Author Archives: Tanya Strydom

Deerailed

Deer in headlights indeed. When a train is fast approaching, deer often pick up not ont he lights themselves, but the sounds and vibrations a train send out. Naturally a deer’s flight instinct kicks in. Yet when deciding where to flee, the ringing of internal alarm bells can sometimes drown out common sense. Turns out more often than not things get to be a bit too much and deer (and moose) tend to go for the path of least resistance (the tracks themselves), which quickly become the path of most resistance…

Read More: Avoiding Collisions With Trains By Fleeing… Onto The Tracks?


Tanya Strydom is a PhD candidate at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Attention Drabber

Aaah yes the tropics. The lands of white beaches, palm trees swaying gently in the breeze and exotic animals flitting among the treetrops. Though this image of the tropics may be coloured by the rose tinted glasses of many a tourist posctard, one thing might be true – the tropics are host to a slightly more colourful chunk of global biodiversity. Early naturalists such as Charles Darwin and Alexander von Humbolt were quick to note that the tropical species tend to be more colourful than their temperate counterparts. That being said, no one has been able to sit down and prove this rule of latitudinal colourfullness (more colourful species at lower latitudes) – until now.

A team of researchers has finally been able to quantify colourfulness in passerine bird species and indeed there is a strong latitudinal gradient for both sexes! This is pretty cool since it means that not only are males more colourful but so are the females (who are often more drab in colour than males of the same species). Although the reason for this colourfulness gradient is still unclear, it is pretty neat that researchers have taken a step towards seeing if this rule exists – although if this rule still holds for other species such as insects is a whole other question!

Read more: Latitudinal gradients in avian colourfulness


Tanya Strydom is a PhD candidate at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Sunstruck

Viruses are weird – they are non-living, yet still contain genetic information and are dependent on a live host to actually replicate and survive. Unlike many other parasites, since viruses are basically just a string of DNA or RNA, they actually need to actually get inside the cells of their host and hijack some of the components of these cells to allow them to replicate. After infection they are (at least partially) in the driving seat and can control and manipulate how some cells behave.

This means that viruses often have the capacity to also alter the behaviour of their host – which can be particularly beneficial to help ensure that the virus can also spread from one host to another. A good example is rabies, whereby the virus triggers infected individuals to become exceptionally aggressive – a surefire way to probably lead to them biting another individual and allowing infection to occur via the bite wound.

Sometimes the behavioural changes can be more nuanced – in this case caterpillars infected by a baculovirus start perceiving then sun in a positive light (pun definitely intended). Infected caterpillars become attracted to sunlight and feel compelled to move towards it (this process is known as phototaxis). Unfortunately in this case is is drawing them to an untimely death. Having the caterpillars die near the tree canopy is beneficial for the virus, as its a better scouting ground for newer hosts.

Read more: Baculoviruses hijack the visual perception of their caterpillar hosts to induce climbing behaviour thus promoting virus dispersal


Tanya Strydom is a PhD candidate at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Making Food Webs Out Of (Almost) Nothing At All

Food web reconstruction through phylogenetic transfer of low-rank network representation (2022) Strydom and Bouskila et al., Methods in Ecology and Evolution, https://doi.org/10.1111/2041-210X.13835

The Crux

Understanding food webs (and more generally how different species interact) is important in helping us to understand ecological processes, but sampling (observing) interactions in the field is pretty challenging. Observing a parrot? Simple. Observing a possum? No problem. Observing a parrot evicting a possum from a tree-hollow? Rarer.

This means that data on species interactions is sparse. But we do have data for some regions, and things like computers and fancy maths (think machine learning) at our disposal. Which leads to the question: can we learn something from the places for which we do have interaction data and ‘transplant’ this knowledge and create an interaction network for a region with no data at all?

The focus here is to try and use predictive methods to help and at least give us a idea of who might potentially be eating who and use this to construct a metaweb (a full list of potential interactions) for a region that has plenty of species data, but no species interaction data.

Read more

Polarised

Polar bears are the poster child of the Arctic, and under serious threat thanks climate change and the reduction of the polar ice caps. But one person’s loss is another one’s gain, and due to warming temperatures case grizzly bears are able to move further north as the icy conditions (and soft, blubbery seals – the preferred food source for polar bears) recede. This means that grizzlies and polar bears are more likely to come into contact with each other and (interestingly) are able to hybridise and produce a pizzly (or grolar) bear.

Interestingly, and unlike most hybrids, pizzly bears are quite robust (having traits of both parents mean they are likely able to exploit the habitats and food sources of both species) and able to produce viable offspring as shown in a study from 2017 that used genetic analysis to determine ancestry. They found some polar-grizzly hybrids to be 75:25 grizzly:polar bear, which means that one parent (in this case the mother) was a polar-grizzly hybrid to begin with.

As the likelihood of grizzlies and polars coming into contact with each other increases, we expect the number of hybrids in the population to increase as well. This won’t be the first time that these two species interbreed but it does still pose an interesting question of how we view ‘species’, as well as how we would approach hybrids in terms of conservation. Are we okay with polar-grizzly hybrids? Do we see them as a new species or simply an unwanted side effect of species range shifts? Do we view the northward-moving grizzlies as invasive?

Read more: Recent Hybridization between a Polar Bear and Grizzly Bears in the Canadian Arctic


Tanya Strydom is a PhD candidate at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Mainstream

Bird and whale song are a way for males to attract members of the opposite sex, and (as the variety of bird calls you might hear out in the garden indicates) these songs vary between species. Similar to how people can have different tastes in music, there is also variation in the the style of the songs between individuals of the same species. This can lead to ‘cultural revolutions’ where some individuals can influence and change the mating calls of the other individuals in the population if they want to stay relevant.

This poses an interesting question of if and how animals value and appreciate aesthetic beauty and how similar that is to how humans view ‘aesthetic beauty’ – and of course implies that bird and whales must have some kind of Billboard 100 chart floating around!

The idea of cultural evolution in non-human animals is a growing topic of discussion but if you want to know more about how whale songs change check out the link below.

Read more: Global cultural evolutionary model of humpback whale song


Tanya Strydom is a PhD candidate at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Catfished

First, to clear the air, yes we know catfish don’t have cat ears but he’s on his way to a masquerade ball!

Second, it comes highly recommended that you check out the entire thread that inspired this comic (see below) because mussels are absolute legends when it comes to making lures to, well, lure in some unsuspecting fishies.


Tanya Strydom is a PhD candidate at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Un-Movable

Zoochory (the dispersal of seeds by animals) is pretty important for a lot of plant species. Many plants have evolved to depend on it, and it allows them to get their seeds from A to B, especially over long distances. When plants no longer have their animal buddies to move their seeds around, they aren’t going to be going anywhere fast.

With an uptick in human induced extinctions and the general movement of animals in response to climate change (who at least have the option to pack up their things and move to where the grass is greener), a lot of plants could end up getting left behind. This means that not only are they losing out on the normal dispersal processes but they’re also missing out on a potential ride to more suitable areas as their habitat conditions begin to decline – a bit of a double whammy really.

Read More: The effects of defaunation on plants’ capacity to track climate change


Tanya Strydom is a PhD student at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Hairy Pawter and the Genetic Mix-Up

Red wolf and coyotes are an interesting conundrum when it comes to thinking of hybrids as ‘good or bad’. Thought to be a product of hybridisation between coyotes and grey wolves, red wolves have a lot of cultural significance in the southeastern United States. Native ranges of captive breeding programmes have worked at trying to re-introduce and establish red wolf populations in their historic ranges.

Yet these wolves have started having hybrid offspring with coyotes. This isn’t ideal, but because the red wolf population is so small, there isn’t a lot of genetic diversity among current red wolves. What if some ‘new’ genetic diversity can be found in wolf-coyote hybrids? There is a population of coyotes-not-coyotes in Galveston, Texas that have red wolf DNA – DNA that isn’t found in current red wolves! This ‘ghost’ DNA could be exactly what the doctor ordered when it comes to injecting some diversity back into the wolf population.

So if we were to breed (hybridise) the Galveston coyotes with red wolves we’d be introducing genetic diversity back into the population (yay!) but then also be making more hybrids, which… goes against what we would want – right? This is quite the tricky situation and has caused some head scratching when it comes to how best to approach this situation and really goes to show that we can’t be too black and white in our thinking.

The original research can be found here: Rediscovery of Red Wolf Ghost Alleles in a Canid Population Along the American Gulf Coast


Tanya Strydom is a PhD student at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

Hippocracy

The idea that we should live in a predator and stress free (for herbivores) has been doing the rounds again these last few days. Apart form it being a very-bad-no-good idea to remove all predators from a system its also easy to forget that herbivores can be just as big of a source of stress for other herbivores as the threat of predation.

I mean we know that herbivores sometimes order off of the meat menu (Omnomnomivores anyone?), can bully smaller species off of/away from resources, and can be a general menace to society ‘just because’. To put it simply there is always going to be something causing an individual some type of stress out there (even from their own species). Saying that predators are the problem is not a sustainable way of thinking, and is also an overly simplistic view of ‘predation’. From the view of a plant herbivores are predators are they not?

For an earlier take on when this issue cropped up last year, check out the link below.

Read More: An Attempt To Understand Painlessly Killing Predators


Tanya Strydom is a PhD student at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.

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