Dr Soulsbury’s research featured at NHM symposium

On the 11th and 12th of November 2017 London’s Natural History Museum hosted HumaNature, a co-sponsored conference between World Extreme Medicine (WEM), the Society for Experimental Biology, brought together experts in the fields of medicine and animal physiology. Our School’s Senior Lecturer, Dr Carl Soulsbury, delivered a talk about his extensive research. 

The symposium was established by WEM’s founder Mark Hannaford and Prof. Craig Franklin- Deputy Head of the School of Biological Sciences / Executive Director of Research Ethics, University of Queensland. The 2 day event provided an opportunity for attendees to share research, best practice and techniques between the worlds of human and animal medicine.

A summary of Dr Soulsbury’s talk can be found below.

Exercising to the limit (and more) in birds

Many organisms carry out exercise as part of their daily lives, be it through behaviours such as finding food, reproducing or avoiding predators. In birds, many species carry out impressive physical feats such as long distance migration, flying at high altitudes, through to intense, energetically expensive mating displays. Exercise can be viewed both in terms of its intensity and its duration. It is the combination of these that determines how physiologically stressful exercise is. In this talk, I compare the relative contribution of duration and intensity of exercise as determinants of exercise’s costs, and how this in turn impacts individual ageing. Using systems where the amount of intensive exercise pushes individuals to their physiological limits, I demonstrate its negative effect on individual physiology and survival. By using comparisons found in nature, it can provide critical insights into the effects of intense and extreme exercise on the human body.

A podcast featuring a selection of the speakers, including Dr Soulsbury, can be found online (credit to Ben Cattaneo of ‘Allthingsrisk’).

 

Touchscreen test reveals new findings on intelligence of birds

 

Birds such as parrots and crows have been using touchscreen technology as part of an international research study examining whether the ways in which animals respond to new things influences how eager they are to explore.
The new research, involving scientists from across Europe, looks at how a number of factors affect the speed and frequency with which the birds investigate new objects that they have never seen before.The study was carried out by researchers from the Messerli Research Institute (University of Veterinary Medicine Vienna) and the University of Vienna in Austria, the Max Planck Institute for Ornithology in Germany and University of Lincoln, UK.It has generally been assumed that neophobic species (species that do not like new things) have a tendency to explore less than those that do (referred to as neophilic). For example, kea parrots in New Zealand have been known to destroy cars because they are so interested in new things.The research results reveal that the neotic style of a bird (how neophobic or neophilic an animal is) has an impact on when they choose to explore new objects, but not on their level of exploration. Those who are more neophobic carry out the same amount of exploration, but simply make the approach much later. The results also show that juvenile animals explore more quickly than adults do.

Significantly, the scientists found that individual differences and characteristics seem to be much more important than species-level differences in determining how eager a bird is to explore. This suggests that neotic style is not, as is frequently assumed, a result of the challenges faced by an entire species, but instead appears to differ depending on the individual bird.

As part of the investigation, the parrots and crows were introduced to a touchscreen which revealed two different coloured shapes on a regular basis, and they were trained to understand that choosing one of the shapes (by pecking it) could result in a food reward. The researchers showed each bird 16 pairs of shapes, and throughout the task introduced a few novel stimuli that they had never seen before. The researchers measured how quickly they responded to the new shapes, and at which point in the test they chose to investigate them.

A video of Sven the Eclectus parrot working the touchscreen is available to view on YouTube.

Dr Anna Wilkinson, a specialist in animal cognition from the School of Life Sciences at the University of Lincoln, explained: “Rather than its species, we found that individual differences have a significant impact upon how quickly a bird begins to explore. This is likely to be due to a combination of the bird’s age, its individual position in the social hierarchy, and its own previous experiences.”

The birds that featured in the study were from nine different species of parrots and corvids – also known as the crow family. They were selected to represent different ecological backgrounds so that factors such as the likelihood of pressure from predators could also be taken into account. For example, species originating from islands such as Goffin’s cockatoos and vasa parrots are less likely to face pressure from predators than those such as ravens, jackdaws and African grey parrots, which are much more widely distributed.

As part of the study, researchers worked with Eclectus parrots from the Lincolnshire Wildlife Park to assess their reactions.

The first author of the study, Dr Mark O’Hara from the Messerli Research Institute and the University of Vienna, said: “Our findings allow for a more accurate interpretation of behaviour and the processes which control responses to changes in the environment.”

The full paper, The temporal dependence of exploration on noetic style in birds, is published in Scientific Reports and is available to read online.

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How the shape of eggs may explain evolutionary history of birds

The eggs of amniotes – mammals, reptiles and birds – come in a remarkable variety of shapes and sizes.

Evolutionary biologists have now addressed shape variety in terrestrial vertebrates’ eggs, pinpointing morphological differences between the eggs of birds and those of their extinct relatives, the theropod dinosaurs.

Researchers from the University of Lincoln, UK, examined eggshell geometry from the transition of theropods – a sub-order of the Saurischian dinosaurs – into birds, based on fossil records and studies of their living species.

The results suggest that the early birds from the Mesozoic (252 to 66 million years’ ago) laid eggs that had different shapes to those of modern birds. This may suggest that egg physiology and embryonic development was different in the earliest birds and so this may have implications for how some birds survived the Cretaceous-Palaeocene extinction event that wiped out the dinosaurs.

Their findings are published in the journal Royal Society Open Science.

Author Dr Charles Deeming, from Lincoln’s School of Life Sciences, explained: “These results indicate that egg shape can be used to distinguish between different types of egg-laying vertebrates. More importantly they suggest Mesozoic bird eggs differ significantly from modern day bird eggs, but more recently extinct Cenozoic birds do not. This suggests that the range of egg shapes in modern birds had already been attained in the Cenozoic.”

The origin of the amniotic egg (an egg which can survive out of water) is one of the key adaptations underpinning vertebrates’ transition from sea to land more than 300 million years ago. Modern amniotic eggs vary considerably in shape and size and it is believed this variety may reflect the different patterns of egg formation and development in these taxa.

Dr Deeming added: “From a biological perspective, it is self-evident that different egg shapes by birds, both past and present, might be associated with different nesting behaviours or incubation methods. However, hardly any research has been carried out on this topic and fossil data are insufficient to draw firm conclusions. We hope that future discoveries of associated fossil eggs and skeletons will help refine the general conclusions of this work.”

Dr Deeming and co-author Dr Marcello Ruta, also from the University of Lincoln, are now investigating how the highly variable amounts of yolk and albumen (egg white) in eggs of different species could be a possible determinant of bird egg shape.

D. Charles Deeming and Marcello Ruta ‘Egg shape changes at the theropod-bird transition, and a morphometric study of amniote eggs’ Royal Society Open Science
DOI: 10.1098/rsos.140311

 

Antioxidants are essential for bird embryo growth

As children we are told the importance of eating plenty of fruit and vegetables, but now scientists have confirmed that antioxidants found in these food groups are essential for the growth of bird embryos.

Research, published in Biology Letters, has confirmed that growth rates in bird embryos are linked to the amount of antioxidants present in the yolk. Dr Charles Deeming and Dr Tom Pike, from the School of Life Sciences, University of Lincoln, UK, investigated the link between the amount of antioxidants in various species of bird egg yolk and the rate of development of the embryos within the egg.

Dr Deeming said: “We are always told to eat fresh vegetables to give us a range of antioxidants, and not eating enough of these has a damaging effect on your health. Developing embryos also need antioxidants to keep them healthy, and the faster they grow the more they need. A bird has to go to a lot of effort to put antioxidants in the eggs it lays, but there has been on going debate about how useful they actually are.”

Antioxidants have the power to protect people from disease and slow the aging process, as they fight the free radicals in the body that can harm cells. If antioxidant levels are low, oxidative stress can occur, increasing susceptibility to many illnesses including heart disease and cancer. Therefore, in order to keep healthy and maintain strong immune systems, we are advised to consume foods containing an abundance of antioxidants such as vitamin C and beta-carotene on a daily basis.

Dr Deeming explained how antioxidants in egg yolk are vital in preventing damage to developing bird embryos from free radicals.

“Oxygen is very important for life, but it can also cause problems,” said Dr Deeming. “During normal metabolism it is one source of free radicals, which cause damage to cells. Fast-growing embryos have high metabolic rates, and so we predicted they would also need high levels of antioxidants to effectively neutralise these damaging molecules. Using data from a large number of bird species, we showed that fast growing embryos do indeed have higher antioxidant levels in their eggs compared with eggs containing slower growing embryos.”

While this work highlights the importance of antioxidants for the healthy development of bird embryos, it may have implications for the embryos of other species too, including humans.

Reference: Deeming DC, Pike TW. 2013 Embryonic growth and antioxidant provision in avian eggs Biology Letters 20130757. http://dx.doi.org/10.1098/rsbl.2013.0757

Mum and dad dinosaurs shared the work

Research into the incubation behaviour of birds suggests the type of parental care carried out by their long extinct ancestors.

The study aimed to test the hypothesis that data from extant birds could be used to predict the incubation behaviour of Theropods, the group of carnivorous dinosaurs from which birds descended.

The paper, out today in Biology Letters, was co-authored by Dr Charles Deeming and Dr Marcello Ruta from the University of Lincoln’s School of Life Sciences and Dr Geoff Birchard from George Mason University, Virginia.

By taking into account factors known to affect egg and clutch size in living bird species, the authors – who started their investigation last summer at the University of Lincoln’s Riseholme campus – found that shared incubation was the ancestral incubation behaviour. Previously it had been claimed that only male Theropod dinosaurs incubated the eggs.

Dr Deeming said: “In 2009 a study in the journal Science suggested that it was males of the small carnivorous dinosaurs Troodon and Oviraptor that incubated their eggs. Irrespective of whether you accept the idea of Theropod dinosaurs sitting on eggs like birds or not, the analysis raised some concerns that we wanted to address. We decided to repeat the study with a larger data set and a better understanding of bird biology because other palaeontologists were starting to use the original results in Science in order to predict the incubation behaviour of other dinosaur species. Our analysis of the relationship between female body mass and clutch mass was interesting in its own right but also showed that it was not possible to conclude anything about incubation in extinct distant relatives of the birds.”

Palaeobiologist Dr Ruta was involved in mapping the parental behaviour in modern birds on to an evolutionary tree.

Dr Ruta said: “As always in any study involving fossils, knowledge of extant organisms helps us make inferences about fossils. Fossils have a unique role in shaping our knowledge of the Tree of Life and the dynamics of evolutionary processes. However, as is the case with our study, data from living organisms may augment and refine the potential of fossil studies and may shift existing notions of the biology and behaviour of long extinct creatures.”

Dr Birchard added: “The previous study was carried out to infer the type of parental care in dinosaurs that are closely related to birds. That study proposed that paternal care was present in these dinosaurs and this form of care was the ancestral condition for birds. Our new analysis based on three times as many species as in the previous study indicates that parental care cannot be inferred from simple analyses of the relationship of body size to shapeanatomyphysiology and behaviour. Such analyses ought to take into account factors such as shared evolutionary history and maturity at hatching. However, our data does suggest that the dinosaurs used in the previous study were likely to be quite mature at birth.”

The project has helped in understanding the factors affecting the evolution of incubation in birds. More importantly it is hoped that the new analysis will assist palaeontologists in their interpretation of future finds of dinosaur reproduction in the fossil record.