Beetles are equal partners in mating behaviour

New research conducted by Entomologists at the University of Lincoln’s School of Life Sciences has discovered the mating habits of beetles.

The research concluded that beetles that copulate with the same mate as opposed to different partners will repeat the same behaviour. This debunks previous suggestions that one sex exerts control over the other in copulation.

Callosobruchus Maculatus (Commonly known as the Cowpea Seed Beetle)
Callosobruchus Maculatus (Commonly known as the Cowpea Seed Beetle)

Mating behaviour of Callosobruchus Maculatus beetles (pictured), more commonly known as seed beetles, was undertaken to determine if either sex controlled the duration of copulation.

During mating, the female will kick her mate to force him to disengage its spiny genitalia which punctures the female’s reproductive tract. The study found that when beetles repeatedly mated with the same partner, the amount of time it took for the female to begin kicking the male, and how long she spent kicking, was virtually the same.

However, when mated to different partners, the duration of both the time it took to begin kicking and how long the female kicked for varied considerably.

Dr Paul Eady from the University of Lincoln’s School of Life Sciences led the study. He said: “Across the animal kingdom the duration of copulation varies enormously from a few seconds to several days, and it has traditionally been seen as a cooperative venture between males and females to facilitate the transfer of sperm.

“However, recent studies indicate that copulation might actually represent an uneasy alliance in which male and female interests are in conflict, which has led to a number of researchers examining which sex controls copulatory behaviour.

“Teasing apart, male and female influences over the duration of mating is difficult because although males may have more to gain, females are often in a position to exert more control.

“We used a very simple experimental protocol that examined the repeatability of male and female copulatory behaviour in the beetle, Callosobruchus Maculatus. When males mated to several females and when females mated to several males, the copulatory behaviour of individuals was inconsistent. This suggests both males and females have a degree of control over the duration of copulation.

“This was confirmed when male-female pairs were permitted to copulate several times in succession, and the behaviour was highly repeatable. This tells us that copulatory behaviour is a product of male-female interactions, rather than one sex exerting control over the other.”

The findings were published in the journal Royal Society Open Science on Wednesday 22nd February.

A tortoise (almost) never forgets!

Research undertaken by the School of Life Sciences shows that the red-footed tortoise is able remember the location of their favourite food sources along with the biggest stashes of food for at least 18 months! These findings were published this month in the Royal Society journal, Biology Letters. 
Image Credit: Sophie Moszuti.
When animals are making decisions in their environment, it is important that they remember not only the location of key food sources, but also where the best or the most food is likely to be.

The new findings from researchers at the University of Lincoln, UK, suggest these reptiles have an even greater long-term memory than previously thought. Earlier studies have shown that animals do remember the location of food, however, this new research reveals for the first time that they are also able to exercise judgements about quality and quantity and retain this vital information for a long period of time.

Dr Anna Wilkinson, from the School of Life Sciences at the University of Lincoln, says, “Long-term memory is an important characteristic for animals which live for a long time, particularly if they inhabit environments where resources are patchily distributed like forests…a long-term memory enables them to retain information that is crucial for survival, such as the appearance and location of key resources.
“Our study shows us that they can in fact remember visual cues associated with different reward values over a period of at least 18 months, demonstrating a significant memory for different quantities and qualities of food. They are able to remember much more than just the presence or absence of food.”

Dr Libby John, another author of the study, said: “This is an important distinction to make because, in nature, decisions are rarely clear cut so it is helpful to be able to evaluate the relative benefits of different resources.”

As part of the research, red-footed tortoises were trained to associate visual cues (coloured sheets) with specific qualities of food (a preferred mango-flavoured jelly and a less-preferred apple-flavoured jelly) and different quantities. The animals learned which colours were associated with which type and quantity of food, and when they were shown the same cues 18 months later, they remembered their preferences.
The researchers conclude that this long-term memory is likely to impact directly on an animal’s foraging decisions. The retention of this information could also improve fitness, as it would make foraging more efficient by eliminating the need to re-evaluate different food sources during each season and reduce the risk of re-visiting inadequate locations.

This new findings suggest that plants which provide better fruit in terms of quality or quantity may receive more visits in a given season, and may also receive repeat visits in successive fruiting seasons. The research suggests this pattern could also have implications for ecological interactions such as herbivory and the dispersal of seeds.

You can read the full paper online.

New research explores the effect of winter dormancy on cold-blooded cognition

New research explores the effect of winter dormancy in cold-blooded cognition

Unlike mammals, amphibians who rest up during the winter do not forget the memories they made beforehand – this is the surprising discovery of new scientific research.

New research explores the effect of winter dormancy in cold-blooded cognition
New research explores the effect of winter dormancy in cold-blooded cognition
Photo: Johannes Hloch

The new study, published in the journal Scientific Reports, reveals that the processes involved in winter dormancy may have a fundamentally different impact on memory in amphibians and mammals.

Researchers from the University of Lincoln, UK, and two universities in Vienna, Austria, discovered that brumation – the period of winter dormancy that is observed in cold-blooded animals, similar to the process of hibernation in mammals – does not seem to adversely affect the memory of salamanders.

This key finding differs dramatically from previous studies of mammals, which show that hibernation often causes animals to forget some of the memories they formed prior to their period of inactivity.

Dr Anna Wilkinson, from the School of Life Sciences at the University of Lincoln, led the study in collaboration with colleagues from the University of Vienna and the University of Veterinary Medicine Vienna.

Dr Wilkinson said: “Long-term torpor is an adaptive strategy that allows animals to survive harsh winter conditions. However, the impact that this has on cognitive function is poorly understood. We know that in mammals, hibernation causes reduced synaptic activity and can cause them to lose some of the memories they formed prior to hibernation, but the effect of brumation on memory has been unexplored, until now.”

The researchers trained twelve salamanders to navigate a maze and remember the path they needed to take to reach a reward. Half of the animals were then placed into brumation for 100 days, while the other half remained under normal keeping conditions.

A post-brumation memory retention test revealed that animals from both conditions recalled how to navigate the maze.

“We demonstrated that each of the animals solved the task using memory, rather than sensory cues such as smell of the reward, and we’re therefore confident that the period of brumation did not impact on their ability to remember,” Anne Hloch, another author on the paper explained. “For these animals, memory retention is essential for survival as it allows them to recall important information about the environment, such as the location of food and the presence of predators.”

The researchers suggest that the differences in retention observed between mammals and amphibians could be caused by their different learning and memory processes, or the nature of their torpor. Mammals regularly rouse from their hibernation and enter intervals of sleep, whereas cold-blooded animals are dependent on the temperature of their surroundings during brumation and are therefore forced to stay torpid until temperatures rise.

The paper is available to read online.

New research sheds light on why plants change sex

Plants with a particular breeding system change their sex depending on how much light they receive, new scientific research has revealed.

Cranesbill (Pixabay image)

The ability of plants to flower one year as male and the next as female, or vice versa, is well documented in ‘dioecious’ plants, however the causes of this ability to change gender have been largely unexplored in ‘gynodioecious’ plants until now.

Gynodioecy is a breeding system that is found in certain flowering plant species in which female and hermaphroditic plants coexist within a population. Gynodioecy is the evolutionary intermediate stage between hermaphrodite plants (each flower has both male and female parts) and dioecious populations (each plant having either only male or female flowers).

The ability to change sex in response to the environment has been studied extensively in dioecious plants but this new research has revealed that gynodioecious plants also change sex depending on their environment.

The results of a four-year study by researchers at the University of Lincoln, UK, show that the level of light received by the plant has a significant effect on sexual expression and reproductive output. The study found that in habitats with high levels of light, plants were more likely to change their sexual expression, and the researchers believe this is because sex lability (readiness to change) is costly and related to the availability of resources.

Dr Sandra Varga, Marie Curie Research Fellow at the University of Lincoln’s School of Life Sciences, led the research. She explained: “The evolution and maintenance of such sexual polymorphism has been investigated by evolutionary biologists for decades. It is one of the most important developments in the evolution of plant breeding systems. However, understanding the causes and consequences is challenging because so many different factors might be involved in the process of changing from one sex to another.

“Our research clearly showed that sex expression was changeable over the course of the study, and was directly related to light availability.”

Throughout the study, the researchers observed the behaviour of 326 different plants for four years and transplanted them between locations with both high and low light levels to replicate the different environments they may encounter. For example, the wood cranesbill plants used in the study can often be found under dense forest canopies and in meadows and road verges.

The researchers monitored how the sex and reproductive outputs of the plants differed depending on their location, to garner a deeper understanding of how their behaviour is altered by their environment.

The paper is published in the American Journal of Botany and is available to read online.

Students visit South Africa for a Life Sciences field trip

Two students from University of Lincoln’s School of Life Sciences relive their field trip of a life time to South Africa.

 

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Life Science students got the opportunity to visit Mankwe for 10 days to learn more about conservation, wildlife and the environment. The School of Life Sciences field trips aim to give students an understanding of how their classroom work and skills can be applied to real-life conservation. Whilst on the field trip, students undertook identification tests of animals and plant species, with a data collection and essay counting towards 70% of the module.

Two students, Chantell Payton and Charlotte Briddon share their once in a lifetime experience with us. From identifying plants and animal species, to tracking animals and going on anti-poaching patrols, the students were given a first-hand insight into the country’s rhino poaching crisis.

They even got the chance to see a White Rhino up close in the wild, which was an amazing experience they’ll ‘never forget’.

Chantell said: “It was a harrowing experience to hear about their poaching problems with the rhinos, and how they are likely to be extinct in around 10 years. Then to hear about the ethical and political disagreements with legalising the trade of rhino horn and ivory.”

Bioveterinary student Charlotte said: “The most memorable part of the trip for me, was learning about the Rhino Poaching Crisis and the extent to which it affects the lives of the workers there, and knowing that while I was there I helped through the anti-poaching patrols.

“A talk about the poaching crisis was eye-opening, and raised so many questions about educating the public on the medicinal properties of rhino horn, but also about the extent to which poachers will go to obtain the rhino horn.”

Students took a trip to the University of Pretoria where they examined models of animal veins, muscles and nerves in a pathology lab. They also got to look at a range of preserved foetuses for giraffes, canines, monkeys, horses, and many others.

Chantell explained: “We got the chance to look at the clinical veterinary testing they do, ranging from blood labs to viruses. We also got an impressive talk from one of their lecturers who deals with rehabilitation of rhinos that have been poached and have severe wounds on their face from the horn removal, and the types of experimental methods they use to aid the healing and rehabilitation of the rhinos.”

For Bioveterinary Science, the first year module of animal anatomy, and the second year module of animal nutrition, students were taught the theory aspect of the 4 chambered stomach in ruminants. Being able to see an antelope dissection really complimented the course.

Whilst there was a lot of work, you can’t go to South Africa without a safari trip to Pilansberg National Park.

From giraffe, to elephants, crocodiles, cheetah’s and their cubs, to lioness and their pride, students got to see so many animals running free.

Chantell added: “There was one amazing moment in particular when the sun was beginning to set and we were at the watering hole, then a herd of elephants with a calf came from the distance.”

Charlotte said: “Overall it was such a memorable experience, and I’m so glad I got the chance to go to Mankwe reserve, I wish I could go again with the university next year!”