I’ve just returned from a fun but fairly hectic trip to the Kalahari. This chance came about because there is a new PhD student starting on the pied babblers but no one was available to train her. So, on a plane I hopped and met up with Amanda Bourne. She’s going to be looking at climate effects on the babblers and be part of the Hot Birds Project. Her work is going to be a mix of: physiology, trying to understand the metabolic costs; behavioural, working out if temperature impacts on social and group cohesive behaviours – trying to see if sociality may act as a buffer to high temperatures; and investigating cumulative impacts of high temperature on groups and individuals. All this is really cool, interesting, and (pardon the pun) hot stuff. She is following on from other hot birds work at the Kuruman River Reserve: van de Ven et al. 2016 found that hornbills can regulate blood flow to their beaks to regulate their temperature without evaporative heat loss; du Plessis et al. 2012 found that increasing temperature caused a decrease in the foraging success of pied babblers, with birds displaying heat dissipation behaviour while foraging. She’ll also be able to build on some recent babbler work by Lizzie Wiley who found that adults provisioned nestlings much less on hot days, resulting in decreased nestling growth (Wiley & Ridley 2016).
 
So why was I there? Well the babblers are a bird with lots of complex behaviours, fairly defined territories and the project has specific protocols to maintain consistent data collection over its 13 year history. The privilege fell to me to basically walk around and look at birds for 10 days solid, life is so hard! But in all seriousness, the study population consists of wild birds who have been habituated to close human presence and without knowing how to act around them it is possible to dehabituate them very quickly and see your PhD data quickly fly away. I was also able to help Amanda figure out potential research questions and experiments that she wouldn’t have been able to think of without seeing how they behave.
 
Before heading off I was anticipating a fairly dull period in the field: its winter, they’re hungry and so they just forage and fly about between the distant patches of low density prey. How wrong I was. This has been a very odd year in the Kalahari, late summer rain in April and a mild winter led to a bumper abundance of food. When food is not a problem the babblers, and all of the other Kalahari animals for that matter, get it on and babies are the result. We arrived to find multiple groups with fledglings, and so the veldt was alive with the begging of babblers – music to my ears. Following these groups of babblers where the scimitar bills taking advantage of babbler sentinels and the ubiquitous drongos. We found groups like Centaurus (pictured below) incubating and even observed some egg eating in a group with females who were competing for reproduction. Whilst other groups were having large aerial battles with their neighbours. Amanda was privileged to observe a dispersal event, the dominant female of Vivaldi was fed up with her light weight male and decided to fly across to join the much heavier male of neighbouring group Noleg, even though at one point she flew back to join her old group for a fight against another group before quickly remembering that she’d left.
 
Whilst looking for groups, and teaching Amanda the babbler whistle (an ululating call to get the birds to fly to you) and group territories, we came across wild groups and individuals who had dispersed from the study population (one may have last been seen in the population in 2004!! – although confirmation is still needed). One of these wild groups was right in the middle of the reserve and feeding a nest, so they’ve been named (Martu- pronounced Mardu – after the aboriginal people of the Western Deserts of Australia) and habituation may start in September when Amanda gets back. 

Amanda’s boyfriend, plant biologist and restoration ecologist extraordinaire, Todd Erickson also came along. He was able to use my camera a lot more than I was, and many of the pictures on the blog post were taken by him. Todd’s botanical leanings allowed me to see the veldt in a new way, paying attention to the small succulents, grasses and flowers that had flourished because of the late rains. The Kalahari was filled with colour, majestic in its flora. This colour had been included in the babbler nests, with many of them decorated with the lovely yellow flowers that littered the landscape. Todd’s insights about how dunes actually hold water better than the slacks, meaning that larger trees and shrubs can grow there, blew my mind and made me look at the landscape in a completely new way. This is why I love science, there are so many disciplines and you can always learn something new that changes your world view.
 
I’ve written mostly about the babblers, and that’s because they are awesome, but there are many other projects at the KRR. There is the over 20 year study of meerkats, who have had a terrible year: prior to the late rains it had been a drought and their groups had been decimated by the combined disasters of no recruitment and TB, but they had started to breed in the winter. The Cape Ground Squirrel Project, started by my friend Jamie Samson, is still going strong and again they have had loads of strange winter pups. And for those of you who want to fly to South Africa, travel for hours to the remote Kalahari and then spend most of your time indoors there are always the molerats to work on. That might sound a bit negative but I like being outside and observing animals behaving in their natural habitat and the idea of spending all day under florescent lights (something you can do in an office) in a building that smells of pee (something you get in public toilets) isn’t something that appeals to me. The other cool birds that are studied at the KRR are the hornbills (mentioned above) and the drongos – who spend their time either stealing food from other animals with their vocal mimicry, catching flying insects with ease using their aerial acrobatics or just pissing off large raptors by bomb diving them.

It was very special to go back to the Kalahari, a place that I have spent a lot of time. Seeing the babblers again, watching them play in shepherd’s trees, feed their fledglings or just have them hop on my feet as I weighed them was very special. I also found out that part of my hippocampus is forever engraved with a map of the reserve: I could still walk straight to ladders hidden behind bushes, find trees that had been used as nests in the past and always point to Whiskers Crossing. Part of me will always be in the Kalahari, and no view will ever be as beautiful as the sun setting over the dunes or a time as peaceful as dawn in the veldt.

So if you’ve read some of my previous blogs or follow me on Twitter (@alex_babbler), then you’ll probably be aware that some of my PhD research was recently shown as part of the BBC 2 documentary series World’s Sneakiest Animals. So I’m sorry if it feels like over kill to write about this again, but hey it’s not every day that your work appears on TV, let alone a BBC doco! Plus it will probably be the last time, so I’ll milk it for all I can!
 
But this post isn’t really just about my work; it’s about the other cool studies shown on camera. The thing that surprised me the most about the most about this series was the amount of the research that I had either seen presented at conferences or had been done by scientists that I personally know or that I had helped out with. This just goes to show how small a world the behavioural ecology field is, but also how many exciting young scientist there are currently picking apart the natural world (as all of the below research is by young academics). So below I will put a brief description of what is shown on the TV show, a comment on how I knew about it and then a link to the research (as it’s always far more exciting than the 5-10 mins of footage you’ll see on screen).
 
Firstly, the mimetic orchid mantis, whose mimicry is good that they actually attract more pollinators to them than the flowers they are mimicking. This work was done by James O’Hanlon, and I first saw it presented at ISBE in Lund 2012. He’s a great speaker, as shown by this YouTube video: LINK. Because the mantis is larger than and appears brighter than (to the insects they are predating on) than the flowers they are mimicking then they are a supernormal stimulus. It’s just a really cool bit of nature and very elegant research.
 
It appears at 4:09 in Episode 2 (The Hunger Game).
 
http://www.jstor.org/stable/10.1086/673858?seq=1#page_scan_tab_contents
http://www.jstor.org/stable/10.1086/673858?seq=1#page_scan_tab_contents
 
Secondly, drongos stealing food from unsuspecting host species. This bit of storytelling was really a combination of a couple of papers. The first is a paper that I helped with and whose first author is Bruce Baigrie, investigated how drongos use sentinel calls to manipulate sociable weavers in a fascinating mutualism. The second paper and third papers, by Tom Flower, delves into the mimetic alarm calls that drongos use to steal food from their host species. Every time the drongos have appeared on TV it has always been with them shown as stealing food from meerkats, but the species that they hammer the most are the sociable weavers and then possibly the pied babblers. In fact, much of the early work was done looking at the dynamics of how drongos and babblers interacted.
 
It appears at 49:12 in Episode 2 (The Hunger Game).
 
http://rspb.royalsocietypublishing.org/content/281/1791/20141232.short
http://rspb.royalsocietypublishing.org/content/278/1711/1548.short
https://scholar.google.co.uk/citations?view_op=view_citation&hl=en&user=W6TB-BUAAAAJ&citation_for_view=W6TB-BUAAAAJ:ufrVoPGSRksC
 
Thirdly, the show describes how honeyguides parasitise other species to have them raise their own offspring. This is based on the work of Claire Spottiswoode, an amazing field researcher who splits her time between Cambridge, Cape Town and Zambia. Honeyguides lay their eggs in the underground nests of bee-eaters and when their young hatch they hatch early and then grow a sharp hook at the end of their beak that they use to kill their unrelated brood mates - very deadly. By doing this they can monopolise the provisioning of their host offspring. This section of the show also goes into the natural history of cuckoos, and who is a better expert on the subject than Nick Davies. So for the cuckoos I will recommend a great book that goes through not only Prof Davies’ work but that of his forbears and contemporaries.
 
It appears at 43:47 in Episode 3 (Sex, Lies and Dirty Tricks).
 
http://rsbl.royalsocietypublishing.org/content/early/2011/09/06/rsbl.2011.0739.short
http://beheco.oxfordjournals.org/content/18/4/792.short
Cuckoo: Cheating by Nature – Nick Davies
 
Lastly, as it was actually the final part of the series, my work on fledgling provisioning in pied babblers. My work shows that young fledgling babblers, who are amazingly incompetent fliers who are very slow to respond to alarm calls can get fed up to 9 times as much food by moving to areas of danger when predators have been spotted in the local environment. Adults feed the chicks to shut them up and move them to safety.
 
It appears at 51:46 in Episode 3 (Sex, Lies and Dirty Tricks).
 
http://rspb.royalsocietypublishing.org/content/280/1760/20130558.short
 
Other notable studies in the final episode of the series are on Kangeroos (that I think an ex-Cambridg classmate Emily Best) and bowerbirds (which is similar to the work of an ex-colleague Jess Isden), and fiddler crabs that I have blogged about before. It’s a very small world.

This week I was interested to see what sounded like some really cool new science reported in the Daily Mail, with the print headline of “Seagull gangs ‘are pricking on women.’” From briefly skimming the article it seemed that the much maligned blight of British seafronts had developed a novel foraging tactic, with “targets more likely to drop food when pecked.” The eponymous words of Jurassic Park rang through my head “clever girl.” But on a closer read it seems that this new revelation, reported as if it were fact, is just the opinion of two lifeguards, Ash and Becca. So is Mail is just reporting non-fact as fact once more?

 

On the face of it yes, as there doesn't appear to have been any research into this and it’s just someone’s view. But seagulls are smart and other smart birds have the ability to remember the faces of humans for decades, so it seems perfectly sensible to suggest that seagulls could tell men and women apart. But what about using some crazy foraging behaviour?

 

It turns out that there is actually precedent for targeting a subset of a population to steal food from. Fork-tailed drongos, amazingly acrobatic birds that have a dual impact on other species: they can act as a sentinel system, allowing others to spend more time foraging, and alerting them when predators are near but they can also make false alarms and steal food. So, there is a both a cost and a benefit to having these duplicitous birds around. I’ve blogged about some of the cool interactions of drongos before. Drongos follow pied babblers, with smaller babbler groups paying more attention to their sentinel behaviour than larger ones. The interesting thing is that within pied babbler groups some individuals respond more to drongo alarm calls than others, with juvenile birds more likely to respond. Drongos will actually preferentially target these juvenile birds, making their stealing more efficient. This is really similar to what the Mail suggests is happening on British beaches.

 

However, it still needs to be researched. So if anyone wants to fund me to go to the beach to collect data and run experiments…..

 

The above research is published in Ridley & Child (2009) Behav Ecol Sociobiol 63:1119-1126

 

Other cool drongo papers:

 

Flower & Gribble (2012)

Flower et al. (2014)

Flower (2011)

The BBC have just finished filming some of the work that I did for my PhD (while I was at the Percy FitzPatrick Institute). The filming involved Chris Packham doing one of my experiments, which is pretty awesome.

They filmed work from my Proc Roy Soc paper
Thompson et al. (2013) The influence of fledgling location on adult provisioning: a test of the blackmail hypothesis

While at the KRR they also filmed the drongo -sociable weaver interaction from work that I helped Tom Flower and Bruce Baigrie carry out, also published in Proc Roy Soc
Baigrie et al. (2014) Interspecific signalling between mutualists: food-thieving drongos use a cooperative sentinel call to manipulate foraging partners

So all in all, a great bit of coverge for research carried out and funded by the Fitz!

The above picture is of the BBC film crew that came out and the members of Babbler Project who helped them with the filming.

So after finishing my PhD I went back the kalahari to help Tom Flower out with some cool work investigating deception tactics and learning in fork-tailed drongos. While I was there I also had a chance to help his honours student, Bruce, out with his research investigating the relationship between drongos and sociable weavers. The kalahari is full of cool inter-species interactions (I'll put a couple of papers below). Bruce's work has just been published in Proceedings of the Royal Society, I have put the abstract and a link to the paper below. The work was really fun to do and highlights how conflict and cooperation have to coexist in both and ecological and evolutionary setting, and that this can lead to cool things evolving.

Baigrie, Thompson & Flower (2014) Interspecific signalling between mutualists: food-thieving drongos use a cooperative sentinel call to manipulate foraging partners. Proc R Soc, 281:20141232
Interspecific communication is common in nature, particularly between mutualists. However, whether signals evolved for communication with other species, or are in fact conspecific signals eavesdropped upon by partners, is often unclear. Fork-tailed drongos (Dicrurus adsimilis) associate with mixed-species groups and often produce true alarms at predators, whereupon associating species flee to cover, but also false alarms to steal associating species' food (kleptoparasitism). Despite such deception, associating species respond to drongo non-alarm calls by increasing their foraging and decreasing vigilance. Yet, whether these calls represent interspecific sentinel signals remains unknown. We show that drongos produced a specific sentinel call when foraging with a common associate, the sociable weaver (Philetairus socius), but not when alone. Weavers increased their foraging and decreased vigilance when naturally associating with drongos, and in response to sentinel call playback. Further, drongos sentinel-called more often when weavers were moving, and weavers approached sentinel calls, suggesting a recruitment function. Finally, drongos sentinel-called when weavers fled following false alarms, thereby reducing disruption to weaver foraging time. Results therefore provide evidence of an ‘all clear’ signal that mitigates the cost of inaccurate communication. Our results suggest that drongos enhance exploitation of a foraging mutualist through coevolution of interspecific sentinel signals.
http://rspb.royalsocietypublishing.org/content/281/1791/20141232.abstract

Other cool interspecies interactions:

Pied babblers and scimitarbills:
Ridley, Wiley & Thompson (2014) The ecological benefits of interceptive eavesdropping. Functional Ecology, 28: 197-205

Drongos and pied babblers:Flower (2011) Fork-tailed drongos use deceptive mimicked alarm calls to steal food. Proc R Soc, 278:1548-1555

It's conference season, and as of this morning most of the Large Animal Research Group (where I am currently doing some work) is somewhere between Heathrow and Iceland, the country not the shop. I have recently found out that flying to the US via Iceland is a very cost-effective/good way to get an extra holiday in. They are all heading to ISBE 2014, in New York city, hosted by the unfortunately named Hunter College City University of New York Hunter (or Hunter CUNY - someone really dropped the ball on that naming). This is the big conference for behavioural ecologists and biologist, and is held biennially with the last one being in Lund 2012. I am of course very jealous, as there will be loads of amazing talks and chances to meet world experts and do some much needed networking. I am also sad to not be going as many of my friends from different universities all over the world will be attending and so it would be a great place to catch up with people. But this isn't supposed to be me feeling sorry for myself, I am going to put up a list below of some talks that would be great to see if you yourself are attending.

Here is a link to the conference website http://www.isbe2014.com, it isn't the best laid out in the world. It looks like it is going to be a really great conference and New York seems like a great place to host it. Good luck to everyone taking part, and hopefully loads of great collaborations come out of it.

So the list of talks that should be good:

BJ Ashton
Saturday session 3, HW615: 
Group size drives cognitive differences in a cooperative breeder

DL Cram
Friday session 2, HN C-002:
The oxidative stress costs of reproduction are mitigated by helpers in a cooperatively breeding bird

JE York
Saturday session 1,Lang HN 4th floor:
‘Dear-enemy’ of the collective: cooperative contributions to territorial defence under experimentally manipulated levels of threat

MJ Nelson-Flower
Tuesday session 1, Assembly Hall:
Male and females use different mechanisms to maintain high reproductive skew in a cooperative bird

T Flower
Friday session 3, HW 511:
The coevolution of an interspecific sentry signal between foraging mutualists

D Lukas
Tuesday session 1, Assembly Hall:
The evolution of male infanticide in mammals

S Cunningham
Saturday session 1, HW 615:
It's cool to be dominant*: social status and thermoregulation in birds

M Zöttl
Tuesday session 1, Kaye Playhouse
Queen succession, female-female competition and forcible eviction in Damaraland mole-rat (Fukomys damarensis) colonies

SW Townsend
Friday session 1, HW 511
The meerkat ‘animal moving’ call: functional reference in highly variable situations

I know this ‘coverage’ is a bit late but I was on a remote Scottish Island when this paper came out and as Tom is the first of my friends to get a paper in Science I obviously had to write about it. And as you will now know, I know the authors and so my slant on this paper will probably be biased in a positive way.

So the paper is:

Flower et al (2014) Deception by flexible alarm mimicry in an African Bird. 344: 513-516

Firstly you’ll need a bit of background on fork-tailed drongos (Dicrurus adsimilis), hereafter drongos. They are extremely agile birds that live in Southern Africa and are very adept at hawking small flying insects. In addition to their aerobatics they are vocal mimics that can copy the calls of other species, and they use these calls to make false alarm calls (i.e. when there are no real predators) to scare individuals from other species (host species) when they have food, then they fly down and steal the food item. Drongos primarily spend time with sociable weavers (Philetairus socius), pied babblers (Turdoides bicolor) and meerkats (Suricata suricatta). Previous work has investigated some of these associations, and I have put the papers at the end.

The problem with using these false alarm calls to gain food from other species, usually food that drongos are unable to gain themselves, is that if you are deceptive too often then your hosts will stop responding. However, these host species don’t just have their food stolen by drongos, they actually use drongos as part of their vigilance system as drongos will alarm at actual predators. Thus there is an interesting ‘mutualism’ that exists within this system. This investigation sought to understand how drongos maximize their gain from these repeated interactions.

Natural observations of this wild population showed that drongos exclusively use mimetic alarm calls in 42% of false alarms and a combination of mimetic and drongo specific calls in a further 27%. To investigate these patterns the researchers carried out a playback experiment using four drongo generated call types:  1) a control territorial call 2) drongo-specific alarm 3) mimic of glossy starling (Lamprotornis nitens) alarm and 4) mimic of pied babbler alarm. The experiment was carried out on groups of habituated pied babblers, a host species for the drongos. Pied babblers were slower to return to foraging after mimetic alarms than drongo specific ones, thus showing that mimetic alarm calls produce a stronger response. They then carried out a second experiment where they played back three calls in one of four treatments: 1) All drongo-specific alarms 2) All mimetic starling alarms 3) two drongo followed by a starling and 4) two starling followed by a drongo alarm. They found that pied babblers habituated to treatments of all one type but not to the treatments that varied. Showing that varying the calls you use has benefits for the drongo. These experimental results fit with the natural data that showed in instances of repeated attempts at theft on the same individual that drongos changed the false alarm call that they used on 74% of occasions. Drongos were more likely to change if their previous attempt had failed.

This paper shows that drongos avoid host species habituating to false alarm calls by varying the mimetic false alarms that they use and thus avoiding frequency dependent constraints.

This paper has a great blend of natural observation and carefully designed experiments. The results speak for themselves and tell an interesting story of how birds in the wild adjust to problems that are familiar to many people. It shows the value of working at a research site with multiple habituated species that associate and interact in interesting ways, and thus the value of long-term research stations.

Some of the media coverage seems to have sensationalized this work, going much further with their assertions than the authors did. Some have even suggested that these birds have ‘theory of mind’. Sciencemag noted that Tom (Dr Flower) is doing some current work to further investigate drongos tactics and learning, work that I assisted with in the Kalahari. From my observations while performing these experiments the drongos seemed to use simple rules and were not as clever as we had hoped. However, that does not detract from the brilliance of their behaviour: many complex behaviours and structures are made using simple rules, e.g. spider’s webs and wasp nests. Even some seemingly complex human behaviours are governed by simple rules. The amazing adaptability of evolution is shown by such seemingly complex behaviours. In fact the authors use examples such as the changing of cell surface proteins by influenza as an analogue to drongo behaviour, and I’m pretty sure that virus’s don’t have theory of mind!

Here are some links to other media coverage:

http://news.sciencemag.org/biology/2014/05/african-bird-cries-wolf-steal-food?rss=1

http://whyfiles.org/2014/deceptive-bird-lies-to-steal-food/

http://www.nbcnews.com/science/weird-science/african-bird-uses-sound-effects-bamboozle-other-species-n94256

More drongo papers:

Flower et al (2013) The ecological economics of kleptoparasitism: pay-offs from self-foraging versus kleptoparasitism. Journal of Animal Ecology 82:245-255

Flower & Gribble (2012) Kleptoparasitism by attacks versus alarm calls in fork-tailed drongos. Animal Behaviour 83:403-410

Ridley & Child (2009) Specific targeting of host individuals by a kleptoparasitic bird. Behavioral Ecology & Sociobiology 63: 1119-1126.