I found this in my archive from last year. It looks like it may be drying its wings or…
… conducting the ‘Ode to Joy’ !?
I found this in my archive from last year. It looks like it may be drying its wings or…
… conducting the ‘Ode to Joy’ !?
Updated July 12, 2019: Added a ‘See Also’ section.
Anyone who regularly watches birds in North America will, at some point, come across a small flycatcher from the genus Empidonax for which species identification may have proven to be difficult or impossible. In many cases the only reliable identification requires hearing the bird’s song which is only sung by the adult male and usually only during breeding season.
There is a second genus of flycatcher, Contopus, (pewees and wood-pewees) that should be considered as some of its species can resemble those of Empidonax. On Vancouver Island the relevant Contopus species are the Olive-sided Flycatcher and the Western Wood-Pewee.
Our house backs onto a small pond and wetland decorated with fairly heavy brush that provides good cover for birds and other critters. The brushy area behind our yard is where I recently encountered the flycatcher shown in the following pictures:
These images were all taken with my Panasonic FZ-200 camera and have not been edited other than to crop the images. No song or call was heard from the flycatcher.
None of the Contopus flycatchers appear to be a match leaving us with Empidonax. Based on the Sibley Guide to Birds (2000 edition) the only Empidonax species that we should see in the Nanaimo area are Pacific-slope, Willow and Hammond’s. The Least, Dusky and Gray Flycatchers have normal habitats that come close to Vancouver Island and should not immediately be discounted when comparing species based on appearance.
I am not comfortable assigning my flycatcher pictures to any of the above mentioned Empidonax species to I will solicit birders out there to propose a species type for the above images hopefully with an explanation for their identification.
Here are some resources for flycatcher identification. I will update this post if I find additional interesting links.
If you think that identifying the Empidonax and Contopus flycatchers is difficult up here in Canada and the US during breading season, consider what it must be like in April and May in South America where migratory species from the East and West coasts of North America are intermixed with non-migratory resident species. To make matters worse they various species may be silent, not singing those songs that are sometimes the best way to separate and identify flycatchers. Here is a link to a document provided by eBird Central America that will give you a summary of the ID challenges and provide you with tips on how to separate: Flycatcher ID challenges in a Central American context.
Our back deck overlooks one end of a wetlands that eBird identifies by the hotspot Oliver Woods Community Centre Pond. This location, which has only been identified as a hotspot since February 2019, has more than 50 species associated with it. I have seen most of these from the comfort of our back deck.
In the last few days Cedar Waxwings have caught my attention. There appears to be a resident population of ten or twenty Waxwings that hand out around our end of the pond. I usually think of this bird as hanging around in flocks looking for berries to gorge themselves on, particularly in the winter months. I would normally expect them to be somewhere else right now. According to the All About Birds information for the Cedar Waxwing, however, this region has year-round populations. of Cedar Waxwings.
In the last few days I’ve seen two interesting Waxwing behaviours.
First, a number of the birds regularly spend time on top of the large lily pads that cover much of the pond. They appear to be foraging for insects. The following picture shows an example:
I noticed the second interesting behaviour at dusk. Here is a picture of the pond just before sunset.The glowing areas are some bushes catching the last daylight. The glow is also attracting lots of flying insects. The Cedar Waxwings were attracted to these insects and were making short excursions from nearby perches to fly-catch.
Here are a some images of perched Waxwings between foraging flights:
I will have to try making short videos of the fly-catching flights.
I did a little more research into Cedar Waxwing behaviour. From the Food section of the All About Birds website Life History for the Cedar Waxwing I found the following:
Cedar Waxwings feed mainly on fruits year-round. In summer, they feed on fruits such as serviceberry, strawberry, mulberry, dogwood, and raspberries. The birds’ name derives from their appetite for cedar berries in winter; they also eat mistletoe, madrone, juniper, mountain ash, honeysuckle, crabapple, hawthorn, and Russian olive fruits. In summer Cedar Waxwings supplement their fruit diet with protein-rich insects including mayflies, dragonflies, and stoneflies, often caught on the wing. They also pick items such as scale insects, spruce budworm, and leaf beetles directly from vegetation.
I also checked Birds of North America Online (requires a subscription) and found the following text:
One of only three species worldwide in the family Bombycillidae, the Cedar Waxwing is named for the red, waxlike tips on the secondary flight-feathers of adult birds. Sugary fruits dominate the diet of this bird, especially in winter. During warmer months, Cedar Waxwings glean insects from vegetation or snatch them from the air in sallies from exposed perches, often near streams or ponds. This is a true frugivore, assimilating nutrients from fruit pulp and passing seeds intact back to the environment.
Apparently this is all normal behaviour. Huh!
Through a Facebook friend I found this link to a New Scientist article suggesting the medication for Diabetes may help slow the progression of PD.
The drug, FDA-approved since 2005, is called exenatide and is used to treat type 2 diabetes. It works by protecting neurones from toxins. One potential downside is that the drug is currently injected twice daily though a once-weekly injection was approved in 2012. The major side-effects appear to be gastrointestinal.
If I have a major criticism with the article it is with the title which implies that there are no current ways to slow PD progression. In fact exercise, diet, social interaction and at least one drug, Azilect, are all known to or suspected of slowing PD progression to varying degrees.
Just for fun.
Find and identify the bird(s) in this picture. It was taken in my backyard a couple of days ago.
It’s been pretty quiet on the birding front but I decided to go on the Nanaimo/Parksville Sunday bird walk to Bowen Park. In the heart of Nanaimo, this park is a jewel with most of its 36 hectares undeveloped.
The walk starts in the parking lot, near the first hole of Nanaimo’s Disk Golf course where we quickly spotted a Brown Creeper while waiting for the group to assemble. This one was quite vocal (for a Creeper) emitting a double note call at fairly regular intervals making us wonder if it was a young bird.
It was pretty quiet today. There were no Starlings or House Sparrows which helped keep the BQI (Bird Quality Index) high.
Shortly after we started down the birding trail we discovered a fairly large paper wasp nest. What I liked was the colour and pattern — different from the grey nests I am used to. Perhaps mocha is this year’s colour in paper-wasp real-estate.
A bit further, someone noticed an interesting spider web hanging between trees. With a bit of light that made it through the thick forest canopy it looked a bit like a suspended compact disk.
Next along the way was a Pacific-slope Flycatcher, making short foraging flights, returning to the same perch. He was quite cooperative, hanging out a few meters from the path so that everyone could get a good look or take a few pictures.
Pileated Woodpeckers frequently are oblivious to us birder-humans as we take shot after shot while they peck away at the trees. This female was pecking at various trees, occasionally do light renovations to existing holes. With the dark under-canopy, the camera shutter speed was in the 1/100 to 1/200 range so you had to snap your shot during the bird’s brief bouts of pounding or the image would be heavily blurred.
We saw a Barred Owl along the way but getting a good image would have been a challenge so I didn’t even try. The following two owls, however, cooperated with my picture taking:
Almost at the end of our outing, we found our ‘Bird of the Day’ — an American Dipper. It was hanging out in a shaded spot at the edge of the Millstone River. The BQI definitely jumped when we found this bird.
That was it. About three hours at Bowen Park. Total species count: 25.
This walk was organized by the Nanaimo Backyard Wildbird and Nature Store. They can be contacted for more information on future Sunday or Tuesday outings.
I dislike unhappy stories and enjoy writing about them even less. However, I have to remind myself that not everything is about the birds — Mother Nature is a much more clever scriptwriter than that.
I mentioned in my last post that there were some moving specks on the vinyl siding behind the nest that I suspected might be some kind of bird mite. Here is what my research found.
At the end I share my opinions as to the effect that the mites had on the nestling development and their departure from the nest.
I went back and looked at video footage to look for evidence of moving specks which I would later confirm to be mites. It turns out that a good way to see them is to fast-forward the video and watch closely — the mites are easy to see when moving, especially those on the light coloured vinyl siding.
I found the first mite evidence in the July 19 webcam footage — (hatch-day + 8). On subsequent days, the quantity of mites increasing dramatically, dare I say ‘exponentially’, until the three nestlings left the nest on July 23. While the initial mites were only seen while moving on the vinyl siding, by July 21 large immobile clusters of mites could be seen on the outdoor light fixture. Here is a picture taken on July 22 with my Panasonic FX-200 camera:
The out-of-focus mites are still visible on the siding behind the nest. More obvious are the the brown patches on the black edge of the light fixture in which individual mites are easily visible. The reddish-brown colour comes from mites that have all taken some blood, probably from one of the nestlings (’empty’ unfed mites are light coloured).
To study the mites more closely, I ran a lint roller along the edge of the light fixture. This was surprisingly effective at removing all of the mites in its path. The sticky lint-roller paper immobilized most of the mites however there were still a number of wandering mites so I sprayed the sample with a mixture of bleach and water to make sure the mites were dead before the sample came into the house.
To demonstrate the mite size and numbers, I took a picture showing a section of lint-roller paper with mites next to a Canadian dime:
A dime is about 1.8 cm in diameter so I estimate the density of mites in the high-density area along the top of the sample to be about 200 per square centimetre. After the nestlings had left the nest, there was extensive coverage of the light as well as 4 or 5 patches of packed mites on the siding. Estimating the visible coverage at around 200 square centimetres that would mean about 40,000 mites. This is just the visible areas and the hidden areas on the light fixture. Any mites on the nest or the nestlings are not included though one might expect both to be heavily infected. My best estimate for the total mite count is somewhere between 50,000 and over 100,000.
We have a Wild M11 microscope which I used to get a better look at the mites. Using my iPhone camera, I was able to take some surprisingly good pictures. The following image was taken at the lowest (4X) magnification:
The wire has a length of about 2.2 mm at this magnification (calibrated with a plastic ruler) making the mites’ length about 0.6 mm. The next image was made at the next highest magnification (10X). Unfed mites are clear so this looks like a mite that has fed on blood — nestling blood most likely.
The two most common North American bird mites are the Northern Fowl Mite (Ornithonyssus sylviarum) and the Chicken Mite (Dermanyssus gallinae) which goes by several other names such as the Red Mite, Red Fowl Mite and Red Poultry Mite. Both are of great interest to the poultry industry because of the costly damage they can do. Both can infect wild bird species. From various sources I have read, I concluded that the flycatcher nest was probably infected with the Northern Fowl Mite.
The best reference that I found summarizing issues around bird mites and humans comes from a 2010 document from the PennState, Department of Entomology series of short Entomological Notes simply titled BIRD MITES (accessed July 28, 2017). Below, I quote a few of the more relevant paragraphs and highlight important sections that helped me handle the flycatcher mite infestation:
Bird mites are very tiny, flattened parasitic arthropods in the order Acari. They belong to two closely related genera in two families; Dermanyssus species in Dermanyssidae (Fig. 1), and Ornithonyssus species in Macronyssidae. Bird mites have piercing mouthparts that enable them to take blood meals from their bird hosts. Although the mites will inadvertently bite people, they cannot reproduce without their bird hosts.
Bird mites have five stages: egg, larva, protonymph, deutonymph and adult. The larvae have three pair of legs; the nymphs and adults have four pair. Adults are about 0.7 to 1 mm in length and are just barely visible to the naked eye. Unless they are moving, they are extremely difficult to see. The color is translucent white until they take a blood meal after which the mites are reddish mahogany to brown. Mite eggs are white, oval and cannot be seen without the aid of magnification. The same applies to the larvae and nymphs.
Most bird mite species can complete development in five to twelve days with optimal temperatures and host presence. This short life cycle makes it is possible for mite populations to attain tens of thousands of mites in bird nests during the rearing of young birds. If the population is too large (or if the fledglings vacate the nest or perish), the mites will migrate in mass to locate an alternative host. It is during this migration that mites can and do enter the living quarters of people. Some mites (i.e. Dermanyssus gallinae, the chicken mite) can survive for several months without taking a blood meal; the northern fowl mite, Ornithonyssus sylviarum, for several weeks. However, the mites do not appear to survive for more than several days in the reduced humidity (<35%) environs typically found in air-conditioned or dehumidified homes.
Birds should be discouraged from building nests in or adjacent to buildings. Close all openings large enough for birds to enter attics, sof ts and similar areas. Install hardware cloth, sheet metal, or other materials to prevent birds from nesting and roosting on porches, breezeways and other exterior sites. Disrupt nest-building efforts by removing partially completed nests in shrubbery and on air conditioners and windowsills.
If mites are detected in the structure, locate the bird nest source. Remove the nest.
My take home message was to monitor the mites both around and away from the nest and be prepared to remove the nest and sanitize the nest area once the nestlings had left the nest to prevent the host-less mites from moving inside the house looking for new targets. I read some accounts of the problems that resulted from houses that became infected by bird mites (readily available on the websites of many extermination companies) and they definitely made me want to keep the mites outside.
Beside the visual evidence of an exploding mite population, the nestlings became increasingly restless as the quantity of mites increased. Frequent episodes of scratching were noticeable on the webcam videos.
My personal belief is that the nestlings left the nest early, before the were ready to fledge, in large part because of their discomfort from the mites. I know that one nestling perished because I found the body on the morning of July 24. The last sighting of a nestling was on the morning of July 25. The last sighting of the female adult sticking close to its foraging area near our house was on July 25.
One final reason why I do not think that there were any surviving nestlings was the presence of a domestic cat nearby. The day that I found the dead nestling, it was lying in our driveway when I returned home from some errands. I have seen the cat, before and since, in and around our yard. An unfledged nestling hopping in the bushes would have had little chance of avoiding the feline if it were spotted.
I have listed below some of the interesting references that I found online.
 This 2005 reference contains some good high-level information on mites: Common Lice and Mites of Poultry: Identification and Treatment.
 One of the best short summaries on bird mites that I have found: UW Madison Department of Entomology information sheet.
 Good reference from Iowa State University: Bird-Mites.
 A good 2014 review article: Mites and birds: diversity, parasitism and coevolution.