecking it. There were some funny moments when the bears had to get a closer look though! One time a bear tried to eat the camera and another it walked straight up to the camera to smell it and fogged the glass. Photography can be risky business for your gear as I found out in this separate anecdote that always makes me chuckle.

Moments in the River

There were many, many images of bears being bears. Strolling up river, being observant, smelling out salmon and being gregarious. These are those moments and I challenge you to learn what you can from them.

Brown Bear, Camera Trap, Alaska
Brown Bear, Camera Trap, Alaska
Brown Bear, Camera Trap, Alaska
Brown Bear, Camera Trap, Alaska
Brown Bear, Camera Trap, Alaska
Brown Bear, Camera Trap, Alaska

Looking to Next Year

I simply cannot wait to continue to watch bears through my camera traps! This coming season I’m expanding my arsenal to two camera traps with upgraded capabilities. Two cameras will allow me to diversify my shots and provide new angles. I’m hoping to answer some questions such as “How do bears use hot feet” and “how to do bears use scratch poles” among others. Keep your eyes posted! You can always follow on Instagram or Facebook for the latest content.

Brown Bear, Camera Trap, Alaska

Looking Down on the Plight of the Tongass

Your Largest National Forest

The Tongass National Forest. Ever heard of it? How about : The Amazon. The Arctic. The Pacific Ocean. These huge tracts of land and sea are critical to life on earth and have vessels into the hearts of our lives – even if we may not know it. A fortunate few will get to dip their toes into all of them and it is not even in question that each experience in those environments will leave an indelible mark on their souls as they connect the people and animals inhabiting them. They quickly realize why protecting them is so damned important. For those who have never been, why should you care about the fate of another land? What will compassion for that place bring you in the long run? The abstract nature of such vast and unseen lands makes it hard to know enough to care. Today my mission is “simple” : connect you to a place I have grown to love and that you may have never seen or smelled. I hope that by the time you read the last word of this article and observe its last pixel you will have a sense of Tongass, its importance, and its plight.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
A long road extends through Old Growth forest in SE Alaska.

Acknowledging My Own Bias

This is not necessarily a light article and it contains both facts and my opinion based on those facts. I want you to trust what I say, so I think it is important that you understand some of my positions and personal views on conservation and resource use. I am a landscape user and a conservationist. My knowledge of the Tongass has been gained by using it while living on an island in rural Alaska for four years– my pantry is stocked with fish, deer, and berries.  I am not only a wildlife biologist, I am also a carpenter and maker-of-things. My small business of framing my imagery relies on wood to make products which I sell to people. I am not hypocritical in my views of conservation – I acknowledge resources are needed and that we need to manage the land to generate them. However, there are some resources that are simply not worth harvesting because of their impact they will have on my children’s children. If they are non-renewable and linked to the health of an ecosystem and its ability to combat climate change then it is pretty cut-and-dried for me : stay away from them and find some other way to do business. In the context of this article, there are many renewable forms of timber in the Tongass. Transitioning to those is key.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Old Growth forests butt up against the ocean.

A New Perspective

A new sense of perspective can change everything. The opportunity to see a new angle or hear a new voice can provide insight otherwise overlooked. A new perspective is where this article begins – through the summer I have been awed by insight I have gained while observing the land from helicopter, plane, and through the lens of my drone.  I have learned new things about places I travel through frequently and about how each decision is connected at the landscape level. My deeper appreciation for the landscape has led me to be a more adamant protector of it.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Beautiful mountains rise out of the Tongass National Forest. These mountains and elevation help contribute to the landscape diversity.

Landscape Diversity

The Tongass is a renowned “Salmon Forest”. Its landscape is bisected with small and large streams that host salmon. 79% of salmon harvest in Southeast Alaska are of fish that start in the Tongass and the average resident of SE Alaska uses 75 pounds of salmon per year. It can be hard to see the prevalence of rivers when you are standing in them or walking along their banks. However, from the air I was awed by the old growth stands bisected the flowing water and how beautiful the spires of old growth were near along the rivers.

A stream full of splashing salmon cuts its way through the Tongass National Forest

The Tongass is so, so much more than a stand of very tall trees – although that is what most people focus on.  It is an interwoven landscape of forest, streams, muskegs, and bogs. An eagle’s eye view will show you the brilliant blue water of the ocean contrasted against green conifers. The Tongass is a place where you can snorkel kelp reefs to touch starfish and urchins, emerge from the water, and dry yourself while sitting on the soft duff under the canopy of 150 or 200 foot trees that may be 800 years old.  When you stand among those large trees the quietness and fresh air make it feel like a holy place.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Brilliant blues of the ocean are contrasted against the greens of tall conifers. These large-tree forests along the coast are quiet and beautiful.

Rivers are not the only thing that connect the land to the water. Red and yellow muskegs may stretch for miles from mountaintop to coast. These wetlands are devoid of tall trees due to moisture and soil conditions and are natural filters during water’s progress downslope. As open, wet, land muskegs house an entirely different ecosystem of plants and life. Short pines replace towering spruces and small, round ponds replace babbling brooks. These wetlands are filled with short shrubs and grasses that provide important habitat for migrating and breeding birds.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
A dotted landscape of Old Growth and muskegs. Muskegs hold water and filter it on its way to the ocean. The ponds are important for birds and wildlife.
Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Muskegs can be vast areas of short grasslands and shrubs. They provide a completely different habitat than the tall old growth forests.

Roaded Areas

The presence of roads is impossible to miss as you look at the Tongass around Hoonah, Alaska. Many of the roads were used for logging and then transitioned to local use. You can see a few patterns when observing the road system from above such as young growth forests along the whole length of the road, and old growth in the river bottom. Landscapes like this are common throughout the Hoonah area. They represent the reality of a correlation : with the establishment of roads comes the sound of chainsaws and the clear-cutting of thousands of acres of old growth forest that will not regenerate to their former state until the year 2200 or more.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
A Coastal Brown Bear crosses over a road. Along the road you can see the young growth and old growth stands.
Over 6,000 miles of road have been built in SE Alaska to support the timber industry which boomed from 1970 until the early 2000s.

We need roads to move through the landscape, but roads can come with a consequence. Until I was in the air I never realized how large a landslide can be. These landslides often occur in steep slopes and roads in logged areas because of the changes to hydrology. Roads also bisect rivers and alter the ability for fish to move river/road crossings..

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
A large landslide cascades down a valley.

Climate Resilience

The climate of the world is changing fast and there are signs that its accelerating.  Since world leaders are not showing signs of making decisions to stem the flow of CO2 into our atmosphere, it is prudent to keep nature’s carbon “sinks” (natural carbon storage) areas in place. Those areas are shrinking daily. A recent report from the United Nations put our impact on the earth’s surface in perspective. The report reveals “Three-quarters of the land-based environment and about 66% of the marine environment have been significantly altered by human actions. On average these trends have been less severe or avoided in areas held or managed by Indigenous Peoples and Local Communities.” When I read that it became apparent; the Tongass and the Native Alaskan Communities embedded in them since time immemorial are critical parts of the 25% of unaltered land on the earth.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Densely-packed Young Growth hold about 50% as much carbon as Old Growth forests.
Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Old growth trees are pretty easy to see from the air. Of course, they are tall, but their crowns are spaced far apart as well. When an Old Growth Forest is cut is releases about 60% of its carbon.

A recent article summarizing the message of Climate Scientist Dominick DellaSala at a recent meeting relayed some powerful statistics about the Tongass :

  1. An acre of old growth has about 1 billion needles that soak up carbon. 
  2. Old growth forests store 50% more carbon than logged forests. 
  3. A single 100-foot tree releases 11,000 gallons of water into the ecosystem.
  4. Logging releases 60% of the carbon stored in the forest

I cannot think of any statistics that demonstrate more fully the importance of how the 16,700,000 acres of the Tongass, the U.S.’s largest national forest, are in our climate change resiliency.

Current Global Response Insufficient : Roadless Modifications

On October 18th, 2019 the U.S. Forest Service entered into the Federal Register a recommendation that the 2001 Roadless Rule be lifted from the Tongass National Forest. This flies in the face of a majority of comments received from Alaskans and U.S. Citizens which favored keeping the protections in place. The 2001 Roadless Rule guaranteed that roads for logging could not be built in 9.2 million acres of the Tongass. These protections were set aside because of the acknowledgement of the global and regional importance of leaving the Tongass in its natural condition. The “Roadless Issue” is a complex one, but this decision can only have negative outcomes for wilderness of the Tongass seeing as the removal of road restrictions are being coupled with increased timber sales.

Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Interspersed in the forest, small muskegs create natural habitat openings that are good for wildlife. Did you know a recent report found that the U.S. Forest Service has lost 600 million dollars in the Tongass during timber sales in the last 20 years? That’s taxpayer dollars.

These five lines are the summary of the United Nation report I referenced above are applicable to the Roadless Rule, the plight of the Tongass, and the plight of global ecosytems:

Current global response insufficient;
‘Transformative changes’ needed to restore and protect nature;
Opposition from vested interests can be overcome for public good
Most comprehensive assessment of its kind;
1,000,000 species threatened with extinction

— U.N. Report May 6, 2019

The Tongass Needs You

I have been told many times that “nothing is final until it is written in law” and that is completely true for this process. There are 5 alternatives to the Roadless Rule that do not remove protections from the entire forest. This is not an issue where anyone one side should get everything they want and it is up to us to ask for better than the “preferred alternative” of a full exemption of the Tongass from the Roadless Rule.  For the next 60 days you have ability to contribute your voice to this discussion and influence the fate of the Tongass. I hope I have helped you connect to the Tongass enough to weigh in. Here are your options:

  1. To learn more information contact me. photographer@ianajohnson.com. I would be happy to help you digest the issues of the Roadless Rule as it applies to the Tongass
  2.  Review project information and learn about the public review process by going to this USDA media release.
Tongass, National Forest, Aerial, Bird-eye, Roadless Rule, Old Growth, Spruce, Hemlock, Trees
Young growth and old growth butted against the mountains of Hoonah. There are proposed alternatives that can provide limited access to old-growth for the timber industry, contribute to Alaska’s economy, and continue the transition to young-growth logging. Those options are better suited to strike a balance between the future needs of our children’s, children and Alaska’s current needs. Make your voice heard!

Re-encountering STEVE in Alaska

On September 1st, 2019 I crept outside into the dark night of Alaska to meet STEVE and it and I had a photo shoot together. It had been awhile! But usually once a year we have a chance to get a look at a each other. I’m not talking about my cousin Steve, in fact, STEVE is not a person at all. STEVE stands for Strong Thermal Emission Velocity Enhancement.

The last time I wrote about STEVE it was to dispel the mis-classification of these images online as “Proton Arcs”. At that time scientists were grappling with what caused this mysterious form of the aurora. There was uncertainty on why it showed up white instead of green and what form of energy would cause the aurora at all. Although it has likely been observed by sky watchers since the point where humans could comprehend its beauty it was relatively new to science and only really entered the literature in 2016.

STEVE, Strong Thermal Emission Velocity Enhancement, Alaska, Hoonah, Aurora, Northern Lights
The green light intermingled with pink and white ribbons is a classic form of STEVE and is what is typically seen by the human eye and camera.

Strong Thermal Emission Velocity Enhancement

” Strong Thermal Emission Velocity Enhancement ” – that’s quite a load of Jargon! However, once you understand how these auroras form it makes mores sense.

Typical auroras are formed when energy from the sun collides with nitrogen and oxygen in our atmosphere. The collision results in green or red light being let off. However, based on recent science published on Space.com STEVE forms when charged particles are super-heated outside of the “auroral zone”. The particles emit the white and pink light we see on the ground.

STEVE, Strong Thermal Emission Velocity Enhancement, Alaska, Hoonah, Aurora, Northern Lights

If you are still a bit unclear remember that light occurs as a physical process – it’s the release of energy. For instance when you heat an electric cooking stove the orange light emitted is the release of energy. STEVE is a bit like a monstrous electric coil in the sky!

A Gallery of STEVE

I think my latitude in Southeast Alaska is a hotspot for STEVE. I have observed it 5 times to date since 2016. I recently added my photos to a database of STEVE observations. The images below are from the same night as the images above. You can see a short timelapse of STEVE that night by going to a video on my Facebook page.

The Rest of the Show

STEVE shows up on the biggest nights of aurora. It definitely seems to be linked to high amounts of energy coming in. During the nights and mornings of August 30 – September 1st the Aurora was visible almost anytime it was dark.

Aurora, Northern Lights, Icy Strait Point, Alaska, Hoonah, Green
After STEVE Disappeared the Northern Lights flooded across the sky

On the second night of the show I focused less on photography. My wife and I curled up on a blanket on the beach and watched the lights dance overhead. We had some pretty amazing coronas for Southeast Alaska!

Aurora, Northern Lights, Icy Strait Point, Alaska, Hoonah, Green
Tall spires of Aurora over beach grass at Icy Strait Point

I’ll be keeping an eye out for any further science and revelations on STEVE. I hope to see it again!

2018 Top Shots

It’s 2019 already. Wow! This last year I’ve been streaky on blogging, but that doesn’t mean I haven’t been taking lots of imagery! I’ve enjoyed seeing and photographing new things as well as learning new things, too! The gallery below shows off some new techniques in drone photography and underwater photography. I worked to select my favorite images across a spectrum of simplicity and complexity, small animals to large ones, and photography genres. Aside from the work here I’ve been writing for Digital Photography School and focusing on custom framing in driftwood and red cedar. 2019 is going to be a great year, so I hope you remember to follow along on Facebook or Instagram!

Be sure to click on the images to enlarge them!

Chasing Lava at Volcanoes National Park

A Barren Landscape

When you arrive on the Big Island of Hawaii one thing is immediately obvious – lava is omnipresent and shapes the land in a big way. I know, you may be thinking to yourself, “Of course it does! It’s Hawaii”, but until you drive through miles on miles of black, barren, lava fields for the first time it is hard to imagine how dominant the lava is over the Big Island. Once you get past the incredible scale of lava fields and begin to zoom in on the lava formations themselves, it is even more difficult to determine how the intricate loops, curls, folds, chasms, and bubbles form in the fields. Bubbles within bubbles, curls over swells, loops and swoops, nothing it seems is impossible for lava. I was grateful to visit the lava leads of Volcanoes National Park which put some of questions to bed.

Lava, Volcanoes National Park, Hawaii, Big Island, Photography
Curtains of hardened lava lie below open leads further up the hillside. How did the lava form all of these unique shapes and formations?

Hiking the Lava Fields

There is no official trail to the lava leads (open flows of lava), so you are “bush whacking” (an ill fitting term considering there are few bushes in the newly scorched earth) across the lava fields. When I took my first step onto the blackened earth it gave a satisfying crunch – like several thousand tiny glass panes had broken simultaneously. This isn’t far from the truth as I learned that the surface of the lava cools in a glass-like structure. With each crunching step we plodded closer to our goal – smoke rising from a hillside. About two miles in we caught sight of a bright orange flash on the hillside. Even in the daylight it was so bright that it seemed a person in a blaze-orange jacket was propped in the rocks. It was my first look at lava, and I couldn’t wait to get closer! 30 minutes later we were standing only 20 feet away from the open leads of lava to observe their beauty and feel their heat first hand. Check out the video below for a taste of the hike in and the beauty of lava.

On the Nature of Lava and Its Formations

Standing and watching the lava leads swell, break their crust, cool, and repeat helped answer a lot of the questions I had. For instance –

  1. How fast does lava flow? The answer all depends on the slope of the hill. Further up from us the lava flowed like a small river – much faster than a person could run. Near us, in the toe of the slope it ran much slower.
  2. The lava fields were incomprehensibly large, so how fast do they form? Much, much quicker than I expected. Open lava leads could form meters of new, scorched ground in just a few minutes. It became evident how quickly the lava leads could create new land or in many cases in Hawaii, new islands.
  3. How does the lava form the different shapes? There are so many complexities to this. I believe it has to do with the temperature of the lava (1300 – 2200 F), the crack it was bursting through, the wind, the air temp, the slope, the rate of flow, and so much more. I did get to watch as the lava formed bubbled as well as more unique shapes such loops and curls like overlapping layers of chocolate from a fountain.

Lava, Volcanoes National Park, Hawaii, Big Island, Photography

An open lava lead flows just a few feet away from me.

Lava, Volcanoes National Park, Hawaii, Big Island, Photography
Lava leads would quickly form and cool creating the black, barren landscape of the lava fields.

Lava, Volcanoes National Park, Hawaii, Big Island, Photography
An open lava lead flows at night.

Darkness Falls Over the Lava Field

Our plan was to stay late into the night and photograph the Milky Way over the lava leads. The night was warm, but even if it had not been it is easy to stay warm in a lava field – if you pick the right rock it is like laying on warm concrete thanks to the percolating lava below. We curled up for naps on our geologically heated sleeping spots and then enjoyed the brilliance of the open lava in the dark night. At 10PM the clouds rolled in thick and light rain started. The rain in particular can create hazardous conditions when it comes in contact with open lava by generating nauseous gas, so we decided to call it a night and made the trek home. Overall the experience was my fondest of in Hawaii and is in the 10 of all-time life experiences!

Lava, Volcanoes National Park, Hawaii, Big Island, Photography
Open lava leads shine bright under the stars.

Lava, Volcanoes National Park, Hawaii, Big Island, Photography
Open lava leads shine bright under the stars.

Lava, Volcanoes National Park, Hawaii, Big Island, Photography
A hillside dotted with open lava leads glowed brightly once the sun set.

Lava, Volcanoes National Park, Hawaii, Big Island, Photography

Planning a Trip?

The lava conditions in Volcanoes National Park change constantly, and you will want to check on current conditions on the National Park Service website before heading out.  Our hike to the open leads of lava ended up being 10 miles round trip, but if you are fortunate the lava will be much closer to the road if you go for a trip. Bring good shoes, lots of water, food, and a camera!

The Hooligans of Haines

The Great Hooligan Run

Alaska is known for its runs of salmon, but each year in the spring an equally impressive and ecologically important run of fish ascend the streams of Southeast Alaska and as far north as Norton Sound. The small, silvery fish, provide bountiful food for birds, bears, and people and signify that spring is here. I had the opportunity to observe the abundance of life that greet the Hooligan in the Chilkoot River, just north of Haines, Alaska.

Thousands of gulls, dozens of eagles, and tens of Stellars Sealions gather at the mouth of the Chilkoot River to feed on Hooligan.

The Chilkoot River system where I stood watching schools of Hooligan is surrounded in spectacular scenery. The 70 yard-wide river valley is dotted with large boulders which were deposited there by retreating glaciers.  High mountains that rise along each shore are covered with snow and feed the cold-water system for several months, until mid-summer.  During April and May, its shallow, clear waters, house thousands of shimmering gray shapes. Hooligan (Thaleichthys pacificus, also known as “eulachon” or “candle fish”) return by the hundreds of thousands to deposit their eggs.

The Ecology of Hooligan

Hooligan are anadromous fish, meaning they spend most of their adult life in the ocean, but return to freshwater to breed. The most well-known example of anadromous fish are salmon species, however Hooligan do not necessarily return to the same river like salmon do.  The timing of their spawning run is determined by water temperature and hence shifts later into the year as you move from Southeast Alaska up to the western coast. After breeding, a majority of Hooligan die, but there are some fish that return to the river. Why only some die after spawning is just one of the many things that are not known about this fish. For instance biologists are also unsure what effects the size of the run which has varied highly in recent years. In the Chilkoot River, the run was estimated at 300,000 in 2015 but >1.8 million in 2016. That is quite a difference! After talking to the locals, it sounds like this year’s run in the Chilkoot was strong and echoed the strong run of 2016.

Hooligan Run, Alaska, Haines, Chilkoot
Thousands of Hooligan swim in the shallow waters of the Chilkoot River.

The Effect of Hooligan

You do not really have to see the effect of Hooligan to understand their importance to the ecosystem – closing your eyes and listening will probably tell you the story that needs to be told. Envision the sound of the lapping surf at your feet and the hum of the wind past your ears. Now layer in the raucous sound of thousands of gulls from multiple species raising from the beaches in an excited chorus. Add the grunting, bold, bellow of an adult, bull, sealion. The chir and ki-ki-ki of many bald eagles. The whistle of a goldeneye’s wingbeats. This is the audio picture of the Hooligan run and I was astounded by its magnitude.

Hooligan, Chilkoot, Haines, Alaska
A rainbow high-lights the amazing scenery around Haines. Gulls, Eagles and Stellars Sealions feed on Hooligan at the mouth of the Chilkoot River.

It was obvious from watching the behavior of various animals that they had mastered the art of catching an easy meal and nutritious meal. Hooligan are an important food source because of their high energy value. Dried Hooligan are so oily they were traditionally burned by Tlingits as candles. One of the most impressive behaviors was how Stellar’s Sealions herded the fish against the shore. Working together the sealions breached from the water in a wall to spook the fish upstream. The breaches ocurred in synchronized sequences, with the whole body of the sealion coming out of the waters, followed shortly by another individual. If the maneuver was successful a large school of finned-dinners would be pinned against the shore and a feeding frenzy ensued. Swirling waters and flippers were all that was visible of the fast-moving sealions as they snatched up fish below the water’s surface. The gulls were equally effective at catching Hooligan and dove repeatedly into the water, coming up with a fish frequently. After successful dives, the fish protruded from the gull’s mouth and were consumed on the wing . It’s amazing to think they could swallow them at all! The bodies of the fish were not the only thing being consumed. Countless eggs (they lay up to 30,000 per female!) were strewn across the beach, stranded as the tide went out. I watched a tiny, Least Sandpiper scoop up mouth-fulls of the eggs, providing a high-calorie caviar snack.

Hooligan, Chilkoot River, Haines, Alaska
A Bonaparte’s gull consume a Hooligan on the wing moments after snatching it from the river.

I wish that my time at the Chilkoot River could have been longer. Two evenings observing it just did not seem like enough! What any one-person takes away from an experience can vary vastly. My viewpoint is one a naturalist and scientist looking to sponge knowledge and learn from what I observe. I hope that you, the reader, can see it some day to see what you learn. Alaska is known for its larger-than-life wildlife spectacles, and in my opinion the Hooligan run and the abundance of life it creates is an experience that should be seen, felt, and heard by anyone that appreciates the wild places of earth.

Sources (also used in hyperlinks through the article):

  • http://www.adfg.alaska.gov/index.cfm?adfg=eulachon.main
  • http://traditionalanimalfoods.org/fish/searun-fish/page.aspx?id=6448
  • http://www.subsistence.adfg.state.ak.us/techpap/tp213.pdf
  • https://www.afsc.noaa.gov/Publications/ProcRpt/PR%202006-12.pdf
  • http://www.alaskapublic.org/2016/04/28/hooligan-make-strong-return-to-chilkoot-and-chilkat/

The Pine Marten Transplants of Chichagof Island

When I think of the American Pine Marten (Martes americana), it invokes an image of giant, rotund spruces and hemlocks in an old growth forest. In my mind, the lithe body of a Pine Marten scurries around in the branches perhaps a hundred feet from the forest floor in search of a red squirrel or bird’s nest. A small squeak indicates that the small mustelid has connected with its prey. This vision could be considered “classic” in the fact that martens are strongly associated with mature, old growth forests (Greg 1995). In fact, their dependence on old growth forests is so strong that traditional logging methods have been cited as a driver of large scale declines of marten populations (Davies 1983). In some regions of Southeast Alaska marten are still abundant, and in general the Tongass National Forest offers great habitat for marten. However, they are most often found on the mainland, and I was told by a friend that they were introduced to Chichagof Island by people. That tidbit of information intrigued me, and as I dove into Pine Marten history on Chichagof I was very interested to find out a marten I crossed paths with is a descendant from a small introduction of intentional transplants.

DSC_5516

Transplanting wildlife to new areas in Alaska has been going on since the Russians began to settle  here (Paul 2009). Frequently transplants happened on the Aleutian Islands or the islands of Southeast Alaska and often the incentive revolved around economic opportunity. A well-known example of this is the transplant of Blue Fox to the Aleutians so they could be farmed and harvested for trapping.  The fox were responsible for extirpating several species of birds from the islands.  Over the years many species including Caribou, Sitka Blacktail, Mountain Goats and Elk have been introduced to new areas throughout Alaska. The first martens were introduced to Chichagof Island in 1949 to create a population for trapping (in fact Pine Martens are still Alaska’s largest fur market earning 1-2 million annually (Alaska Department of Fish and Game)). By 1954, 21 marten had been introduced to the Island and despite the low number of starting individuals, their numbers climbed rapidly in their new environment. It is estimated in 2006 over 2,200 marten were trapped on Chichagof Island. It’s a remarkably successful population here!

Blue Fox
It was fascinating to see this account from the early 1900s of Blue Fox farming. At the time it was implemented as a branch of the USDA. You can read the full text at : https://archive.org/details/bluefoxfarmingin1350ashb

Since transplants can have negative effects on resident populations, did the transplant of marten to Chichagof Island impact populations there? Anecdotally I have been told that Dusky Grouse (Dendragapus obscurus) numbers have declined on the island and that Northern Flying Squirrel (Glaucomys sabrinus) are not as abundant as they used to be.  Certainly each of these prey items are consumed by the martens. Buskirk (1983) found birds and squirrels made up a strong majority of the marten’s diet in Southcentral Alaska, but that voles, mice, and shrews were the most important items in the diet.  On Chichagof Island, the diet patterns are the same, although Ben-David et al. (1997) found high variation in the autumn and the presence of salmon and crab.  In the summer a marten’s diet may be made up 80% of birds and squirrels. Marten populations are normally not very large and hence would be unlikely to strongly influence prey, but Chichagof Island holds the highest abundance in the region (Flynn and Ben-David 2004). With these high populations and a diet favoring birds and squirrels, is it is possible that marten populations on Chichagof Island exert a top-down pressure on their prey? I believe based on the effect of being a successful transplant makes it it possible. However, I can find no data on the population trends of Dusky Grouse or Flying Squirrels on Chichagof Island and there are many other factors at play. For instance,  Dusky Grouse may find protection from predators in old growth  and flying squirrels are likely to benefit from old growth structure. Hence, removal of old growth by logging may lead to a reduced population. Rather than conjecture on a speculative answer, I will put it out there that a graduate student and the Alaska Department of Fish and Game could pair up on this venture.

I will leave you with a description of my encounter with an American Pine Marten. On October 16th, Hoonah received measurable snow before Fairbanks, Alaska.  The 14 inches of snow that lay on the ground was the first time Southeast Alaska had beat the Interior to snow in over 70 years. I started up my truck, my wife jumped in, and we headed out the road with the hope of photographing a bear in the snow. The lower elevations were slick and wet. 6 inches of slush lay heavy on the roads, but we made it the 10 miles to the turn towards False Bay. As we slowly climbed the pass the truck seemed to shrink into the ground as the snow levels rose. After only a couple of miles we were plowing snow with the bumper of the truck and it was evident that we would not go much further. The only catch was we could not find a place to turn around. On we drove hoping that our luck held out, when up the road we saw a small figure bound into the ditch. It plowed into a snow drift and then burst back out again. In a flash I was out with my camera clicking away. Pursing my lips I made small rodent sounds which intrigued the inquisitive creature. Turning its head rapidly it dove back into a snow bank and emerged a few feet away. To me it seemed as if the little fellow was simply enjoying the snow rather than doing anything too serious. He wove in and out of cover, posed for me and eventually bounded into the woods in search of greener (or whiter) pastures.

Pine Marten, American Pine Marten, Chichagof Island, Hoonah, Southeast Alaska, Martes americana
American Pine Marten on Chichagof Island near Hoonah, Alaska.

 

Cited:

R. Flynn and M. Ben-David. 2004. Abundance, prey availability and diets of American martens: implications for the design of old growth reserves in Southeast Alaska. U.S. Fish and Wildlife Service Grant final report. Alaska Department of Fish and Game.

Ben-David, M., Flynn R.W., Schell D.M. 1997. Annual and seasonal changes in diets of martens: evidence from stable isotope analysis. Oecologia. 111:280-291.

Buskirk, S.W. 1983. The Ecology of Marten in Southcentral Alaska. Doctoral Disertation. University of Alaska Fairbanks.

http://www.biokids.umich.edu/critters/Dendragapus_obscurus/

Davis, Mark H. “Post-release movements of introduced marten.” The Journal of Wildlife Management (1983): 59-66.

Drew, G. 1995. WINTER HABITAT SELECTION BY AMERICAN MARTEN (Martesamericana) IN NEWFOUNDLAND: WHY OLD GROWTH?. Dissertation.

Paul, T. 2009. Game transplants in Alaska. Technical bulletin #4. 2nd Edition.

Schoen, J., Flynn R., Clark B. American Marten. Southeast Alaska Conservation Assessment. Chapter 6.5

Ashbrook, F.G. Blue Fox Farming in Alaska. Accessed : https://archive.org/details/bluefoxfarmingin1350ashb 10/27/2016

https://www.fws.gov/refuge/Alaska_Maritime/what_we_do/conservation.html

 

Why Do Whales Try To Fly?

Last week I was floating under gray skies and windless conditions on a whale-watching boat outside of Hoonah, Alaska.  We drifted with engines off while Humpback Whales (Megaptera novaeangliae) fed around a rocky reef a hundred yards that was exposed by a shrinking tide. The distinct kee-kee-kee of hundreds of marbled murrelets, (Brachyramphus marmoratus, small pelagic birds) rang out around us and the bellow of sea lions droned from a distance green channel buoy. Towards that buoy an enormous nose broke through the surface and in a fraction of a second a mature Humpback Whale hung in the air with only the tips of its tail in the water. Its re-entry sent water far into the air with a crash. On its second breach I was ready and captured a series of shots as it arched into the water. My heart was racing as I soaked in what had just happened! Ultimately its leap from the water set my mind turning on why a whale would try to fly at all.

Mature Humpback Whales are gigantic creatures weighing between 45-50 tons (NOAA) and reaching up to 45 feet. I think Whitehead (1985) has it right when he states, “A Whale’s leap from the water is almost certainly the most powerful single action performed by any animal.” He found that a 12-m long adult humpback must travel at about 17 knots (3 times their normal cruising speed) to break the surface and expose at least 70% of their body. The energy required to thrust their entire body comes at an expense of energy, and begs to question about what they gain from it.  It is possible whales breach to communicate with others, to act aggressively towards another whale, to show strength, or to “play” (Whitehead 1985).

Humpback Whale Splash
A huge splash results from the breach of a humpback whale.

A lot of research on aerial behavior has tried to associate breaching with group dynamics. These studies have yielded interesting correlations. Whales breach more often in groups (Whitehead 1985). They were more likely to breach within 10km of another whale. Humpback whales surface activity (including multiple behaviors above surface) increases with group size and also occurred more with underwater vocalizations (Silber 1986). There also seems to behaviors which foreshadow breaching. For instance, breaching often comes after a tail lob. A tail lob is another visual and audio spectacle where the whale slaps its tail against the water.  Since breaching occurs more often in groups, these lends to the notion that it is a form of communication.

For some researchers, time spent on water results in findings that have little explanation. For instance, whales may breach more as wind speed rises (Whitehead 1985). Although support for why that would be is nearly impossible to determine, it has been shown that surface slaps can carry for several kilometers and the amount of sound created changes depending on what angle the whale strikes the water (Payne and McVay 1971, Deakos 2002 citing Watkins 1981). The distance that a breach can be heard is unknown, but it certainly surpasses the visual extent lending to the hypothesis that it is a form of communication, however, what message it conveys is unknown.

DSC_2066

By listening to whale vocalizations (for which humbacks are famous) that occur leading up to breaches, researchers found there is a relationship between the amount of vocalizations and breaches. Male to male interaction and above water behavior were often correlated with increased vocalization between males (Silber 1986). It is likely these vocalizations are aggressive and that males are plying for position or to mate with a female. The subsequent breach is probably an “exclamation” (Whitehead 1985) on the underwater vocalization rather than an attempt to harm the other whale during the breach.  Certainly it would demonstrate to a female the prowess and strength of the male (Whitehead 1985).

Insight into breaching behavior may be gained from researching other percussive behaviors. Deakos (2002) found that pectoral slapping varies with age class, sex, and social position. Females were likely to slap pectoral fins on the surface to indicate readiness to mate, while males often did it to compete with other males without full-on combat. Pectoral slapping was shown to be frequent in young whales and is likely an important piece of their development (I was fortunate to see a calf breaching last year).   However, pectoral slapping and frequent breaches from young and feisty individuals taper off as the whales mature and get older (Whitehead 1985). This likely means it not a form of play for older animals. From these findings in pectoral displays we likely assume that a breach from male, female or young calf means separate things.

Humpback Whale Pec Slap
The same humpback whale that breached also showed off pectoral slapping. The behavior went on for 5 or 10 minutes after the breach.

Humpback Whale Pec Slap
The resulting splash of a pec-slap from a humpback whale.

My review of the science and literature surrounding whale behavior is stumped by the same issue that plagues the field : the true question of “why” a whale breaches is illusive because “what” they are trying to convey is likely different for each whale.  Much like the way that we clap our hands different at sporting events, golf tournaments, at a wedding, or after a concert, whales likely use the clap of the water to communicate different feelings.  Answers are relegated to vaguery due to the inherent difficulty of researching an underwater animal. I can only conclude that whales breach to communicate.  It seems most plausible that humpback whales and other species breach to add emphasis to a message or to get a point across.

Cited:

Deakos. (2002). Humpback Whale (Megaptera Novaengliae) Commication : The context and possible functions of pec-slapping behavior on the Hawai’ian wintering grounds. Thesis.

Payne, R. S., & McVay, S. (1971). Songs of humpback whales. Science, 173, 585-597

Silber, G. 1986. “The relationship of social vocalizations to surface behavior and aggression in the Hawaiian humpback whale (Megaptera novaeangliae)”. Canadian Journal of Zoology. 64(10): 2075-2080

Watkins, William A. (1981). “Activities and underwater sounds of fin whales [Balaenoptera physalus].” Scientific Reports of the Whales Research Institute (Japan).

Whitehead, H. 1985. “Why Whales Leap”. Scientific American.

 

 

An Ivory Gull in Duluth, So What?

What does it mean when one of the least researched and understood marine birds in the Arctic turns up in Duluth, Minnesota 1,500 miles outside of its range? Locally, it ensures a birding rush of in-state and out-of-stater birders eager to see the rare bird, but what does it say about the global status of this unique bird? How can we use its presence to  educate ourselves of human impact on the high Arctic? Is the Ivory Gull (Pagophila eburnea) an indicator species of a greater issue in the Arctic? The suspicion that their unprecedented, 80% population decline over the last 20 years may be linked to mercury suggests they are.

Ivory Gull, Duluth
The Ivory Gull at Canal Park in Duluth sits on the piers a few hundred feet from the human observers on shore.

Population Free-fall of the Ivory Gull

Ivory Gulls are colonial birds, meaning that large numbers gather into groups to breed. By monitoring the nesting colonies of colonial birds, population trends may be established by researchers. However, surveys for Ivory Gulls  were only conducted in 1985 (Thomas and MacDonald, 1987) making it impossible to understand population trends. Compounding the lack of population data, Ivory Gulls are considered to be one one of the least understood marine birds. This is partly due to wintering along the ice pack between Greenland and Labrador ensuring they are not a bird which is in-sight of many people. However, indigenous knowledge has suggested declining populations since the 1980s (Mallory et al. 2003). In light of this, researchers  flew surveys of known nesting islands as well as newly found Islands in 2002 and 2003 and found something shocking. The number of nesting Ivory Gulls had declined by 80% since the 1980s (Gilcrest et al. 2005).

Ivory Gull, Identification
The Ivory Gull is a distinct bird with a blue bill, black feet, and stunning black tips on the wings.

Gilcrest et al. (2005) started to hypothesize at alternative reasons for the lack of gulls. They explored the possibility that the Ivory Gulls had simply shifted their nesting locations. However, a significant move is not inline with the known biology of the bird which generally move less than 1-2 kilometers.  Food sources of fish and carcasses have remained relatively stable in their study area giving them little reason to move. They noted that Ivory Gulls were not seen flying along the survey paths. It seems that the Ivory Gull was truly dying off.

Ivory Gull, Duluth, Minnesota
In Duluth, the Ivory Gull was gracious enough to land close to my camera, offering exceptional looks at the details of this beautiful bird.

 

The Driver of Change

Since the startling revelation of population decline, researchers have been trying to understand why Ivory Gulls are disappearing. It is probable that ice-pack changes and altered forage have contributed to the population decline (Gilchrest et al. 2005), but researchers think a stronger factor is in play . In his interview with the BBC World Service (full interview below) Dr. Alex Bond  hypothesizes that mercury is a leading stressor on Ivory Gulls based on findings that levels of mercury have risen 45 -50 times the levels found 130 years ago. There is strong evidence showing mercury levels in the eggs of Ivory Gulls is significantly higher than any other known marine bird. Braun et al. 2006 found that mercury in the eggs of Ivory Gulls were 2.5 times greater than even the next highest species, and were almost 3 times greater the amount which impairs reproductive success. Where is that much mercury coming from? And how exactly might it effect Ivory Gulls?

Ivory Gull, Underwings
The Ivory Gull in Duluth shows off its beautiful, white underwings.

To understand where the mercury is coming from, its important to know the basics of the mercury cycle. Mercury falls into the oceans from atmosphere pollution originating from coal-fired power plants, or is directly input from Alkali metal processing . There are also natural sources of mercury like volcanic eruptions and “volitilization of the ocean” (USGS 2000).  Once deposited in a waterbody, mercury becomes available to marine animals when it is transformed to methylmercury. Once in the that state, it moves up through the food chain into plankton, and then to fish, and finally to top level predators like birds and marine mammals.  Levels of mercury grows in organisms through bioaccumulation and biomagnifcation. To clarify that jargon, bioaccumulation means that the older you are, the more mercury you have since it is difficult to get it out your system once ingested. Biomagnification means that if you feed higher on the food chain you gain mercury more quickly. Marine mammals like seals have very, very high levels of mercury due to the effect of both bioaccumulation and biomagnifacation. With that information in mind it is easier to understand why Ivory Gulls accumulate mercury; they scavenge on carcasses of marine mammals and feed on fish which have high levels of mercury. They also have a high metabolic rate and consume more fish (Braun et al. 2006).

To date, the effect of mercury on Ivory Gulls has not been studied, but we can gather clues from looking at other species.  Common Loons (Gavia immer) also accumulate high levels of mercury due to eating fish (biomagnification) and having long lives (bioaccumulation). Evers et al. 2008 found a 41% decrease in fledged loon young in parents with >3 micrograms of mercury per gram of tissue compared to those with <1 microgram. They predict total reproductive failure of Common Loons if levels exceed 16.5 micrograms. Based on hundreds of hours of observation, they report that loons with elevated levels of mercury are lethargic and spend significantly less time foraging for food and less time taking care of their young. Each lead to fewer chicks growing to adulthood.  It is important to note in their study that mercury levels of a species change throughout their range due to climate, forage, and many other factors. Transferring the lessons of Common loons to Ivory Gulls, variation in  mercury levels changes are observed in Canada as well; in general levels of mercury increase from east to west in Canada. Although the effect of mercury on Ivory Gulls has not been directly studied and may effect gulls differently than loons, a good hypothesis for their decline is poor parenting and lethargy due to extraordinarily high levels of mercury. Only future research will help tease out the true effect of mercury on their decline.

Ivory Gull, Flying, Duluth
The Ivory gull in Duluth takes to the wing showing off its beautiful plumage and black feet.

When an Ivory Gull shows up in Duluth, Minnesota it is a chance to reflect. Reflect on the beauty of an animal. Reflect on the joy of seeing such a rarity. However, do not miss the opportunity to acknowledge that its prescense is out of the norm of the species and that an unseen driver which we do not fully understand is at play. Reflect on the fact that the impact of humans in a nearly un-inhabited region is undeniable. Human consumption of fossil fuels is depositing mercury into the Arctic at rates which may be directly effecting a species. The Ivory Gull is a red flag, an indicator that things are not right in the Arctic and that we should pay heed to what else may be going wrong that we just have not taken the time to study yet.

Sources:

http://www.bbc.com/news/science-environment-31921127

Braune, B. M., Mallory, M. L., & Gilchrist, H. G. (2006). Elevated mercury levels in a declining population of ivory gulls in the Canadian Arctic. Marine Pollution Bulletin, 52(8), 978-982.

Evers, D. C., Savoy, L. J., DeSorbo, C. R., Yates, D. E., Hanson, W., Taylor, K. M., … & Munney, K. (2008). Adverse effects from environmental mercury loads on breeding common loons. Ecotoxicology, 17(2), 69-81.

Gilchrist, H. G., & Mallory, M. L. (2005). Declines in abundance and distribution of the ivory gull (Pagophila eburnea) in Arctic Canada. Biological Conservation, 121(2), 303-309.

Mallory, M. L., Gilchrist, H. G., Fontaine, A. J., & Akearok, J. A. (2003). Local ecological knowledge of ivory gull declines in Arctic Canada. Arctic, 293-298.

Thomas, V.G., MacDonald, S.D., 1987. The breeding distribution and
current population status of the ivory gull in Canada. Arctic 40,
211–218.

USGS. 2000. http://www.usgs.gov/themes/factsheet/146-00/