Adjacent to my work site yesterday were some coyote pups! They were coming out of their den to sun themselves and play in the weeds. I do not really know what to say about these, other than that they were cute! I wish I had my 300 mm, but did not bring it, so these are all taken with the 100 mm. I was surprised by how dimorphic they were, with the dark one looking a bit dog-like. It is common for urban coyotes to have some dog admixture in their heritage, so perhaps that explains it.
I had been doing work at this same site in the fall, and would often look up from my ant nests to see an adult coyote watching me from a short distance away. The adult coyote never even tried to steal my lunch, although that would have been easy. It seems these coyotes have learned to coexist with humans relatively well.
I am working again with ants this summer, and have been getting out a bit for work and on the weekends for special outings. I have been accumulating a number of excess photos over the past few weeks that don’t really fit in with the special topics (Guyana, Expeditions, Okanagan) so I have put them together here. I hope you enjoy them!
So Catherine and I have a week off this coming week, so we are planning to go for a bit of a vacation in the Okanagan. We will be mostly in the boonies, camping and searching for critters, so will be out of contact for a bit. It also means I will have to interrupt my series on the Guyana trip. When I come back it will be all Guyana, all Okanagan, all the time!
Our transport will be a venerable old Honda Civic that Catherine picked up for 500 bucks! It has new brakes and everything so should be a safe and reliable steed to carry us eastwards.
We are going to look for a long list of interesting animals, from scorpions and rattlesnakes to a few special spiders (Argiope, Antrodiaetus, Latrodectus [of course!)). Catherine and I will be trying to get some shots of rubber boas as well. Who knows what we will see! This will be a time for us to get out and get busy searching for whatever we can find. I think it will be awesome.
Compared to my time in French Guiana, I found that travel by river offers a much greater volume of observations than walking in the forest. When I was in French Guiana travelling trails on foot, I was lucky to encounter one example of a particular habitat in a day, but on the boat I could see the same type of habitat many times over. Needless to say, this was a great natural history lesson in the making.
One of the particular habitats we saw a lot of was the meanders of the river, where the river loops and bends around long curves. These bends form spontaneously via the action of vortices along curves in the river, and on the inside of each curve there is high deposition of silt (on the outside is a high level of erosion). This is the process by which oxbow lakes are formed. The result is that the inside curve is an area that was formerly river-scoured, but now has abundant new soil. Within these areas are a sparser forest, dominated by a few fast-growing tree species such as Cecropia and Triplaris (called “Long John” in Guiana). These are habitats that harbor a beautiful example of tropical symbiosis.
One of the first things that I noticed about these meander forests is that they more often than not contained a large colony of nesting Icterid birds, either Green Oropendolas, or Red-rumped or Yellow-rumped Caciques, with the latter being the most common. All of these birds are known to preferentially nest in association with large, aggressive wasp species, such as Polybia rejecta and Polybia liliacea. This is thought to benefit the birds in two ways. Number one is that the wasps can help dissuade nest predators, such as monkeys. Number two is that populations of predaceous wasps may reduce the parasite burden (particularly parasitic Philornis flies) that the nestlings endure.
In turn, the wasps nest in these particular trees for a reason. They nest in trees that are occupied by Azteca ants, a type of dolichoderine ant that basically owns the tree, with large carton nests containing perhaps millions of moderately small workers and hundreds of queens. The wasps nest here because the Azteca repel one of the wasps’ worst enemies: army ants. Although army ants (Eciton burchellii and Eciton hamatum) vastly outweigh the Azteca individually, the Azteca, by virtue of their overwhelming numbers, can keep army ant columns from advancing quickly up the tree (Servigne 2003). As army ants are all about blitzkrieg, and quickly stripping an area of profitable prey (Kaspari et al. 2011), they have learned to avoid the Azteca trees, which would take a protracted guerilla campaign to overcome. It has been recently shown that the wasps in turn benefit the ants, helping to repel some of their predators, such as woodpeckers (Le Guen et al. 2015)!
In examining again and again the morphology and placement of the nests in these associations, I was struck by a thought: perhaps the birds are also a net benefit to the wasps and the ants as well! I know from my research how formidable Red-throated Caracaras are in destroying wasp nests….What if these large numbers of nesting caciques help protect the wasps from the caracaras? It is not so outlandish a hypothesis, as the large nesting aggregations of caciques have been shown to mob bird nest predators such as monkeys and Black Caracaras and drive them away (Robinson 1985). Perhaps the Red-throated Caracaras may be driven away as well by large numbers of defensive caciques.
I was amazed by the numbers of large wasp nests we encountered at these sites, in stark contrast to the relatively low numbers I encounter in normal forests. It is not just the presence of ants which is keeping these nests safe, as Azteca occur in large numbers all over the forests. I think something else is going on here to help protect these wasp nests, and I bet it is the birds. Anyway, I would love to go and study this sometime, but this story just reinforces to me the inspiration that I only get by going to the field.
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.
MCCANN, S., MOERI, O., JONES, T., SCOTT, C., KHASKIN, G., GRIES, R., O’DONNELL, S., and GRIES, G. 2013. Strike fast, strike hard: the Red-throated Caracara exploits absconding behavior of social wasps during nest predation. PLOS One 8:e84114.
SERVIGNE, P. 2003. L’association entre la fourmi Azteca chartifex Forel (Formicidae, Dolichoderinae) et la guepe Polybia rejecta (Fab.) (Vespidae, Polistinae) en Guyane Française. Universite Paris-Nord.
Remember that Payara head we had left over from our meal? Well, we found a use for it!
We left it out for the Black Caracara (Daptrius ater) a small riverine caracara that often scavenges at human settlements and temporary camps. This behaviour seems pretty ingrained, and most times when we stopped along the river the caracaras would drop by in order to check whether we were cleaning fish or discarding waste.
Black Caracaras are small raptors with light wing loading and graceful flight. They are both generalist predators and scavengers (and have been reported to fish!), and were once considered closely related to Ibycter americanus (Red-throated Caracaras). The Black Caracara is also associated with tapirs and capybaras, picking ectoparasites off of their skin. These seem to be the only animals that tolerate these birds, as most others chase them away (they are significant nest predators of other birds, such as oropendolas and caciques).
Nesting behaviour is virtually unknown in this species, with only a single reported nest being observed. I quizzed the locals I met on this trip and met very few who claimed to have seen a nest.
Watching these observant and seemingly intelligent birds is a true joy, and was very inspiring. The relative lack of study of these birds leads me to contemplate studying them in the future. The rivers of this region would be a great base of operations for comparative study of four species of caracara.
I was delighted to discover that right across our street is a thriving metropolis of solitary bees (my guess is
Halictus EDIT: my guess was wrong! Thanks Erin! These are likely from the family Andrenidae). I was out taking some shots of these insects, when an elderly woman (from Italy I think) paused to look at what I was doing. I often get looks when photographing in public, so I explained how happy I was to see these bees right next to a community garden, and how cool it was to watch them work. She replied: “Too many bugs! Have to put down cement!”, and walked off.
Sometimes the light of a cloudy day is beautiful for photography, making features soft and creamy, eliminating harsh shadows, and enhancing colours. But this is a bright cloudy day we are talking about, not a gloomy, dark and depressing day like we tend to get around Vancouver this time of year. On a day like that, the photographer can only do one thing: eat Cheetos and veg out.
But wait! There is something you can do to get nice defined images of wildlife despite the terrible conditions and your way-too-old, way-too-noisy Canon sensor. Of course! Supplemental light!
I tested out throwing some hard light from trigger-controlled flashguns on a few species at Stanley Park this Saturday, and I am pretty pleased with the results!
Overall, I like this method of shooting, but would prefer natural light. For a gloomy day, when all I would get otherwise is a noisy mess, this is a good thing to try. With an actual lighting assistant, I am sure it could be even more fun.
Photography 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.
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: