Category: Guest Posts

Guest post: Catching Invasive Beetles before they get boring

This is a guest post by a student in my graduate course.

Wood-boring beetles can be found cozied up in trees, lumber, furniture and other sources of wood worldwide, posing both ecological and economic concerns. These beetles lay their eggs beneath the bark of trees, where their larvae hatch and feast on the tree’s nutrients before developing into adults, tunneling their way out of the tree, and continuing on to infest new trees. These beetles have classically been restricted to the environments from which they originate, but the influx of international trading has allowed for “alien” species of wood-boring beetles to infest new lands. Although protocols are in place to stop the spread of wood-boring beetles, larvae of these bugs are able to remain undetected in wood that is used for packaging during international shipping, allowing them to hatch, reproduce, and spread upon arrival. These invasive beetles are especially problematic in their new environments because they frequently do not face the same ecological constraints that they would in their natural ecosystem, such as risk of predation or lack of suitable host trees to infest. While wood-boring beetles are rarely able to reach populations large enough to pose a risk in their native environments, they are often able to flourish in new ecosystems, spreading rapidly, destroying tree populations.
One example that you may be familiar with is the Emerald Ash Borer . It originates from Asia, where it is only a minor pest, as populations can rarely grow dense enough to kill healthy trees. However, after arriving in packaging material during the 1990s the emerald ash borer has thrived in North America, spreading rapidly while leaving a trail of decimated Ash trees in its wake. For over a decade, North Americans have struggled to limit the spread of the Emerald Ash Borer, with no easy solution in sight. It is apparent that wood-boring beetles must be further studied in order to track and limit their dispersion.
In order to improve the efficiency and cost effectiveness of measures to prevent the arrival and dispersion of invasive wood-boring beetles, the Italian researchers Davide Rassati, Massimo Faccoli, Edoardo Petrucco Toffolo, Andrea Battisti, and Lorenzo Marini investigated the factors that influence the arrival and establishment these beetles. As trading ports are considered the most likely point of entry for alien wood-boring beetles, the researchers selected fifteen Italian trading ports and surrounding forests to set up traps that were specially designed to attract and capture wood-boring beetles. Over 150 days the traps caught fourteen alien species, four of which had not been seen in Italy before. The more imports a port received, the more beetles that were found in the port and the surrounding forests. As these invasive beetles feed on broadleaf trees, they heavily preferred broadleaf forests, taking little time to infest their preferred host species. Upon arrival, the beetles quickly established themselves in the surrounding forests; more beetles were found in the forests than the ports they originated from. As it is desirable to stop the spread of beetles to the forests once they have entered a port, the researchers argued that that an early detection system is necessary to quickly catch and eradicate any invasive wood-boring beetles. They recommend that ports that receive high volumes of commodities, especially those surrounded by broadleaf forests, should be actively tapped and monitored for invasive beetles.
I agree with the researchers that the early detection of invasive wood-boring beetles is important to stopping them from spreading; however I believe that the emphasis should be placed on developing shipping practices that prevent the transport of invasive species, rather than hoping to detect and eliminate invasive species once they have arrived. By the time wood-boring beetles are detected, it is likely that they have already dispersed, requiring a long, costly cleanup, such as the Asian Long horned Beetle infestation Toronto suffered in the last decade. To prevent the spread of invasive wood-boring beetles, manufacturers must either use packaging materials that cannot be infested by the beetles, or more carefully treat their wood before shipping, both of which would come at increased international shipping costs. One must then ask: is it worth compromising the integrity of our ecosystems in the name of globalization?

Rassati D, Faccoli M, Petrucco Toffolo E, Battisti A, Marini L (2014) Improving the early detection of alien wood-boring beetles in ports and surrounding forests. Journal of Applied Ecology, online in advance of print.
Rassati D, Faccoli M, Petrucco Toffolo E, Battisti A, Marini L (2014) Data from: Improving the early detection of alien wood-boring beetles in ports and surrounding forests. Dryad Digital Repository.

Guest Post: Ski Bunnies Poop To Tell You How They Feel!

This is a guest post by a graduate student in my Ecological Physiology course.

Imagine for a moment, a place of blissful peace. What would it look like? A place with crisp fresh air, snow covered slopes and lush green forests. A place so quiet, that the only things interrupting the tranquillity are the odd howls of wolves, the rustle of small animals scurrying about and the cracking sound of tree branches under the weight of the snow cover. It is in just such a place, in the Swiss Alps, where our story of Lepus timidus, a happy little mountain hare, begins.
Lepus lived with his family in a cozy hole he had dug under the roots of an old pine tree. Many of his friends had done the same at nearby trees. Lepus (or Lepi as he liked to be called) and his friends were so close that they often gathered food, played and groomed together. Their grooming involved many hygienic procedures but none were as strange as eating their own feces. YES, I say, eating their own poop! Right about now you’re probably making faces and saying things like ‘Eeeew, gross or yuk’, and who would blame you? But did you know that this is a common and necessary behaviour for all animals involved in coprophagy (the act of eating poop)? Rabbits produce two types of droppings: fecal pellets from the colon and slime covered pellets that come from their caeca. By eating the latter type, bunnies are able to re-ingest nutrients they may have missed the first time around (still gross). In fact even pet bunnies will do this, followed by snuggling and bunny kisses (Mmmmmm, just food for thought). Ok, back to our bunny tale. Lepi, his friends and family were famous across the land for being so happy and relaxed all the time. Oh, sure they had the odd scare, when the neighbourhood fox fancied hasenpfeffer for dinner, but overall life was pretty serene.
One day all the peace and quiet came to an end when humans decided to move into the mountains to have some fun. They brought skis, snowshoes and snowmobiles and began to explore the forests where Lepi had lived for so long. They even erected buildings and tall metal poles strung with wires that allowed them to climb the mountain faster. They just hung there, off the wires, looking down at poor little Lepi and his friends, their enormous shapes casting dark shadows as they eerily moved along. All this human activity made Lepi and his friends very nervous. They began spending more time in their holes hiding and were afraid to go play and gather food. They were hungrier than ever which made their desire to groom very low priority. In fact they even stopped eating their own poop.
“This is not right”, yelled Lepi. “I am going crazy with all this commotion going on”.
Lepi took a deep breath, checked to see if the coast was clear and hurried over to see the family psychologist. The psychologist understood what Lepi was going through, in fact citing that he, himself, had been experiencing similar symptoms. He recommended that Lepi go see his scientist friends who could possibly determine what was happening to the once happy bunnies. So Lepi packed his bunny bags and hopped off to see Maik Rehnus, Martin Wehrle and Rupert Palme, prominent wild life researchers. Once there, the scientists assured Lepi that they would do everything in their power to determine the problem. Lepi was told that all he and his friends had to do is to try to go about their normal business and deposit poop pellets which they would collect and analyze. Excited, Lepi hurried back to share the news, although he wondered what the scientists were going to do with their poop. Lepi’s quick internet search revealed that there are hormones called corticosteroids which become elevated with increased stress. The metabolites of these corticosteroids are collected in the feces and excreted, therefore, an analysis of the poop could determine if the bunnies were stressed in certain situations.
The scientists began their testing in the Swiss Alps in three different locations where the hares lived. The first site was very busy with tourists and activity, the second site had medium activity and tourism while the third site was a natural reserve where no human activity and tourism was allowed. They worked feverishly over several winter months to collect all the bunny poop from the three different sites. Once back at the laboratory they determined that the poop of mountain hares that lived in the busiest tourism areas contained the highest levels of corticosteroid metabolites. The hares who lived in medium traffic areas had poop with medium amounts of metabolites, while the hares from the reserve had the lowest levels. This told the scientists that the presence of humans in the natural habitat of the mountain hares, caused unnecessary stress on the animals. This stress caused an elevation in corticosteroids concentrations in the hares. Corticosteroid release is a normal physiological response to the ‘fight or flight’ reaction, which enables the animal to make critical lifesaving decisions in face of perceived danger. Although some base level corticosteroids are always present in the blood, prolonged high levels may lead to various illnesses, presenting with symptoms such as lethargy, abnormal behaviour and loss of appetite.
In addition to this on site study in the mountains, the scientists invited a few select mountain hares to join them for a little while in their laboratory where they could perform some more psychological and physiological tests. The bunnies were divided into two groups and offered a nice enclosed place to do what they please, with plenty of food and a cozy shed to sleep in. One of the groups were left alone to live in peace with no disturbances, but as before their poop was regularly collected. The other group, however, was allowed visits from a curious dog who rummaged around the bunny compound. Also the scientists occasionally flew a kite above the bunny enclosure to simulate birds of prey. These bunnies also had to surrender their poop. Once again the scientists found that the hares that were being regularly disturbed had much higher levels of corticosteroid metabolites in their poop compared to the hares that were left alone. The scientists concluded that human activity and predation literally scared the crap out of these animals.
After the lengthy research the scientists called a meeting with Lepi and his friends to reveal their findings. The hares were understandably upset and concerned, but the scientists provided some compromises that would allow the mountain hare population to continue thriving without any further disturbance. It was recommended to limit human winter activity to the already developed ski slopes, not allowing backwoods skiing and exploration. This would allow the animals to get used to sharing the space without threat of disturbance. Other suggestions included a stop or reduction to further tourist development as well as limiting the number of tourists allowed per year per site.
Unfortunately not all stories have a happy ending. Although Lepi and his friends were glad to comply with these new compromises, humans were less enthused. These were important studies performed by the scientists, making recommendations to protect the animals; however, the owners of tourism based businesses are not under legislature, obligating them to follow these recommendations. The socioeconomic status of a small country such as Switzerland is highly dependent on the ever growing tourist industry and therefore it is unlikely that these compromises will ever be enforced. Last the scientists heard, Lepi and company were forced to uproot their families and move deeper into the woods further away from human activity. Hopefully development of these mountains will stop before the eradication of forests and ultimately countless animal species.

Citation: Rehnus M, Wehrle M, Palme R. 2014. Mountain hares Lepus timidus and tourism: stress events and reactions. J Appl Ecol 51: 6-12.