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leculler:

A quick re-blog about a paper published on my research on damselflies. (Yes, I do study things other than Arctic mosquitoes.)

Originally posted on Entomology Today:

Previous studies have shown that warming temperatures make insects eat more and grow faster. In fact, scientists often measure the effects of temperature on insect growth to predict how climate change will affect their distribution and abundance.

However, a new study from Dartmouth College indicates that other factors — in this case, fear — play a role as well, and some can actually decrease the rate of growth.

“In other words, it’s less about temperature and more about the overall environmental conditions that shape the growth, survival, and distribution of insects,” said Lauren Culler, lead author of the study, which was published in the journal Oecologia.

Culler and her colleagues looked at how fear, which typically lowers food consumption and growth rate, affects an insect’s response to warming temperatures. They brought damselfly nymphs into the lab and measured how much they ate and grew at different temperatures, and how…

View original 150 more words

A few weeks ago, I was setting up some curious equipment that looked like sunny-side up eggs on wires. One hundred of them on the tundra overlooking a glacier.

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They were for the Global Dryas Project, which is a collaboration among arctic scientists and residents to study pollination and seed production of Dryas flowers. The sunny-side-up eggs were pollinator sticky traps made to resemble these beautiful white and yellow flowers.

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Dryas flowers

I wondered if pollinators around here would actually fall for the faux flowers.  They did! When I brought the “flowers” out to the study area, it was like bringing free pizza to starving grad students. Flies started landing on them before I even had a chance to set up the plots.

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Flies on the faux flower sticky traps.

With the sticky traps, we now have a better idea of what insects visit and potentially pollinate Dryas in Greenland. These results and other data will be sent to the project organizers at the University of Helsinki in Finland.

It is great to squeeze as much as much science as possible out of a Greenland field season and to learn more about pollination across the Arctic. I look forward to seeing the results from the other participants.

More information about the Global Dryas Project:

http://www.helsinki.fi/foodwebs/dryas/index.htm

http://www.sciencemag.org/content/345/6196/492.full (need Science subscription).

Flying South

One of the most incredible parts about spending an entire field season in Greenland has been getting to see how dynamic this landscape can be. We’ve watched icy lakes melt, flowering plants bloom, wither, and bear fruit, rivers rise and fall, mosquitoes swarm and dissipate, and nights darken. One of my favorite changes of all to watch was the progression of the breeding season of the Lapland longspur (Calcarius lapponicus).

Lapland longspur (male)

Lapland longspur (male)

Since the start of the season, these migratory songbirds have always been somewhere nearby in the tundra. When we arrived in early June, the male longspurs could dependably be found singing from their perches on willow branches. As Ruth and I were hiking in to one of her sites one day in early June, we flushed a female out of the shrubs a couple feet ahead of us. After our hearts settled a bit from the initial surprise, we took a closer look at the spot she had flown from and found a grass-lined nest hollowed out at the base of the shrubs. In it were 5 sort of olive-tan eggs dabbled with brown spots!

I couldn't find a photo of the first lapland longspur nest we saw, but here's another with three eggs.

I couldn’t find a photo of the first lapland longspur nest we saw, but here’s another with three eggs.

Over the following weeks, we all kept our eyes peeled for startled females and informally tracked the progress of the nests we found. By June 15, two of the eggs in that first nest Ruth and I found had hatched (though they weren’t yet particularly recognizable as birds).

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By June 29, a group of five nestlings in a different nest were starting to really stretch their necks and beg, eyes still closed.

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On July 6, Christine and I found a couple of oversized longspur nestlings staring back at us for the last time.

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We liked to imagine that each bumbling fledgling we saw testing its wings was one of the ones we had seen in its earlier stages.

When it comes to birds, Greenland is primarily a place of part-timers. Of its 240 or so known species, only 60 of those are considered permanent residents; most fly south for the winter. The northern wheatear (Oenanthe oenanthe) — a bird that seems enchanted with our red truck, whether they’re hopping upon the mirrors to get a peek inside when it’s parked or springing up from the roadside bushes to perform acrobatics in front of it while we’re driving  — has a particularly impressive migration among the passerines. Wheatears have a huge breeding range that spans parts of Eurasia, Greenland, Canada, and Alaska but overwinter in sub-Saharan Africa, where they bulk up on insects to do it all again come spring. That means the Alaskan birds travel almost 9,000 miles twice a year! – not to mention connecting two extremely different ecosystems.

Northern wheatear (male and female)

Northern wheatear (male and female) – from arkive.org

As the summer draws to a close, in some ways I’ve been feeling a bit of kinship with the little guys. My journey should be a bit easier than theirs, though, even with customs.

To learn more about wheatears and how scientists are able to track their migrations: http://www.bbc.co.uk/nature/17027565

I stood at the edge of the river in awe. The river had swallowed half of my study site, leaving niviarsiaq flowers and my temperature sensor poking through ice-cold rapids.

There must have been a spectacular glacier calving event to cause the river to violently spill over its banks. Waterfalls almost doubled in width, the river found new courses to handle the large volume of water, and chunks of ice were carried downstream.

I grabbed my camera and started taking pictures. This is crazy cool,  I thought, but what about my research?!

Study Site #1

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DURING FLOOD: My study site is on the left. It didn’t used to be an island…the water in the foreground wasn’t there the day before.

We returned the next day to survey the aftermath. Things looked like they were almost back to normal.

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AFTER: The site is almost back to normal. See Becca standing on the rocks? The water would have been over her head!

The niviarsiaq flowers were extremely resilient.

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AFTER: These flowers were covered with two meters of rushing water the day before. Two days later, the flowers were producing pollen and buds were opening, like nothing happened.

Study Site #2

The day the river went rogue, we had to hike to our study site at seahorse lake because the road was flooded.

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DURING: The road to the seahorse lake study site was flooded – we continued on foot.

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DURING: The flooded landscape produced some great scenery.

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DURING: Looking out from our study site the day of the flood.

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AFTER: The beach and the boulders reappeared the next day.

Study Site #3

We visited a third site the day after the flood. Signs of the surge were abundant.

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The water etched ripples into the sand and left behind ice at a third study site.

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Ice deposited near our third study site.

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The grounded ice chunks were hefty.

Had I not been there the day the river went rogue, I would not be able to grasp the extent and power of the flood.  Fortunately, niviarsiaq, aka dwarf river beauty,  is  presumably adapted to such disturbances despite its delicate appearance. So, my research continues, and I am left with a much deeper respect for the ice-fed river.

There are about 25,000 species of bees in the world but only two wild species in Greenland: Bombus polaris and Bombus hyperboreus. Both are bumble bees well adapted to the chilly climate, and they are recognized as especially effective pollinators.

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Bombus polaris checking out a closed niviarsiaq flower. Niviarsiaq is dwarf fireweed and seems to be quite popular with the bees.

In other parts of the world, like the United States, there is great concern that parasites in native bees, including bumble bees, are contributing to population declines. But what about Greenland? Are the bees healthy, or are there parasites lurking? We don’t know yet, so one of my goals this season is to survey the bee population in Kangerlussuaq for parasites like Crithidia and Nosema.

The first step of this research is catching bumble bees, which can be challenging! Catching bees reminds me of trout fishing – it requires a lot of patience and determination, good technique and speed, and some ability to read the landscape.  The bees aren’t always very active, and sometimes we only see a couple the entire afternoon.

Here’s Becca demonstrating proper form to catch a bee foraging on niviarsiaq flowers.

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Becca demonstrating how to catch a bumble bee foraging on niviarsiaq. The bees fly to the top of the net once it is lifted up.

I’ll later be dissecting the bees back at Dartmouth, staining their guts, and looking for parasites under a microscope.  Here’s what Crithidia looks like:

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Chrithidia bombi. Image source: http://www.ethlife.ethz.ch/

The research will give us a baseline for tracking the response of bumble bees and their potential parasites to environmental change.

“Hey hey hey.. Check it out, Hans! Someone left their tent just a little open.” Martin cackels.

“Dang – nice find! Let’s go in!”

“You don’t just GO IN, Hans. Entry requires a certain know-how. You have to open the zipper contraption just so. And I do believe I’m more qualified to handle that than you are.”

“Oh yeah? How so?”

“Well, for one, my raven IQ is 140 and yours is 123. Besides, your larger stature makes you a good look out.”

Hans on the look out.

Martin ducks under the vestibule and bustles about, dragging something across the ground and kicking out sand. One minute later he emerges, proudly holding one black winter boot as long as he. He reenters, grabs the other boot and brings it out.

“Gosh darn it, Martin!”  yells Hans. “I know you have a thing for practical footwear, but what are we going to do with those, genius? Anything else?””

“They were blocking the door. Now that the entry is clear, I will proceed,” Martin huffs as he goes back to the vestibule.

Hans hears some guttural grunting, the zipper opening slowly, and his comrade hopping on the tent floor. Marin then marches out of the tent with a box of dried hummus. They tear open the package, taste the yellow powder, and spit it out. Hans gives Martin a disgusted look. “What do you call that?! Rancid flour?”

“Hummus, Martin. Dried hummus. The migrating birds have told me about it.  But certainly not what I imagined. Let’s go see if there’s roadkill.”

With the flap of their wings, Hans and Martin head west, leaving the scene to be discovered first by the arctic fox and then Becca and Christine, returning from work.

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The scene.

Or at least, that’s how I picture it going.

Hans, Martin, and their friends are becoming frequent visitors to our campsite. They circle each tent on foot, inspecting them, and  managing to enter mine that one time.  In addition to being obnoxiously loud and impressively large, ravens are highly intelligent. In fact, they belong to the most intelligent family of birds in the world, the corvids, which also includes jays and crows.  Problem solving is their forte. Expert juice thieves, they gulped down some orange juice after punching out the container’s spout.

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Ravens got into the orange juice by  tearing out the spout.

We have now taken proper precautions to deter further unwanted behavior (don’t leave dried hummus in your tent!).

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Raven and fox tracks leading to a securely closed cooler.

Photo credits: Becca Novello and Christine Urbanowicz

I always feel so conflicted at the end of a field season. I have grown so accustomed to life here in Kangerlussuaq that the thought of living without my tent, our trusty Toyota Hilux, or the amazing views of the Greenland Ice Sheet seems foreign. But at the same time, the thought of heading back to Hanover, where fresh food, friends, and summer are waiting is really quite exciting.

After driving this Toyota Hilux every single day for 6 weeks, I'm definitely going to miss it.

After driving this Toyota Hilux every single day for 6 weeks, I’m definitely going to miss it.

The last two days in Greenland are always full of small yet necessary tasks. Take down the tent. Clean out the truck. Fuel the truck. Pack science equipment. Return all keys. Return the satellite phone. And the list goes on. Generally I try to complete these annoying errands as quickly as possible so I can check them off the list. But the one small task that made me pause was packing all the soil samples I’ve collected over past six weeks. Each small plastic bag of soil brought back the memory of working in the field that day, at that particular site. Will I return to that site again? Or is this soil all I have to remember that spot?

I really do hope I get to see some of these views again. For now, I at least have pictures (and samples) to remind me.

I really do hope I get to see some of these views again. For now, I at least have pictures (and samples) to remind me.

While some of my thoughts were this nostalgic, I also started thinking ahead. What will these samples tell me? What story about biological soil crust will I learn after analyzing these hundreds of bags of soil? And this is what got me excited about heading home. The end of the field season is only the beginning: I have data to enter, soil and rock samples to analyze, and so much new information to process.

This week it seemed as though animals were coming to say goodbye. We had multiple close encounters with arctic hares -- amazing!

This week it seemed as though animals were coming to say goodbye. We had multiple close encounters with arctic hares — amazing!

So as much as I will miss the frequent animal sightings, the breathtaking views, and the camaraderie of the field, I have things to look forward to. But the data will have to wait until I unpack, eat fresh food, and adjust to New England summer. I’m ready!

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