​In a recent blog post I mentioned the research of the Hot Birds Project and the new research into how pied babblers respond to high temperatures that is going on. Amazingly, a new paper which is really relevant to that sort of work has just come out in Science. This research, by Mariette and Buchanan looks at acoustic communication between parents and their offspring in birds. This isn’t the normal adult bird chirping to a chick but communicating to their unhatched offspring. Zebra finches acoustically signal high ambient temperatures (>26°C) to their unhatched embryos, resulting in developmental changes to the offspring. This is brought about solely by using acoustic cues. This type of work is especially exciting because it shows potential coping mechanisms that animals may have for changing climates, it is also an exciting meeting point of parental effects, phenotypic plasticity and climate science. I’ve put the abstract and link to the article at the end of the post.

Link to video to help explain the 'talking to their eggs when hot' paper: http://www.sciencemag.org/news/2016/08/video-zebra-finch-call-prepares-their-eggs-climate-change?utm_source=newsfromscience&utm_medium=facebook-text&utm_campaign=zebrafinch-6739

The other cool paper that has come out recently is work looking at Atlantic canaries and inbreeding. Males who were inbred were worse at singing and females mated less often with inbred males, producing fewer eggs. So for canaries it seems that singing is a honest signal of male genetic quality, adding credence to the ‘good genes’ hypothesis – the idea that male signals are a true representation of their genetic quality and females choose mates for this reason. Work on lizards, mice and lemurs have shown that olfactory cues are linked to genes related to immunity. I love this kind of science, I find it so fascinating. It also has impacts for helping to understand conservation issues with species range and population sizes and how to ensure viable populations. Again, the abstract and link are below.

Mariette & Buchanan (2016) Prenatal acoustic communication programs offspring for high posthatching temperatures in a songbird. Science, 353:812-814
In many species, embryos can perceive and learn external sounds. Yet, the possibility that parents may use these embryonic capacities to alter their offspring’s developmental trajectories has not been considered. Here, we demonstrate that zebra finch parents acoustically signal high ambient temperatures (above 26°C) to their embryos. We show that exposure of embryos to these acoustic cues alone adaptively alters subsequent nestling begging and growth in response to nest temperature and influences individuals’ reproductive success and thermal preferences as adults. These findings have implications for our understanding of maternal effects, phenotypic plasticity, developmental programming, and the adaptation of endothermic species to a warming world.

De Boer et al. (2016) ‘Out of tune’: consequences of inbreeding on bird song. Proc Roy Soc B
The expression of bird song is expected to signal male quality to females. ‘Quality’ is determined by genetic and environmental factors, but, surprisingly, there is very limited evidence if and how genetic aspects of male quality are reflected in song. Here, we manipulated the genetic make-up of canaries (Serinus canaria) via inbreeding, and studied its effects upon song output, complexity, phonetics and, for the first time, song learning. To this end, we created weight-matched inbred and outbred pairs of male fledglings, which were subsequently exposed to the same tutor male during song learning. Inbreeding strongly affected syllable phonetics, but there were little or no effects on other song features. Nonetheless, females discriminated among inbred and outbred males, as they produced heavier clutches when mated with an outbred male. Our study highlights the importance of song phonetics, which has hitherto often been overlooked.

  There are many species that do not just exist with one specific colour pattern. These different colourations are called polymorphisms, existing in a variety of taxa from crabs to lizards to birds. There have been many explanations for the existence of these differences within a species, from protecting against predators to being important for mate choice. There is even a species of lizard, the side-blotched lizard, that exists in three colour morphs that are linked to their behaviour that was famously studied by Barry Sinervo. The orange males are more dominant, the blue males cooperate and the yellow males mimic females. These three morphs live in a state of perpetual flux as none can get the upper hand in the mating game. Basically colour morphs are interesting and we’ve really not touched the surface in understanding the evolutionary mechanisms that lead to and maintain them.

Some really cool studies have been done at the Percy FitzPatrick Institute in Cape Town by Arjun Amar to investigate the two colour morphs of the black sparrowhawk (Accipiter melanoleucus). These majestic birds are either a white or black morph. A new paper has just come out showing that one of the factors that may be keeping these morphs going is the difference in hunting success that they face. Black morphs, unsurprisingly because of their colour, have a higher success in low light levels, while their white breather have the opposite success rates. These success rates tie in with the breeding season of these morphs and may go a long way to explaining the variation in morph distribution across the species South African range. Abstract below:

Tate et al. (2016) Differential foraging success across a light level spectrum explains the maintenance and spatial structure of colour morphs in a polymorphic bird. Ecology Letters
Detectability of different colour morphs under varying light conditions has been proposed as an important driver in the maintenance of colour polymorphism via disruptive selection. To date, no studies have tested whether different morphs have selective advantages under differing light conditions. We tested this hypothesis in the black sparrowhawk, a polymorphic raptor exhibiting a discrete white and dark morph, and found that prey provisioning rates differ between the morphs depending on light condition. Dark morphs delivered more prey in lower light conditions, while white morphs provided more prey in brighter conditions. We found support for the role of breeding season light level in explaining the clinal pattern of variation in morph ratio across the species range throughout South Africa. Our results provide the first empirical evidence supporting the hypothesis that polymorphism in a species, and the spatial structuring of morphs across its distribution, may be driven by differential selective advantage via improved crypsis, under varying light conditions.

These results tie in nicely with previous work that has looked at the ratio of morphs across South Africa. This work found that the Cape peninsula had a very high proportion of black morphs but that this was unlikely to do with a founder effect. More likely it was because of higher rainfall rates during the breeding season, fitting nicely with the recent hunting findings. However, as is often the case in biological systems, hunting and light are not the only potential drivers for polymorphism in this species. It turns out that black morphs have a lower parasite load than white morphs.
 
The great thing about this particular subsection of research on the black sparrowhawk is that it all initially came from the observation that there seemed to be more black morphs in Cape Town than normal. This simple natural history note has spawned a growing number of scientific papers and led to wonderful new insights into evolution. So the next time you notice something when walking about just think that it might be far more interesting than may initially be apparent!

Other black sparrowhawk papers:
 
Amar et al. (2014) Clinal variation in the morph ratio of Black Sparrowhawks Accipiter melanoleucus in South Africa and its correlation with environmental variables. Ibis

Lei et al. (2013) Differential Haemoparasite Intensity between Black Sparrowhawk (Accipiter melanoleucus) Morphs Suggests an Adaptive Function for Polymorphism. PLoS ONE

​I’ve not done this for a while so I thought I’d collate some recent(ish) papers that I found interesting and thought would be good to share. As my interest in mainly family dynamics there is a strong leaning to this in my selection of papers. Below at the names, abstracts and then links to the papers. I hope you enjoy them!!
 
Pilakouta et al. (2015) State-dependent cooperation in burying beetles: parents adjust their contribution towards care based on both their own and their partner's size. JEB, DOI: 10.1111/jeb.12712
Handicapping experiments on species with biparental care show that a focal parent increases its contribution when its partner is handicapped. Such results are interpreted as evidence for negotiation, whereby each parent adjusts its amount of care to that of its partner. However, it is currently unclear whether the focal parent responds to a change in its handicapped partner's behaviour or state. To address this gap, we conducted an experiment on the burying beetle Nicrophorus vespilloides where we first generated different-sized males and females by varying the duration of larval development. We then used a 2 × 2 factorial design in which a small or large male was paired with a small or large female. Small females provided less direct care (food provisioning and interactions with larvae) than large females, and both males and females provided less direct care when paired with a small partner. Thus, the focal parent adjusted its contribution towards care based on both its own state and that of its partner. There was also evidence for negotiation between the two parents as the focal parent adjusted its contribution based on the amount of care by its partner. However, there was no evidence that negotiation accounted for how the focal parent responded to its partner's size. Our results have important implications for our understanding of biparental cooperation as they show that each parent adjusts its contribution not only based on the amount of care provided by its partner but also based on its own state and its partner's state.
LINK
 
Kilner et al. (2015) Parental effects alter the adaptive value of an adult behavioural trait. eLIFE, DOI: http://dx.doi.org/10.7554/eLife.07340
The parents' phenotype, or the environment they create for their young, can have long-lasting effects on their offspring, with profound evolutionary consequences. Yet, virtually no work has considered how such parental effects might change the adaptive value of behavioural traits expressed by offspring upon reaching adulthood. To address this problem, we combined experiments on burying beetles (Nicrophorus vespilloides) with theoretical modelling and focussed on one adult behavioural trait in particular: the supply of parental care. We manipulated the early-life environment and measured the fitness payoffs associated with the supply of parental care when larvae reached maturity. We found that (1) adults that received low levels of care as larvae were less successful at raising larger broods and suffered greater mortality as a result: they were low-quality parents. Furthermore, (2) high-quality males that raised offspring with low-quality females subsequently suffered greater mortality than brothers of equivalent quality, which reared larvae with higher quality females. Our analyses identify three general ways in which parental effects can change the adaptive value of an adult behavioural trait: by influencing the associated fitness benefits and costs; by consequently changing the evolutionary outcome of social interactions; and by modifying the evolutionarily stable expression of behavioural traits that are themselves parental effects.
LINK
 
Gasperin & Kilner (2015) Friend or foe: inter-specific interactions and conflicts of interest within the family. Ecological Entomology, DOI: 10.1111/een.12259
1. Interactions between species can vary from mutually beneficial to evolutionarily neutral to antagonistic, even when the same two species are involved. Similarly, social interactions between members of the same species can lie on a spectrum from conflict to cooperation.
2. The aim of the present study was to investigate whether variation in the two types of social behaviour are interconnected. Is the fitness of the various classes of social partner within species (such as parent and offspring, or male and female) differently affected by interactions with a second species? Moreover, can inter-specific interactions influence the outcome of social interactions within species?
3. The present experiments focus on the interactions between the burying beetle Nicrophorus vespilloides Herbst and the phoretic mitePoecilochirus carabi G. Canestrini & R. Canestrini. The approach was to measure the fitness of burying beetle mothers, fathers, and offspring after reproduction, which took place either in the presence or absence of mites.
4. We found that male, female, and larval burying beetles derive contrasting fitness costs and benefits from their interactions with the mite, despite sharing a common family environment. From the mite's perspective, its relationship with the burying beetle can, therefore, be simultaneously antagonistic, neutral, and possibly even mutualistic, depending on the particular family member involved. We also found that mites can potentially change the outcome of evolutionary conflicts within the family.
5. We conclude that inter-specific interactions can explain some of the variation in social interactions seen within species. It is further suggested that intra-specific interactions might contribute to variation in the outcome of interactions between species.
LINK
 
Kuijper & Johnstone (2015) Parental effects and the evolution of phenotypic memory. JEB, DOI: 10.1111/jeb.12778
Despite growing evidence for nongenetic inheritance, the ecological conditions that favor the evolution of heritable parental or grandparental effects remain poorly understood. Here, we systematically explore the evolution of parental effects in a patch-structured population with locally changing environments. When selection favors the production of a mix of offspring types, this mix differs according to the parental phenotype, implying that parental effects are favored over selection for bet-hedging in which the mixture of offspring phenotypes produced does not depend on the parental phenotype. Positive parental effects (generating a positive correlation between parental and offspring phenotype) are favored in relatively stable habitats and when different types of local environment are roughly equally abundant, and can give rise to long-term parental inheritance of phenotypes. By contrast, unstable habitats can favor negative parental effects (generating a negative correlation between parental and offspring phenotype), and under these circumstances even slight asymmetries in the abundance of local environmental states select for marked asymmetries in transmission fidelity.
LINK
 
Flower et al. (2015) Dual parasitism of Fork-tailed Drongos by African and Jacobin Cuckoos. Ostrich, 86:1-2
Different species of brood parasitic birds, which lay their eggs in the nests of host foster-parents, rarely target the same host species population. We report brood parasitism of Fork-tailed Drongos Dicrurus adsimilis in the southern Kalahari Desert by both African Cuckoo Cuculus gularis and Jacobin Cuckoo Clamator jacobinus serratus. Drongos are the only known host for the African Cuckoo, and were more frequently parasitised by this species (21.8% nests). Nevertheless, parasitism rates suggest that in the Kalahari, drongos are also an important host for Jacobin Cuckoo (4.6% nests). Jacobin Cuckoos likely compete with African Cuckoos for drongo hosts, as exemplified by the occurrence of both African and Jacobin Cuckoo eggs in the same drongo clutch. The drongo's defensive adaptations to parasitism by African Cuckoos, including egg rejection, may also curtail parasitism by Jacobin Cuckoos. The extent of competition between these cuckoo species and whether they possess adaptations to prevent one another's access to drongo hosts remains to be explored.
LINK

One of my friends, Jamie Samson, has just had a paper published and it's pretty cool. He work on Cape ground squirrels, an animal that sends most of its day just calmly searching for food around their large burrows and then occasionally go crazy and have fights that could be scenes from the Matrix. These guys stash food away to save it for later in a behaviour known as caching. What Jamie found was that they pay attention to who is looking when they do it, to avoid being seen. This makes sense, as they can avoid their caches being stolen, but Jamie also found that the dominance rank impacted caching behaviour. Dominant individuals were less concerned with being observed than subordinates. It's cool work that builds on other investigations of caching species like scrub jays.

Samson & Manser (2015) Caching in the presence of competitors: Are Cape ground squirrels (Xerus inauris) sensitive to audience attentiveness? Animal Cognition 
When social animals cache food close to their burrow, the potential for an audience member to observe the event is significantly increased. As a consequence, in order to reduce theft it may be advantageous for animals to be sensitive to certain audience cues, such as whether they are attentive or not to the cache event. In this study, observations were made on three groups of Cape ground squirrels (Xerus inauris) in their natural habitat when they cached provisioned food items. When individuals cached within 10 m of conspecifics, we recorded the attentiveness (i.e. whether any audience members were orientated towards the cacher, had direct line of site and were not engaged in other activities) and identity of audience members. Overall, there was a preference to cache when audience members were inattentive rather than attentive. Additionally, we found rank effects related to cache avoidance whereby high-ranked individuals showed less avoidance to cache when audience members were attentive compared to medium- and low-ranked individuals. We suggest this audience sensitivity may have evolved in response to the difference in competitive ability amongst the ranks in how successful individuals are at winning foraging competitions. This study demonstrates that Cape ground squirrels have the ability to not only monitor the presence or absence of conspecifics but also discriminate individuals on the basis of their attentive state.
LINK

I had the amazing opportunity to go back to the Fitz last week to give a talk and get an award. Somehow I'd managed to get an award for the best PhD thesis submitted to the Science Faculty. The best part was that I got to go back to UCT, give a talk about the babblers and catch up with some friends I've not seen for a while.

So this is a random blog to inform people of the cool work that is being done by people at the Fitz (which is a great place to go and study birds).

Firstly, there were three people (my old office mates) who were away. Susie Cunningham, who is an amazing expert on the bill tip organ of kiwi and how they use it to find food (as well as the bill tip organ of a number of other birds), was away in the UK. Susie is working on the effects of heat on birds, with a view to understanding how climate change will impact bird populations [one of Susie's papers]. Secondly, Susie's PhD student and fellow Kalahari veteran Tanja van de Ven. Tanja is studying the same hornbill population that I helped Mike Finnie set up and looking at temperature effects on these amazing birds, using some cool thermal imaging video! Thirdly, Marie-Sophie Garcia-Heras (a mouthful of a name!) who is doing a PhD investigating factors that influence the movement of black harriers.

But I did get to see some people, and spend some time in the pub (where all serious science is done). Arjun Amar, who is now collaborating with Susie on the red-winged starlings that inhabit the campus, has been really successful with his work on sparrowhawks. Arjun has recently been involved in some slightly controversial but really important work on grouse and bearded vultures. Margaux Rat has just started a post doc with Susie on the Hot Birds Project after finishing her PhD on social weavers. Margaux's PhD was looking at the social interactions of this species that lives in such large complex colonies, she's got some papers in the works so watch this space! I also got to catch up with Chevonne Reynolds, who's just wrapping up her thesis investigating the much maligned Egyptian goose (which I always get told is actually a shell duck!) and she's recently had a paper published in Diversity and Distributions.

So all amazing scientists doing great work. If your interested in any of the stuff they are doing then look them up and I'm sure they'd be happy to speak to you!

The Fitz is a great place to do research and the people are one of the things that makes it.

Just three cool papers that are worth a quick read:

Cunningham et al. (2015) Can behaviour buffer the impacts of climate change on an arid-zone bird? Ostrich 86: 119-126
Behavioural thermoregulation, particularly the use of cool microclimates, is one method by which organisms could avoid the worst effects of climate warming. However, retreat into cool microsites, e.g. shady vegetation or burrows, may carry important lost-opportunity costs. These could include reduced opportunity for foraging, breeding or territorial defence, each carrying implications for fitness. We investigated patterns of microclimate use and foraging behaviour by Southern Fiscals Lanius collaris in the Kalahari. We used Ivlev's electivity index to assess preference of breeding males for perch types with different thermal properties. We found that Southern Fiscals preferred to hunt from high, sunny perches at all times, except on hot afternoons (air temperature >35 °C), when they switched their preference to high, shaded perches. Black-bulb thermometers indicated shaded perches were always cooler than sunny perches, especially on hot afternoons. Therefore, Southern Fiscals could reduce thermoregulatory costs by switching foraging locations. However, Southern Fiscal foraging success rates were highest when hunting from sunny perches, and were reduced by c. 50% when hunting from shaded perches. Our data suggest that Southern Fiscals were making a trade-off on hot afternoons, compromising foraging intake in return for thermal benefits. We discuss potential costs and consequences of this trade-off under climate change. http://www.tandfonline.com/doi/abs/10.2989/00306525.2015.1016469


Westrip & Bell (2015) Breaking down the species boundaries: selective pressures behind interspecific communication in vertebrates. Ethology DOI: 10.1111/eth.12379
Studying heterospecific communication provides an opportunity to examine the dynamics of cross-species social behaviour. It allows us to ask questions about the extent to which the transfer of information is adaptive or accidental and provides an empirically tractable context for manipulating relationships. To date, most studies of heterospecific communication have focussed on receivers. However, the selective pressures on signallers can be as important in determining the dynamics of interspecific communication. Here, we propose a simple framework for thinking about cross-species information transfer, which (i) considers whether information exchange is either accidental or adaptive and (ii) whether it is unidirectional or bidirectional. To clearly classify interactions, it is necessary to quantify all of the payoffs of interspecific communication to both signallers and receivers. This requires accurate characterisation of the currency influenced by cross-species communication (e.g. weight gain, foraging success, survival). However, quantifying the payoffs may be difficult, because each side may be benefiting via different currencies. To date, studies on heterospecific communication have focussed on only one dimension of a niche (usually antipredator or foraging signals). However, because niches are multidimensional, investigations should incorporate multiple aspects of a species’ niche, to get a better perspective on why we see certain patterns of information use between species.
http://onlinelibrary.wiley.com/doi/10.1111/eth.12379/abstract;jsessionid=27595B1F63B33763D53AC2405EBA6067.f03t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false

Flower et al. (2015) Dual parasitism of fork-tailed drongos by African and Jacobin cuckoos. Ostrich 86: 1-2
Different species of brood parasitic birds, which lay their eggs in the nests of host foster-parents, rarely target the same host species population. We report brood parasitism of Fork-tailed Drongos Dicrurus adsimilis in the southern Kalahari Desert by both African Cuckoo Cuculus gularis and Jacobin Cuckoo Clamator jacobinus serratus. Drongos are the only known host for the African Cuckoo, and were more frequently parasitised by this species (21.8% nests). Nevertheless, parasitism rates suggest that in the Kalahari, drongos are also an important host for Jacobin Cuckoo (4.6% nests). Jacobin Cuckoos likely compete with African Cuckoos for drongo hosts, as exemplified by the occurrence of both African and Jacobin Cuckoo eggs in the same drongo clutch. The drongo's defensive adaptations to parasitism by African Cuckoos, including egg rejection, may also curtail parasitism by Jacobin Cuckoos. The extent of competition between these cuckoo species and whether they possess adaptations to prevent one another's access to drongo hosts remains to be explored.

http://www.tandfonline.com/doi/abs/10.2989/00306525.2015.1029032

For charities, maximizing how much money they get donated is probably one of their biggest issues. Without money from generous people a lot of the great charitable works can't be done. So one very interesting question is what effects how much money people give. Step in behavioural ecology and my PhD supervisor Nichola Raihani. She's just published a paper in Current Biology, getting a fair amount of press coverage (Independent and Huffington Post to name a few).

What she and her co-author found was that men's response to donating is effected by two factors: how attractive a female fundraiser is and how much other men have donated. Males actually appear to compete with each other when donating to a 'high quality' (my words) potential mate. Interestingly, and potentially useful for the fundraising sector, females don't compete when donating to attractive male fundraisers. So there seems to be an aspect of sexual competition between males...

All really useful and cool stuff. Plus it's come from the use of a large database, and more studies are likely to come out as big data becomes more available for biologists. I just hope that people don't take this literally and that facebook now doesn't start bombarding me with charity adverts featuring scantily clad women telling me that my male friends have donated £100! This is great research into how humans cooperate and what drives our behaviour when performing seemingly altruistic behaviours.

Raihani & Smith (2015) Competitive helping in online giving. Current Biology, 
Unconditional generosity in humans is a puzzle. One possibility is that individuals benefit from being seen as generous if there is competition for access to partners and if generosity is a costly—and therefore reliable—signal of partner quality [ 1–3 ]. The “competitive helping” hypothesis predicts that people will compete to be the most generous, particularly in the presence of attractive potential partners [ 1 ]. However, this key prediction has not been directly tested. Using data from online fundraising pages, we demonstrate competitive helping in the real world. Donations to fundraising pages are public and made sequentially. Donors can therefore respond to the behavior of previous donors, creating a potential generosity tournament. Our test of the competitive helping hypothesis focuses on the response to large, visible donations. We show that male donors show significantly stronger responses (by donating more) when they are donating to an attractive female fundraiser and responding to a large donation made by another male donor. The responses for this condition are around four times greater than when males give to less-attractive female (or male) fundraisers or when they respond to a large donation made by a female donor. Unlike males, females do not compete in donations when giving to attractive male fundraisers. These data suggest that males use competitive helping displays in the presence of attractive females and suggest a role for sexual selection in explaining unconditional generosity.
http://www.cell.com/current-biology/abstract/S0960-9822(15)00211-0

It's something that every child wonders at some point while splashing around in the bath or at a swimming pool: 'Why are my fingers all wrinkly?' The rest of your skin stays pretty much the same after a prolonged soak but your hands and feet take on prune like characteristics. I always assumed that your hands just absorbed the water and that caused the problem. I formulated this opinion before I knew much about biology and never really scrutinized this idea, which really doesn't stand up to much scrutinization.

But a cool bit of research (abstract below) has found that it's all to do with being able to handle wet objects better.WE have evolved a mechanism for improving how do things in the wet. Water being absorbed into the fingers isn't even a part of this phenomenon, as it's actually driven by the autonomic nervous system.The authors of the paper talk about theories as to why we don't have wrinkled fingers more often but the question I find interesting is why do we have them at all? Surely results like this tell us about our evolutionary past and the environments in which our ancestors lived and foraged. I have no idea if chimps, gorillas or orangutans have this adaptation. If they don't then it suggests it evolved after we diverged from our closest relatives. Ideas about humans foraging along the seashore have been a big part of understanding how humans evolved and spread out of Africa, so maybe this finding a clue to that? 

A lot of this post is speculation, but that's the part of science that drives future areas of research and the joy of think about 'why?' is what I love so much about science.

Abstract:


Kareklas et al. (2013) Water-induced finger wrinkles improve handling of wet objects. Biology Letters 
DOI: 10.1098/rsbl.2012.0999
Upon continued submersion in water, the glabrous skin on human hands and feet forms wrinkles. The formation of these wrinkles is known to be an active process, controlled by the autonomic nervous system. Such an active control suggests that these wrinkles may have an important function, but this function has not been clear. In this study, we show that submerged objects are handled more quickly with wrinkled fingers than with unwrinkled fingers, whereas wrinkles make no difference to manipulating dry objects. These findings support the hypothesis that water-induced finger wrinkles improve handling submerged objects and suggest that they may be an adaptation for handling objects in wet conditions.
http://rsbl.royalsocietypublishing.org/content/9/2/20120999

One of my old colleagues, who's just finishing up his PhD has just had a paper published. James Westrip, supervised by Matt Bell, is working on interspecific communication through the pied babblers. Here's the abstract for the paper and a link to it:


Bell & Westrip (2015) Breaking down the Species Boundaries: Selective Pressures behind Interspecific Communication in Vertebrates. Ethology, DOI: 10.1111/eth.12379

Studying heterospecific communication provides an opportunity to examine the dynamics of cross-species social behaviour. It allows us to ask questions about the extent to which the transfer of information is adaptive or accidental and provides an empirically tractable context for manipulating relationships. To date, most studies of heterospecific communication have focussed on receivers. However, the selective pressures on signallers can be as important in determining the dynamics of interspecific communication. Here, we propose a simple framework for thinking about cross-species information transfer, which (i) considers whether information exchange is either accidental or adaptive and (ii) whether it is unidirectional or bidirectional. To clearly classify interactions, it is necessary to quantify all of the payoffs of interspecific communication to both signallers and receivers. This requires accurate characterisation of the currency influenced by cross-species communication (e.g. weight gain, foraging success, survival). However, quantifying the payoffs may be difficult, because each side may be benefiting via different currencies. To date, studies on heterospecific communication have focussed on only one dimension of a niche (usually antipredator or foraging signals). However, because niches are multidimensional, investigations should incorporate multiple aspects of a species’ niche, to get a better perspective on why we see certain patterns of information use between species.


http://onlinelibrary.wiley.com/doi/10.1111/eth.12379/abstract

Just a collection of random papers, theme issues and a blog that I thought looked pretty cool and that some people might find interesting.

First up, a paper about sexual conflict in a hemaphroditic species, plus it involves love darts! Snails have a really interesting mating system and this paper looks into how the costly behaviour of having love darts leads to conflict, sexual arms race and diversification of morphologies.

Kiruma & Chiba (2015) The direct cost of traumatic secretion transfer in hermaphroditic land snails: individuals stabbed with a love dart decrease lifetime fecundity. Proc R Soc B
http://rspb.royalsocietypublishing.org/content/282/1804/20143063

Next up, a themed issue on the biological impacts of artificial light, put together by Gaston, Visser and Holker. Its in Philosophical Transactions and my favourite paper in it is by Dominoni & Partecke called 
"Does light pollution alter daylength? A test using light loggers on free-rannging European blackbirds (Turdus merula)"
http://rstb.royalsocietypublishing.org/content/370/1667.toc

A paper about duetting in wrens. Using playbacks the authors show that females preferentially sing duets with mates to ward off intruders over singing overlapping songs with the 'intruding' female - which they do in the absence of their mate singing.


Templeton et al. (2015) Female happy wrens select songs to cooperate with their mates rather than confront intruders. Proc R Soc B
http://rsbl.royalsocietypublishing.org/content/9/1/20120863


Vocal duetting occurs in many taxa, but its function remains much-debated. Like species in which only one sex sings, duetting birds can use their song repertoires to signal aggression by singing song types that match those of territorial intruders. However, when pairs do not share specific combinations of songs (duet codes), individuals must choose to signal aggression by matching the same-sex rival, or commitment by replying appropriately to their mate. Here, we examined the song types used by female happy wrens (Pheugopedius felix) forced to make this decision in a playback experiment. We temporarily removed the male from the territory and then played songs from two loudspeakers to simulate an intruding female and the removed mate's response, using song types that the pair possessed but did not naturally combine into duets. Females were aggressive towards the female playback speaker, approaching it and overlapping the female playback songs, but nevertheless replied appropriately to their mate's songs instead of type matching the intruding female. This study indicates that females use song overlapping to signal aggression but use their vocal repertoires to create pair-specific duet codes with their mates, suggesting that duetting functions primarily to demonstrate pair commitment.



Lastly, a nice blog about sex ratios in bumble bees. Eusocial hymenoptera are fascinating, they have enthralled scientist for generations. Because of the asymmetric relatedness caused by haplodiploidy the conflicts and cooperation within these societies provide so many avenues for investigation and manipulation.


A little snippet from the blog: "Analysing my data I realised there were two types of colonies: those that quickly started to produce sexual individuals, and others that took much longer. The former invested much more in male production, whereas the latter mainly produced new queens. Hence, it appeared colonies adopted different strategies, and I hypothesised that both strategies could be equally successful, provided a population contains both."


https://blogs.royalsociety.org/publishing/sex-ratios-in-bumblebees-and-an-influential-experience/?utm_source=social_media&utm_medium=hootsuite&utm_campaign=standard--