Friday, 7 November 2014

Behavioural adjustments that improve reproductive timing

Timing is everything, especially when it comes to reproduction. Well-timed reproduction improves reproductive success. For example, offspring that hatch when food is abundant or predators are scarce are more likely to survive. However, changing environmental conditions may cause organisms to miss the best time to reproduce. Since environmental variability is ubiquitous on a wide range of spatial and temporal scales, the ability to adjust to changing conditions can improve an organism’s chances of reproducing “on time”.

Ovigerous Uca deichmanni female. Photo by Arthur Anker
During my time as a NEO student, I focused on how fiddler crabs respond to temperature changes to maintain the timing of hatching of their larvae. Temperature is a major factor affecting the timing of reproduction in ectothermic organisms because it determines the rate at which embryos develop. As temperature increases, the period of time between mating and when the babies are ready to hatch decreases, and vice versa. Fiddler crab females precisely time the release of their larvae during the large amplitude nighttime high tides that occur approximately every two weeks. By timing the hatching of their offspring during these particular tides, the females minimize the risk of predation by fishes to themselves and to the newly hatched larvae. But in order to hit this targeted timing, the females must either account for the developmental period of the eggs (and temperature-induced changes in it), or they must control it.  

Most, though not all, of the ways that organisms can maintain reproductive timing in response to temperature changes are behavioural. For example, as changing climate is causing earlier springs, some bird species are laying eggs earlier in the year so that their offspring still hatch when their food is most abundant. Another possible response is to select the location where the eggs will be laid and incubated based on temperature, such as a relatively warmer location if temperature decreases before the eggs are laid, or a cooler location if temperature increases. Some lizards and spiders use this method of adjustment. For species that carry their eggs throughout incubation or that can control the temperature of the incubation site throughout development, there is the option of actively regulating the temperature that the embryos experience. Some bird species actively maintain the temperature of their nests. This is also probably a more common response in egg-carrying invertebrates than has been documented thus far.

Uca terpsichores courting male. Photo by Kecia Kerr
As part of my PhD project, I studied the timing of courtship and hatching of larvae of two species of fiddler crabs across seasonal and spatial differences in temperature. My research was conducted in Panama, based out of the Naos Marine Laboratories at the Smithsonian Tropical Research Institute (STRI). My colleagues and I found that Uca terpsichores respond to changes in temperature by changing when they court: when temperature decreased, males courted earlier. In addition, we found that these shifts in timing of courting and mating minimize errors in the timing of larval release… most of the time…. Since this method of adjustment does not allow the crabs to account for changes in temperature that occur after incubation begins, this species makes errors in timing when temperature is variable. In contrast, despite large changes in temperature in its habitat, Uca deichmanni does not adjust its courtship timing BUT, for the most part, they maintain timing of larval release in the field. This species only made errors in timing when temperature was low and constant. It appears that female U. deichmanni may, to some extent, regulate the temperature of their embryos during incubation by moving up and down in their burrows and exploiting the thermal gradient in the sediment, although this hypothesis has not yet been tested. This species is vulnerable to large prolonged changes in temperature that may exceed the limits of their thermoregulating abilities. Thus, these two closely related species that often inhabit the same beaches, both appear to adjust to temperature variations behaviourally, but in different ways.
Uca deichmanni courting male. Photo by Kecia Kerr

Surprisingly, behavioural adjustments to environmental variability, and the diversity of responses that species employ, remain underappreciated. However, over the last few years there have been calls for increased attention to the potential importance of plastic behavioural responses in mitigation of detrimental effects of environmental variation (Kearney et al. 2009, Sih et al. 2010). While many species are already being negatively affected by climate change, many others are likely able to diminish the impacts, at least to some extent, via behavioural responses. Much more research is needed to better understand how organisms respond to variable environmental conditions and what impacts these responses may have on their ecology.

Kearney M, Shine R, Porter WP (2009) The Potential for Behavioral Thermoregulation to Buffer “cold-Blooded” Animals Against Climate Warming. PNAS 106:3835–3840

Sih A, Stamps J, Yang LH, McElreath R, Ramenofsky M (2010) Behavior as a key component of integrative biology in a human-altered world. Integrative and Comparative Biology 50:934–944

Thursday, 9 October 2014

Fighting the war on science

There has been a long-standing dogma within the scientific community that scientists can not, and should not, be activists. “To be effective,” my undergraduate mentor told me, “scientists need to be impartial, they need to do science and let others worry about the advocacy. If you want to go into advocacy, that’s great, but you have to choose that route or choose science.” As 120 heads of state met at a critical United Nations Climate Summit in New York last month, this dogma has never been clearly more out-dated and indeed, in need of “major revision."

On September 21st, more than 2,500 independent mobilization events were held in cities (including Montreal) across 160 countries around the world in what was collectively called the Peoples’ Climate Mobilization. The mission was this: to demand that the heads of state representing governments around the world make tangible commitments to work together to solve the climate crisis. Given the increasingly dire predictions of the international scientific community, including the Inter-governmental Panel on Climate Change, there has never been a more urgent time for action to reduce greenhouse gas emissions, especially from the largest per capita carbon polluters in the world, which include the United States and Canada.

People's Climate Mobilization in Montreal!

In order to make these momentous changes, not only in global climate policy, but also in environmental conservation and natural resource management, an informed public needs to have access to and understand science. It does not take a scientifically literate populace to see that dramatic climate changes is already taking place, but it does take scientific literacy to understand the potential consequences of increasing levels of carbon in the atmosphere and to recognize that human activities are driving these changes. However, the science that is essential to inform the public, and the scientists that provide this information, are under attack. Indeed, in Canada as well as the United States, there is a war on science on several fronts.

Founding director of McGill's Neotropical Environment (NEO) Program, Dr. Catherine Potion. Professor Potvin is the Canada Research Chair in Climate Change Mitigation and Tropical Forests and a UN Framework Convention on Climate Change negotiator for Panama and special advisor to Indigenous communities. She spoke at the protest, and I had the pleasure to march beside her (a hip, hip lady).

Several well-documented examples have now been made public that demonstrate a directed political agenda to undermine research on climate change and other environmental issues in North America. The first example is of the control of scientific information through the muzzling of government scientists working for Environment Canada. Under a directive put in place in 2007, scientists are required to have permission from several government agencies to be interviewed by the media and in some cases, need written approval for answers to journalists’ questions regarding the findings of peer-reviewed research. The result, according to a leaked internal policy review at Environment Canada, was an 80% decline in media coverage on climate science (1,2) and perhaps more importantly, a mis-informed public on critically important environmental issues, such as depleting fish stocks (3), ozone-layer depletion (4) and other major environmental issues.

This war on science has not only made the science less available to the media and thus the general public, but has also made the access to the data much more difficult for scientists to obtain through systematic budget cuts to research. These budget cuts have sliced their way through scientific research through 1. termination of employment for thousands of scientists working for Environment Canada (5) and the Department of Fisheries and Oceans (6), 2. closure of the Polar Environment Atmosphere Research Laboratory (PEARL), a failure to renew funding for the Canadian Foundation for Climate and Atmospheric Studies in 2011, and massive budget cuts to the Experimental Lakes Area, a vital program for long-term research that has been instrumental for discovering processes such as acid rain and eutrophication that elucidate the impacts of industrial processes on freshwater resources and aquatic ecosystems around the world (7).

Furthermore, these cuts to research coincided with a crushing blow to the environment in 2012 through the Omnibus Budget Bill C-38, which effectively dismantled government agencies, including The Canadian Environmental Assessment Agency, and gutted decades worth of environmental legislation working to protect the environment and local communities (including the Canadian Environmental Protection Act, The Canadian Environmental Assessment Act, Energy Board Act,  Species at Risk Act,  Fisheries Act,  Navigable Waters Protection Act, Coastal Trade Act, Parks Canada Agency Act, Canadian Oil and Gas Operations Act, Nuclear Safety Control Act, and the Canada Seeds Act, to list a few (8). Last but not least, this single piece of legislation also dismantled the Kyoto Protocol Implementation Act, thereby revoking Canada’s ratification of the Kyoto Protocol (9). Alarmingly, these cutting attacks on science will continue, as the Toronto Star reported earlier this year that Environment Canada's plans and priorities report reveals massive budget cuts, from 1.01 billion in 2014-2015 to 698.8 million in 2016-2017 and a more immediate gutting to their climate change and clean air program, from 234.2 million in 2014-2015 to a mere 54.8 million in 2016 - 2017 (10)

Clearly, there is a war being waged on both science and scientists (so far I have focused on Canada because I live and study in Montreal, but this war on science has been widely documented in the United States as well… In fact, it took me two minutes to find important examples in the US on the war on science from the federal government on basic research and climate science (11-12), and examples of Congress’ own Science and Technology committee’s war on science policy, specifically the autonomy and impartiality of the peer-review grant approval processes of the National Science Foundation (13) and more recent news on the committee’s war on climate science (14). 

This is a very real war on science and it has gotten personal for scientists. Remember the bogus “Climategate controversy” concerning the Climatic Research Unit email on statistical transformations that were taken as tweaking the numbers? What you may not remember was that this hacking incident and subsequent media frenzy that made the scientists look like the criminals rather than the victims, was just weeks before the UN climate change negotiations in Copenhagen?), the question remains… What are we to do? How can we stand by, aloft in our “Ivory Tower,” when there is a war raging below to burry us, our science and with it, the truth?

The Sustainability Canada Dialogues, an initiative spear-headed by Dr. Catherine Potvin, is a powerful group of scientists, scholars, colleagues and friends who are leading efforts to influence climate policy in Canada. Check them out!

In my view, scientists need to speak out about our science, and we need to stick up for ourselves and for each other. In my opinion, the world is not a playground full of schoolyard bullies. The world is a place where very powerful people, with vested interests and enormous concentrations of wealth and power attained by the wanton pillaging of natural resources, will subvert any and all efforts that they perceive will destabilize their position. When these activities not only endanger local communities but also reach the point where they affect the Earth’s life-support systems, an informed public needs to act. In order to inform the public, scientists need to know the facts and sound the alarm. When the alarm is silenced, scientists need to put ourselves out there, to respond. Louder.

That is why I, and thousands of other scientists, marched, and will continue to mobilize in advocacy of the science and in defense of scientists (…yes… wearing my lab-coat!!!!)

"[The federal government] is making it very difficult for scientists that are publishing on climate data, on fisheries data, on all kinds of environmental data, they are making it very difficult for scientists to make public their conclusions and their recommendations on how to move forward in a sustainable and responsible way." - yours truly

On a personal level, I was thrilled at the chance to march in New York City and be a part of an historic event. However, I decided to organize locally and join the mobilization effort in Canada, which has a tragic recent record on environmental issues and an alarming agenda against science. To add insult to injury, the Prime Minister of Canada, Stephen Harper, did not attend the UN Climate Summit even though he was in New York City, rolling through photo opportunities in an attempt to save face. Nice try, Stephen. But in effect, this attempt to save face and launch a public relations blitz (that highlights commitment to science and leadership in addressing climate change (15)…. WHAT!?!?!?!?!?!) demonstrates that he knows that people were paying attention, that Canadian citizens are alarmed and embarrassed at his lack of leadership.

In an effort to help with the mobilization effort in Montreal, I felt it was most effective for me to mobilize the academic community in Montreal and help to ensure that students, as well as faculty, were involved in the mobilization effort. In any social movement, students have always played a central role, be it in the Independence Movement in India, the Civil Rights and Anti-War Movements in the United States and the Anti-Apartheid Movement in South Africa. In the mobilization effort on climate change, it is also imperative to involve scientists as these men and women can be, and should be, the most informed and thus most powerful advocates for the reality of climate change and the role of human society as the major driver for unprecedented rates of changes in climate.
Multi-tasking scientists: representing at march as they educate in NYC. They are so rad!

The Peoples’ Climate Mobilization can be deemed a success for several reasons. First and foremost, it was the single largest climate mobilization event in history, with the centerpiece being the march in New York City that gathered hundreds of thousands of people from many parts of the world. Second, the mobilization, not only in New York but around the world, highlighted the diversity of people that are part of the collective effort to build political momentum to pressure governments to address the climate crisis. Third, and perhaps most importantly, it put climate change and the environment back at the forefront of discussion and debate, not only at the local level, but at the international stage. This unprecedented level of attendance by heads of state gathered at this Climate Summit demonstrates that momentum is indeed building, and that maybe, just maybe, “a change is going to come.”

So, to make that change, will you continue to mobilize with us, and march again when we have to?

Don't forget to bring your lab coat!


(A special thanks to two amazing women, Dr. Catherine Potvin and Dr. Aerin Jacob for their leadership and inspiration!)

Works Cited:
10) environment_canada_braces_for_belttightening.html

Tuesday, 30 September 2014

Can diet specialization be a way of taming the beast?

One of the most intriguing aspects of biological evolution, at least for me, is the arms race between insect herbivores and plant chemical defenses. Plant-insect interactions should definitely make their way into Andrew Hendry’s Evolution Bucket List (read Andrew's post below). For example the interaction between the milkweeds and Danainae male butterflies involving pyrrolizidine alkaloids should find a spot inside the already crowded bucket. The alkaloids protect the milkweed from any generalist herbivore but are essential to the success of the specialist Danainae males. The male butterflies, that require the plant’s alkaloids as precursors for the biosynthesize of their own sexual pheromone, pass any excess of the compound to the female as a nuptial gift so that she can protect the eggs. Females assess the quality of males through their scent, which is indicative of their overall toxin load. In short, a set of compounds that very likely evolved to deter a set of herbivores is now essential for the success of others.

It is true that herbivory is not the only driver of chemical complexity in plants, many other environmental factors are responsible for the diversity of plant compounds (i.e. pathogens, draught, uv radiation, etc.). However, there are well-documented examples that support an escalation of plant chemistry in response to constant herbivore pressure (see Becerra et al. 2009 PNAS on Bursera). Chemicals that confer plants resistance against herbivory will be advantageous no doubt about it. The resistance can be achieved either by deterring the insect, affecting its development, directly poisoning it or recruiting natural its enemies. In return, the insect detoxification machinery is under constant selection, and as agriculture has taught us, insect resistance to particular chemicals can evolve fairly quickly.

Keeping the arms race between plant and insects in mind, I would like to pose a question. Can diet specialization be a way of taming the beast? In a particular plant-insect interaction, specialization of the herbivore to a single host could be advantageous to the host if it implies the insect could not survive without its host and this dependency would translate to an overall reduction of the damage inflicted. The rarer the plant the rarer the herbivore. Keep your friends close but your enemies closer, kind of a thing. The stochastic nature of many insect populations make generalist insects unpredictable. On the other hand specialists are completely in tune with their hosts and hence they are a lot more predictable.
Maybe the same question has already been asked in other interactions like those of parasites and their hosts, and hence this text just shows my ignorance to the subject. In any case, we are far from a comprehensive understanding of the mechanisms that sort insect assemblages to their hosts, and little is known about the steps towards host specialization.

Two factors are thought to be important in host specialization, 1) plant chemistry and 2) nutrient balance.  Plant chemicals are not just defenses to overcome but also strong cues that are useful for making the right host choice (Bernays 2001). When there are more items to choose from, making the right decision is harder and takes longer. It seems that there is a tradeoff between the efficiency in choosing a suitable host and the amplitude of the diet (Bernays 2001). Specialists have less information to process in regards of finding their host while generalist have to fiddle with competing signals. A few studies show that when presented with hosts of low and high quality, specialists are always able to choose the high quality host, while generalists often make bad decisions.  On the other hand generalists seem to have a better ability to cope with an imbalanced diet and are better at compensating a lack of a specific nutrient (Raubenheimer & Simpson 2003).

Comparisons of sister insect species that exhibit contrasting diet breadths is an interesting way of unraveling the route to specialization. But can specialization be beneficial in the long run to the plant host? Probably the answer to this question is case dependent and a HUGE caveat is the differences in time scales between the evolution processes that lead to specialization and the time scale of the interactions we are able to study and measure (ecological time scale).  

Becerra JX, Noge K, Venable DL. 2009. Macroevolutionary chemical escalation in an ancient plant-herbivore arms race. Proceedings of the National Academy of Sciences 106: 18062-18066.

Bernays E. 2001. Neural limitations in phytophagous insects: implications for diet breadth and evolution of host affiliation. Annual review of entomology 46: 703-727.

Raubenheimer D, Simpson SJ. 2003. Nutrient balancing in grasshoppers: behavioural and physiological correlates of dietary breadth. Journal of Experimental Biology 206: 1669-1681.

Friday, 19 September 2014

Assessing Complex Adaptive Systems: Resource-based livelihoods in the face of tourism development in the iconic Galapagos Islands - A comparative analysis


I have the great fortune of being from one of the most biodiverse places in the world. The rich cultural and natural diversity of my home country, Ecuador, has led me to pursue studies that integrate the natural and social sciences in order to conserve the environment, and at the same time promote social-economic development of the communities that depend on local natural resources. A degree in Ecotourism and a graduate degree in Ecology have helped me integrate human and natural systems and further my interests in understanding the different environmental challenges that Ecuador and Latin America are facing today from a holistic and integrative point of view.

I started my PhD studies in fall 2013 in the Department of Geography. I am student in the NEO program because my main research aims are focused in Latin America. The development of my PhD research proposal is a continuation of Masters thesis developed in San Cristobal Island in 2010. The research was focused on assessing the changes of the white fin fishery using an iconic species (Galapagos grouper, Micteroperca olfax) as an indicator of broader changes to the ecological community. Using fishers ecological knowledge and shifting baselines as the methodological approach, I assessed changes in the practice of this fishery and the status of the main fishing target species due to almost 70 years of continued fishing activity. Additionally, this study briefly explored social-ecological relationships amongst the fishermen household and their fishing activity.

Biodiversity conservation is important, especially in sensitive places as the Galapagos Islands. However, it creates potential conflicts (trade-offs) amongst stakeholders, most notably between external, science-based, educated and often wealthy elites, and local households and resource users.  The goal of conservation management research is to find win-win outcomes, but these are rare and may depend on the narrative selected to assess outcomes. Outcomes are influenced by power imbalances at many levels, from institutions at the global and national level, to the level of individuals within the community. In this regard, sustainable development implies both non-destructive use of environmental resources, and acceptable levels of social justice for stakeholders.

Marine protected areas (MPAs) have demonstrated their effectiveness as a tool to preserve natural resources; however, their management and enforcement policies have substantial socio-cultural impacts, which have produced poor local consensus, and in some cases, hostility among social groups. Although effective for conservation purposes, this management tool has shown examples of unequal access of natural resources by different economic sectors within the protected area. For instance, the inherent economic advantages enjoyed by the tourism industry have marginalized the fishery and agricultural sector in terms of access and control of some MPAs.

Tourism, and the income it generates, is cited as an option that can support sustainable development in biodiversity conservation sites. It can bridge opposing expectations because, in theory, it gives market value to biodiversity resources and so, on the one hand, should ensure their protection, and on the other, should provide substitutes for other local livelihoods. There are clearly inherent contradictions in this approach. Most notably, the idea of increasing the number of guests and providing improved infrastructure and services for them in areas whose value derives precisely from the lack of prior exposure and development. In addition,  the idea that providing local residents with new livelihood options that are necessarily based on limiting flexibility in exploiting environmental resources, will not eventually stimulate rising expectations and place new demands on the protected resource base. 

Galapagos Islands are unique, not only in the geographic and ecological characteristics, but also by virtue of their status as a focus of conservation management. The value of the biodiversity resource is unquestioned, the importance of tourism as a way of monetizing that value is well advanced, and the stresses arising from the inherent paradoxes of this approach are evident as human population levels rise, tourist infrastructure increases, and the ecological impacts of tourism industry intensify. Moreover, the expectations of local populations continue to evolve, both with respect to individual livelihood expectations and to the understanding of the nature and importance of decision-making processes. Local rights, aspirations, capabilities and demands are essential elements of the islands ecosystems.

My research considers both social and ecological indicators to compare three populated islands with respect to drivers and impacts of environmental change, and their effects on the interactions amongst stakeholders. The objective is to provide an understanding of the Galapagos system. The reason for attempting to replicate the assessment in the three islands is that certain factors are held constant across the islands (notably national and international actors and management interventions and legal frameworks), while other factors (notably population size, history, and livelihood options) are different. This comparison will allow some control of variables that influence the effectiveness of local engagement in conservation, tourism, resource exploitation, and decision-making.

Identifying the socio-cultural, economic, and political differences of the three islands in relation to resource-based livelihoods in the face of tourism development will contribute to the understanding of the islands as subsystems, and advance the knowledge of the overall Galapagos social-ecological system. Given the intense effort that has gone into developing a management structure for this archipelago, it is expected that identifying differences in outcomes amongst the islands will help provide insights for its adaptive management, and sustainable development. Finally, considering the intense effort that has gone into developing the management structures in the Galapagos, it is expected that evidence of successes and failures in their management will provide valuable information for other biodiversity conservation initiatives in other parts of the world. 

Burbano, D.V. 2011. Shifting baselines en la pesca blanca  de Galápagos: relaciones socio-ecológicas en ambientes marinos. Ms.c. Thesis Ecology. Universidad San Francisco de Quito, Ecuador.
Burbano, D.V., C.F. Mena, P. Guarderas, L. Vinueza, and G. Reck. 2014. Shifting baselines in the Galapagos white fin fishery: Using fishers anecdotes to reassess fisheries management. The case of the Galapagos grouper. In: J. Denkinger and L. Vinueza (eds.) The Galapagos Marine Reserve: A dynamic social-ecological system. Social and Ecological Sustainability in the Galapagos Islands. Springer Science+Business Media, New York.

Photos: Alfonso Tandazo, Diana Burbano

Wednesday, 20 August 2014

An Introduction...

Unlike many of the posts of NEO past, I am a new student in the NEO program, and beginning my Masters in Biology in the fall of 2014. While my research scope is still being defined, I can provide a brief overview of the projected work and its relevance.

In 2011 the world’s largest roller-compacted concrete arch-gravity dam completed construction and was put in operation on the Changuinola River in Bocas del Toro province, Panama. The dam is under the operation and ownership of AES Changuinola, a subsidiary of AES Corporation. As a result of the dam operation, more than 1000 people, including the indigenous Ngäbe people, were re-settled. The dam itself is located inside a protected forest area, the Bosque Protector de Palo Seco (BPPS), and while residents were relocated, they were allowed to remain within the BPPS (AES Changuinola, 2013).

Figure 1 Google Earth view of the research area, and the relative locations of the Changuinola I dam, and the manatee habitat.

As a result, the AES Changuinola I Dam has been the topic of controversy from indigenous rights and conservation groups (Kennedy, 2012; Kennedy, 2014). This dam is not alone in its infamy, as hydroelectric dams have been simultaneously lauded as social, environmental and economic benefactors and antagonists alike. The cross-disciplinary nature of hydraulic dams and their impact presents a complex problem for researchers to tackle.

I will be working with Dr. Brian Leung and Dr. Hector Guzman, and we will be evaluating the impacts of the Changuinola I Dam on the local watershed and human and manatee population. The exact parameters that will be evaluated have yet to be entirely fleshed out, but this will hopefully become clearer as we gather data. Fortunately, we have the support of AES Changuinola, government officials and the local environmental authority (ANAM).

The project is divided into three main components; the first is to establish the current state of the river, using the information that is publicly available (e.g. land use, rainfall, soil type, land slope, etc.) and the Environmental Impact Assessment conducted prior to construction. Any information that can be provided on the relocation and/ or consultations that occurred with the local communities will also be collected. We hope to create a snapshot of the watershed prior to the dam construction, and at present by comparing historical remote sensing imagery. The second step of our research will be to develop a watershed model of the Changuinola River using the Soil and Water Assessment Tool. The models developed will inform the last phase of the project, which is a manatee population model. This last analysis will involve the monitoring of the local manatee population and habitat to establish the effects of modifying the watershed.

While my thesis is, quite evidently, in the preliminary stages, I am very excited to get started and to be a part of the NEO program.

Here’s a brief introduction to my own background: I grew up (mostly) in Kingston, Ontario. I moved to Halifax, Nova Scotia at the age of 18 to attend Dalhousie University. I also happened to be in the first year of their new College of Sustainability program. My degree morphed into a combined honours degree in Environment, Sustainability and Society and Biology. A key component of my undergrad was a 6-month exchange trip I did to Wellington, New Zealand in my third year. It was an amazing experience to really throw myself into another country and its culture.

When my feet touched back on Canadian soil, I was ready to tackle my fourth year. I wrote my honours thesis on the effects of a water-monitoring program in First Nations communities in Atlantic Canada. It was this work in the Centre for Water Resources Studies in 2013 that lead to my employment there after graduation. I learned a great deal at the Centre, though my time there has drawn to a close as I prepare for my upcoming move (and next great adventure!) to Montreal at the end of the month.