Over-Bearing

The paparazzi are out – and this time no one is safe!

Using photos to identify individuals in a population has long been used for species that have unique markings or patterns – for example Wild Dogs or Orcas. Recent developments have used deep learning and facial recognition to identify individuals of less differentiable species such as brown bears. This allows researchers to ‘follow’ individuals in populations without the need for invasive marking/tagging methods.

Although it remains to be seen if this will pass the ratings of the annual Fat Bear Week…

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.

Out of Time

Phenological asynchrony: a ticking time-bomb for seemingly stable populations? (2020) Simmonds et al., Ecology Letters, https://doi.org/110.1111/ele.13603

Image Credit: Ian Kirk from Broadstone, CC BY 2.0, Image Cropped

The Crux

When we think of climate change we tend to think about extreme weather events and melting ice caps, but the way in which our environment is changing is giving the planet more than just unseasonal weather. Phenology (the timing of biological events in nature) dictates when an organism begins a given part of its life cycle, and changes in phenology are one of the most frequent responses to climate change. Take bees and flowers; bees feed on the flowers of certain plant species, and in turn spread the plants’ pollen for them. They both depend on the other being around at the same time, and if flowers bloomed too early, or if the bees came around before the flowers were “ready” for them, both parties would suffer.

Such a mismatch is known as an asynchrony, and it is hypothesized to cause population declines due to the harmful impacts on one or more of the interacting species involved (see another recent post to understand how the loss of one or more interactions can lead to cascading effects throughout a local community). While many theoretical models have investigated these processes, today’s authors wanted to combine such models with long-term data on the phenology and population size of great tits (Parus major). Great tits rely on a small period of insect abundance to feed their young, and as such the more closely they can match the needs of their young to the abundance of insect populations the more they will increase their fitness.

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Wilderness: A Place of Untouched Ecological Processes

Image Credit: European Wilderness Society, CC BY 4.0, Image Cropped

What comes to your mind when you think of Wilderness? Maybe it is a dense rainforest filled with a cacophony of bird calls, or plain filled with lagre grazing animals and free-roaming carnivores? They certainly qualify, but by definition, Wilderness is any area that hasn’t (or has only slightly) been modified by human activity in the past. This means that Wilderness areas can be incredibly diverse, from the aforementioned tropical forest to a murky swamp. These areas represent nature in its purest form, with the absence of human interventions allowing for dynamic, open-ended natural processes. These processes not only create marvelous landscapes and offer refuge for species, but also provide many benefits for humans.

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Fear and Hope for Britain’s Mammals: An Overview

Look to the wilderness of Northern Europe and you will find brown bears, grey wolves, wild cats, and some of the best remaining strongholds for large mammals on the continent. Look to the UK on the other hand, and you see a state of overgrazed grasslands, skeletonized hedgerows, and monocultured forests. In the face of the global extinction and climate crisis, even the most praised of Britain’s mammals are facing decline, as the IUCN red list declares one in four species at risk of extinction, and the persecution of wild populations continues. 

In this article, I offer a brief summary of some of the UK mammal species that have experienced their share of ups and downs throughout 2020, and hopes for UK mammal conservation for the future.

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How Influential is the Platypus in Freshwater Dynamics?

Image Credit: Maria Grist, CC BY-SA 4.0, Image Cropped

Platypus predation has differential effects on aquatic invertebrates in contrasting stream and lake ecosystems (2020) McLachlan-Troup, Scientific Reports, https://doi.org/10.1038/s41598-020-69957-1

The Crux

A trophic cascade occurs when a predator’s effects of its prey goes on to affect ‘lower’ levels of that ecosystem. A great example is the effect that sea otters have on kelp: the sea otters prey extensively on sea urchins, which in turn increases the populations of kelp, which the sea urchins prey on. While this is a result of direct predation by otters, often this can occur through a prey species changing its behaviour to avoid the predators.

Yet most ecosystems are more complex than a simple three-level trophic system. Cascades are therefore more likely to occur when the ecosystem is less complex, or when there are well-defined relationships between species, as a result of a predator having preferred prey species or only a few groups of species making up an ecosystem.

This week’s authors investigated how the platypus (our recently-found-to-be-fluorescent friend) influences the abundance and species richness of invertebrates across both rivers and lakes, and whether it’s capable of affecting an ecosystems algae and sediments as well.

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Forest Parasols and a Thirsty Atmosphere

Have you ever sat down to a cold drink on a hot day and sucked down most of the glass in the first sip? Increasing thirst with increasing temperature also applies to Earth’s atmosphere – as air warms, it can ‘hold’ more water. The difference between the air’s level of moisture and its moisture capacity is dubbed the ‘vapour pressure deficit’ or ‘VPD’, which is essentially a measure of the thirst of the atmosphere.

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Platy-Party

Generally the platypus is considered a bit of an oddity. It’s an egg-laying mammal, has the bill of a duck, tail of a beaver, webbed feet, uses electrolocation, oh and its one of the few venomous mammals. Clearly the platypus was designed for the spotlight though – the UV spotlight that is.

It has recently been found that platypus fur glows a bluish-green colour under blacklight and is one of the few recorded cases of mammals exhibiting biofluorescence – alongside opossums and North American flying squirrels. Although it isn’t currently clear why a platypus is always ready for a night out at the disco (or if they can even perceive UV rays).

What other nocturnal animals may be hiding their own fluorescent secrets?

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.

Like a House of Cards

An empirical attack tolerance test alters the structure and species richness of plant–pollinator networks (2020) Biella et al., Functional Ecology, https://doi.org/10.1111/1365-2435.13642

Image Credit: Adamantios, CC BY-SA 3.0, Image Cropped

The Crux

Put simply, ecosystem function is the process that control how nutrients, energy, and organic matter move through an environment. Think about a forest. You have small plants that are eaten by small animals, small animals that are eaten by larger animals, and those larger animals are eaten by even larger animals. When those animals die, they are broken down and consumed by scavengers, fungi, and bacteria. These processes result in a continuous flow of nutrients and energy through the ecosystem. However, if one link (organism) in this chain breaks (goes extinct), the ecosystem could lose its function, and other species that depend on this cycle could go extinct as well.

The way in which a given ecosystem reacts to or recovers from any negative impact that it sustains is key to understanding how ecosystems function. Classically, this is tested with attack tolerance tests, in which all species on a given trophic level are removed and the ecosystem is then monitored to see how/if it maintains its function. In studies of plant-pollinator networks, this is usually modeled with computers, but studies which use natural systems are lacking. Today’s authors wanted to use a natural plant-pollinator system to see what happens.

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How Dead Whales Form Unique Ecosystems

A young octopus (Graneledone verrucosa) moves across the seafloor. Observed during the Okeanos Explorer Northeast U.S. Canyons 2013 expedition. (Image Credit: NOAA Ocean Exploration & Research, CC BY-SA 2.0, Image cropped)

In nature every death brings new life. A fascinating example are whale-falls: when a whale dies, its carcass will sink down to the ocean floor where it creates a unique ecosystem for bottom-dwelling organisms. Whales’ bodies can weigh up to 200 tons and contain massive amounts of fat and proteins. When a dead whale reaches the ocean floor it brings a lot of resources to an environment which is usually limited by food availability. The fortunate creatures experiencing the whale-fall welcome such a great source of nutrition, and use up everything they can, until the last vertebra is decomposed. 

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Reframing Evolution to Focus on the ‘Stupid, Icky And Small’

Endless forms most stupid, icky, and small: The preponderance of noncharismatic invertebrates as integral to a biologically sound view of life (2020) Jesse Czekanski‐Moir & Rebecca J. Rundell, Ecology & Evolution, https://doi.org/10.1002/ece3.6892

The Crux

When we think about evolution, too often our perception is that it drives species towards larger, more complex, more beautiful forms. It’s driven by popular media in part, but also by the way we teach it and the organisms we choose to focus on. This goes right back to early conceptions of evolution, with Darwin’s seminal text The Origin of Species referencing “endless forms most beautiful and most wonderful”, instead of “most basic and abhorrent”.

But the authors of today’s paper want to challenge that preconception of evolution as favouring larger or more complex or beautiful organisms, and they have some truly magnificent examples to do so with.

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