Wolves Are Good Boys Too

brown wolf standing on green grass
Figure 1: The grey wolf (Canis Lupus)

We’ve all been there, trying to get some out of reach object only to dejectedly ask for the assistance of another. Turns out, this behavior has been with us for most of our lives. It is known that children as young as 12 months will start to point at certain objects that they desire but are, for obvious reasons, unable to obtain (Figure 2). This behaviour is known as imperative pointing and, as it turns out, you don’t even need to point to be able to do it. In fact, gaze alteration, the process of looking between the desired object and a specific individual, is seen as an analog of this in our four-legged friends, the canines. This behavior has been widely examined in domesticated dogs, who humans have a long history of cohabitation with. Indeed, many of us can probably offer anecdotal evidence of this in our own dogs, be it looking at treats on a shelf, or their favourite toys on kitchen tabletops. However, surprisingly, it has never been studied in wolves, the wild relatives of our beloved pooches. In 2016, Heberlein et al. set to change this, and their findings have some important implications, not least concerning our understanding of the very domestication of dogs itself.

Figure 2: A cartoon of imperative pointing in infants

The experimental premise was relatively simple. A group of grey wolves (subspecies: timber wolf) and a group of dogs (breed not given), were both obtained from animal shelters in Europe and were raised from puppyhood with daily human interaction. When the canines were around 2 years old, the experiment began with a pre-feeding and training phase. This involved an experimental room with 3 boxes (Figure 3), each too high for the canines to reach by jumping, the poor guys. In this phase, food was first shown to the animals, one animal at a time, and then clearly placed in each of the boxes. If the animal looked at the box and then at the human, the human would automatically get the food for them. The wolves and dogs were then introduced to 2 new humans, a mean competitor who would steal the food, and a helpful cooperator, who would share any food the animals identified. This whole process would serve to inform the canines that the humans could provide them with out of reach food, but that only the cooperator would actually give them any of it. Why go through all this trouble you may ask? Well, turns out there were some very clever scientists involved in the experiment. Those involved wanted to avoid the possibility that gaze alteration for food could simply be the result of a food human association, i.e., if I stare at a box and then a human, then the human must give me food. If gaze alteration reflects some true communicative intention on the part of the animals, then one would expect that they should ask for help mainly from the cooperative human, I know I definitely prefer working with cooperative humans. Once trained, the test was ready to begin.

The actual experiment involved a tasty sausage being presented to a lone wolf/dog and then being hidden in one of 3 boxes located in the room, the same room used in pre-training. Then, either the cooperative human or the competitive human, the same humans the animals had been trained with, entered the room. They would passively observe the animal for 1 minute after which they would go to the box they believed the animal was looking at. If correct then the sausage would wither be given to the animal, if the cooperator was present, or eaten by the human, if the competitor was present. The process was repeated a total of 4 times, twice with each type of human.

Figure 3: The experimental setup. Stars represent the food boxes, the circle is where the human was positioned, and D is the rooms door. 

The results were incredibly interesting. In most cases, the canines, both wolves and dogs, showed the correct food location to the cooperator but not the competitor (P = 0.006) (Figure 4). Importantly, there was no difference between this behaviour between the two species (P = 0.24). As an aside, P values are statistical values that tell you if there is a significant difference between two things. All you need to know is 1) Any P value less than 0.05 means that the event is unlikely to have happened by chance and 2) That scientists are very fond of including them in their papers. In any case, what’s even more interesting is what these results can tell us about their evolutionary histories. While both directed the cooperative human to the food box, wolves spent more time looking at the food itself when compared to the dogs (P = 0.03). This may reflect a higher food motivation present in wolves. Intuitively this makes sense, as, while some of us would surely like them to be, wolves are not pets and so need to hunt for food themselves. In addition, the ability of dogs to referentially communicate with humans was thought to be a result of their domestication and close association with us ever since. The results of this experiment would, however, suggest that this ability was at least present in the common ancestor of the wolves and domestic dogs. Therefore, rather than this communication being a product of domestication, it is more likely that the skill of referential communication had evolved in canines to promote the social coordination needed for group living, i.e., living in their packs. In other words, the common ancestor of today’s canines may have also been a good boy.

Figure 4: A graph comparing the percentage of showing behaviour, i.e., gaze alteration, in wolves and dogs towards competitive and cooperative humans.  

In summary, dogs, are not alone in their ability to ability to referentially communicate with us. This ability is shared with the grey wolf and the choice to work with a cooperative human over a competitive one provides evidence that there is some conscious thought in this decision-making process (both in dogs and wolves). While this raises important questions about the evolutionary histories of these animals, more intriguing questions remain. Namely, what other well-known traits of dogs are also present, but undiscovered, in wolves. Personally, I am very much excited to find out.  

Figure 5: Grey wolf puppies playing next to their mother.

For more information on this topic, you can read the paper discussed here (free of charge)

Blog written by Niall Moore, a final year undergraduate student, as part of an assignment writing blogs about an animal behaviour paper!

The 2020 EcoEvo Hall of Fame

At the start of each year we ask the EcoEvo contributors to share their favourite scientific publications from the past year and why they found them interesting, inspiring, or otherwise worthy of inclusion in the Hall of Fame. Keeping with tradition, here are the EcoEvo Hall of Fame entries for 2020! And if you enjoy reading about our favourite papers from 2020, remember you can also check out our favourites from 2017, 2018 and 2019, too!

Chosen by Andrew Neill

Read the full People and Nature paper here.

I really enjoyed this paper because it tackles a really difficult topic at the intersection of poverty, human rights, development, conservation, and sustainability. It is important to remember that conservation will never meet its objectives without considering how people depend on nature for their needs and livelihoods. The areas of richest biological diversity (and therefore conservation potential) are usually in developing countries with communities experiencing poverty. This paper collects responses from conservation practitioners to examine their viewpoints on poverty in the context of their work. 

F I G U R E 3. Comparison of discourses on five key dimensions of difference. Discourses are compared on a simple ordinal scale, and accordingly should only be interpreted in relative positions to one another (for instance, D3 is more ecocentric than D1).
© 2020 The Authors. People and Nature published by John Wiley & Sons Ltd on behalf of British Ecological Society. The article is distributed under the terms of the CC-BY 4 license.

They found some areas of agreement such as the poorest people should not be expected to shoulder the costs of preserving a global public good (the conservation of biodiversity). However, they also identify differences between responses: Is the focus placed on meeting the needs of people or more closely aligned with the “do no harm” principle? Is poverty a driver of nature’s decline, or is it the over-consumption that drives environmental degradation? This paper was a great opportunity to question my own views on these very complex ideas and to appreciate the wide diversity of thought going on across the world of conservation. 

Fisher, J.A., Dhungana, H., Duffy, J., He, J., Inturias, M., Lehmann, I., Martin, A., Mwayafu, D.M., Rodríguez, I. and Schneider, H. (2020). Conservationists’ perspectives on poverty: An empirical study. People and Nature2 (3), pp.678-692.


Chosen by Fionn Ó Marcaigh

Read the full Nature Communications paper here.

This paper is based on a truly colossal undertaking: to collect their data on dispersal ability, Sheard et al. measured the wings of 10,338 bird species, i.e. 99% of all bird species on Earth. They used the Hand-Wing Index, a measure that correlates with aspect ratio and basically tells you how long and pointed the bird’s wing is. The higher this number (i.e. the pointier the wing), the better the bird will be at dispersing and flying long distances.

a Diagram showing linear measurements used to calculate HWI taken on a standard museum study skin (secondary feathers shown in pale grey; primary feathers in dark grey). Wing length (Lw) is the distance from carpal joint to the tip of the longest primary feather; secondary length (S1) is the distance from carpal joint to the tip of the first secondary feather; Kipp’s distance (DK) is the difference between Lw and S1b Open wing of a passerine bird showing how Lw and S1 are related to the wing’s span and width, and hence to its aspect ratio. c Because it is correlated with the aspect ratio, HWI is in theory positively associated with flight efficiency and key aspects of dispersal ability, including dispersal distance and gap-crossing ability.
© The Author(s) 2020. This article is distributed under the terms of the CC BY 4 license.

This is important for evolution, as the more birds that are able to fly between distant populations the more gene flow there will be and the less likely the populations are to diverge. Sheard et al. found important links between dispersal ability and geography and ecology, as tropical and territorial birds, had lower Hand-Wing Indices and migratory species had higher ones. It’s fascinating to see how these traits affect the ability of a species to move around, which in turn dictates where that species will be found in the world. The authors have made this incredible dataset freely available and it is sure to inform new insights into bird ecology and evolution for years to come.

Sheard C., Neate-Clegg M. H. C., Alioravainen N., Jones S. E. I., Vincent C., MacGregor H. E. A., Bregman T. P., Claramunt  S. & Tobias J. A. (2020) Ecological drivers of global gradients in avian dispersal inferred from wing morphology. Nature Communications, 11 (2463).


Chosen by Sam Ross

Read the full Science paper here.

The COVID-19 pandemic has been extremely challenging for many, so it was great to see some excellent science coming from the ‘natural experiment’ offered by COVID-19 movement restrictions. The authors show that during the COVID-19 restrictions anthropogenic noise (from vehicles etc.) in the San Francisco Bay Area reached a 70-year low, characteristic of the mid-1950s. They use a long-term dataset of White-Crowned Sparrow recordings to show that during the COVID-19 lockdown, when human noise pollution was minimal, Sparrows exploited the emptied acoustic space (usually occupied by human-related noise) by producing higher-performance songs at lower amplitudes, to maximise song distance. The authors highlight the rapidity with which behavioural traits (song characteristics) adapted to changes in human activity, suggesting incredible plasticity and potential resilience to pervasive anthropogenic pressures like noise pollution. To me, this study is a perfect example of nature’s resilience, and also on finding opportunity from tragedy (research made possible by a global pandemic).

Derryberry E.P., Phillips J.N., Derryberry G.E., Blum M.J., Luther D. (2020). Singing in a silent spring: Birds respond to a half-century soundscape reversion during the COVID-19 shutdownScience, 370, 575-579.


Chosen by Jenny Bortoluzzi

Read the full Marine Policy paper here.

This paper looked at the human behavioural responses to a blanket ban on thresher shark fisheries in Sri Lanka and fisher’s perceptions of different aspects of the ban. A blanket ban means a complete prohibition on exploitation of a species, and Thresher sharks are considered to be the most vulnerable species of pelagic sharks. A blanket ban might therefore seem like a straightforward and easy conservation measure to protect them. But this study looked at the human impact behind such a drastic policy decision. A ban like this has consequences for the livelihoods of fishers – particularly smaller fishermen who rely highly on thresher shark landings to provide for their families. The study clearly shows the disparity in the impact this conservation policy has had between fishers who rely on these catches to survive and those for whom they are not the primary catch.

The biggest message I took from this paper is how important it is that human lives are taken into account when making conservation decisions; and more importantly that scientists and policymakers need to involve communities early on in the process, communicate better and work together, not against each other if we want conservation to be effective – and supported. This is a message I think more scientists need to hear and integrate into their work and one I hope to take forward in my future career.

Collins C., Letessier T. B., Broderick A., Wijesundara I., Nuno A. (2020). Using perceptions to examine human responses to blanket bans: The case of the thresher shark landing-ban in Sri Lanka. Marine Policy, 121 (104198).

The Opti-Mum condition: How brown bears use humans to prolong maternal care

Sexual conflict between males and females is well documented in the animal kingdom. Often, the best strategy for one sex is not the optimum for the other. In mammalian species, lactation of new mothers suppresses ovulation. Therefore, males gain a reproductive advantage (earlier mating opportunity) by forcing early mother-offspring separation. On the other hand, females benefit from prolonging care for their current young, so it has been hypothesized that they adopt counter-tactics to avoid premature separation from their offspring.

Continue reading “The Opti-Mum condition: How brown bears use humans to prolong maternal care”

The 2018 EcoEvo Hall of Fame

As we launch into another year of research, we thought it would be interesting to look back on some of the work that came out in 2018, so we asked the School of Natural Sciences what papers they would like to induct into our second annual Hall of Fame. Read on for the papers we thought were fascinating, notable, or just cool. When you’re finished, you can check out 2017’s Hall of Fame here.

Continue reading “The 2018 EcoEvo Hall of Fame”

Natural Capital: Making nature pay?

“Proponents of natural capital accounting offer a compelling argument: by quantifying and valuing natural capital impacts and dependencies, and translating those assessments into systemised accounts, decision-makers in government and the corporate sector will be able to make more informed and, ultimately, sustainable decisions.

But can we assume that reliable and accurate economic information will translate into radical and effective action? It is over a decade since the Stern Review (2006) made the economic argument for Climate action. The 700-page Report concluded that failure to act would result in costs amounting to 5% of Global GDP per year, now and forever. Despite the sound economic warnings, action on climate change has not moved ahead at anything like the pace that is required. So what, if anything, is different about natural capital; why and how will putting nature on the balance books make a difference to how governments and corporations make decisions?…”

Read the full blog post on the Irish forum on Natural Capital.

The arguments outlined in this blog are developed in more detail in a report written for the National Economic and Social Council this year; Valuing Nature: Perspectives and Issues.

______________

About the Author

Dr. Patrick Bresnihan is a lecturer in Geography, Trinity College Dublin. His work spans the fields of political ecology, science and technology studies, and environmental humanities. Areas of research include the fisheries, water services, alternative energy and natural capital.  Find out more about his research here:

Website | TCD Profile
Twitter | @pbresnihan
Academia.edu | Profile

The 2017 EcoEvo hall of fame

As the year draws to a close, we thought we’d reflect on a some of our favourite scientific papers from 2017. There were only five entrants this year, but representing a broad range of work from across ecology and evolution, as chosen by PhD students and postdoctoral researchers from the School of Natural Sciences. So, without further ado, here are the papers from 2017 being entered into the EcoEvo hall of fame:

Carlson CJ, Burgio KR, Dougherty ER, Phillips AJ, Bueno VM, Clements CF, Castaldo G, Dallas TA, et al. (2017). Parasite biodiversity faces extinction and redistribution in a changing climate. Science Advances 3, e1602422.

“This paper got a lot of press this year as it is essentially the poster paper for the parasite conservation movement. The authors suggest that within the next 100 years, 5% to 10% of parasitic species may go extinct based on habitat loss alone and up to 24% of species are predicted to go extinct based on co-extinction with hosts. Thankfully, Acanthocephala (my study organisms) are predicted to fare well enough in the next 100 years, but it was an eye-opening analysis that provides important information to the parasite conservation cause.” Maureen Williams. Continue reading “The 2017 EcoEvo hall of fame”

Iguana vs Snakes | Planet Earth 2

 

Most of us were glued to the hugely anticipated premier of Planet Earth 2 this Sunday. We watched lovesick sloths meander through the mangroves, giant dragons battle it out on Komodo, and penguins getting fecked off cliffs by monstrous waves.

But if there was one scene that got us talking more than any other it was the literal race for survival that took place between a newly hatched marine iguana and an ominous pack of southern black racer snakes. The baby iguana had us shouting at the telly and clutching our faces while we watched its mad dash to the freedom of the ocean’s edge, avoiding the snakes’ fangs.

While we hoped against hope that the hatchling would make it, David Attenborough reminded us that for the snakes this was also a matter of life and death. Snakes have to eat, and for them the iguana hatching season means their best chance all year for hunting food. Continue reading “Iguana vs Snakes | Planet Earth 2”

Evolution is – surprise! – Darwinian!

800px-Human_pidegree

I sometime come across papers that I missed during their publication time and that shed a new light on my current research (or strengthen the already present light). Today it was Cartmill’s 2012 Evolutionary Anthropology – not open access, apologies…

Cartmill raises an interesting question from an evolutionary point of view: “How long ago did the first [insert your favorite taxa here] live?”. This question is crucial for any macroevolutionary study (or/and for the sake of getting a chance to be published in Nature). If one is studying the “rise of the age of mammals” (just for example of course) the question of the exact timing is crucial to see whether placental mammals evolved after or before the extinction of avian dinosaurs.

Because Cartmill published in Evolutionary Anthropology let’s replace [insert your favorite taxa here] with humans. He proposes to answer to the question “How long ago did the first humans live?” by looking at the different ways people have addressed it through time. It all starts back with Simpson’s quantum evolution stating that clades share “adaptive shifts” or “adaptive trends”. For example, for humans, that will be bipedalism and an increase in brain size: “Everybody can sort humans out instantly from other sorts of things: […] they share a unique reliance on technology, a capacity for culture, and a gift for gab.”

This is an unfortunate classical view of evolution based on morphological data leading to a series of morphological discontinuities – the adaptive shifts (“human origins, primate origins, mammal origins, amniote origins, and so on” – I already discussed this gradualistic view about tetrapod origins). Cartmill uses a pertinent quote from Simpson to comment this trend: “Is this not, in fact, simply a recrudescence of the old naïve conception of a scala naturae[?]”. However, this raises a cladistic problem. Assuming we have the data on the oldest human. What defines his or her humanness? “Humanness [whatever that means] is not a coherent package. We have known since the 1960s that our terrestrial bipedality evolved more than two million years before the onset of what was long held to be the fundamental human characteristic, that is the great development of the brain.’’

Cartmill’s point is that, morphologically, there is no adaptive shift or trend that can define any group. Morphological evolution acts more like a succession of slow and discrete incremental changes rather than the Simpsonian quantum model: “there is only a long, geologically slow cascade of accumulating small apomorphies” and adaptive trends or shifts within clades “are fantasies, born ultimately of our wish to see ourselves as more decisively set off from other animals than we actually are.”

Will I have to rethink my current project looking at mammals morphological evolution? Well by using molecular data as well as morphological data we can accurately trace back the small incremental changes (the DNA mutations) as well as the actual changes in morphology through time. My PhD is not just a series of failures after all!

Author

Thomas Guillerme: guillert[at]tcd.ie, @TGuillerme

Photo credit

http://en.wikipedia.org/wiki/Great_chain_of_being#/media/File:Human_pidegree.jpg