|Spring arrived early in Vancouver this year with
beautiful weather in the early part of March which coincided with
the early arrival of the first migrant hummingbirds. After a long,
dark and wet Pacific Northwest winter where there are virtually no birds
left in the park, the hummers were an early reminder that spring
banding was just around the corner as we waited patiently to start
our banding and monitoring operation again.
Our migrant hummers on the coast are mainly Rufous
(RUHU) and our
resident hummers Anna's (ANHU). Speaking of Anna's Hummingbirds Mike Yip
sent these amazing photos of a white Anna's he was able to capture
on Qualicum Beach, Vancouver Island in July.
Most white birds are "leucistic" a condition in which there is
partial loss of pigmentation resulting in white, light, or patchy
coloration of feathers, caused by a reduction in multiple types of
pigment, not just melanin. A leucistic individual usually has white
or patchy white plumage, but its eyes, feet, and bill show
normal black pigment as was the case with this bird.
There are very few true albino birds that have no melanin at all
where the feathers are pure white and where the eyes, feet, and bill
appear pinkish because the absence of black pigment allows red
hemoglobin to show through.
|Whether leucistic or albinistic, there are very few
white hummingbirds in the world with reports of less than a hundred
or so white hummers among all hummingbirds that have ever been
seen so Mike's bird really was quite amazing and to get such
fabulous shots more amazing still! (Thanks for sharing Mike!)
(Photos by Mike Yip - Please note that all images are copyrighted and are not to be
used without permission)
|Well, if a white Anna's isn't exciting enough this
after hatch year (AHY) male Calliope Hummingbird (Stellula calliope)
was an exciting and surprising capture as it was the first ever
Calliope to be banded at Colony Farm, bringing the total of species
banded for the station up to 98!
Similar to the commonly captured Rufous
Hummingbird, the Calliope Hummingbird can be distinguished by its
short thin bill and short tail. Rufous Hummingbirds have a longer
bill and tail and a richer rufous wash to the underparts and tail
feathers, while Calliope Hummingbirds have cinnamon edging on tail
feathers and a cinnamon wash to the undertail coverts.
|These hummingbirds are the smallest species of bird
that breed in North America, this bird weighing in at just 2.7
grams! Since they breed in
montaine conifer forests generally ranging from 4000-1000 feet in
elevation, and prefer the drier, chaparral habitat of the BC
interior, it is rare to spot these birds in coastal British
Columbia. As few as two sightings in the Lower Mainland have been
reported this year, with only three sightings reported in all of 2015.
(Photos by Debbie Wheeler - Please note that all images are copyrighted and are not to be
used without permission)
|Although by no means as rare as the birds above the
after hatch year (AHY) male Anna's Hummingbird below makes the blog just
because it is such a striking individual.
Anna's Hummingbirds are now common
birds along the Pacific coast and throughout the Vancouver area,
their range having increased dramatically since the 1930s, when they
were found only in California and Baja California. The combination
of the planting of exotic flowering trees in parks and gardens and
the widespread use of backyard nectar feeders have resulted in its
breeding range expanding as far north as the Comox Valley on the
east coast of Vancouver Island.
Adult males like this one really are
like flying jewelry with their iridescent magenta-rose crown and
throat feathers. The
gorgets of hummingbirds contain highly iridescent feathers which are
among the most specialized feathers in all bird species. It’s not
pigments that give the feathers colour but the refracted light
falling at certain angles on the gorget.
Only a portion of each feather is modified for iridescence but the
overlapping of adjacent feathers creates the unbroken colour effect
of a single block of feathers as can be seen in the photo below.
|The technique we use for banding hummingbirds is
quite different from songbirds and
involves placing them in soft 'strait-jackets' which allows the
safe handling, banding and measuring of these tiny birds.
Hummingbirds are always firm favourites with visitors to the station
who, like us, can't fail to marvel at these tiny dynamos with wings
beating up to 80 times a second and hearts beating up to 1,200 a
minute in flight!
|We make the bands for Hummingbirds ourselves from
thin sheets of aluminum stamped with 100 band numbers provided by the federal Bird Banding
Laboratory, each strip of bands is carefully and precisely sliced to
1.4mm width and each band then cut to 5.6 or 6.0 mm lengths before
being filed and sanded with fine glass paper and formed and placed
on to safety pins.
The finished band is not much larger than the tip of a
retractable pencil (photo below left) and doesn't even register on a
digital scale weighing to a hundredth of a gram (photo below right).
|Hummingbirds are Apodiformes which comes from the
Greek word meaning 'no feet' and although they do of course have
feet to perch they are too far back on their bodies to walk. This
means that a Hummingbird placed on a hand will normally stay there
for a few moments allowing for fabulous photo opportunities for
visitors who never fail to be totally captivated by them like the
after hatch year (AHY) female RUHU below.
|Once banded, a number of biometric measurements are
carefully taken including wing chord, tail length and exposed culmen (the
length of the upper edge of the bill from the base of the feathers
to the tip - photo below) and each bird assessed for fat deposits.
|A final measurement prior to release is body mass -
our after hatch year (AHY) female below weighing in at a mighty 3.57
grams, slightly less than a Canadian nickel!
|A full photo essay on ageing and sexing Rufous
Hummingbirds can be found in our
June 2012 blog
the change of weather the first wave of migrants arrived including a
number of Yellow-rumped Warblers, this dazzling male Myrtle Warbler
in full alternate (breeding) plumage. The early returning migrants
are such a welcome splash of colour after months of drab resident
birds in basic, winter (non-breeding) plumages and we all get
excited wondering what each net round will produce!
Ageing and sexing
wood warblers in the spring requires a complete understanding of the
molt cycle of the individual species being studied. Adult birds like
this one will have undertaken a prebasic molt following the breeding
season last year when all body and flight feathers are replaced.
In species where the prebasic molt is the only molt occurring
annually breeding occurs in basic plumage and the result (when
looking at an adult bird, which has undertaken this complete
definitive prebasic molt) in the spring is that there are no
discernible molt limits on the wing between replaced and retained
However, in many
species there is a SECOND molt that occurs in the late winter /
early spring prior to the next prebasic molt. This molt called the
prealternate molt occurs in both adults and first year birds so that
in the spring first year birds will show three generations of
feathers but adults will also show molt limits. In adults however
there are only two generations of feathers, definitive basic and
definitive alternate feathers.
The after second
year (ASY) male Myrtle Warbler wing below is showing such a molt
limit (shown with red arrow) between the outer four greater coverts
replaced as part of the birds definitive adult prebasic molt last
year and the six inner greater coverts replaced as part of its
prealternate molt this spring.
spoken before about overlap in tail shape among the age groups in
Setophaga warblers and how tail shape alone is not therefore
reliable for ageing as all age classes can show rounded rectrices.
But the outer rectrices of the adult (ASY) male Myrtle Warbler below
is not only showing very truncate outer rects but also extensive
white on rectrices r2 to r6 and extensive black centers to the
uppertail coverts (red arrow) both of which which are diagnostic of
Adult male wood warblers are normally the first to
return like these three after second year (ASY) males - Townsend's
Warbler (left), Orange-crowned Warbler (below right) and Wilson's
Warbler (below left).
This spring marked the second year of
our special species study on Tree Swallow nesting behaviour using
Radio Frequency Identification (RFID) Technology. We are continuing
to use the technology to monitor parental activity during nesting.
Volunteer Kyle Norris built us a new “Super Coil” to test out in one
of our nest boxes. The Super Coil has a larger gauge wire than the
previous coils, which decreases the overall DC resistance of the
wire. This allows for a stronger magnetic field and greater
sensitivity. By comparing logged data to video of the nest box, we
have determined that the Super Coil is more effective at picking up
|Tag readings tell us
the time at which the female leaves the nest box to begin daily
activity and the time that she returns to the box for the night, as
well as each entry throughout the day. Our swallows tend to leave
that box between 7:00 and 8:00 AM and return for the night between
7:00 and 8:00 PM. The volunteers at VARC can only dream of getting a
12-hour sleep—most of us wake up at 4:00 AM for spring and summer
||Nest building began at the start of May with egg laying in
mid-May, a female laying one egg per day at dawn. A typical Tree
swallow nest has three to six eggs. At the beginning of this season,
7 out of 10 nest boxes had active nests. Eggs were laid in 6 of the
7 completed nests. After eggs were laid, we began catching female
swallows to apply Passive Integrated Transponder tags (PIT tags) and
bands. While most of the nesting females were unbanded second year
(SY) birds, one was a returning after hatch year (AHY) female. She
had nested in Box 10 last year with a successful brood and returned
to the very same box this year.
We will continue to monitor
nesting behaviour and fledgling success throughout the season.
|House Wrens have an
enormous geographic range in the Americas but are uncommon birds for
us on the coast - this hatch year bird was however the second for
the season and it is a species becoming increasingly common. Despite
their small size, they can be fierce competitors for nest site
cavities, sometimes evicting larger species such as Bewick's Wrens
and removing eggs from nests.
House Wrens are larger than the
more common Pacific Wren, lack the short, buffy supercilium, have
longer bills and tails and barred undertail coverts.
We also banded both Bewick's and
Marsh Wrens during this period. Bewick's Wrens are larger than
House Wrens with longer, barred tails and prominent, white superciliums.
Marsh Wrens are also small, dark wrens with a whitish supercilium
but have bold black and white streaking on the back.
|Other notable captures included a
Chipping Sparrow, Chestnut-backed Chickadee, 3 Bullock's Orioles
(all 3 of these species uncommon for us in the old field habitat
where we band at Colony Farm) and 5 Lazuli Buntings including this
stunning after second year (ASY) male.
also came through in good numbers with 46 Traill's (Willow)
Flycatchers caught for banding and 3 Western Wood-pewees which can
look quite similar in the hand but have longer wings extending to
the tips of the undertail coverts (photo left).
|Another nice tyrant
flycatcher was this gorgeous after hatch year (AHY) Western
Kingbird. Although not as common for us on the coast as they are in
the interior of BC, the open habitat at Colony Farm provides
suitable foraging habitat for these acrobatic flycathers.
|What would have been a
new species banded (and species #99!) for the station was an elusive
Yellow-breasted Chat which infuriatingly spent an entire morning
vocalizing and flying backwards and forwards above one of our
|And no VARC banding season would be complete without the
plethora of visitors which included a Bird Monitoring and Banding workshop
which included our friends from WRA (Wildlife Rescue Association),
monthly VARC Family Days, visits from Nature Kids, Brownies and Boys
|And proving that you can mix
business with pleasure we also hosted an entire Prospera Credit
Union branch managers developmental day at the station which was a
huge success with the managers saying it was the best developmental
day they'd ever had - even finance people can be persuaded that
birds are brilliant!
|And look at these
little girl's faces - who says public outreach programs like these
don't impact kids to consider birds and the environment?!!
||A total of 7,099.5 net hours were
completed during the spring/summer season thanks as always to all the
amazing VARC volunteers who set alarm clocks for ridiculously early
hours during the summer months to get to the banding station for
dawn at 4.45am!
1,621 new birds of 48 species
were banded and 432 significant retrap were processed. The most
commonly banded species were Song Sparrow, Common Yellowthroat and
Orange-crowned Warbler. The table left shows a complete list of new
captures and the table below a complete list of retraps.
interesting retrap was a stunning 6 year-old male Black-headed
grosbeak with breeding characteristics (cloacal protuberance) first
banded at Colony Farm in 2010 and amazing to think this bird has
survived 6 fall migrations to Mexico and has likely returned to the
park each spring to breed.
|And finally, a VIP visit from Bob Elner who is the
Convener of the 27th
International Ornithological Congress 2018
which will be held in Vancouver (19-26 August, 2018) and which VARC
will be involved with supporting the conference and hosting
one of the field trips.
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