Where Are the People? /  by Michael Johns

Aside from a major city and a handful of townships, Tasmania is mostly an island of rugged landscapes and remote wilderness. There are roughly 522,000 people currently living on this island state of Australia, nearly half of whom reside in the greater Hobart region; Tasmania’s only city center. The heat maps above depict the spatial distribution and densities of people across the island. Each circle represents a 0.05 x 0.05 degree pixel within a larger spatial grid, colored by the total number and density of people within each pixel. Rather than using a raster or contours to display the population data, I went with a simple grid of points using the package ggplot2 in R, which I think gives it a retro “Lite-brite” look. If you never had one as a kid then you missed out. Hobart glows red hot, followed by the town Launceston (called “Launy” by the Aussies) and the northern coastline. We will be flying into Hobart and exploring the city for a few days, before heading out in a camper van rental to check out some of the darker corners of these maps.

Population data used to create the maps above can be found at the following link: http://sedac.ciesin.columbia.edu/data/set/gpw-v4-admin-unit-center-points-population-estimates-rev10/data-download

Rather messy but mostly functional R code used to make maps can be downloaded HERE.

Waiting for Australia /  by Michael Johns

Casey and I still have 5 weeks to go before our belated honeymoon to Tasmania, and already I’m dreaming up cool ways to display data from our trip. So far I have plans for comparing our heart rates in response to different situations using data collected from our Fitbits, tracking the routes we take during our 3-week road trip around the island, and summarizing the different species of plants and animals encountered along the way. To kick things off, I’ve put together a map showing the 8 different flights required to complete a roundtrip ticket from Fairbanks Alaska to Hobart Tasmania. Aside from some text, airplane vector art, and a custom legend (designed to look like a passport stamp) which I added in Photoshop, all of the features of the plot were assembled in R using the ggplot2 package. The coord_map( ) function in ggplot created a spherical projection of the earth, and the white stipples you see on the continents depicts light pollution data, highlighting the city centers. Not counting layover times, it will take us nearly 46 hours to complete the journey.

Seabird Sizes /  by Michael Johns

This figure depicts the relative sizes of seabirds that breed on the Farallon Islands. Larger circles mean more massive birds, smaller circles less massive. Species in the order Pelecaniformes, colored in shades of blue, are among the largest birds that breed on the island. The Ashy Storm-petrel in yellow, although a part of the order Procellariiformes which includes some of the largest seabirds like albatrosses, is small enough to fit inside the palm of your hand. The diverse order Charadriiformes in shades of red includes all of the gulls and auks, the latter of which contains all of the wing-propelled pursuit divers like puffins, murres, guillemots, and auklets. Mass information was gathered from the Sibley guide to birds. This plot was made almost entirely in R, with a few minor tweaks made in Photoshop. A full size image can be downloaded HERE.

Make It An Animation /  by Michael Johns

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Sometimes, an animated figure tells the story better than a static one. We have been tracking the non-breeding movement patterns of Cassin’s auklets from Southeast Farallon Island since 2015, in an effort to understand the environmental drivers of their winter dispersal. Part of the work I’m doing for my PhD is linking the movements of auklets to remotely sensed conditions relevant to their foraging ecology, in the case of this animation chlorophyll-a concentration (left) and sea surface temperature (right) from November 2017 through January 2018. Chlorophyll, the photosynthetically active molecule that gives plants, algae, and certain types of bacteria their green pigment, is used as a measure of the concentration of phytoplankton. Krill, which comprises much of the Cassin's auklet diet, graze on phytoplankton, so it’s reasonable to assume productive areas with high concentrations of chlorophyll-a likely contain greater densities of krill than areas of low chlorophyll-a. Similarly, lower sea surface temperatures are generally associated with nutrient rich cold water from depth, which help spark blooms of phytoplankton. One hypothesis, visualized with this animation, is that Cassin’s auklets are searching for colder regions of higher productivity during the winter months. The next step is to test this hypothesis with a series of competing models, to see which best explains the patterns observed in the data.

Denali Road Lottery /  by Michael Johns

More than a century ago, the United States congress was persuaded to create Denali National Park, a now 6 million acre wildlife preserve named after the tallest mountain in North America. By design, the human footprint within the park remains minimal, with few facilities, no real hiking trails, and a single 92 mile-long dirt road. Private vehicles are restricted beyond the Savage River Campground, at mile 15 on the park road. From there, a fleet of buses services the remainder of the road, allowing visitors to hop on and off wherever they like. This enables the public to access the spectacular wildlife and scenery the park has to offer, without the headache and chaos of thousands of vehicles clogging up the road every time a brown bear crosses.

At the end of the summer tourist season in mid September, the buses are parked for the winter and the full length of the Denali park road opens to select group of lottery winners. Every year people can enter what is called the Denali Road Lottery, where up to 1600 private vehicles (400 per day over a 4-day period) are selected at random and allowed to drive the 92 mile stretch of wilderness road all the way to its terminus at Wonder Lake. Winners of this lottery have the freedom to drive at their leisure, stopping whenever and wherever scenic vistas and wild animals are encountered.

According to the National Parks Service website, roughly 11,400 applications were received in 2017, equating to a 1 and 7 odds of getting drawn. Casey was lucky enough to be drawn, which aligned perfectly with a visit from our good friend Amy. So on the final day of the road lottery, we got to experience the fall colors, sweeping views, and iconic Alaskan wildlife of Denali. Except the actual mountain itself, which was cloaked in low clouds and fog…

One of the big draws to visiting Denali National Park is the chance to get close looks at wildlife that is otherwise more elusive outside the park’s boundaries. Just minutes into the drive, we spotted a large flock of willow ptarmigan waddling along the gravel shoulder. Birds don’t stop up traffic in quite the same way as the large mammals like bears, moose, and caribou do. It was easy to tell when a grizzly had been sighted, where sometimes 20 or more cars would pull over with long expensive lenses sticking out of passenger windows, aiding newcomers by pointing out which direction to look for the bear. The following is our sightings list for the day:

Birds
Horned Grebe - 2
Greater Scaup - 12
American Widgeon - 8
Spruce Grouse - 1
Willow Ptarmigan - 27
Grey Jay - 5
Black-billed Magpie - 10

Mammals
Brown Bear - 3
Moose - 3
Caribou - 8
Dall Sheep - 49
Red Fox - 1
Porcupine - 1
Arctic Ground Squirrel - 1

We were lucky to win the road lottery, but not so lucky with the weather. A very wet and rainy fall this year in interior Alaska meant that most of the towering mountains, including the biggest of them all, were obscured from view. Still, what we could see at ground level was more than enough to make the trip worth while. Perhaps next year we will win another day in the park and try our luck again.