Vancouver Avian Research Centre

.....Research - Conservation - Education
Spring/Summer 2016

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

With 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 feathers.

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 definitive (adult) prealternate molt this spring.

We've 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 birds.

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.

 

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 banding!
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.

 

 

Tyrant flycatchers 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 woodland nets!

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 Adventure groups.

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.

 

 

 

  
 

 

A particularly 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.

VANCOUVER COMES ALIVE WITH BIRDS IN AUGUST 2018

IOCongress2018 is a game-changer by combining the prestige of hosting the 27th International Ornithological Congress with the City of Vancouver’s annual Bird Week, the organizers are creating the first ever World celebration of BIRDS in all their dimensions – nature, art, music, performance, film, photography and adventure. Two thousand bird scientists from 100 countries plus thousands more public will be engaged, educated and entertained through exhibitions, a bird fair, trade show, tours and workshops on BIRDS -

Building an Educational and Environmental Awareness Legacy through Birds
 

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