What we learned

Blog 8/1: Lucie Duffy and Gretchen Schreiner

 

What We Learned: Michigan Thermoregulation Study

 

It seems like ages ago we were in Grayling, Michigan studying C. aequabilis and C. maculata, but we now have some data to report from our extended thermoregulation study. Recall that Svensson and Waller (2013) used surface temperature to investigate the thermoregulation response in damselflies of two European Calopteryx species, C. splendens and C. virgo, the latter of which extends further north and has darker wings. They found that C. virgo had a significantly higher body temperature than C. splendens at low ambient temperatures, and C. virgo body temperature had a suprisingly negative relationship with ambient temperature while C. splendens body temperature had a positive relationship. The negative slope of the more northern species could be adaptive, raising body temperatures in cooler, wetter northern climates and cooling temps in a warm southerly climate. This study inspired our work with C. aequabilis and C. maculata, two North American species that display a similar northern and southern distribution, respectively, and exist over a broad region sympatrically. In contrast to the European species, however, the more northerly distributed species has less darkly pigmented wings.

Comparing thorax temperature to ambient temperature is a way to quantify ectotherm thermoregulation. Here are some of our main questions about the thermoregulation of C. aequabilis and C. maculata:

  1. How do thorax temperatures of different species and sexes change as ambient temperatures increase?
  2. Do our findings support or contradict those of Svensson and Waller (2013)?

 

As we mentioned earlier on the blog, while we were in Michigan we measured thorax temperatures of more than 1000 damselfly individuals using a SeekThermal camera, while simultaneously measuring ambient temperature. We used this data to answer our proposed questions. Here is what we learned!

termalFigure 1. Effect of ambient air temperature on thorax surface temperature of C. aequabilis and C. maculata damselflies collected from AuSable River in Michigan. C. aequabilis females: n=89. C. aequabilis males: n=295. C. maculata females: n=324. C. maculata males: n=485.

 

Question 1: How do thorax temperatures of different species and sexes change as ambient temperatures increase?

As we expected, ambient temperature significantly determined the internal temperature of C. maculata and C. aequabilis thorax muscles (see Figure 1 above). All species and sexes had lower thorax temperatures at lower ambient temperatures, and all thorax temperatures increased as ambient temperatures increased. We have evidence that these damselflies are not perfect conformers, since their body temperatures did not perfectly match the air temperature. If they were perfect conformers, the slopes of all regression lines would be 1. As the figure above shows, slope = 1 is represented as a black line, which none of the other lines match. Instead, we believe these damselflies are behavioral thermoregulators, or there is a slight time lag between air temperature rising and body temperature increasing. Overall, our analysis revealed that the bodies of all four groups of damselflies – C. maculata and C. aequabilis males and females – heat up at about the same rate.

 

Question 2: Do our findings support or contradict those of Svensson and Waller (2013)?

Our findings provide inconclusive evidence about the thermal melanism hypothesis, which predicts the most pigmented phenotype will have the greatest rate of temperature gain. Our data supports the thermal melanism hypothesis for three reasons: (1) males, the more melanized phenotype, increase in heat faster than females (slopes of male regression lines were the steepest, although not significantly greater than those of females), (2) males are hotter than females, given the ambient temperature, and (3) although not statistically significant, C. aequabilis females, the least melanized phenotype, heated up most slowly. However, our data also contradicts this hypothesis, as there was no significant difference between species thermoregulatory ability, despite pigment differences between species and sexes; all four groups of damselflies – C. maculata and C. aequabilis males and females – increase in internal temperature at about the same rate. Our findings also do not support those of Svensson and Waller (2013) in finding (in European species) that the more northerly species had a negative slope for thorax vs. ambient temperature.

What We Learned: Exposure Trials

 

In addition to immersing ourselves in local culture while living and working in Hawai’i, the overarching goal of the summer was to prepare M. calliphya samples for biochemical assays to quantify oxidative damage in the fall. To prepare these damselfly samples, we performed the exposure experiment that many of us have posted about thus far in our blog, in which we exposed a portion of damselflies to solar radiation for 1 hr and left half unexposed. Recall that in Grinnell we will analyze these samples to see which morph – green females, red females, or (red) males – underwent the most oxidative damage during the 1 hr UV exposure.

In previous years of doing exposure experiments as part of this project, several unanswered questions were raised. Particularly…

  1. How much hotter are exposed damselflies than unexposed damselflies?
  2. Do our data support the thermal melanism hypothesis?
  3. How does UV radiation affect the internal temperature of the damselflies during the experiment?
  4. Does damselfly temperature affect how much they are damaged by UV radiation?
  5. How does weather (namely, ambient air temperature and wind speed) affect the oxidative damage the damselflies incur during exposure?

In order to answer these questions, we measured the ambient air temperature, average wind speed, and damselfly temperature throughout the exposure experiment. Here is what we learned!

 

Question 1: How much hotter are exposed damselflies than unexposed damselflies?

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Figure 2. Average thorax surface temperatures of M. calliphya morphs during 1 hr exposure experiment. Green females: n=98. Red females: n=86. Males: n=92. Bars represent ± 1 S.E. of the mean. ANOVA Treatment: F=553.76, p<0.001; Morph: F=0.47, p=0.627; Treatment*Morph: F=4.59, p=0.011.

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Figure 3. Deviation of mean thorax temperature from ambient air temperature of M. calliphya morphs during 1 hr exposure experiment. Green females: n=98. Red females: n=86. Males: n=92. Bars represent ± 1 S.E. of the mean. ANOVA Treatment: F=770.89, p<0.001; Morph: F=0.25, p=0.781; Treatment*Morph: F=7.11, p=0.001.

Overall, the damselflies in the exposure group were 6.7 ºC warmer than those in the unexposed group (see Figure 2 above)! This makes sense, because those damselflies receiving solar radiation for an hour, while the rest were in the shade. Additionally, the exposed damselflies had thorax temperatures that were 6.6ºC higher than the ambient air temperature, while those in the unexposed group had temperatures the same or just slightly higher than ambient air temperature (see Figure 3 above). This supports unpublished data of Dr. Idelle Cooper (James Madison University), who found in a similar experiment that the different morphs of damselflies – males, red females, green females – have about the same internal thorax temperature after exposure. After we test the oxidative damage of these Hawaiian damselflies, we will analyze whether oxidative damage is related to temperature.

 

Question 2: Do our data support the thermal melanism hypothesis?

The thermal melanism hypothesis predicts that the most pigmented – or darkest – phenotype will have the highest rate of temperature gain and higher body temperatures, which, in the M. calliphya model system, expects males to have the greatest thorax temperature during the exposure experiment. While we did not measure color quantitatively, our results confirm Cooper’s previous study that illustrates that color differences do not result in differences in brightness (or darkness!) or in internal thorax temperatures. (see Figure 2 above). Thus, the thermal melanism hypothesis is perhaps not relevant for this species, since brightness varies within, rather than between morphs.

 

Question 3: How does UV radiation affect the internal temperature of the damselflies during the experiment?

We used a UV meter to determine how much UV radiation was hitting the damselflies in the exposed group during the 1 hr exposure. As we expected, the amount of UV hitting the damselflies significantly affected the temperature of their thorax muscles, with higher levels of UV related to higher thorax temperatures. Within the exposed group, all morphs had similar deviations from ambient temperatures, and the effect of UV radiation levels was the same across all morphs. We will eventually use these UV levels in our final analysis, to investigate the relationship between UV level and oxidative damage.

 

Question 4: Does damselfly temperature affect how much they are damaged by UV radiation?

Question 5: How does weather (namely, ambient air temperature and wind speed) affect the oxidative damage the damselflies incur during exposure?

To address these two questions, we will need to wait until we complete the biochemical assays in the fall, which will reveal the level of damage from these Hawaiian M. calliphya samples are. Only then can we investigate whether a relationship between thorax temperature, ambient air temperature, mean wind speed, and oxidative damage exists.

 

What We Learned: Pool Mapping and Physical Parameters

 

We collected damselflies from four sites – Gulch 56, Waterfalls, Waia’ele, and Upper Mountain House – during the portion of our summer on the Big Island. At each site, we identified about 25 pools and analyzed the physical conditions of each (conductivity, pH, temperature, dissolved oxygen, and area) to learn more about the environment in which damselfly larvae live. Since Eve and Bella took the lead on analyzing this data, they will discuss their findings in a different post!

 

Side note: Today was Jackie’s birthday, and we all celebrated together! We performed a hula dance about the beauty of Ka’u – the region we are staying in – that we had been practicing over the last couple of days, we ate pineapple upside-down cake (with fresh pineapple), and we tried soursop for the first time. It was a great final day in Hawai’i.

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7/30 post

by Lucie Duffy

In light of Bella’s post about our trip to Hilo, and Jackie’s response to her post we had a discussion as a group about tourism, “localness” and how science and scientists do or do not fit into these categories.

 

In some ways scientists do engage in the industry of tourism — they rent houses and cars, and bring more business to food industries. But scientists may not engage in “tourist attractions” or activities because they are working during their travels so they spend their time in field sites (or labs). We also discussed the historic context of scientists in Hawaii. European scientists were some of the first people to begin traveling to and colonizing Hawaii. The context in which we engage with science in different ecological and social communities is important and should be incorporated into all science education. We will continue to have these discussions as we continue engaging in scientific research back at Grinnell.

 

Now I will tell you about some of the more “touristy” things we did today.

Today, in addition to going to Gulch 56 to measure pool conditions, we were able to visit a few new places around Na’alehu and Pahala. We had tentative plans to go to the Waterfalls site so we were up early, but when the clouds rolled in we decided instead to go to South point, the southern-most part of the United States. It was beautiful and bright in the morning and we watched some people fishing off the edge of the cliffs there. At the edge of one of the cliffs there was a little dock where a couple jumped off into the water. We did not jump off any cliffs.

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Jackie and Eve in the morning sun

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Waves crashing at the southern-most point

After measuring pools at Gulch 56 mid-morning, we went to Coffee Mill, a store in Pahala that sells Macadamia nuts and local Ka’u coffee. We tasted all the coffee and Macadamia nut selections before making our purchases. We enjoyed lunch in a pavilion outside the shop while watching a video about how Macademia nut production has brought jobs ad visitors to the Ka’u area. Down the road from Pahala we visited Nechung Dorje Drayang Ling, Buddhist temple and retreat center. It was a nice place to be quiet and reflect on our time in Hawaii.

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Cloudy day at Gulch 56

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Roadside views in the Pahala area

Finally, we stopped at Punalu’u beach to take a quick dip in the ocean before returning back to the house to work on analyzing the data we have collected over the past three weeks. We are excited to share some of our results from this analysis in an upcoming post!

 

Trip Reflections

7/30/18

by Bella Jacobsen

As my time in Hawaii comes to a close, I have started reflecting on my experience here, a perfect combination of studying and experiencing Hawaiian culture. Today we were able to visit a few places that displayed this culture. Our first stop was the southernmost point in the United States, South Point, HI. After driving through a terrain reminiscent of Iowa –flat land full of long grass and cows– we stopped at the most southern point of Hawaii. Composed of both fishermen catching from a 50-foot cliff, and tourists jumping from said 50-foot cliff, this destination provided exciting sights. One unusual aspect of this area is the wind turbines harvesting energy. These turbines provide energy to 18,000 homes per year; however, many people complain that the structures disrupt the view. Additionally, South Point hosts the SSC (Swedish Space Corporation) U.S station, which provides many services involved with space exploration and research. The large satellites and sparse signage around the facility create a very ominous feeling.

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The view on the way to South Point.

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   The cliff at the tip of South Point.

After South Point, we ventured into the field followed by a visit to the Ka’u coffee mill. At the field, we were surprised to find many dried up pools. The lack of rain and dark rock, heated by the sun, contributed to this problem. Following the field, we were able to taste Ka’u’s three different beans, washed, semi-washed, and natural. Washed beans remove the outer skin of the coffee bean; semi-washed beans contain some of the outer skin; natural beans are left with all of the skin remaining. Upon tasting the coffee, we noticed that the washed beans had the weakest taste, and natural beans had a strong taste. The store also offered various flavored macadamia nut samples and information on the coffee mill.

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The three varieties of beans sold at Ka’u Coffee. (Picture Credit: https://www.inspirock.com/united-states/pahala/ka-u-coffee-mill-a9146305549)

Finally, we stopped at a Buddhist temple outside of the town of Pahala. Located in one of the most remote places in Hawaii, this temple was serenely peaceful. Only the sound of singing birds drifted through the single-roomed temple that smelled of incense and was decorated with colorful artwork and offerings to Buddha. I observed that most of the offerings were packaged foods, such as coffee and crackers, and fresh, ripening fruit. We then proceeded to a nearby Japanese cemetery, which consisted of crumbling tributes to those who had deceased. Although most grave markers were in a tattered state, a few unique graves, with rare English writing, rested under a shelter. The ground covered in decaying leaves, rotting avocado, and falling graves contrasted the life-infused temple greatly. After a final trip to the beach for a quick swim, we returned to the house to start the data analysis.

Overall, my experience here in Hawaii has been one I will never forget. I have really enjoyed conducting field research, as I have never had this opportunity, while soaking in the Hawaiian culture. My highlights of the last three weeks are the trip to the breath-taking waterfalls and the day spent exploring Hilo. The waterfalls were one of the most beautiful places I have ever visited; the secluded wonder of the running stream is like no other site I have experienced. In contrast, the bustling center of Hilo provided excitement and interesting cultural observations. I look forward to sharing our findings from this trip in the coming posts and am excited for my next adventure!

 

References:

http://www.tawhiri.us/

https://www.sscspace.com/services/#satellite_ground_communication

https://kaucoffeemill.com/

Rainy day trip to Hilo

Editor’s note:  Below are two posts about the same trip last week, by Eve and Bella.  I have a very different impression of the Hilo market than they got on a non-market day, perhaps from visiting it regularly during the 1.5 years we’ve been Hilo residents (during sabbatical leaves) and many research visits.  And Hilo has LOTS of local culture — it’s a place with a complex and interesting history, though very different from small town Ka’u. Here’s what the market looked like this past Saturday morning:

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Bella’s views of tourism (or the “visitor industry”) on the Big Island raise some critical questions in my mind. Should we blame folks for meeting the demands of consumerism when the cruise ships pull in? What constitutes a ‘better’ tourism and who decides that? And are visiting scientists tourists?  These are timely thoughts, as the recent volcanic activity has cut into visitor arrivals, with a big hit to the island’s economy.

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7/28/2018

By Eve Galen

Foiled by cloudy weather yet again, last week’s weather allowed for an exploratory trip to the city of Hilo on the western side of the Big Island. Falling in the middle of our time here in Hawai’i, exploring Hilo provided an important opportunity to learn more about different regions on Big Island. Lucie, Gretchen, Bella and I traveled independently on the local bus that travels each way once a day. The buses are fashioned identically to the M31 I grew up riding in New York City, except with wood paneling rather than the black plastic I am accustomed to seeing. The familiarity of the bus provided an unexpected comfort while traveling in a new place. The two and a half hour bus ride gave us the chance to catch up with each other, rewind, and observe the local commuters. Many commuters traveling on the 7AM bus rode back with us on the 2:40PM return trip, sporting work apparel or shopping bags. Others matched a common haole (white person in Hawaiian) hippy aesthetic traveling within regions we passed through.

Upon arriving in Hilo, our first stop was the Hilo Farmers Market. The market fluctuates in size—big market days (Wednesday and Saturday) boast over two hundred vendors while smaller market days usually have approximately thirty vendors. Tuesday is usually a smaller market day, however an entire lot was filled with stands of fresh fruit, vegetables, and prepared foods. Interestingly, many of the fruits and vegetables were packaged in plastic bags. Individual stand-operators would package their fruits and vegetables in plastic bags behinds their stands as we walked through the market, pre-preparing for customers. This felt a bit unusual, as all the farmers markets I have been exposed to are usually frequented by alternative customers who arrive with canvas bags in hand. The plastic bags may have been for the convenience of tourists.

Market

The Hilo farmer’s market.

Our next stop was Bears Coffee, a local coffee shop selling Kona coast coffee. Kona coffee is renowned due to the unique climate of the Kona-side of Hawai’i. The intermingling of volcanic soil, elevation, and weather that fluctuates between frequent sun and rain provides an ideal environment for growing coffee. In fact, Kona coffee is so delicious that it is well known as one of the most expensive coffees in the world. Tasting some local coffee was a necessary stop after our 6am wake up—and it truly was delicious!

 

Fueled by a kick of adrenalin, we headed to the Mokupāpapa Discovery Center. The center serves to educate the public on the Papahānaumokuākea Marine National Monument. https://www.papahanaumokuakea.gov/ The monument is the largest contiguous protected area in the United States and one of the largest marine conservation areas in the world. The name Papahānaumokuākea comes from Papahānaumoku (the Hawaiian goddess of the earth and underworld) and Wākea (the Hawaiian god of light and the heavens). Papahānaumoku and Wākea embody the creation of the Hawaiian Islands and the ancestors of the Native Hawaiian people. At the educational center, we learned about the most recent activity at the active eruption site on Kilauea from National Park Service volunteers.

 

After walking along the bay front, window-shopping at a few boutiques specializing in aloha wear (Hawaiian shirts), the salvation army, and a local artist gallery, we headed to Two Ladies Kitchen, a mochi shop in downtown Hilo. Two Ladies Kitchen is famous for delivering mouth-watering pouches of sweet rice dough filled with azuki bean, fresh fruit, and a myriad of other options. We opted for peach-filled, ginger, coconut, lilikoi, azuki, and peanut butter mochi.

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(Mochi from Two Ladies Kitchen)

In keeping with the theme of Japanese influence in Hawai’i, our next stop was Ebisuya Sushi. We enjoyed some delicious sushi, including Hawaiian-influenced rolls that contained pineapple!

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(Out front of Ebisuya Sushi)

Bellies content, we decided we couldn’t possibly be full yet! Mesmerized by the prospect of ice shave, a delicious Hawaiian dessert consisting of shaved ice topped with flavored fruit syrup, we headed to Wilson’s by the Bay. After some discussion with the teenagers manning the store, three of us decided on the flavores li hing mui, lychee, and lilikoi (the female ice shave operator’s favorite combination). Lucie added a sweetened condensed milk drizzle on top of her ice shave. The homemade fruit syrups perfectly complemented each other–a little bit of tang and a little bit of sweet in perfect balance and harmony.shave

Stuffed from all our culinary excursions, we meandered back to the waterfront where we people-watched, enjoyed the sea breeze, and prepared to board the bus for another two and a half hour bus ride back to Na’ālehu.

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7/26/18

Bella Jacobsen

Hawaiian Tourism

 

Tourism, something our research group does not experience often, is a vital part of Hawaiian culture. The industry employs thousands of people and creates economic growth. Millions of tourists visit Hawaii every year; in 2017, over 3,500,000 people came to the island. With each person spending significant amounts of money, tourism brings in billions of dollars every year (over $15 billion in 2016!). This impressive profit causes tourism to be the top Hawaiian industry, followed by defense, raw sugar/molasses, and pineapple.

Tourism affects more than just the economy; it creates a unique culture. When in Hilo, we found it easy to spot the tourists and the locals, which led to a discussion on life in a tourism-heavy city. To me, it seemed like Hilo lacked a distinct vibe. It contained the staples of Hawaiian life, like shave ice, an ocean view, and homemade aloha wear, but the local feel was missing. In Na’alehu, where we are staying, nearly everybody is local, and I feel that we have truly been able to experience the life of a local Hawaiian. However, the tourists in Hilo took away that feeling. Each location was geared towards tourists rather than Hilo locals. For example, half of the farmers market was selling crafts littered with “Aloha” rather than homemade, local art. At the Na’alehu farmers market, vendors wandered between stands greeting their neighbors and trading goods. Although the Hilo market displayed some comradery, vendors were not part of a community; they were separately competing for business. Additionally, I noticed that some stands were selling produce that they had purchased elsewhere that had tags and labels still attached. This food was obviously not grown local, and the vendors were looking to sell to earn the most money rather than supply local food. Overall, Hilo greatly lacked the local culture I enjoy in Na’alehu.

Often, scientists become wrapped up in the facts and figures of their research and forget to examine how sociological factors, such as tourism, may affect scientific findings. These effects may not change the mechanisms behind biological or chemical functions, but they could impact public reception of the findings. A relevant example is the current eruptions of Mount Kilauea. Scientists must keep tourism in mind when informing the public. Recently, a lava bomb hit a tourist boat (More information: https://www.cnn.com/2018/07/16/us/hawaii-lava-bomb-boat-12-injured/index.html), causing an uproar about the safety of lava observation. Geologists had to keep tourism in mind when responding, will unsafe conditions deter tourists? Perhaps, the public does not hear the whole story to prevent fear and continue profits. A history of allowing human invasion of ecology for profit exists everywhere. Animals, plants, and insects are disturbed, and fear of the dangers of the earth are ignored in order to increase profits. Although this action immediately seems like a negative, it can allow tourists to discover science. For example, an animal in a zoo may not have a high quality of life, but it may instill a love for biology in a child. Scientists should work with others to analyze the best way to balance preservation with displaying the wonders of the earth to all.

TouristslavaTourists observing lava. (Source:   http://www.foxnews.com/travel/2017/05/16/tourists-keep-returning-cursed-lava-rocks-to-hawaii-volcano.html)

References:

Tourism statistics: http://files.hawaii.gov/dbedt/visitor/tourism/2018/May18.pdf

Click to access 2016-annual-visitor.pdf

Invasive Geckos and Chameleons

 

Author: Gretchen

When we first arrived in Hawaii, we all made a valiant attempt to “stay up late” – 8 PM – in excitement and to beat jet lag after a long day of travelling from the mainland to the Big Island. Drowsy and exhausted, I was greeted by an unexpected green visitor in my room, who was making quite a large ruckus for such a small lizard. The small gecko was scampering about and making screeching noises – calling out to all his friends to invite them into my room, I suppose – throughout the whole night. I have always been intrigued by reptiles, so I enjoyed the unwelcomed guest. Admittedly, I would much rather have a gecko in my room instead of creepy crawly insects. One could argue that this gecko was Hawai’i’s way of extending a warm welcome to our research group.

The next night, I enjoyed watching a gecko hunt down insects on my windowsill. The gecko waited patiently, while innocent insects were lured toward the light coming from my room. I soon found myself an audience member to a war between gecko and insect. When the insect was in striking range, the gecko leaped into action and, with an insect in its jaws, swung its head back and forth rapidly to kill its dinner. What caught my attention about this event was the noise the little gecko made. Large thumps from its head and tail wrapping against the siding of the house echoed throughout my room as the gecko and insect continued to struggle. After the show was over, I fell asleep to the hissing from geckos creeping around the walls and ceiling of my room. I am impressed by the intelligence of the geckos, because I continued to see them waiting outside near the windows to catch unsuspecting meals each night.

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(Gold Dust Day Geckos waiting to catch dinner on our lanai.)

While the Hawaiian Islands are not home to any species of snake, eight species of gecko – called mo’o in Hawaiian – inhabit the lush and diverse landscape. The first mo’o likely came to the islands as stowaways on Polynesian ships before 1778 – as some species were already established by the time of Captain James Cook’s arrival to the islands (smithsonianmag.com), and others, like the Common House Gecko, likely came on cargo ships in the 1940s before making the islands their permanent home (mauiinvasive.org). However, some species were introduced illegally to Hawai’i and other islands in the Pacific.

gold(We saw this Gold Dust Day Gecko while enjoying shave ice near Kona.)

The species I have seen the most so far is the Gold Dust Day Gecko (Phelsuma laticauda). Feeding on insects, fruit, and nectar, P. laticauda is a diurnal gecko in the Gekkonidae family that can reach 4 to 6 inches at maturity. Although native to northern Madagascar, this species was introduced to Hawai’i and is now considered an invasive species. Because P. laticauda can adapt to a variety of climates, it can live successfully on many of the Hawaiian Islands (Goldberg, S.R., and F. Kraus 2011). Thus, P. laticauda does not face imminent risk of extinction (Van Heygen, E. 2004). According to popular lore, the Gold Dust Day Gecko is said to be the mascot of GEICO, and many keep this reptile as a pet. It can live for more than ten years in captivity.

At this point, it is not certain the impact that the introduction of the Gold Dust Day Gecko has had on the Hawaiian ecosystem. Reptiles were unable to colonize the islands for thousands of years due to the islands’ isolation, which generated a flourishing abundance of insects. Before the arrival of small lizards, like the Gold-Dust Day Gecko, many insect species – including tens of thousands that are unique to Hawai’i – thrived on the islands. Thus, such a question is important to pursue, because reptiles, like the Gold Dust Day Gecko, likely caused a permanent change in the trophic interactions and ecosystem of Hawai’i as a whole.

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(Orange-spotted Day Gecko. Source: geckoweb.org)

 

giant.png(Madagascar Giant Day Gecko. This one is a small one. Source: Pinterest – Reptile Pets Direct)

 

Other species of day gecko, the Orange-spotted Day Gecko (Phelsuma guimbeaui) and the Madagascar Giant Day Gecko (Phelsuma madagascariensis) were introduced illegally to the island of O’ahu. The Orange-spotted Day Gecko can grow to be 7 inches long, and the Madagascar Giant Day Gecko can reach lengths of 10-12 inches (mauiinvasive.org). The Madagascar Giant Day Gecko can often be found inside the walls of human homes (reptilepark.com.au).

 

JC.png(Jackson’s Chameleon – Chamaeleo jacksonii xantholophus. Source: cbreptile.com)

In addition to geckos, many keep Jackson’s Chameleon (Chamaeleo jacksonii xantholophus) as a pet that can become feral if released into the wild. Male Jackson’s Chameleons can grow 10-12 inches long and have three horns. In contrast, female Jackson’s Chameleons are smaller and hornless. The introduction of Jackson’s Chameleon to Hawaii (McKeown, 1991) in 1972 from its native Kenya and Tanzania is especially problematic, because they prey upon insects native to Hawai’i (Kraus et al. 2012), including Megalagrion damselflies. Species threatened by Jackson’s Chameleon include M. blackburni (see Lucie’s post “Pane’ene’e Pali streams” below) and the auriculella and Achatinella mustelina snails (cabi.org). Additionally, several snake species prey on chameleons, which could allow snakes to become established on this currently snake-free island chain if ever introduced (dlnr.hawaii.gov).

Sightings of both invasive geckos and/or Jackson’s Chameleon should be reported immediately to the Hawai’i Department of Agriculture pest hotline at 643-PEST to protect the delicate environment of the Hawaiian Islands.

Pane’ene’e Pali streams

Author: Lucie Duffy

7/25/18

Today we were on the road at 6:00 am to travel to what the locals call “Waterfalls”, a mid-elevation field site near Pane’ehe’e Pali that we had not yet explored on this trip to Hawaii. We left early to optimize our time there before the area clouded over. There is also a 45-minute hike from the car up to the streambed, so the earlier the start the better.

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Jackie and Gretchen on the road to Waterfalls

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Views of pu’u (hills) on the ranch road to site

This site was my favorite so far, and probably the most beautiful place we have been in Hawaii. We set up a home base near a large clear pool of water and started off the day by mapping and measuring pools in the area. The pools here were much clearer than any of the other sites we have been to, and I am curious to compare the physical conditions of these pools to the others. The clear water may be a result of the intact native forest that dominates the area. Except for a few tibouchina plants within the streambed, the watershed consists of almost entirely native plants. In the native forest, the large vegetation surface area holds the water and releases it more slowly, allowing it to infiltrate the shallow soils and volcanic substrates and emerge in springs. This is the reason why this stream is one of the few that flows continuously, even during this current dry period.

The water in the stream leads to a large 800-ft waterfall (far away from where we were working). There are two waterfalls in the area but one of them is usually dry. The running stream was not very high, its consistent flow and occasional floods creat lots of little pools for the larvae of M. calliphya to inhabit. Because the water in this pools was so clear we could see them moving around.

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Pool mapping and measuring at Waterfalls

 

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Overlook point from dry Waterfall

After we mapped twenty-five pools we switched our focus to catching M. calliphya males and females for an exposure trial. There were a lot of damselflies out on the streams, but the ratio of red to green females was lower than at Waiaele and Upper Mountain House Road. It was also slightly more difficult to catch all of the damselflies here. Tandems and individuals would perch on the rocks around the stream so it was difficult to swipe the net close enough to catch them. Instead I used the technique of placing the net over the tandem on the rock and waiting for them to fly up into it. Additionally, because the stream bed has flowing water, it’s harder to move quickly to catch the flies. Still, we were able to catch enough flies to do one full exposure trial and one trial with slightly less red individuals.

The Waterfall site is also home to another Megalagrion damselfly – M. blackburni. These damselflies are much bigger than both calliphya and hawaiiense. The female of this species that we saw was teal, as is pictured below, but the colors of these species vary among populations, according to previous work by Jackie, Idelle, and their students.

blackburnifemale

Female M. blackburni

                     hike

Hike down from Waterfalls

Once we were done with collecting damselflies we enjoyed lunch by the large pool and then went for a swim. The water was very, very cold but it was refreshing and fun after a long day in the field. I really appreciate that throughout this time in Hawaii we have been able to experience new things both related to and unrelated to our field work. After our swim we packed up the equipment and hiked back down to our car. As we hiked down we stopped at the dry waterfall to look out onto the pastures and pu’u. It was much foggier in the afternoon but the view was misty and beautiful. It is hard to describe how breathtaking it was to be in such a secluded and natural environment, and I feel very lucky to have shared the day as a research group.

Diving into Hawaiian culture

7/23/18

Author: Gretchen

I feel extremely blessed to have this summer research opportunity. I find it both rewarding and exciting to explore the Hawaiian culture through science – ascending the slopes of Mauna Loa during our days in the field and reading about Hawaiian history and culture from the perspective of a biologist in “Islands in a Far Sea” are just two examples. Living on the Big Island amidst Kiluea’s many eruptions puts the Hawaiian mythology of the goddess Pele into an entirely new perspective. For instance, a volcanic observation cruise admiring the flows entering the Pacific was recently battered by molten lava, and 23 people were harmed. (Do not worry — everyone in our research team is safe as we are 60 miles away from the lava!) This event in particular spoke to me. I imagined the first Hawaiians telling the mythological story of the feud between Pele, goddess of lava, and her sister, Namakaokahai, the goddess of the ocean waves, to explain the event.

lava bomb(Photo of “lava bomb” damage to tour ship from July, 16. Source: interestingengineering.com)

In Hawaiian mythology, Pele seduced Namakaokahai’s husband, which convinced him to take her as his wife instead. Angered, the ocean goddess sent massive tides toward Pele, forcing her to flee across the Hawaiian Islands until finally settling atop of Mauna Loa. Safe from Namakaokahai’s waves, Pele and her sister continued to argue, which is realized in the explosions when flowing lava meets the ocean. The volcanic activity of Kiluea is evidence that the spirits of Pele and Namakaokahai are still present on the Big Island.

Additionally, living in Hawai’i differs drastically from researching Hawaiian organisms offsite. What I mean is this: although, Lucie and I conducted assays on the same M. calliphya damselfly in the lab in Grinnell, our lack of field experience in their native habitat prevented us from taking a wholistic approach to studying the species. For example, since doing field work, we have learned to easily identify the sexes of damselflies based on behavior and morphology.

Not only have I experienced culture through science, I also have experienced science through the lens of the intricate Hawaiian culture as well. Like Eve wrote about previously (see her “Wao akua” post below), we, as researchers, have a direct responsibility to preserve the ecosystem we study. If researchers are not careful or ill-informed, diseases like Rapid ‘Ohi’a (Metrosideros polymorpha) Death advanced by researchers’ vehicles, clothing, and equipment could quickly and easily wipe out the very terrain they hope to study. I find this relationship extremely complex, because most research poses a temporary harm for a long-term good. For instance, we temporarily decrease the damselfly populations with our research projects (unfortunately, they are not immune to liquid nitrogen!), but we do so to learn how they are successful as a species in the long run (i.e. understanding the function of their pigmentation).

beach

Honomolino

(Walking from Miloli’i toward Honomalino Bay.)

Honomolino2

(Beautiful salt and pepper beach at Honomalino Bay)

Today, the weather was overcast and suboptimal for exposure experiments, so we headed off to Miloli’i, a small fishing community in the tsunami zone on the south western coast of Hawai’i. Upon arriving, we hiked for about 15 minutes along the coastline through lava rock and trees until we reached Honomalino Bay. In contrast with Black Sand Beach, Honomalino Bay is very secluded and private; there were only two other people on the beach. We enjoyed exploring an offshore reef, teeming with yellow tangs (Hawaiian: lau’ipala, Zebrasoma flavescens) and threadfin butterflyfish (Hawaiian: kikakapu, Chaetodon auriga), and swimming in clear water with minimal waves. Other highlights from the morning were seeing several species of fish for the first time. I watched a large male spectacled parrotfish (Hawaiian: uhu uliuli, Chlorurus perspicillatus) and a spindly cornetfish (Hawaiian: nunu peke, Fistularia). I also watched a small octopus swim from rock to rock!

lanai

(Working outside on the lanai to enjoy the nice afternoon weather!)

As Lucie has written about previously, the weather in Hawai’i is highly variable and changes quickly. After an hour of exploring the underwater world at Honomalino Bay, we got word from Discovery Harbour that the weather was clearing up. So, we went back to Discovery Harbour to conduct exposure experiments. It ended up being a beautiful afternoon, and we conducted two successful exposure experiments with damselflies from Waia’ele and Upper Mountain House Road. The UV level was the highest we have seen in our experiments yet, so we have high hopes for the samples we prepared today.

 

 

 

Hawaiian Culinary Staples

Bella Jacobsen

7/22/18

During our stay in Hawaii, we have been able to explore various local foods, which represent Hawaii’s unique blend of cultures. Our trip from the airport to the south of the island involved a stop at a small store that sold one of these foods, shave ice (often called “ice shave” on the Big Island), which originates in Japan and was brought by immigrant sugar cane workers. Shave ice is very similar to a snow cone, but it has one distinct difference. Rather than being created by crushing ice, one must instead shave a block of ice. This technique creates a much smoother texture. The shaved ice is then flavored, often with fruity syrups. It was at this shave ice store that I first experienced lilikoi — the Hawaiian word for passion fruit — which is a very popular flavor. After a hot day on the beach (or 12 hours of traveling), lilikoi shave ice is very refreshing.

shave Enjoying shave ice after arriving in Kona.

Another traditional treat that we have eaten also stems from Japan. Mochi is a sweet rice paste created by pounding rice. It can be eaten in many ways, but in Hawaii usually as a dessert. It can be filled with ice cream or simply eaten in the style of a brownie. The mochi is often itself flavored with mango, chocolate, sesame, and other flavors. In Japan, mochi can be eaten as a savory dish in soup, which helps warm up the body because it holds heat effectively. Japanese typically enjoy mochi around the New Year, but it makes a delicious treat any time of the year.

At the farmers market in the town of Na’alehu, we enjoyed a food that blends a Japanese dish with a Hawaiian staple. Musubi mimics Japenese omusubi, . rice ball covered in sea weed, but it is filled with SPAM. SPAM (headquartered in Austin, MN, very close to where I’m from!) rose to popularity in Hawaii during World War II. The government supplied soldiers stationed in Hawaii with SPAM because it was easy to ship and store because SPAM can be left safely without refrigeration in the heat of Hawaii. Musubi blends SPAM and omusubi together by surrounding SPAM with rice and wrapping it in seaweed. It is often made in the SPAM can itself, creating the shape shown in the picture. Needless to say, musubi is a very salty dish.

musubi

SPAM musubi ready to be eaten!(Picture from:                https://www.seriouseats.com/recipes/2008/04/tutorial-how-to-make-hawaiian-spam-musubi-sushi.html)

Finally, we have indulged in Hawaiian-grown macadamia nuts. Often nicknamed “mac nuts”, they are one of Hawaii’s leading exports. Macadamia nuts are native to Australia, but were brought to Hawaii and have been an agricultural staple ever since. These small, pale nuts are enjoyed bare, with salt, covered in chocolate, or baked into desserts. One often sees mac nut farms and tasting locations around the island, as they are very popular for tourists. They tend to be very expensive, so their unique flavor should be savored with every bite!

For more information, check out these sites:

Shave Ice: https://en.wikipedia.org/wiki/Shave_ice#History

Mochi: https://en.wikipedia.org/wiki/Mochi

Macadamia nuts: https://hawaiioceanproject.com/a_brief_history_of_macadamia_nuts/

Musubi: https://en.wikipedia.org/wiki/Spam_musubi

SPAM: http://www.thehawaiiplan.com/why-do-hawaiians-love-spam/

Weather and exposure

Blog post 7/21

Author: Lucie

Yesterday Gretchen and Eve traveled to the Waiaele and Upper Mountain House Road sites to collect fresh damselflies to continue our exposure experiments. Our goal is to complete exposure experiments within one or two days of collecting the flies to minimize damage. This morning, early, the sky was completely clouded over and we thought our plans of an exposure experiment were foiled. When it is very cloudy the UV index is low, and we want to induce as much UV damage as possible to the damselflies we collect. Our backup plan for the day was to head to Hilo, a city to the east of where we are living, but just as we were getting ready to head out the sky cleared up! We quickly adapted our plans for the day and were able to set up two very successful exposure experiments.

EveinShade

Eve sorting through damselflies to use for exposure experiments – look how sunny it is!

There are a lot of differences between working in a biology lab and working in the field, and I have been lucky enough to experience both work settings throughout this summer. When you work in the field there are a lot of factors out of your control – the main factor we have to face is quickly-changing and unpredictable weather. First of all, there is no functioning weather station that reads the weather in the mountain regions where we work, so predicting weather comes down to looking towards the mountains to see if the sky is clear or cloudy. Luckily, Jackie has a lot of experience with field work in the area and is able to make judgment calls on when we go into the field. Once we are at the mid-elevation sites, we have been working recently, the sky can cloud over very quickly due to trade winds and it may start raining. Back at the house where we are setting up exposure experiments the clouds can set in quickly and the past week have been clouding over pretty early in the morning, as early as 10:00 am. This weather pattern of sunny mornings and cloudy afternoons is very characteristic of this area of the Big Island.

It has rained a bit in Naalehu over the past few days, but the rain up in the field sites has been very limited. Jackie downloaded the information from some of the weather logging equipment up in the field sites for the past couple of months and found that it has only rained about 3.3 inches in the last month, and 2/3 of an inch since we arrived 12 days ago. This is very uncharacteristic of the area. Jackie was surprised when we first arrived at the sites to see how low the water in the streambeds was, and his suspicions of limited rainfall were confirmed by the weather logs. Just in the past week alone a few of our mapped pools have dried up. Based on the very dark skies we think it may have rained up in the mountains today, so tomorrow we plan to measure the physical parameters of the pools to see if there is a change in size.

rainfall

Working in a research team has been a tremendously fun experience. Over the past week we have spent a lot of time together in the field, in the car, and living together. One of the greatest benefits of working in a team is when we have to change plans or make tricky decisions, we have each other to bounce ideas off of. There is a lot of energy in working together and I think it has made celebrating success more fulfilling, but it also has helped us to stay motivated when things do not go as planned. There are definitely challenges to working in a group, for example knowing who is responsible for certain tasks, but we are working through these challenges by improving our inter-group communication and designating clear roles. This morning we had more hands than usual when setting up our exposure experiment, so we modified our method to utilize all the help we had, and the trial went smoother than ever.

Wao akua

7/20/18

By Eve Galen

The Island of Hawai’i boasts more climatic regions than any single island or nation in the world. For its small size, this is an incredible feat! Tropical forests and arid deserts co-mingle below the towering snow-crested peaks of Mauna Loa and Mauna Kea. The great diversity in habitat here gives way to an even greater array of native organisms. Yet, the ecological balance of Hawai’i’s many spheres is delicate. Native species are highly vulnerable to invasive non-native organisms due to Hawai’i vast oceanic separation from any other mainland. Cordoned off from the rest of the world’s flora and fauna, the native organisms of Hawai’i have seldom been faced with the threat of migration or invasion. Early Polynesian settlement foreshadowed the mass debilitation of native Hawaiian habitat that occurred with European colonization and the annexing of Hawai’i as an American territory. The delicate symbioses of Hawai’i’s ecosystems continue to be under threat as increasing volumes of tourists, mainland immigrants, and scientists track organisms to and around the Hawaiian Islands.

climate

               (Variety of climatic regimes present on Hawai’i)

Ceratocystis is a deadly fungus infecting native ‘Ohi’a (Metrosideros polymorpha) trees on the islands of Hawai’i and Kaua’i. The infection is called Rapid ‘Ohi’a Death. An important part of our daily routine in the field has been washing, scrubbing, and treating our shoes with rubbing alcohol in order to prevent the spread of Ceratocystis and other organisms between field sites. We also thoroughly wash and brush the truck used for transportation between field visits. The practice of washing and brushing down any objects that may track invasive organisms between field sites (for example: shoes, tires, floor mats in cars) is vital to preventing the spread of diseases and invasive species in vulnerable habitats.

UMHR

(Upper Mountain House Road: a middle elevation field site that contains a high percentage of native habitat)

Over the last week, I have been thinking critically about the threat scientists pose as “colonizers of nature”. What consequences may be the result of habitat disruption? Can disruption be excused if it is for the “sake of science”? Understanding methods for minimizing damage to the environment (such as washing our shoes) has been a key component of ensuring our time in Hawai’i is productive, respectful, and ethical. In addition to valuing the ethical consequences (both to humans and nature) of our research, learning about Hawaiian myth and tradition has served as a turning point in my perspective on the importance of conservation and preservation in Hawai’i. I greatly value the time spent discussing the goddess of fire and volcanoes, Pele, who resides in Mauna Loa, and the mythical reasoning for the explosive lava flows and spectacular ocean entry on display in Hawai’i this summer. In my time here, however, I have come to think of one aspect of Hawaiian tradition and nationalism as most representative of the spirit of conservation—Aloha ‘āina. Aloha ‘āina means, “love for the land” and represents the Hawaiian belief that we are direct kin with the biotic and abiotic elements of our native ecosystems. Aloha ‘āina demands physical, spiritual, and cultural stewardship of the Hawaiian land and way of life. We have been embodying Aloha ‘āina when we wash our shoes and our car, treat the land we collect samples from with respect, and learn about the tradition of Hawai’i’s great Gods and Goddesses that live in the mountains we ascend everyday.

waiakua(Wao akua—the realm of the gods—are the mountains that house the sacred forests and streams that we do research in)

Dr. Sam ‘Ohu Gon III, a scientist and cultural advisor to the Nature Conservancy of Hawai’i, has been influential in my understanding of Hawai’i’s diverse ecosystems and the cultural impact of Aloha ‘āina. Dr. Gon’s Ted Talk (https://www.youtube.com/watch?v=l9fv_2XIJBk) has been instrumental in building my experience as a scientist and anthropologist.

Site for more information on Rapid ‘Ohi’a Death: https://cms.ctahr.hawaii.edu/rod/