Tag: Mammals

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Misunderstood by Michael Mills

On innocent wings…
a black messenger of death
sings a silent song

by Michael Mills

The bat is the only mammal capable of true flight, and one of the few that are capable of echolocation. Bats are nocturnal, were once thought to be bad omens or representations of evil, and are frequently misunderstood as all blood-sucking or disease vectors.

Further reading:

‘Bats are one of the most important misunderstood animals’, Courtney Celley, U.S. Fish & Wildlife Service, available: https://www.fws.gov/story/bats-are-one-most-important-misunderstood-animals

Author bio:

Michael Mills is a second semester Graduate Student at Stonybrook University, working on a master’s degree in Science Communication Journalism. Michael’s passion is firmly rooted in communicating to BIPOC and other marginalized groups about the importance of their voices being heard and understood in the world of sci-comm. Michael’s love for art comes from his lifelong fascination with graphic illustration and digital art, and the fantasy worlds and figures that can be created therein. He cites illustrators Hajime Sorayama, Jim Lee, and Bengus as inspirations, and pulls ideas from high fashion couture, religious idolatry, Americana and queer identity when creating.

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Boys Whale Be Boys by James Penha

humpbacks copulate
in photos for the first time—
out of the closet

by James Penha

The world’s first photographs of humpback whales copulating are even more groundbreaking because both individuals were male.

Further reading:

‘An observation of sexual behavior between two male humpback whales’, 2024, Stack, S.H., Krannichfeld, L. & Romano, B., Marine Mammal Science. Available: https://doi.org/10.1111/mms.13119

‘Humpback Whale Sex Observed for the First Time Ever, between Two Males’, 2024, Hobson, M., Scientific American. Available: https://www.scientificamerican.com/article/humpback-whale-sex-observed-for-the-first-time-ever-between-two-males/

Author bio:

Expat New Yorker James Penha (he/him 🌈) has lived for the past three decades in Indonesia. Nominated for Pushcart Prizes in fiction and poetry, his work is widely published in journals and anthologies. His newest chapbook of poems, American Daguerreotypes, is available for Kindle. Penha edits TheNewVerse.News, an online journal of current-events poetry. You can find out more about James’ poetry on his website https://jamespenha.com and catch up with him on Twitter @JamesPenha

Enjoyed James’ sciku? Check out more of his sciku here: ‘Quantumku’, ‘DNAncient’ and ‘If a Tree Talks in a Forest’, and ‘Air-Gen-Ku ‘.

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Redundant Ergot by Sarah Das Gupta

The equine ergot
is mysterious and odd
someone blundered

by Sarah Das Gupta

Having had many horses in a long life, I can’t see the importance of the ‘ergot’ in 2023. For those unaware, the ergot is a small callosity on the underside of the fetlock of a horse. In horses, ergots can range from pea-sized to 3.8 cm in diameter and can be found on all four legs or absent on some or all of them.

The ergot has long been felt to be a vestige of the multi-toed foot of ancestral horses, and some horse owners trim them down to near skin level. However, the ergot’s redundancy may only be skin deep, as recent research suggests that the internal structure of the ergot beneath the visible external callus continues to have a function in modern horses.

Lusi and Davies (2017) studied the subcutaneous ergot tissue and found that “its overall connectivity, and the presence of nerve fibers and Ruffini endings strongly suggest that the ergot and its derived ligaments contribute to joint support, movement, and tension distribution in the distal limb.”

Further reading:

‘The Observer’s Book of Horses and Ponies’, R S Summerhays, Frederick Warne & Co. Ltd.

‘The Connectivity and Histological Structure of the Equine Ergot—A Preliminary Study’, Carla M. Lusi and Helen M.S. Davies, 2017, https://doi.org/10.1016/j.jevs.2017.01.003

Author bio:

Sarah Das Gupta is a young 81 year old. Loves writing haiku and most forms of poetry. Is learning to walk after an accident. Main outside interests include equine sports. Lives near Cambridge, UK. Read other sciku by Sarah here.

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Fussy Eaters

When it comes to food,
a devil may indeed care.
Picky scavengers.

Scavengers are opportunists, feeding whenever and on whatever they can. If an animal relies primarily on scavenging (instead of hunting) then food is not guaranteed and so it’s important to feed when they can. As a result, scavengers shouldn’t be picky eaters.

Yet recent research by Lewis et al. (2022) suggests that the Tasmanian devil may buck these expectations. The researchers took whisker samples from devils caught around Tasmania and analysed the stable isotopes present in them to determine what the devils had been eating.

Rather than seeing the generalised diet typical of a scavenger, the researchers found that most Tasmanian devils are actually dietary specialists, preferring to feed on specific foods (for example birds, wallabies or possums). Curiously, heavier devils were more likely to show this specialisation in feeding behaviour, although the reasons for this are as yet unknown.

So why are Tasmanian devils different from all other scavengers?

It may be because there are no larger predators to compete with in Tasmania – their main competition is each other. Medium-sized mammals, such as wallabies and possum, are common victims of road collisions which may mean that there’s an abundance of carcasses of these species for devils to choose from, which combined with reduced competition enables dietary specialisation.

Further reading: http://dx.doi.org/10.1002/ECE3.8338

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Rigs to Reefs

Oh puffing pig fish –
torn between disturbance and
piscine temptations.

Noise pollution from oil and gas drilling platforms can have huge negative impacts upon marine life. However, such rigs can also act as artificial reefs, providing shelter and a hard substrate for predators and prey alike. Moreover trawling isn’t permitted close to rigs, meaning that the seabeds around them are mostly untouched.

Harbour porpoises, Phocoena phocoena, have previously been shown to change their behaviour or avoid areas as a result of unnatural noise levels. Yet a recent study by Tubbert Clausen et al. (2021) has revealed that the temptations of high prey availability can overcome such affects. The team use 21 acoustic loggers, placed on the seabed for up to 2 years to monitor noise levels and harbour porpoise activity.

They found that despite the high noise levels from the largest rig in the Danish North Sea, the porpoises were still found close to the rig, emitting echolocation noises that indicate they were hunting for fish. The platform’s artificial reef effect appeared to increase fish numbers which drew the porpoises closer.

The findings suggest that as platforms come to the end of their lifespans, they could be partially left in place to continue acting as artificial reefs – the rigs-to-reefs concept.

The first line of the sciku refers to two names for the harbour porpoise:

– The ‘pig fish’ from the Medieval Latin porcopiscus, a compound of porcus (pig) and piscus (fish).

– The ‘puffing pig’ which comes from the noise the porpoises makes when surfacing to breathe.

Original research: https://doi.org/10.1002/2688-8319.12055

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Hedgerow Snuffling by Roy McGhie

Hedgerow snuffling and
intensive farming practices.
A prickly issue.

By Roy McGhie

Hedgehog numbers are declining. Although hedgehogs are often thought of as a countryside animal, recent studies have shown that they are now most likely to be found in urban habitats in the UK.

A recent paper by Yarnell and Pettett (2020) has reviewed the difficulties they face in the rural environment (namely lack of food availability, habitat connectivity and shelter) and highlighted some of the agri-environment options from which they could benefit. However, there is a lack of empirical evidence around the precise benefits such options (like establishment of field margins and boosting hedgerow cover) would bring. More studies are urgently required before hedgehogs and other insectivores are driven out of the countryside entirely.

Original research: https://doi.org/10.3390/ani10091566

Roy McGhie works for Natural England as an Uplands Advisor. You can connect with him on LinkedIn here. If you enjoyed his sciku, check out his previous poems Ghost Ponds, A Heady Mixture and Fluttering by at Dusk.

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Aye-Aye!

The northern monkey.

Never in need of a lift

with its pseudothumb.

The aye-aye is a curious primate found in Madagascar that has possibly the most unusual hands in the animal kingdom. Their hands are so elongated that they account for around 41% of their total length of the forelimb. The aye-aye’s long, bony third finger is its calling card – unique in the animal kingdom, it’s a specialised tool for getting grubs out of deep holes and probing for food whilst foraging.

Yet such specialisation can have costs, including weakening the ability of aye-ayes to grip. Hartstone-Rose & Dickinson et al. (2019) suggest that the aye-aye’s pseudothumb may have evolved to combat this disadvantage. The researchers found the pseudothumb has bony, cartilaginous and muscular features, suggesting that it enhances the aye-aye’s grip of smaller items such as thin branches.

A note about the sciku – Aye-ayes are lemurs and are not monkeys (they’re strepsirrhine primates). The sciku calls them northern monkeys because ‘aye’ is a common term in the north of England and in Scotland meaning ‘yes’, and ‘why-aye’ or ‘wey-aye’ are northern (mainly Geordie) terms for ‘well yes’ or ‘well, yes of course’. The term northern monkey is also a derogatory term in the UK for someone from the north of England (the counter of which is southern fairy).

Original research: https://doi.org/10.1002/ajpa.23936

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Whale strike

To avoid striking
whales, great creatures of the sea,
use the app. Impact!

Blue whales can be injured or killed in collisions with ships, particularly in regions where migration routes cross shipping lanes. Yet because they travel huge distances, predicting where whales will be at any given time is difficult. However, now research by Abrahms et al (2019) suggests that statistical modelling techniques may be able to help.

The researchers used satellite tracking data from 104 blue whales across 14 years along with daily information on three-dimensional oceanic habitats to model the whales’ daily distribution. By using an ensemble modelling approach they were able to produce daily, year-round predictions of blue whale habitat suitability in the Californian Current Ecosystem.

The statistical approach allows the researchers to quantify the spatial and temporal distribution of exposure to ship strike risk within shipping lanes in the Southern California Bight. The researchers plan on converting this approach into a downloadable app which would alert ships to the risks of whale collision and could recommend alternative shipping lanes or vessel slow-downs.

It’s a truly fascinating piece of research that seems likely to have a huge impact upon a real-world problem – research at its best.

The sciku also includes a line from Mr Scruff’s truly excellent track ‘Shanty Town’ from his ‘Keep It Unreal’ album released in 1999. The full line is ‘Whales! Great creatures of the sea! Please listen to me!’ It’s well worth checking out!

Original research: http://dx.doi.org/10.1111/ddi.12940

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Resources forecast

Resources forecast

bat foraging. Alone? Group?

You are what you eat.

 

Whilst Darwin’s finches are a classic example of selection acting on bird morphology and resulting in species that are able to eat different seed sizes and shapes, food characteristics can result in evolutionary impacts that are less immediately obvious.

Egert-Berg et al (2018) investigated the impact of ephemeral food sources on bat social behaviour. By tracking the foraging behaviour of 5 species of bats the researchers found that in bat species where food sources were predictable individual bats foraged alone, reducing the impacts of conspecific competition. In contrast, where food resources were unpredictable and transient bat species foraged in groups. The research is a fantastic example of a collaboration between researchers in different countries and continents.

Original research: http://dx.doi.org/10.1016/j.cub.2018.09.064

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Domino effect

Domino effect.

Ocean-behaviour-hookworms

lead to seal pup deaths.

 

The web of life, food chains, ecological balance – there are a lot of terms that indicate how interlinked ecosystems are. A recent, tragic example of this is how a rise in ocean temperatures can indirectly result in increased seal pup death from hookworm infection.

Seguel et al (2018) found that sea temperatures influenced the survival of South American fur seal pups. Sea temperatures effect wind patterns and ocean currents, changing the abundance of nutrients and as a result fishes. Higher sea temperatures resulted in lower fish abundance, meaning that fur seal mothers needed to spend more time at sea feeding, consequentially spending less time with their pups. The reduced maternal care led to lower pup growth rates and a less effective immune system, making the fur seal pups more susceptible and less likely to successfully fight off hookworm infection.

Original research: http://dx.doi.org/10.7554/eLife.38432

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Wild, rural, urban

Mammal density

wild, rural, urban – the same.

Rocking the suburbs.

 

Urban development encroaches on natural spaces, reducing and altering animal habitats. A consequence of this is that many species have evolved to live around humans, although developed areas are thought to have low species diversity and abundance.

Yet research by Parsons et al (2018) in coordination with citizen scientist volunteers suggests this might not be the case. Using camera traps placed in areas of varying development (from wild to urban) and scale (from forests to yards) the researchers found that mammals were found in similar or higher levels of abundancy and species richness in developed areas compared to wild areas. The research highlights the need to conserve wild areas and preserve green spaces within cities.

The keen eyed may spot that the final line of this sciku is a reference to Ben Folds’ first solo album ‘Rockin’ the Suburbs’, released in 2001.

Original research: https://doi.org/10.7554/elife.38012.001

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Lingering threat

PCB. Lingering threat.

Slinking up food chains, silent.

Killing the killers.

 

PCBs – polychlorinated biphenyls – were widely used in a variety of manufacturing techniques until they were linked to health problems such as increasing the risk of cancer, disrupting the immune system and impairing reproduction. Despite a ban on their use, the compounds remain an environmental contamination and can accumulate in the tissues of animals, passing up the food chain to accumulate in dangerous levels in apex predators.

Whilst killer whales are one of the most populous mammal species on the planet, research by Desforges et al (2018) suggests that PCB pollution could result in a collapse in over 50% of the world’s killer whale populations. The researchers amalgamated data on PCB concentrations in killer whale tissues from across the world and modelled the predicted impacts of PCB pollution over the next 100 years. The results highlight how important it is to be aware of potential environmental issues, even with species that appear to be thriving.

Original research: http://science.sciencemag.org/content/361/6409/1373

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No catch-22

Does the protected

lion eat conserved zebra?

Phew! No catch-22!

 

Recovering predator populations as a result of conservation work can result in impacts on their prey species populations, causing issues if those prey species are themselves endangered. One case in particular is whether lions exert top-down pressure on Grevy’s zebra in Kenya – does the recovery plan of one species negatively affect the conservation of another?

A study by O’Brien et al (2018) suggests we need not worry in this case – working in Laikipia County in Kenya the researchers found that lions were less likely to prey on Grevy’s zebra than expected. In fact, population trends suggest that the Grevy’s zebra population in Kenya may be stabilising. The researchers conclude that the most likely threat to Grevy’s zebra are competition for grass with Plain’s zebra and the impact of livestock.

Original research: http://dx.doi.org/10.1371/journal.pone.0201983

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Fluttering by at dusk by Roy McGhie

Fluttering by at dusk,

dawn, and in between.

Crop diversity!

Recent research by Olimpi & Philpott (2018) concludes that crop diversity as a management practice drives bat activity, and that crop diversity and less frequent pesticide use increase bats’ insect prey populations. The study notes that this could be a useful management tool where other options, such as hedgerow or tree management, are not available.

Original research: https://doi.org/10.1016/j.agee.2018.06.008

Roy McGhie works for Natural England as an Uplands Advisor. You can connect with him on LinkedIn here. If you enjoyed his sciku, check out his previous poems Ghost Ponds, A Heady Mixture and Hedgerow Snuffling.

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The year’s best species

Mystery protist.

Apes, snailfish and amphipods.

The year’s best species.

 

Every year since 2008 the College of Environmental Science and Forestry has released a Top 10 New Species list. 2018’s selection include single celled organisms, plants and animals (including two species of beetle) as well as a prehistoric marsupial lion identified from fossils. All 10 species are fascinating but those highlighted in the sciku are:

Protist – Ancoracysta twista, a single celled predatory Eukaryote with harpoon-like organelles that it uses to immobilise its prey. Intriguingly its evolutionary origins are unclear and it doesn’t fit neatly within any known groups.

Ape – Orangutans now come in three flavours: Bornean, Sumatran and now a newly identified Southern Sumatran species of orangutans. It is the most endangered great ape in the world.

Snailfish – Whilst snailfish are found at all depths, 2018’s species is the deepest fish in the sea, found in the Mariana Trench at 7,966 meters below the surface. It appears to be the top predator in its benthic community and is tadpole-like and around 4 inches long.

Amphipod – Epimeria quasimodo is found in the Antarctic Ocean. The 2 inch long crustacean takes its name from the hunchback of Notre Dame and has beautiful vivid colours.

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How you handle mice

How you handle mice

affects response to rewards.

Science improves too!

 

There is an increasing body of research to suggest that handling laboratory mice by the tail is both bad for their welfare and the science that the mice are studied for. Tail handling has negative impacts on mouse behaviour and physiology, with tunnel and cupping handling techniques resulting in behavioural improvements across various common behavioural bioassays, including the elevated plus maze, the open field test and the habituation-dishabituation paradigm.

Now new research suggests that handling is also important for reward-based behavioural assays. A study by Clarkson et al (2018) examined mouse response to sucrose solution (a common reward). They found that tail handled mice showed a reduced response to the sucrose than the tunnel handling method, a finding indicative of the tail handled mice having a ‘decreased responsiveness to reward and potentially a more depressive-like state’.

Across eight years and five research papers, from three distinct research groups in two countries, the field of laboratory mouse research has been irrevocably changed. Combined, the research suggests that tail handling results in poor animal welfare and potentially erroneous scientific results. The National Centre for the Replacement, Refinement & Reduction of Animals in Research now has extensive information on mouse handling techniques, example videos, tips and testimonials for researchers and animal carers to find out more about changing their current mouse handling methods to the tunnel or cupping techniques.

Original research: http://dx.doi.org/10.1038/s41598-018-20716-3

 

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Tunnels and cupping

Tunnels and cupping

beat tail handling mice for

behavioural tests.

 

Laboratory mouse handling method can affect mouse behaviour and physiology, and new research suggests that it can also impinge on mouse performance in behavioural tests. Research by Gouveia and Hurst (2017) found that tail handled mice performed poorly in a habituation-dishabituation paradigm test in comparison to cupped or tunnel handled mice. The tail handled mice ‘showed little willingness to explore and investigate test stimuli’ and even prior familiarisation with the test arena didn’t improve their performance much.

Combined with the previous research findings on mouse handling this research continues to expand on the long-reaching impacts of mouse handling technique on both mouse welfare and scientific experimental rigour and asks the question – just how valid are behavioural tests using laboratory mice that have been tail handled? Yet the story of mouse handling is not yet done, click here for the final instalment of this tale/tail!

Original research: http://dx.doi.org/10.1038/srep44999

 

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Cup handled mice

Cup handled mice show

improved glucose tolerance

and less anxiousness.

 

When performing scientific research with animals, it’s important to ensure that the procedures used do not themselves impact upon the results obtained. Laboratory mouse handling method has already been shown to impact upon mouse anxiety in common behavioural tests. However it seems that handling can have physiological impacts too.

Ghosal et al (2015) compared the behavioural and physiological responses of laboratory mice to either tail handling or cupped handling techniques. Cupped handled mice showed fewer anxious behaviours in a common behavioural test, reduced blood glucose levels and a lower stress-induced plasma corticosterone concentration in response to an overnight fast compared to tail handled mice. The researchers also found that obese laboratory mice handled using the cupped method demonstrated improved glucose tolerance.

Replication and repeatability are crucial components of science and this paper is a perfect demonstration of this – the researchers are from different research laboratories and in a different country to the mouse handling work that preceded it. In this way not only does it build on what came before, it also strengthens those earlier findings. Yet the mouse handling story is not finished yet, click here for the next chapter of this tale/tail!

Original research: https://doi.org/10.1016/j.physbeh.2015.06.021

 

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Reducing mouse anxiety

Further reducing

mouse anxiety using

familiar tunnels.

 

Building on the finding that handling laboratory mice using a tunnel resulted in lower anxiety than picking them up by the tail, Gouveia and Hurst (2013) next investigated whether familiarity with the tunnel might be an important factor. Once again they found that tunnel handling resulted in lower anxiety than tail handling during an elevated plus maze (a common behavioural test for laboratory mice).

This time they found differences between mouse strains, with C57BL/6 mice being most interactive towards tunnels from their home cage and ICR mice showing no difference in interaction between familiar home cage tunnels and novel tunnels previously used for handling mice from other cages. The researchers suggest that ‘as home cage tunnels can further improve response to handling in some mice, we recommend that mice are handled with a tunnel provided in their home cage where possible as a simple, practical method to minimise handling stress’. The tunnel would also act as a form of environmental enrichment for the home cage.

In science it’s rare to tell a complete story through the findings of two research papers, click here for the next chapter of this tale/tail!

Original research: https://doi.org/10.1371/journal.pone.0066401

 

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The little changes

The little changes

can make a big difference:

Handle mice with care.

 

Traditionally laboratory mice are handled by picking them up by the tail, yet increasing evidence suggests that this is bad, both for the mice themselves and the quality of the science they are being used for. The evidence for this started building from Hurst and West’s 2010 study which demonstrated that handling by the tail resulted in increased aversion and anxiety.

The researchers proposed two alternative methods for handling laboratory mice: holding the mice cupped in the hands or using tunnels that the mice can crawl into and be transported by carrying the tunnels. These novel methods of handling led to the mice approaching the handler voluntarily, being more accepting of physical restraint and showing lower levels of anxiety.

In science it’s rare to tell a complete story through the findings of a single research paper, click here for the next chapter of this tale/tail!

Original research: http://dx.doi.org/10.1038/nmeth.1500

 

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When I talk about running

What I remember

when I talk about running:

Stress fading away.

 

Proponents of exercise have long sung its praises as a way of staying physically healthy, but there is increasing evidence that it has mental health benefits as well. Miller et al (2018) found that exercise (and specifically running) helped reduce the impact of chronic stress on the brain.

The scientists compared stressed and unstressed mice that either had access to a running wheel or not. Mice that were able to exercise mitigated some of the negative impacts of stress, whilst mice that were unable to exercise showed a reduction in the long-term potential of their hippocampal function (the part of the brain responsible for learning and memory).

In honour of World Book Day the poem references Haruki Murakami’s excellent meditation on running and life ‘What I Talk About When I Talk About Running’, which itself was a play on Raymond Carver’s ‘What We Talk About When We Talk About Love’.

Original research: https://doi.org/10.1016/j.nlm.2018.01.008

 

 

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On a knife edge

Life on a knife edge:

The metabolic demands

facing polar bears.

 

Polar bears rely on marine mammals such as seals which are high-fat prey. Despite the richness of their diet however, new research suggests that a reduction in the prey availability can have severe consequences on polar bear survival.

Pagano et al (2018) monitored nine free-ranging female polar bears over 2 years, measuring their metabolic rates, daily activity patterns, body condition and foraging success. They found that more than half of the bears had an energy deficit resulting from a high metabolic rate (1.6 times higher than previously assumed) and a low intake of the high-fat prey. As fragmentation of sea ice continues and seals become harder to catch the high metabolic requirements of polar bears is likely to become increasingly catastrophic for the species.

Original research: https://doi.org/10.1126/science.aan8677

 

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Increase carpet tog

Cold stress avoided

in laboratory mice –

increase carpet tog.

 

Temperature is an important element of animal care and it’s crucial to ensure that captive animals don’t overheat or suffer cold stress. Laboratory mice are often housed with a floor substrate of wood chips which may be useful in reducing cold stress.

Freymann et al (2017) found that the depth of this floor material influenced mouse physiology. Specifically a deeper wood chip layer resulted in mice with reduced adrenal, liver, kidney and heart weights and an increased tail length. These traits have previously been observed in mice housed under warmer conditions suggesting that the deeper substrate material is acting as an insulator and could be used to reduce cold stress in this captive species.

Original research: https://doi.org/10.1177/0023677217694400

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Underground sound

Listening for sound

whilst deep underground requires

middle ears to hear.

 

Animals living in different environments will face different auditory challenges. To investigate how environment shapes evolution Koyabu et al (2017) compared middle ear morphology across terrestrial, aquatic and subterranean species from the order eulipotyphla (including hedgehogs, moles and shrews).

They found that a subterranean lifestyle involved adaptations that allow for improved sound transmission at low frequencies and reduced transmission of bone-conducted vibrations. The adaptations observed included “a relatively shorter anterior process of the malleus, an enlarged incus, an enlarged staples footplate and a reduction of the orbicular apophysis”.

Original research: https://doi.org/10.1098/rsos.170608

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Black and white cat-foot

Black and white cat-foot.

Your numbers are rising but

your home shrinks and splits.

 

The giant panda (whose Latin binomial name literally means black and white cat-foot) is a poster species for animal conservation yet recently the IUCN Red List downgraded the species from endangered to vulnerable based on an increase in adult population since 1988.

Despite this population increase there remains concern for the future of the species. A study by Xu et al (2017) using remote sensing data suggests that both the total amount of available giant panda habitat and the average size of habitat patches (an indication of habitat fragmentation) have decreased substantially. Whilst total area and habitat patch size have shown signs of an recovery since 2001, they still remain below 1988 levels (1.7% and 13.3% lower respectively).

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Cause and effect

They’ll blow your house down

as they grasp cause and effect

much better than dogs.

 

The process of domestication is thought to impact on a number of cognitive and physical properties as species adapt to the human environment. The close social ties between humans and dogs are an extreme example and comparing the cognition of dogs with wolves can reveal information about the impact of domestication.

Using animals housed under similar pack conditions and with prior experience of interacting with humans, Lampe et al (2017) found that whilst wolves and dogs can follow human-given communication equally well, wolves were better at understanding causal cues in the absence of humans (such as a rattling container indicating the presence of food). Domestication may have led to a reduction in the ability of dogs to solve some problems independently of humans.

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Just nicker!

Don’t make yourself hoarse

in anticipation of

good times, just nicker!

 

Vocal communication is an important element of behavioural interactions within many social species.  Przewalski’s horses produced more whinnies and squeals in response to negative contexts (agonistic interaction, social separation), but more nickers in positive contexts (anticipation of food or affiliative interactions).

Przewalski’s horses are the closest living relative of domestic horses and a comparison between the species revealed both similarities and intriguing differences in their vocalisations, suggesting that the expression of emotional valence (positive or negative) might be species specific as opposed to conserved across species. Maigrot et al, 2017.

Being able to understand vocal expression of animals could lead to the increased welfare of captive species and a better understanding of animal interactions and group behaviour, which in turn might help to aid population management or conservation in endangered species.

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Can herbivores relax?

My how big you are!

and yet your range contracts. Can

herbivores relax?

 

As the human population around the world expands, the impact we have on wildlife increases due in part to more land being used for habitation or agricultural purposes. Large carnivores are particularly vulnerable to anthropogenic threats such as loss of prey base and human-wildlife conflict (often to do with livestock).

Wolf & Ripple (2017) created and analysed large carnivore range maps from present and historical (~AD1500) data. They found that large predators historically occupied 96% of the world’s land area whereas now they occupy 34%. A number of species have suffered an decline in range of over 90%, including the red wolf (99.7%), Ethiopian wolf (99.3%) and the tiger (95.3%). Overall the greatest range contractions occurred in South-eastern Asia and Africa.

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Plenty of fish

Plenty of fish yet

male voles choose monogamy

… but do their partners?

 

Monogamy is relatively rare in the animal kingdom, with extra-pairs matings happening a lot more than you might think. Males in particular are thought to gain the most from polygamy by being able to sire multiple offspring, whilst females may gain from monogamy through defence or paternal care of their young.

Yet despite having access to multiple females, male prairie voles choose to form exclusive pair bonds with individual females (Blocker & Ophir, 2016). In contrast,  female prairie voles readily engage in promiscuous mating (Wolff et al, 2002).

So why (under laboratory settings) are male prairie voles monogamous whilst females are promiscuous?

Blocker & Ophir, 2016 argue that one explanation could be that the costs to males of trying to hang on to multiple females at once are too great, and that male prairie voles gain the most by aggressively monopolising just one female. Females on the other hand have nothing to lose from polygamy so will mate with other males if the opportunity presents itself.

In prairie voles it seems that monogamous behaviour may be male-driven.

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How small the harvest

How small the harvest

for sustainability,

this cream-coloured gold.

 

Illegal poaching and the ivory trade have decimated African elephant populations, but could ivory be harvested sustainably at a level to both maintain the species and satisfy the trade?

By modelling a reference population of African elephants, Lusseau & Lee (2016) show that only a very small amount of ivory can be harvested sustainably without endangering the species and that this amount is well below the current demand. They comment that ‘any overexploitation very quickly runs the risk of driving elephants to extinction’.