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.

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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 intrepid guide during our 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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Weekend Expedition 57: Thanksgiving in Victoria

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This weekend, Catherine and I visited Victoria, for the Canadian Thanksgiving holiday. The weather was not super cooperative for outdoor activities, and Catherine was working hard on her PhD NSERC proposal, but we did manage one trip out to Island View Beach to check up on the local arthropods. I also went for a stroll in Uplands Park to get some of the following shots.

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This is how the rain looked on Saturday morning…

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Better to be sheltered inside, or under the eaves of a house!

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Quite a few grasshoppers were out and about. This one I shot as it was hiding on a Garry Oak leaf (you can see I was holding a white card below).

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A juvenile wolf spider looking odd and elegant with two very prominent eyes.

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A Dysdera crocata male in Uplands Park.

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An Aphaenogaster occidentalis worker carrying brood in Uplands Park. This species does well in Garry Oak meadows.

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Catherine, my friend Jeff, and a borrowed golden retriever (Jackson) at Island View Beach.

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The fall selection of resting Hymenoptera was much more limited than previously, with this impressively-ovipositored ichneumonid being the only example we could find.

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Resting snakes were about though; this garter snake was torpid and remained in a ball rather than trying to flee when we found her under a log.

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Spiders were to be found in large numbers though, this being Arachtober and all. Here is a tetragnathid backlit with a bare flash.

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Here is a running crab spider, of the genus Tibellus; the same one appears at the top of the post. These are very elegant-looking little spiders, and make great photographic subjects.

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Most of the creatures we found were covered by a light dew. This cranefly sparkles.

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This female Araneus diadematus was particularly large. That is Catherine’s finger for scale.

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Speaking of large, here is a giant! A giant house spider, formerly Tegenaria duellica, now this species is called Eratigena atrica. Since Catherine is scheduled to give an upcoming talk on spider bites (and how they are very unlikely) at the ESBC conference, we decided for an illustrative photo shoot.

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Here is the same spider sinking her fangs into resting peacefully on Catherine’s nose.

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Apparently, the feet tickle. Not that I would ever try this, that would be crazy. 

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A female Castianeira we found under some old plywood.

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A penultimate male black widow. These ones that overwinter always seem to be more robust and darker than the juveniles that develop quickly in the summer. I would imagine this is a textbook example of phenotypic plasticity; one that deserves more careful study.

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Again with an eye to Catherine’s upcoming talk, we took some shots of black widow defensive behaviour. Here a female throws glue-like silk on an offending finger. This is so reliable, I might have to try this in a studio setting with some nice backlight!

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Last but not least, on our final morning in Victoria, we walked on Mt. Tolmie, where we found this male Anna’s hummingbird, still defending territory. It is impressive these little birds are still nesting in the cold wet fall!

Arthropod sampling with the Future Science leaders!

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This past week has been pretty busy, so getting out and shooting has not really been on my list of accomplishments (my “Ta Da!” list). On Tuesday, I did manage to get interviewed by Global News about invasive ants, and then schlepped across town to assist my friend Tanya Stemberger with a field exercise for high school students in the Future Science Leaders program.

Due to high tides, the planned transect based survey of intertidal organisms had to be scrubbed, so instead, we attempted a transect-based survey of a forest near Lost Lagoon in Stanley Park.

I planned to show the students a simple technique for sampling called beating, wherein you strike foliage forcefully and collect any falling arthropods in a sheet placed below. We used small photographic shoot-through umbrellas to do our collection, and then used a simple aspirator to collect the catch. We had planned on sampling 5 sites along a 50 m transect, beating 4 small bushes at each site. Due to time constraints, we only managed to get a single site done.

Nonetheless, with only beating 4 bushes (2 salal, 2 salmonberry) we secured 25 spiders, 1 isopod and 1 harvestman. Many of these spiders were tiny juveniles, but some were just tiny adults. Identifying them in the field was definitely not going to happen in the limited time frame, but there may be hope of at least getting some identifications. Here are some of the spiders that were large enough to photograph well:

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It seems the spider diversity seems pretty high, and interestingly, of these spiders I photographed, 4 of the 5 are males.

The most striking thing about this sample (to me anyhow) was the lack of insects. Usually, at this time of year, I expect to see barklice (Psocoptera), springtails (Collembolla) and perhaps a stinkbug (Pentatomidae) or plant bug (Miridae). Nonetheless, it is tough to draw conclusions about the diversity of taxa we found, with only one sample being taken.

Of course, finding such a predator-biased range of taxa seems a little strange, until you consider that every sampling method has its biases. In the fall, when plant growth is limited, finding phytophagous insects out and about is much more difficult, but at a sites such as this, adjacent to a large freshwater source (Lost Lagoon) there is ample prey for web building spiders. These freshwater bodies are still producing abundant chironomid midges, and a few caddisflies.

All in all, this was a great (albeit short) little introduction to terrestrial arthropod sampling. Special thanks to the Stanley Park Ecology Society volunteers for leading us on the great nature walk!

 

 

Weekend Expedition 56: To the realm of the pikas

 

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This weekend, Catherine and I were invited by Sofi Hindmarch and Brian Coote (along with his kids Alexa and Jamie) to go down to Mt. Baker, a stratovolcano in Washington State near the Canadian border. On Sunday, we went on a trip to Lake Ann, a 13 km alpine trail. Catherine had to sit this one out due to knee issues, but I went to document our trip. This was my first outing to the alpine zone in quite a while, and it was not disappointing!

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A Hericium abietis! These are great edibles, but as we were in a reserve, we did not take it. There were also numerous King Boletes nearby.

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Alexa stops for a water break.

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The view going up the trail, Sofi in the lead, followed by Jamie and Alexa.

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Near the crest! 

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An American Pika, Ochotona princeps. These odd lagomorphs make a whistling alarm call when disturbed.

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These animals prefer talus slopes, and spend much of the summer gathering and drying plant material for a long cold winter buried beneath the snow.

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We saw these giving alarm calls in response to both Red-tailed Hawks and some kind of mustelid (possibly a marten or a mink).

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At the end point of our trip, I found this wolf spider under a rock.

 

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To prove we did it: Brian, Sofi, Jamie and Alexa in front of Lake Ann.

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Of course, on the way down I could not resist more pika shots.

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Awww!

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Yet another pika scanning the skies.

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Blueberry break on the way back.

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Much needed fuel for the last leg of the trip.

The end of summer

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Things are really winding down here in Vancouver, with colder nights, falling leaves, abundant spiders, and a distinct lack of bees, wasps and plant-feeding insects. This is one of the more melancholy seasons for an insect lover, but there are still some treasures to be found.

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In the mornings, the dew sparkles on the webs of numerous orb weavers, such at this tetragnathid at Iona Beach.

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There are even some syrphids still about, although the floral resources are dwindling rapidly.

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Some spiders are still guarding egg sacs, keeping a lonely vigil despite their deteriorating condition. This Castianeira longipalpa looks a bit shrivelled.

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Odd to see a male of these Myrmica incompleta still in the nest!

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Some really odd, but abundant spiders…Could they be Dictynids? Check out the palps on this guy!

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these have a great pattern!

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A gorgeous chrysomelid on tansy.

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Soon I will have no more of these lovely sphecids to shoot!

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As the sun goes down on Iona Beach, this grasshopper contemplates leaner days and its inevitable demise.

A few from McDonald Beach

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Like a fairy god, this grass veneer moth sits on a bejewelled seat.

The summer insect fauna is winding down, so I thought I would go out for a quick stroll at McDonald Beach to see some of my favourites before they disappear. If you want to know what else I was up to this weekend, check out this awesome post by Catherine Scott on the Spiders Unravelled event at Iona Beach!

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When the Ammophila are gone, so will be one of the best opportunities to practice lighting and composition. I will miss them! Here is a shot with the morning sun flaring the lens and highlighting the wings.

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A slightly different angle and the flare is gone, and the sky takes on a creamy hue.

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With my bounce card behind, I have the makings of a studio-style “Meet Your Neighbours” shot.

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The cool fall weather allows close approach to otherwise flighty species.

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Again, the grass veneer, showing its pretty white wings.

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A shy wolf spider on the beach.

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A male Castianeira with a missing palp. I would bet he has some raunchy stories to tell about that.

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A long-jawed orbweaver, finishing her meal.

Spider rappelling! A great way to get around.

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When a spider wants to make a long distance traverse between two objects, or just wants a quick way to ascend an obstacle, what can he do? Lets find out by watching a male crab spider.

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Well, as in ballooning, the spider can jet out a thread of silk, letting it be carried by the wind.

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The spider then turns and checks the tension on the web to see if it has snagged a target. In this case, there is no tension, so the spider reels in the thread. I am not sure if crab spiders consume the spent silk.

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Another try, in another direction.

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This time the tension is right, and the spider quickly disappears from the frame.

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And arrives safely at another, more lively flower.

Bugs ‘n’ More! Insect outreach with kids

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Getting out to talk to kids about bugs has got to be one of the coolest things to do in science outreach….As we did last year, we went to the Richmond Nature Park for their insect (and spider!) show. Great thanks to all the volunteers and especially Emily Toda for putting this together.

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Tanya Stemberger was out to get the kids into entomophagy (eating insects), serving up tasty insect treats with Grant Olson. Tanya is subtly indicating that this is going to be awesome.

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Grant is a professional in the world of insect cuisine, as he works for Enterra, a company that produces animal feed from insects. Of course, all the bugs served up were human grade!

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Catherine Scott was on hand to talk to kids about our native spiders, and to show some great examples, including black widows and jumping spiders. Here she is with a Madagascar hissing cockroach, one of the great insects we had on hand for kids to touch and handle.

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It was great to see Mike Hopcraft, the Reptile Guy, back again with his awesome collection of scorpions, tarantulas and more!

We had an absolute blast showing these cool insects and spiders to the kids. If you ever get the chance to do this kind of outreach, DO NOT HESITATE! It is awesome!

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OK, bear with me here. I got so many great shots of kids playing with insects, I put them in a gallery. Just click on the first image below, and a slideshow should appear. Enjoy!

 

Further shots from Naramata

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The Rubber Boa I wrote about yesterday was just the icing on the cake of my recent trip to Naramata.

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Here is a large mayfly by the shores of Lake Okanagan.

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The owner’s friendly dog at the Village Motel.

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My first sighting of a very elegant myrmicine, Manica invidia

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One of the coolest wineries in BC!

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With the namesake!

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This is probably BC’s smallest ant, Solenopsis molesta.

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This gives an idea how tiny these ants are!

 

Another elegant myrmicine, Aphaenogaster occidentalis.

Framed spider art on a fence in town.

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A large tenebrionid in a defensive posture.

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A Cooper’s Hawk with some prey.

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