Category: Biology

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Tiny migration

The dusky grouse wait,

girding their loins for the trip –

Tiny migration.

 

As the seasons change many species migrate across hundreds or even thousands of miles to reach fertile breeding or feeding grounds. In contrast, the North American dusky grouse (a species of blue grouse) may sometimes migrate less than a mile, with females travelling shorter distances than males (Cade & Hoffman, 1993). Often these tiny distances are travelled on foot rather than flying.

The migration is so small that the species is recognised by Guinness World Records as being the shortest bird migration at 300 meters (although individual birds have been recorded as travelling even shorter distances) and has featured on the BBC quiz show QI.

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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’.

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Bumblebee football

Bumblebee football:

Learning to score for sugar,

self-improvement – Goal!

 

Tool use is an indication of cognitive complexity and has been demonstrated in a number of species, including among primates, marine mammals and birds. Bumblebees trained to manipulate a ball to gain a reward were able to improve on their performance by taking shorter routes and moving the closest ball when presented with multiple balls. The bees were also able to learn socially by watching other bees solving the task. Together this shows a degree of cognitive flexibility that has not previously been recognised in an insect. Loukola et al, 2017.

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Snail shepherds

Cichlid snail shepherds

help their fry play masquerade

…if the crowd’s willing.

 

Keeping your children safe is one of the most important things you can do as a parent. Cichlid fish have young that have striped patterns similar to a species of snail that sometimes lives in the same area – a form of masquerade camouflage protection. The fry only have these patterns in populations where the species of snail is present, and the cichlid parents further help their young by removing other species to snail from their territory, helping to drive up the proportions of striped snails and so increase their offspring’s charade. Satoh et al, 2017.

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Crafty little goats

Crafty little goats –

watching humans solve problems.

See, they learn faster!

 

Many animals can learn how to solve tasks by watching how members of their own species solve the problem. Learning by observing other species is less common and few species have been shown to learn from watching humans. Goats struggle to learn how to solve a detour task (navigating around a ‘V’ shaped hurdle) by themselves but observing a human solve the task just once enables goats are able to solve the task much faster. Nawroth et al, 2016.

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Foundress

Paper foundress queens

Influence their colony

In character and size.

 

We often look for similarities between ourselves and our parents/children, in the way we look or behave. In paper wasps the personality of the queen influences the size and aggressiveness of the colony they found: Bolder queens tend to produce more workers that as a colony are less likely to attack a simulated agonistic stimulus, however whilst shyer queens tend to produce a more aggressive colony with fewer workers. Wright et al, 2017.

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Just a warm up

Oh how sweet dawn’s song!

Yet this choral crescendo

is just a warm up.

 

Many of us enjoying waking up to the sound of birdsong. But whilst we might enjoy the various trills and tweets as the sun rises, the Adelaide’s warbler’s song actually improves over the course of the morning. To appreciate the best of its voice, perhaps the early bird doesn’t catch the worm! Schraft et al, 2017.

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Paternal spider

Paternal spider

to die at the ‘little death’,

worthy sacrifice.

 

Mating is a dangerous game for males of many species of spider, with females often winding up with a nutritional meal to help fuel egg production. Taking their paternal responsibilities to an extreme, male dark fishing spiders spontaneously die during copulation. Females that are allowed to eat their dead mates produce a greater number of offspring, of a greater size and with an increased survivorship compared to females prevented from eating their mate or females provided with an equivalently sized cricket. It seems cannibalism isn’t all bad. Schwartz et al, 2016.

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No saturation

Aliens spreading,

their invasion continues.

No saturation.

 

Increased globalisation over the past 200 years has helped to spread flora and fauna species around the world, with some non-native species disrupting local habitats to a devastating degree. Despite efforts to mitigate such invasions, the rate of alien species establishment appears to be increasing and no saturation point has been observed. Seebens et al, 2017.

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Enemy within

Enemy within:

Trojan tapeworms plotting for

reckless behaviour.

 

Sticklebacks infected with a tapeworm behave in ways that appear to maximise the tapeworm’s transmission to a new host: swimming near the surface of the water and so increasing the risk of being eaten by birds. A study by Talarico et al (2017) suggests that this change in behaviour is down to the influence of the tapeworm itself rather than a “general, systematic impairment of infected sticklebacks”, although other recent studies have demonstrated that there may also be additional reasons for this behavioural change.

Original research: https://doi.org/10.1007/s00265-017-2265-9

Discussion of study: https://doi.org/10.1007/s00265-017-2272-x

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The drink of the gods

The drink of the gods

curbs oxidative stress through

clever conversions

 

The energetic demands of flying causes muscular oxidative damage. Whilst some foods have antioxidants, nectar doesn’t – a potential issue for flying nectar-feeding animals. To get around this issue hawkmoths appear to be able to “generate antioxidant potential by shunting nectar glucose to the pentose phosphate pathway”. Levin et al, 2017.

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Immigrant crabs

Immigrant tree crabs

Move from mangrove to salt marsh

…but it’s not the same.

 

Mangrove tree crabs have responded to climate change by moving northwards into a novel habitat: salt marsh. The crabs used to show site fidelity in their historic habitat but the faecal cues they used for this are now often washed away in the salt marsh which is regularly flooded. Climate change may therefore be indirectly affecting foraging behaviour and predation risk. Cannizzo & Griffen, 2016.

Original research: https://doi.org/10.1016/j.anbehav.2016.08.025

 

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Fight, flight or pee

To fight, flight or pee?

That is the question for the

Aggressive cichlid.

 

Aggressive interactions between individuals can be dangerous and energetically expensive and it is important that the two competitors are able to communicate effectively to avoid such costs. When competing cichlid fish engage in agonistic interactions they are known to communicate via visual cues, but new findings suggest they also use chemical cues by urinating during encounters. Bayani et al, 2017.

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Hunger no more

Hungarian men

hungering for a snack should

hunger no more – bugs!

 

A questionnaire of consumers in Hungary found that almost 60% of respondents were aware of eating insects as an alternative to meat, however high food neophobia is still a barrier for actually consuming insects. Men were more likely to consider trying insects than women, but a ‘willingness to eat insect-based food products could be increased by giving more information to consumers’. Gere et al, 2017.

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How safe the trader?

How safe the trader?

The agricultural costs

of invasive pests

 

Invasive pest species threaten global agriculture and can devastate crops. A study of almost 1,300 agricultural invasive species and 124 countries suggests that whilst the biggest agricultural producers (USA and China) “could experience the greatest absolute costs from further species invasion”, their trade patterns mean they are also the greatest potential source of invasive species and so represent the greatest threat to the rest of the world. In contrast, the countries most vulnerable to invasive species were found to be from Sub-Saharan Africa. Paini et al, 2017.

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Locked-In

Complete locked-in state.

Infra-red plus oxygen:

Communication!

 

Complete locked-in state is a condition where patients are suffering from motor paralysis but retain their mental processing abilities. The inability to control their own body movements has made communication with people suffering from this condition effectively impossible. However, by using functional near-infrared spectroscopy measure changes in frontocentral oxygenation patients were able to answer yes and no questions. Chaudhary et al, 2017.

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Gregarious sharks

Gregarious sharks:

Cohabiting siblings and

multiple lovers

 

Whilst the bluntnose sixgill shark is a widely known species of shark, little is known about its biology. A genetic study looking at polymorphic microsatellites revealed that individuals sampled at the same time and place were often siblings, whilst one female was found to have had up to 9 males fathering her offspring. Larson et al, 2011.

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Fauna crime

Holmes solves fauna crime.

The case of invading smelt –

Released with intent

 

‘Translocation of freshwater fish… to new localities where they do not already exist’ is illegal in Norway. Understanding how a population of smelt has rapidly appeared in Lake Storsjoen is therefore important for population management. By using microsatellite markers Hagenlund et al (2015) were able to determine that it is likely that a large number of individuals were translocated at one time, potentially to create a population of large-sized trout, a species that feeds on smelt and is popular for fishing.

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Road-safety

Road-safety crucial:

Engine noises distract from

predator odours.

 

Noise pollution can have a number of effects on wild animals. Morris-Drake et al (2016) found that road noises meant that dwarf mongooses were slower to detect a predator odour and did not increase vigilance in response to the odour (whilst mongooses exposed to normal ambient noise found the odour faster and showed increased vigilance).

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Unhappy Whio

Unhappy Whio –

Your populations estranged,

split by the Cook strait.

 

The rare blue duck (named the Whio in Maori after the male call) is found on the North and South islands of New Zealand. The genetics suggest that the populations on the two islands diverged in the late Pleistocene, with very limited gene flow since. The current conservation strategy not to translocate individuals between the populations is therefore sensible so as to avoid potentially negative issues arising from crossing distant genetic pools. Grosser et al, 2016.

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Lugging worker

Lugging worker ants

use a celestial compass.

Is this a moonwalk?

 

Ants often need to walk backwards when dragging heavy food items to their nests, but how do they navigate when moving in reverse? Rather than relying on visual memories of terrestrial cues, ants instead use their celestial compass – this can be disrupted by presenting ants with a mirror image of the sun’s position in the sky. Schwarz et al, 2017.

Original research: https://doi.org/10.1016/j.cub.2016.12.019

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Ancient female dynasty

DNA reveals

ancient female dynasty

of Chaco Canyon.

 

Hereditary leadership is often an indicator of early political complexity and governance. Kennett et al (2017) used mitochondrial and nuclear DNA to identify an elite matriline that persisted between 800 and 1130 AD in Chaco Canyon, New Mexico.

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Perfect storm

Spreading fungal scourge

salamanders succumbing

perfect storm draws near.

 

Many of the world’s amphibians are under threat from a chytrid fungus (Bd), particularly in the tropics where it is driving many amphibian species towards extinction. More recently a sister species (Bs) has been observed in Western-European salamanders. Observations of a salamander population across two years following initial detection of Bs suggest a rapid population collapse with little recovery. Bs also has an increased transmission strategy over Bd and may behave as a “perfect storm” as it spreads through European populations of salamanders. Stegen et al, 2017.

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When courting

When courting with song

do take turns with your neighbour –

Gentlemen hermits!

 

Male long-billed hermits (a sub-group of humming birds) form leks to attract mates by singing, but competing birds close together could overlap singing and confuse each other’s song. To counter this, males close together coordinate to alternate singing bouts whilst males further away from each other (and not at danger from vocal obscuration) overlap their songs. Araya-Salas et al, 2017.

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Blossoms

Cherry blossoms dance

across the road like heat haze

on a summer day.

 

Ok, this is not technically a sciku but since haiku have traditionally had a strong association with cherry blossoms it felt right for The Sciku Project to feature a cherry blossom based haiku.