As mentioned in the previous post, and here at SpiderBytes, Catherine and I are temporarily leaving the field for rest, recuperation, and riting (?) back in Canada. We had to make an emergency medical landing in Denver, so I purchased some internets to warn Antonia (who is picking us up) that we would be a few hours late, so here is a post from the skies north of Colorado.
When it became evident that we were leaving Honduras for the colder regions of the world, with surely far fewer active insects and spiders, I took the opportunity to do some last-minute shooting for both this blog and for Catherine’s. I had not been doing very much until then, as we were still getting used to the country and our work schedule. So the following is a small selection of insects and spiders found in our last few days in Gualaco, all found within 20 m of our apartment. I found the shooting a bit difficult, not being in good practice, and worried about our project, but I did manage some adequate documentary shots. Coming up, I will discuss the second field trip and more about the caracaras and the problems facing them in Central America. Until then, enjoy these shots!
Looks like some kind of Wood Nymph.
This egg mass has an unwelcome visitor.
This is a Lyssomanes jumping spider, doing their freaky eye thing, where the eyes go from green to black. I am not sure what it is all about, but probably some kind of focusing.
I tried to get this “creamier”, but did not get the f-stop low enough. Illuminating the background sometimes makes the composition harder to control.
So Catherine, Isidro Zuniga, and I finally got out to the field this past week, and ended up in a small hamlet outside of Gualaco. We were guests of some incredibly hardworking people, so we tried to work hard as well, cramming 54 kilometres of trail walking into just 3 days. We decided the best thing to do would be to do some walking, mapping and call playback to get the lay of the land, and to figure out where these birds might be. We had informants everywhere, as the people are often working in the forest, tending cattle, cutting pine or maintaining small milpas on the hillsides.
At the end of our first long day of walking, we got a hot tip that we had missed seeing a group of caracaras by a couple of hours in the morning. The next day we headed out in the direction of the previous day’s sighting, and along the way got further info steering us to a valley just south of the town. We walked about a kilometer down the valley and did a call playback. Soon enough, we heard a distant group of caracaras to the southwest. Being unsure of whether it was a true reply or not, we scrambled up a large hill on the south side of the valley, and played back another call. Within a minute, three caracaras came screaming in within 20 metres of us, loudly contesting what they presumably perceived to be a territorial incursion.
I managed to get some good pictures and observations in, finding that these Ibycter americanus guatemalensis are not much different from the South American I. a. americanus, and their supposedly larger stature is not very evident in the field. The behaviour was identical to what we had seen in French Guiana, except that it was all occurring in a mid-elevation pine forest full of people, cattle and anthropogenic alterations. These three caracaras were later joined by at least two others, making this a group of 5 or more birds. In all likelihood, these are the same birds that reared a chick last year, although if that is the case, there should be 6 (assuming there has been no mortality or emigration).
The major revelation of this trip, however, came from the interviews we did on the fly with people out working in the forest. It seems, at least initially, that these birds have much larger territories than the ones in South America, and may cover distances of 6 km or more during daily foraging. Considering the difficulty of navigating the terrain (it is steep! see below!), It worries me quite a bit that our planned radio tracking project will be very difficult to carry out, at least from the perspective of distance. While we may not have the insanely thick vegetation and radio attenuation of the rainforest to deal with, the terrain is very rugged, and chasing these birds down over large distances is going to be physically very challenging…Not to mention, radio attenuates very steeply when it hits rock!
Enough griping! I will lay out the specifics of the work situation in a later post. For now, please enjoy these images of the extremely rare Red-throated Caracaras of Honduras!
Check out this new paper in Frontiers in Zoology. describing experiments that show that male hobo and black widow spiders use low amplitude vibrations to court females and avoid sounding like prey. This paper was written by my labmates Samantha Vibert, Catherine Scott and Gerhard Gries, and congratulations are in order for pushing through a tough research project.
It seems that spiders are finally starting to get a lot more attention from behavioural studies, and they seem to strike a chord with the public too, especially when reporters refer to the spider movements as “twerking“. Have a look at what Catherine has to say about this paper over at SpiderBytes.
We did manage to get out on the weekend for a small expedition, to see a working farm/ranch and some remnant oak and gallery forest near Gualaco. This was a muddy undertaking, as there had been some considerable rain the night before. We did see some cool stuff, including this Laughing Falcon (Herpetotheres cachinnans).
The scrubby ranchlands do not have very large trees,
Catherine and I rode this horse, which had a fresh vampire bite wound on its neck, across the river. That is our host, Don Rafael, on the right.
Upon returning home, we did some shooting of insects and spiders. This is some kind of blister beetle (Meloidae). Catherine has more spider photos here.
We have arrived (finally) in Gualaco, after a crazy few days passing from Vancouver to San Pedro Sula to Tegucigalpa.
It has been quite hectic getting settled, and I am having difficulty re-adjusting to Spanish. We have an apartment now, and so are feeling a bit less nomadic than when staying at the hotel.
We went out and saw the areas we will be working in yesterday, and they are in really really rugged terrain! The forests are mostly pine (Pinus oocarpa), and the terrain is mountainous and steep in many paces. Much of the region is second growth, and is used for ranching. The forest is rather open, due to periodic burning and grazing, but getting around is still rather difficult due to the topography. We tried some caracara call playback, but had nothing responding whatsoever. This is very different from the situation in Amazonia.
The rolling pine forests northwest of Gualaco. This is right near the are where caracaras nested last year.
We are planning on staying put for the next few days, but will head out to Tegucigalpa next week for permit applications, and then will do a scouting mission starting on the 20th. With terrain like this, we will most definitely be getting our exercise!
Things have been rather quiet here at Ibycter lately, with less in the way of Weekend Expedition posts and no Cheapskate Tuesday posts for a while. The reason for this is that Catherine and I are getting ready to make a trip to Honduras to do a preliminary conservation study on Red-throated Caracaras.
If you remember from back in June, the Honduran Conservation Coalition found and monitored a nest site in the Olancho Department, and they believe there is still a sizable population of caracaras nearby. I have wanted to work on Red-throated Caracara conservation biology for a long time, as no formal study has been done on the conservation of these birds in Central America. They are in steep decline across the region, and have disappeared from Mexico and Guatemala.
I was invited by Mark Bonta to come and do some research on these birds, and so, because I had funding from the National Birds of Prey Trust to do conservation research, I informed them of a change in venue to the heart of the region where caracaras are declining. We have since secured some more funds from the Zoo Conservation Outreach Group, as well as a private donor, and so we will be going to implement the start of the project.
This project will see us engaging the local volunteers and researchers to help us determine home range sizes and habitat occupancy of caracaras in the forests near Gualaco. We will do radio tracking of birds from various caracara groups in the area, and will hopefully be able to get a preliminary estimate of home range size. We will also do call-playback surveys of the forests in order to determine the numbers of groups occupying the area. A third objective is to make further documentation of nesting behavior and food habits of the caracaras, as this is relatively unknown for the region.
Anyway, we ship off Monday, and will arrive in Tegucigalpa on Tuesday. After that we will be guided around the region and introduced to the stakeholders and collaborators. This is my very first field research conducted outside the bounds of a research camp, so making sure that everything is in order is a bit stressful.
We hope, however to continue to blog both here, at Catherine’s SpiderBytes blog and also at the ESC blog about all the cool stuff we encounter and the process of doing exploratory field research.
It turns out that the 140 lb Rottweiler cross I have been living with on and off with for the past 5 years has a dirty little secret…He poos in my room sometimes, but only when he really has to go and only as a last resort. Nonetheless, it is a stinky terrible mess.
Well, a few days ago, he did the same thing, but afterwards he wasn’t getting any better. He started having bloody stools, so his owner Buffie (my roommate) took him to the vet today. The vet gave him an X-ray, and look what he found:
Yep, that is a bullet! Someone, sometime, shot this poor dog, and we have no idea who, where, or when. He is a total homebody, and only goes out in the backyard and on walks with Buffie. To me, it looks like a 9 mm round, fired from the front of the dog and above. It does not appear fragmented or mushroomed in any way, so either it was a jacketed round, or was not going very fast when it entered his body (perhaps a chance hit from a shot fired in the air?).
There is no obvious entry wound, and so it is a mystery when and where this happened. Buffie got the dog from the pound when he was 2 or 3, and he looked like he had a rough life, so maybe Taiko was some drug dealer’s guard dog or something…and got shot in the process, ending up on the street?
Anyway, the bullet is in soft tissue, and the vet did not think it needs to be removed, so there it will stay. The digestive problems are unrelated and are being treated with antibiotics. They probably result from consuming some awful thing on the ground during a walk. Hopefully his stinky butt will get better soon. That enlarged intestine bodes no good for anyone nearby….
If you happen to be in Vancouver this coming Sunday, please consider dropping by for my talk at UBC’s Beaty Biodiversity Museum.
The talk is at 1 pm at the Museum’s lecture hall. The talk is geared to a general audience, and will be filled with cool videos from our recent paper, as well as other unpublished stuff about territoriality and social behaviour.
Here is the blurb:
Red-throated Caracaras are way cool because…They are the wasp-murdering superheroes of the rainforest! Not many animals like to attack and eat social wasps because the stings of these insects are usually an effective defense. The Red-throated Caracara manages to overcome this defense daily, bringing 9 to 15 wasp nests per day to its chicks, and somehow avoiding a painful death from wasp stings. Sean McCann, PhD student at Simon Fraser University and his team investigated the nesting, territorial, and wasp predation behaviour of these wasp specialists over five years to get a better picture of the fascinating life history of these amazing birds.
2013 has been a great year for shooting as well as for getting my images out to people who are interested, via this blog! There are so many decent images to choose from, and I am a bit pressed for time right now, so I will organize the pictures that stood out for me phylogenetically.
Insects
One of the beautiful Ammophila featured in Ibycter Illustrated. Photographing sleeping Hymenoptera at sunrise gave me a new appreciation for mixing ambient and flash.
I love the way the dew sparkles on this Lycaenid.
In 2013, I got to indulge myself with many opportunities to shoot Coelioxys, my favourite Megachilid.
Using flowers as colourful backdrops was something I explored in the gardens this year.
Not the best technically, but it was great to come upon this scene of predation between Laphria and Apis. Productive slacking indeed!
Another Laphria found on a window provided a good long photo session so I could explore lighting against the sky.
Getting out to YVR with the Wildlife Control people was a really fun experience. This molting Peregrine tiercel was one of the better shots I ever got of a peregrine.
Red-throated Caracaras are specialist predators of the brood of social paper wasps, as our previous research confirmed. The big question we wanted to answer was: how do they manage to attack and subdue the workers of these well-defended wasp nests? A previous study by Jean-Marc Thiollay suggested that Red-throated Caracaras may possess a chemical repellent that keeps the wasps from approaching and attacking them, but this hypothesis was never tested.
We sought to shed more light on this by sampling chemicals from the birds and by observing the predation behavior firsthand.
To do this, we set up a “feeding station” to record the caracaras attacking wasps. We lured the caracaras near to the video arena by playing recordings of their vocalizations from an amplifier near the site. The birds would come to investigate the source of the calls, and once they saw the wasp nests we had set out there, the caracaras went in for the kill, and we captured the behaviour on video.
This is the video arena we set up in the forest behind the camp. Maintaining the condition of the “waterproof” video cables and connectors was very difficult in the rainy season!
These are the five species of paper wasps we managed to get the caracaras to attack.
The caracaras did not seem to have significant problems with the smaller wasp species Polybia bistriata, Polybia scrobalis or Polybia affinis. None of these seemed to attack the caracaras at all. But check out the following video of an attack on a larger Polybia jurinei nest:
The caracaras knocked two of these nests to the ground, and later flew down to retrieve them. In another attack on a nest of Polybia jurinei, the caracaras repeatedly slammed into the nest, and eventually the wasps abandoned their defense. These situations where the wasps abandon their nest represent a behaviour known as absconding. The swarm-founding wasps, with sufficient nest disturbance, can fly off en masse to quickly found a new nest elsewhere. They lose that batch of brood, but save the workers from an ultimately futile defense of the nest.
My suspicion is that larger nests than these would put up much more of a fight. Unfortunately, we never got to record attacks on some of the truly huge nests that can occur in the tropics. We did record the aftermath of one such attack on Polybia dimidiata:
The video data do tell us that the type of chemical defense envisioned by Thiollay does not seem to be how the caracaras avoid wasp stings, but we did look for potential chemical repellents anyway.
Sampling from a caracara face using solvent-soaked cotton swabs. We also sampled the feathers and feet, using both methanol and hexane.
We anticipated that any potential chemical repellents would be detectable by the antennae of sympatric wasps, so we brought nests of Polybia bistriata back to the lab to test the caracara extract for compounds perceptible to wasps using coupled gas chromatography/electroantennography (GC/EAD)
As you can see from this example GC/EAD recording, Polybia bistriata antennae respond to several components of the caracara foot extract (the top trace shows the chemicals, the bottom shows the antenna’s response). Compound A is sulcatone, while the compounds labelled B are iridodial isomers, and compound C is a boring old fatty acid (which is found on most animals). Iridodial and sulcatone are repellent compounds, but best known from dolichoderine ants, such as Azteca.
We suspected that the caracaras may have picked up these compounds from Azteca ants. To follow up, we sampled Azteca chartifex near the field station at Saut Pararé and compared their pygidial gland secretions with the caracara foot extracts using GC/MS.
At the top is the GC/MS trace of the Azteca sample, at the bottom is the trace from the caracara feet. Notice the shared ketones and the iridodial isomers. We found these ant-type compounds only on the feet, suggesting that the caracaras are attacked by Azteca while perching.
And this is why we suspect caracaras come into contact with Azteca! Polybia rejecta nests in close association with Azteca, which protect the wasp nests from army ants. It could well be that the caracaras are attacked by Azteca while preying on these wasps. It is also possible that the caracaras are just incidentally attacked while perching on Azteca-infested trees. Photo provided by Pablo Servigne.
In summary, the caracaras do not have much difficulty with smaller species such as P. bistriata; just tearing into the nest is sufficient to cause these wasps to abscond. With larger species, the caracaras have to use more persuasive tactics, such as knocking the nest to the ground or striking it repeatedly. While it does not seem the caracaras have chemical repellents, the discovery of the ant-derived defensive chemicals highlights the surprisingly intricate connections between organisms in the rainforest.
