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Counting wasp attacks: investigating alarm pheromones in yellowjackets

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This is a post to announce my new paper, which has a bit of a mouthful for a title: Developing a paired-target apparatus for quantitative testing of nest defense behavior by vespine wasps in response to con- or heterospecific nest defense pheromones

This is a paper that was long in the making, and there are two important things you should take away from it: 1) the bioassay setup is cool and 2) three species of the genus Vespula recognize each other’s alarm pheromones

OK, so why alarm pheromones? Well, many social insects coordinate their defences against predators using chemical signalling. These signals can arouse a colony into defensive behaviour, and often can be applied to attackers to attract other workers to attack the intruder. In some cases these chemicals are one and the same, in others, they may be different. No matter! Although our efforts here were part of an attempt to describe the alarm pheromone chemistry of these yellowjackets, we never did succeed in isolating the exact chemicals needed to mimic the naturally-occurring alarm pheromones.

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Vespula pensylvanica, the western yellowjacket

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Vespula alascensis, the common yellowjacket

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Vespula germanica, the German yellowjacket

 

Many wasp species have their alarm pheromones in their venom sac, and presumably, when disturbed extrude a little venom to signal other workers, or deposit venom on nest predators to “mark” them for attack by the colony. We worked with three species of yellowjackets, Vespula pensylvanica, Vespula alascensis and Vespula germanica. The substances we tested in this study were venom sac extracts of these wasps dissolved in acetonitrile, an easy-to-work with polar solvent.

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We dissected out venom sacs (the translucent jelly-bean looking thing) and crushed them in acetonitrile, at a rate of 1 sac per 10 microliters. We filtered the extracts and stored them cold for later use.

To test the effect of the putative alarm substances in these extracts, we needed a bioassay device. Because no standard protocol existed, I designed one that I hope will become the standard for any future experiments:

The paired-target bioassay

In 1995, Visscher and Vetter (yes, that Vetter! The spider guy!) developed a resonant-target attack counter for use in quantifying defensive attacks by yellowjackets and bumblebees. It so happens that when these flying stingmeisters attack, they fly at high speed toward their victim and strike it with force. Visscher and Vetter’s device utilized this important fact by surrounding an audio microphone with a resonant plastic target, and using an electrical counter to count the hits. The device requires construction of  the counting circuit, but I thought, why not just record an audio file and count the strikes later?

Basically the device I designed is an elaboration of Visscher and Vetter’s strike counter, only it can be assembled with off-the-shelf components, and utilizes free software to count the strikes recorded to an audio file. In addition, my design is explicitly for use in paired assays, as wasp attack behaviour is often quite variable from one situation to the next, and experiments to test the effect of alarm pheromones  can benefit greatly by pairing the treatment and control in each replicate. Think of it as blocking! at 9 am, the wasps are really feisty, and hundreds come out to strike, at 10:30, the attack is less fierce. If we did a control run with a single target at 9, and a treatment target at 10:30, we would be misled, but with a paired design we can determine that our treatment has an effect in both replicates. This saves immensely on the number of replicates required to see a difference.

OK, so here is how the device looks:

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The vast majority of the components are very easy to acquire, and the only construction requires a bit of drilling and screwing in of wingnuts and bolts. Everything else is off-the-shelf, and  the device folds up neatly for transport and storage. The targets are formed from thin black polystyrene weigh boats, which make a drum-like sound when struck, and they can be disposed of between each replicate so that residual alarm pheromone is not a problem.

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Onour Moeri bringing the paired target device to the wasps.

Here is what it looks like when a wasp strikes a target:

 

The basic process of doing a bioassay is to place the device so that the targets are equidistant from the nest entrance, apply a test substance to one target, a control solvent to the other, start the recording, and then tap the nest entrance to get the wasps activated (note, this step not ALWAYS needed! Some nests are on high alert anyway!)

Here is a video of the device in operation, with audio derived directly from the paired microphones. In this case, the pheromone extract is placed on the left-hand side of the device.

 

 

After each assay, the device is removed, the targets replaced, and then the treatment and control are re-applied for another replicate. I always alternated the left-right placement from one replicate to the next, to avoid any side bias.

After a number of replicates (at least 10, better 15 to 20), the audio files are offloaded from the digital recorder, and split into treatment and control files for each replicate. You can use Audacity (a freeware program) to do this.

A simple oscillogram of each file often shows an effect: This is how the two oscillograms look for the left (top) and right (bottom) channels.  As you can see, the left hand side experienced more strikes in this short clip.

 

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But how to count these strikes effectively? Well, the solution is another freeware program, SoundRuler, developed by Marcos Gridi-Papp for his teaching in bioacoustics. My application of this software is really wasting its potential, but it works quite well for counting these loud percussive strikes!

In the SoundRuler interface, some simple rules for counting the strikes are programmed in, then automated counting of the entire range desired is simple:

 

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The SoundRuler interface with an open audio file of 240 seconds.

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The same file after automated counting enabled. In this case, 123 strikes were counted.

 

Alright! So that is the development of the paired-target bioassay device, as well as its operation. What did we use it for?

Well, we tested whether three species of ground nesting yellowjackets, Vespula pensylvanica, Vespula alascensis and Vespula germanica have an alarm pheromone in their venom sacs. We also tested whether or not these species would recognize the alarm pheromones of the other species. It turns out that they do!

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So what would be the advantage of responding to the alarm pheromone of another yellowjacket species? Well, each of these species has a very similar life history, being ground-nesting, and needing to defend the nest from the same kinds of predators (bears, skunks, raccoons, humans). I can see the advantage of responding early to a “pheromone-marked” predator which had just attacked another species, stinging it and driving it away before it has the chance to attack your own nest. These alarm pheromones probably evolved once in the vulgaris species group, and there was no selection for differentiation, and possibly selection against it.

So there you have it! An inexpensive, easy to construct bioassay device that you can use to test alarm pheromones in large stinging wasps! A counting protocol that is easy and fast! What more could you want? Well, I suggest that the first thing you could wish for is very good luck  and/or insight into the complicated chemistry of these alarm substances, but this study has at least provided some new tools to get there.

OK! So that is the paper. I hope you enjoyed it, and be sure to read the whole thing over at the journal website! In the meantime, please enjoy these awesome pictures of the bioassay device in operation.


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A photographic species record

5073254804_71691f2caa_bPhotography brings me a great deal of pleasure, and I indulge in it whenever I can. A few years ago, I was with my dad, driving north from Victoria to my brother’s wedding. Along the way is Goldstream Park, a  real gem where the Golstream River empties into Saanich Inlet. We had some time to kill, so we went out for a short stroll with our cameras. It was a beautiful fall day, although the early morning forest was still dark. After photographing some salamanders in the forest, I decided to check out the highway bridge over Niagara Creek for overwintering mosquitoes.

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A western red-backed salamander we found under a log.

 

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Many overintering arthropods can be found in man-made structures. Here are three harvestmen and three Triphosa haesitata under the abutment of the Niagara Creek trestle. I have also found bats, camel crickets and five species of mosquito under similar structures.

 

During my undergrad, I did an Honours thesis on overwintering mosquitoes, and one of my field sites was just upstream, at the railroad trestle above the creek. Here I found several species of mosquito, including Anopheles punctipennis, Culex tarsalis, Culex territans and Culiseta incidens. So when I checked out the highway bridge, I took a few shots of of the mosquitoes. Most of these were the large and very common Culiseta incidens, but I saw a smaller and browner one that I knew was a Culex. Not having many good shots of Culex tarsalis, I strained to reach the camera over my head to shoot the insect. Like many overwintering mosquitoes, this one was still able to fly, so I only got the one shot. Upon reviewing it however, I saw that it was not Culex tarsalis, as I expected, but rather Culex restuans! This species looks much like the common house mosquito, but is distinguished by the two light scale patches on the scutum. I had never encountered this species during my thesis research, as it had not been reported for BC. In talking with Dr. Peter Belton, he urged me to write up the sighting for the Journal of the Entomological Society of BC as a new species record for the province.

Several years passed, where I was busy with tropical field research, and I had put the Culex record on the back burner. When Dr. Belton presented me with a draft of the report, I knew I had to do my part. I added some detail to the manuscript and sent it off. Click here to see the paper!

Not bad for a quick snapshot. Here are some other pictures I took that day:

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On top of the bridge I found this jumper with a droplet for a hat.

 

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Heather (my new sister in law) and my brother.

 

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Pablo !

 

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My dad, with some palinka we smuggled in.

 

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Are ants really the primary predator of wasps in Neotropical forests?

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“Ants, particularly army ants, exert such strong predation pressure that they are considered to be the main driving force in the evolution of Neotropical social wasps, to the point of influencing their nest architecture.” –Corbara et al. 2009

It is not too surprising that many tropical ecologists consider ants to be such superior predators. Come across an army ant swarm, and you are likely to witness many hundreds of acts of predation playing out before your eyes on the jungle floor. An army ant swarm is like a blitzkreig, and it would seem that nothing can stand in its path. Even social wasps, normally so aggressive in nest defence, will abandon their nest immediately rather than risk the entire colony in a vain attempt to repel the tens of thousands of army ant raiders.

But is it really accurate to infer from these types of observations that the risk of predation by ants on nests of social wasps surpasses that of all other predators? This never really sat right with me, particularly considering how an army ant predation event on social wasps is a random, and probably relatively rare event. Army ants cannot see, and they do not target wasp nests in particular. Even those species which prefer preying on social insects are much more likely to be raiding other species of ants rather than wasps.

How would army ants stack up against a true specialist wasp predator, such as the Red-throated Caracara? Luckily, I had some data to work with to answer these questions.  I have written this up in a paper in Insectes Sociaux, which unfortunately is not open access, but you can email me for a copy!

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A Polybia nest brought via an overhead branch.

From our nest camera study in 2008 and 2009, we had footage which showed adult provisioning of single caracara chicks (McCann et al. 2010).  In order to calculate the number of wasp nests per day consumed by the chicks, we lumped all events of provisioning with nest fragments of the same genus being brought within 30 min of each other.

Each of these events was then termed a “unique nest delivery”. By summing the unique nest deliveries daily for the two sampling periods, we found that a single caracara chick eats between 7.8 and 12.4 nests per day. If we assume that the adults are eating just as many wasp nests, a group of 6 adults would consume 46-74 nests per day (not counting the chick). On a per-hectare basis, caracaras could possibly be consuming 0.117-0.186 nests/ha/day.

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Wasp-eating machine! Is the Red-throated Caracara a major source of colony failure in Neotropical social wasps?

 

To compare this rate of predation with that of army ants, we needed an estimate of army ant density. Unfortunately, only one method for assessing Eciton density has been developed, for Eciton burchellii.

This method was developed by Nigel Franks, and relies on the predictable behaviour of swarms of this species (Franks 1982). These ants raid in a roughly linear column from their bivouac site, extending the raid 7 m per hour. The landscape at any given time is thus like a plane with many lines of ants of similar length scattered about it at random. The probability of encountering a swarm is thus proportional to the density of colonies in the area, and by repeated walks of suitable length, an estimate of the total density can be made. Mathematically-inclined readers may realize this is an extension of the problem of Buffon’s Needle*, and relies on similar calculations Incidentally, Buffon also published the first species description of the Red-throated Caracara. You can read about that here.

Catherine Scott and I went to the Nouragues station in 2012 to perform an estimate of the Eciton burchellii density in order to calculate the potential impact of army ant predation on social wasps.

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Here are the three trails we surveyed. We walked each trail 5 times, for a total of 72 km. Each encounter with an Eciton swarm is marked with an X. We encountered Eciton burchellii only 5 times, translating to a density of only 0.021 swarms/ha.

Our estimate for Eciton burchellii density was a moderate 0.021 swarms/ha, pretty well comparable to other lowland rainforest sites. But how many wasp nests could each swarm take? Well, there is no easy answer for this, but there was only one study that documented rates of army ant predation on social wasps. Ruth Chadab published an estimate of 1-3 nests per day taken by Eciton hamatum, a related species with a greater predilection for social insect nest plundering (Chadab, 1979). Because we had no estimate for daily wasp nest predation for E. burchellii, we used Ruth Chadab’s estimate of 3 nests per day as a rough approximation. This translates into 0.06 nests/ha/day, or 24 nests per day in a 400 ha caracara territory.

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We conclude that Red-throated Caracaras, as specialist wasp predators, are comparable to army ants in their predatory impact on social wasps. Taken together with other species, such as monkeys, antshrikes (McCann et al. 2014) and woodpeckers (Sazima 2014), social wasps are at considerable risk from vertebrates.

So what about vertebrate predators and the adaptations of social wasps against them? If we look carefully at social wasp behaviour, it is easy to see how much vertebrate predation has influenced both behaviour and nest architecture. For one, massed stinging attacks are ineffective against ants, and are definitely a feature that protects wasp colonies from vertebrate attack. Audible warnings, such as those produce by Synoeca, would not be effective against ants, nor would visual camouflage (ants hunt by scent, and army ants cannot see anyway).

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Visual crypsis of Leipomeles dorsata nest.The envelope of this nest is fitted carefully to the underside of the leaf, and made to resemble it in colour.   Photo by Alex Popovkin, used under a Creative Commons 2.0 licence.

Likewise, armouring of a nest, such as is seen in some Epipona and Chartergus wasps (Richards 1978), would have limited effect on ants, as they can enter and take prey through any opening a wasp can. Analogous armouring consisting of a mud envelope is evident in this Polybia singularis nest. In 5 seasons I worked at the Nouragues camp, this nest never fell prey to the caracaras.  What is  notable about the nests of most wasps with armoured envelopes is that they are often located high up in trees, easily visible on distal branches. The wasps may gain some protection from ants by nesting so high, which they can afford because they are (by virtue of the strength of their nest) already relatively safe from vertebrate attack.

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Nest of Polybia singularis, with an envelope of hardened mud. Such nests can weigh up to 5 kg! This nest was never taken by caracaras in all the years I studied at the Nouragues station.

 

As more and more naturalists describe and publish their observations of Neotropical biology, we are continually discovering new things. I hope that this study, gained in a few short months of research adds to the understanding of the role of vertebrates as predators of social wasps, especially the important role of the Red-throated Caracara. In a future post I will take up the issue of the diversity of wasps taken by caracaras, and what some of the numbers might mean for tropical wasp biologists.

Please do go and read the paper, and if you do not have access to it email me for a copy!

References

CHADAB, R. 1979. Army ant predation on social wasps. PhD Thesis. University of Connecticut, Storrs, CT.

CORBARA, B., CARPENTER, J. M., CÉRÉGHINO, R., LEPONCE, M., GIBERNAU, M., and DEJEAN, A. 2009. Diversity and nest site selection of social wasps along Guianese forest edges: assessing the influence of arboreal ants. C. R. Biol. 332:470–479.

FRANKS, N. R. 1982. A new method for censusing animal populations: The number of Eciton burchelli army ant colonies on Barro Colorado Island, Panama. Oecologia 52:266–268.

MCCANN, S., MOERI, O., JONES, T., and GRIES, G. 2014. Black-throated Antshrike preys on nests of social paper wasps in central French Guiana. Rev. Bras. Ornithol. 22:300–302.

MCCANN, S., MOERI, O., JONES, T., O’DONNELL, S., and GRIES, G. 2010. Nesting and Nest-Provisioning of the Red-throated Caracara (Ibycter americanus) in Central French Guiana. J. Raptor Res. 44:236–240.

RICHARDS, O. W. 1978. The social wasps of the Americas excluding the Vespinae, p. vii, 580 p., 4 p. of plates : ill. (some col.) ; 2. British Museum (Natural History), London.

SAZIMA, I. 2014. Tap patiently, hit safely: a preying tactic of the White Woodpecker on social wasp nests. Rev. Bras. Ornitol. 22:292–296.

 

 

 

 

One pheromone to rule them all: elderberry longhorn chemical ecology

IMG_9741bThis post is about a paper recently published in PLOS-ONE, on the chemical ecology of elderberry longhorn beetles. If you want to read it in its entirety, click here. Below is the story of my end of the collaboration leading to this publication. 

In 2011, I attended the annual meeting of the International Society for Chemical Ecology (ISCE). This was one of my easiest conferences ever, as it was being held at Simon Fraser University, where I was doing my PhD. I had the great pleasure of meeting with Dr. Annie Ray, who was then researching chemical ecology of lepturine longhorn beetles, commonly known as flower longhorns.

She gave a great talk about her research topic, which was at the time a fairly neglected area of research, as there are few lepturine pests, and hence little interest in researching their sex pheromones.

Nonetheless, there are definitely applications for this knowledge, especially to better study the endangered valley elderberry longhorn beetle (Desmocerus californicus dimorphus, hereafter VELB), which has been of major conservation concern in California’s Central Valley for decades.

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(4R,9Z)-hexadec-9-en-4-olide: (R)-desmolactone

 

Dr. Ray, along with Dr. Jocelyn Millar and others had recently identified the VELB pheromone as (R)-desmolactone, and had showed that it was effective in trapping male VELB in the field.

We got to talking after her presentation, and Dr. Ray mentioned that we had a species of Desmocerus in BC. I told her that if she ever needed any help trapping these beetles, she should look me up. I did not think it was likely that anything would come of it, as our local Desmocerus aureipennis is not endangered, but sure enough, the next season, a bunch of traps and some chemicals arrived at the lab. Dr. Ray and Dr. Jocelyn Millar wanted to test out their synthetic candidate pheromone for VELB on its relatives!

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I quickly racked my brain for areas to test these compounds. We had extensive elderberry as understory vegetation on Burnaby Mountain, so I set up some replicates just outside the Biology Department in the woods. These traps caught nothing, so doing some reading on VELB, I realized that the California species likes “elderberry savannah” habitat. The only place I could think of that fit that description close by was Colony Farm Regional Park, a location where I had done some volunteer bird banding.

After applying for and receiving permits, the flight season for the beetles was almost over. Nonetheless, the traps caught many beetles. This was a promising start.

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Banding birds at Colony Farm. The bushes in the background are Red Elderberry.

 

The next season, we were ready. We had new traps, plus two enatiomers of the candidate pheromone, in order to determine which of the two, or perhaps both were active. We prepared traps with a mixture of the two chemicals (called a racemic mixture or racemate), in order to determine whether one would inhibit the effectiveness of the other. This is important in chemical ecology of insects, as preparation of a racemic mixture is vastly cheaper than production of an enantiomerically pure chemical, and if the racemate is attractive, there is no need to go to the trouble of producing the pure substance.

With the traps out, we waited a week. When we came back, the traps with the racemate and the (R)-desmolactone had caught many many beetles, whereas the control and the traps containing S-desmolactone only had only caught a single beetle each (one trap almost caught a bear, but that is another story). Therefore, the (R)-desmolactone appears to be the sex pheromone of Desmocerus auriepennis, as it was for D. californicus.

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I had never seen these beetles in the field until I did the trapping experiment, so I took the opportunity to do some photography of a few males we had caught.

When the results started coming in from other trapping sites in the experiment, we quickly saw that this pattern held true for a number of Desmocerus species and subspecies. Desmocerus palliatus, D. auriepennis auriepennis, and D. lacustris all responded well to the (R)-enatiomer and somewhat less strongly to the racemic mixture.

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FIGURE 1: Photos of the species and subspecies of Desmocerus included in the present manuscript. A: D. a. aureipennis; B: D. a cribripennis; C: D. a. lacustris; D. D. c. dimorphus (VELB); E. D. palliatus. (Photo of D. palliatus by Paul Bedell). doi:10.1371/journal.pone.0115498.g001

When Dr. Ray sent me the first draft of the paper, I thought it might be good to have some photos of the species under study, so I prepared Figure 1 above. Since we did not have any pictures of Desmocerus palliatus, I reached out to Paul Beddell, and asked if we could publish his great photo in the paper. I was also interested to learn that my Colony Farm traps were by far the most effective, catching many times more individuals than other sites.

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Desmocerus auriepennis cribripennis shot on some Red Elderberry. Their flight season at Colony Farm seems to coincide with the flowering of this shrub, and ends when the fruits are formed.

Using the results from these studies, areas can be more effectively surveyed for the endangered VELB, making this kind of surveillance cheaper and more effective. The pheromone catches only male beetles, so risk to females is low, and using a live trap design, males can usually be released unharmed.

In addition, now that we know that the pheromone is effective for VELB’s congeners, any studies of these beetles have got a great head start. I for one would be interested to survey the distribution and abundance of the beetles in BC, as Red Elderberry is a common shrub in forested habitats. Why are they so abundant at Colony Farm? Are there some populations to be found in other habitat types? Are there any differences in the pheromone mixtures produced by the various Desmocerus species?

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When the (human) is at the door

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Gray wolves in Alberta. Photo by Paul Paquet.

 

We have an expression “when the wolf is at the door” meaning that bad times are upon us, and poverty/ill health is looming. This implies a feeling of despair and anxiety, and when the wolf is at the door, it is likely that our hormonal systems reflect our stress.

So too with the wolves, when humans are at the door, so to speak. Recent research by Heather Bryan shows that both stress hormones and sex hormones seem to increase as a result of human persecution.

Dr. Bryan and her team quantified hormones in hair from wolves from populations which varied in the level of human persecution: tundra/taiga wolves from Nunavut and the Northwest territories, and boreal forest wolves from the Northwest territories and Alberta. The tundra/taiga wolves experience on the whole a greater level of persecution than those in the boreal forest, but Dr. Bryan also examined an outgroup of boreal wolves with high levels of persecution.

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Cortisol is a hormone which is produced under various stressful conditions, such as injury, starvation and social conflict. Tundra/taiga wolves had greater levels of these hormones than wolves from the boreal region. The increases associated with human hunting pressure could reflect changes in the social structure wrought by mortality of members of these tight-knit groups of animals.

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Likewise, Bryan observed increases in progesterone and testosterone with hunting pressure, perhaps as a result of disruption of pack dynamics brought on by excess mortality. In wolf societies, breeding females (the mothers) suppress reproductively mature subordinate females (usually their daughters) reproduction, resulting in a pack structure in which only the dominant female breeds. In packs with unstable social conditions, as when hunting removes individuals, this suppression of subordinate reproduction is interrupted, which could result in population-wide increases in sex hormone production.

Dr. Bryan also notes a possible confound in the comparison of the two groups: the tundra taiga wolves also differ in their ecology. These populations have much greater long-distance movements as they follow migrating herds of caribou, and the increased cortisol may reflect the stresses of these long-range movements.

Nonetheless, this study provides an fascinating glimpse at the inner lives of wolves. It will be very interesting to see what follows from this research, especially if we can determine how the hormonal state of populations influences their behaviour.

 

 

 

White Woodpecker preying on wasp nests!

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Melanerpes candidus approaching the nest of social paper wasps. Photo by Miguel Rangel Jr. used under terms of a CC-BY-SA licence.

In the latest issue of Revista Brasileira de Ornithologia, I found a paper on a topic near and dear to my heart: birds preying on wasp nests. In this case, it is an account of the White Woodpecker, Melanerpes candidus preying on the nests of Polybia paulista.  In this paper, Ivan Sazima describes the predation tactics used by this woodpecker when attacking a large, well-defended  nest. Ivan conducted this research at Parque Ecológico Prof. Hermógenes de Freitas Leitão, in the state of São Paulo, Brazil.

Like the Red-throated Caracaras I studied, the White Woodpecker appears to exploit the absconding response of these swarm-founding wasps in order to secure its meal of wasp brood. Rather than inflicting rapid, catastrophic damage, however, the woodpecker takes its time, approaching the nest gradually and tapping the branch to which the nest is attached. During this approach, some of the wasps come out to sting, and if this gets too fierce, the woodpecker will retreat. Sazima attempted this tactic himself with a similar nest of P. paulista, and got stung severely for his efforts. Sazima suspects that the continuous nature of the woodpecker’s disturbance is what is required to induce the wasps to abandon their nest. Also, the agility of the birds at evading attacking wasps also means they can keep this harassment up longer than an unprotected human.

This paper is a valuable contribution to the study of wasp and bird behaviour, as it highlights that certain anti-predator strategies of social wasps (stinging, alarm recruitment) can be defeated by exploiting the evacuation swarming (absconding) behaviour of these wasps. Bearing this in mind, it is no wonder that so many species of swarm founding wasps have cryptic nests to escape the detection of diurnal vertebrate predators.

I especially love one of the concluding sentences:

The foraging behaviour of the White Woodpecker reported herein results from so-called anecdotic, natural history oriented observations, often disregarded by theory-trained biologists. Nevertheless, this kind of observation draws attention to phenomena that later may prove more widespread or commoner that previously thought.

 

I could not agree more. Please head over to read the paper yourself, as the photos of the behaviour are great,  and the text well worth the read.

Update: See another wasp predator in action here.

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Photo by Márcio Vinícius Pinheiro, shared under the terms of a CC BY-NC-ND 2.0 licence.

 

 

Successful tagging of Three-wattled Bellbirds in Honduras

Michael Loukides

Male Three-wattled Bellbird (photo by Michael Loukides) released under a CC-NC-SA licence.

I just received in an email a press release for the Zoo Conservation Outreach Group describing recent successes in fieldwork on Three-wattled Bellbirds (Procnias tricarunculatus) in Honduras. This project aims to use satellite tags to study the migratory movements of these endangered frugivores in the Sierra de Agalta cloud forests of Honduras. I have no doubt that Isidro Zuniga, our Honduran colleague during our last field season in Honduras was greatly involved in this research.

The big mystery surrounding these odd  birds (Family Cotingidae) is their complex migratory movements between cloud forests in the region. Each of these cloud forests is like an individual island of habitat in a great sea of lower level pine forests and agriculturally-dominated valleys. The birds are very evident from July to September in the Sierra de Agalta cloud forest, but then disappear for the balance of the year. The team on the ground in Honduras, led by Dr. Robin Bjork, has managed to outfit four of these birds with satellite tags which are transmitting data already.

The data generated by these tagged birds should be very interesting to say the least, and will help identify key habitat for conservation efforts.

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A bird in the hand is worth quite a bit! Male Three-wattled Bellbird outfitted with 5 g satellite tag.

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