New Journal of Zoology Podcast

9 04 2014

Journal of Zoology PodcastA new episode of the Journal of Zoology podcast is now available and you can listen to it here.

In this episode, David Hone tells us how the behaviour of extinct animals like dinosaurs can be deduced from the fossil record, we learn from Tomasz Wesolowski about parasites that manipulate the behaviour of their hosts for their own advantage, and Gus Mills talks to us about their new findings on cheetah cub mortality and how they affect conservation planning for cheetahs.

You may subscribe in iTunes to receive the latest Journal of Zoology podcasts.

Elina Rantanen

Hidden Gem

6 03 2014

The Experimental Proof of the Protective Value of Colour and Markings in Insects in reference to their Vertebrate Enemies

This ‘hidden gem’ from 1887 published in the Proceedings of the Zoological Society of London, the predecessor of Journal of Zoology, is an article written by E.B. Poulton about aposematism before he actually introduced the term in his book The Colours of Animals, published in 1890. It is essentially a review article summarising, comparing and discussing the existing data from various experiments testing Alfred Russel Wallace’s original idea of the use of warning colours in prey to put off predators from attacking them.

The article begins with a brief history of the idea, originating from correspondence between Darwin and Wallace. Puzzled by bright, conspicuous colours in caterpillars which could not possibly be explained by sexual selection, Darwin asked Wallace to suggest some other explanation and adaptive value for these bright colours. Wallace proposed that, as Poulton put it, ‘the gaudy colouring acts as an indication of something unpleasant about its possessor’, such as a nauseous taste or smell, and it would thus be to the advantage of the prey to be as conspicuous as possible to warn experienced predators of their foul qualities. Wallace’s idea had subsequently been tested and proven plausible. However, in this paper, Poulton points out that ‘the acquisition of an unpleasant taste or smell, together with a conspicuous appearance, is so simple a mode of protection, and yet ex hypothesi so absolutely complete, that it seems remarkable that more species have not availed themselves of this means of defence. What can be the principle which works in antagonism to such a mode of protection?’ As one explanation, Poulton proposes that this strategy would become less effective the more common it becomes among the prey, as predators might then start eating the foul-tasting prey if they would otherwise starve. It was indeed Poulton who introduced the idea of frequency-dependent selection in his later work, but he was clearly already contemplating this idea when he wrote this article.

This paper acts as a wonderful summary of the development of the theory of aposematism and is teeming with references to Wallace and Darwin as well as other famous names such as Bates and Müller regarding their respective theories on mimicry. It is available for free in our ‘Hidden Gems’ section of the Journal of Zoology website.

Elina Rantanen

Author Spotlight – Matt W. Hayward

27 01 2014

Matt HaywardPrey preferences of the lion (Panthera leo)

Matt W. Hayward & Graham I. H. Kerley, Journal of Zoology, 2006, vol. 267, pp. 309-322

Many years ago I moved to South Africa’s Addo Elephant National Park to conduct a post doc on the reintroduction of lions, leopards and spotted hyaenas there. The regional manager for SAN Parks was concerned that the lions would target valuable buffalo and posed a simple question to me – “What are they going to eat?”  I set about answering that question (and this video presents how I did that). Myself and collaborators at the Nelson Mandela Metropolitan University identified the preferred prey of lions and then extended this work to predict and test their diet at other sites. We then found that there was a tight relationship between the biomass of the preferred prey of lions and the density of lions themselves and there is a negative relationship between lion home range size and preferred prey biomass.  This information has been invaluable to conservation managers as they can now predict the diet, home range and carrying capacity of their large predator guild based on the suite of prey present at a site.

Since then, we have expanded this work to look at the rest of the African large predator guild, Eurasian predators and are now working on the prey preferences of American and Australian predators.  We now hold a database of prey preferences based on over 100,000 kills and we will use this to test various hypotheses relating to optimal foraging theory, mesopredator release and the impacts of invasive predators.  It’s an exciting time, but worth pointing out that this research is based on a plethora of natural history style studies and the demise of natural history makes the kind of meta-analysis that we are conducting very difficult in the future.  The publishing paradigm of only valuing high impact papers is not of particular benefit to practical biodiversity conservation.

Matt W. Hayward

New Journal of Zoology Podcast

17 12 2013

JZO Podcast Autumn 2013A new episode of the Journal of Zoology podcast is now online and you can listen to it here.

In this episode, Sara Helms Cahan talks to us about reproductive division of labour in eusocial species and how it emerged spontaneously in harvester ant queens in their lab experiment, we learn from Rudemar Ernesto Blanco how the ecology of extinct sabretooth predators could be deduced from their living analogue such as the southern short-tailed opossum, and Justin Carroll tells us about their field experiment comparing the effectiveness of two contrasting anti-predator strategies, crypsis and aposematism, using artificial prey.

You may subscribe in iTunes to automatically receive the latest Journal of Zoology podcasts.

By Elina Rantanen

Recently published in the Journal

10 12 2013

Cheetah cub survival revisited: A re-evaluation of the role of predation, especially by lions, and implications for conservation

It is widely held that cheetahs are prone to high cub mortality rates, mainly due to predation by lions.  This perception resulted from a landmark study on the Serengeti Plains, which found that only 4.8% of cheetah cubs survived, indicating that areas where large carnivores need to co-exist may not be suitable for cheetah conservation.  However, a recent study by Michael G.L. Mills and Margaret E.J. Mills, published in Journal of Zoology, has revealed that survival of cheetah cubs in the Kgalagadi Transfrontier Park was seven times higher than on the Serengeti Plains.  Although predation was the most common form of mortality, there was no evidence of lion predation, indicating that a range of other predators could also be involved.  Moreover, the authors suggest that scrutiny of the Serengeti data does not unequivocally prove the dominance of lions as predators of cheetah cubs there, and conclude that predation is an integral part of cheetah dynamics.

copyright Gus Mills

copyright Gus Mills

Importantly, the paper challenges the belief that cheetah cub mortality is always inordinately high, and that lions are their major predator.  The results suggest that cheetahs can potentially coexist successfully in protected areas with other large carnivores.  This paper sheds new light on ecological relations in carnivore community ecology that could influence long-term conservation planning for cheetahs.

Linda DaVolls

Zoology in the News

10 10 2013

Moon jellyfish. Credit: Gilles San Martin

This post highlights zoology-related articles which have featured recently in the news.

Jellyfish are the most efficient swimmers of all animals, a study published in Proceedings of the National Academy of Sciences has found, as they spend the least amount of energy per mass to swim a certain distance than any other swimming animal. The study discovered that moon jellyfish use a spinning vortex of water created by each of their swimming ‘stroke’ to give them an extra push that spends no extra energy. This energy-saving technique could be useful when designing energy-efficient underwater vehicles. You can read the news story in Nature News and NewScientist.

Social networking is affected by personality in great tits, a paper published in Ecology Letters suggests. The researchers were able to track individual wild birds and their associations with one another by using unique PIT tags on them as identifiers. The study found that males that were deemed “shy” in a personality experiment appeared to have fewer but more stable and longer-lasting associations with other birds than “bold” males. Shy males also tend to associate with other shy males rather than with bold males, possibly because bold males are also more aggressive. You can read the news article in BBC Nature News.

Insects change their mating behaviour in anticipation of bad weather, according to a paper recently published in PLOS ONE. The researchers found that males of the curcurbit beetle, the true armyworm moth and the potato aphid showed a decreased response to female pheromones under conditions of falling air pressure compared to stable or increasing pressure, and the majority of the males also started copulating faster when air pressure was dropping. As such conditions are associated with heavy rains and strong winds which could cause injury or even death, these insects appear to be making their own weather forecasts based on changes in barometric pressure and adjusting their behaviour accordingly. You can read the news article in ScienceDaily.

Scientists have proved for the first time that alpine swifts can spend as long as six months at a time airborne, according to a paper published in Nature Communications. This was shown by data from 1.5-g data loggers attached to three alpine swifts in Switzerland before the birds migrated to Africa for the winter, and the data-loggers were recovered when the birds returned the following year, having recorded data on the birds’ acceleration and geographic location. The swifts were apparently able to feed and even sleep while airborne. You can read the news in NewScientist.

By Elina Rantanen

New Journal of Zoology Podcast

7 08 2013

Journal of Zoology podcastThe summer 2013 episode of the Journal of Zoology podcast is now online and you can listen to it here.

In this episode, Neville Pillay talks to us about group living in the African ice rat and how this animal is unusually fickle in its behaviour towards fellow colony members, and we will learn from Fiona Cross what ‘aggressive mimicry’ is and how it could help us better understand the animal mind. Moreover, we will hear from Nicolas  Hanuise about how king penguins optimize their diving behaviour for efficient foraging, and Aurore Avarguès-Weber tells us about social learning and how animals obtain useful information from each other even when they are members of different species.

You may subscribe in iTunes to automatically receive the latest Journal of Zoology podcasts.

By Elina Rantanen


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