Vancouver Avian Research Centre

.....Research - Conservation - Education
Spring 2014

Spring has to be every birder and bander's favourite time as migration gets underway with the return of migrant wood warblers in alternate plumage!

The first wave included both the Audubon's (below left) and Myrtle (below right) groups of  Yellow-rumped Warbler this photo clearly showing the difference between the two, Audubon's with the plain face and yellow throat compared to Myrtle with the distinct supercilium and black auricular and white throat. Myrtle Warblers breed further north in BC and we see them in good numbers in the spring but less commonly in the fall.

A trip to Point Pelee in Ontario at the beginning of May produced 160 species of birds with 31 species of wood warblers and although we can't boast the same diversity on the west coast our ones are pretty gorgeous too!

Adult males are normally the first to return like these three after second year (ASY) males - Townsend's Warbler (right), Orange-crowned Warbler (below right) and Wilson's Warbler (below left).

Setophaga warblers like the Yellow-rumped and Townsend's above have extensive prealternate molts in the late winter early spring which results in adult birds having molt limits but unlike second (SY) birds which show 3 generations of feathers, juvenal, first basic and first alternate, adult birds show only two, adult basic and adult alternate.

The wing of the ASY male Myrtle Warbler below is showing such a limit in the greater coverts (blue arrow) having replaced all body and flight feathers in its definitive adult prebasic molt after the breeding season last year and the inner greater coverts again in its adult prealternate molt this winter/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 retrices. But the outer retrices of the adult (ASY) male Myrtle Warbler below is not only showing very truncate outer rects but also extensive white on retrices r2 to r6 and extensive black centers to the uppertail coverts (red arrow) both of which which are diagnostic of adult birds.

A constant stream of visitors kept us busy this spring with a Bird Monitoring and Banding Workshop, Bird Identification Workshop, BCIT (British Columbia Institute of Technology) field trip, TWO VARC Family Days and a Young Naturalist's field trip among a number of other individual visitors! (whew!)

Family Days are a lot of fun for both parents and kids and the feedback we get from parents really makes these events special and very worthwhile providing kids with a unique opportunity to interact with wild birds and learn the importance of safeguarding habitat for both breeding and migratory birds.

A full house for our first spring Bird Monitoring and Banding Workshop when another great group of people from as far away as Alberta and Washington sacrificed their entire weekend to learn about molt and ageing of NA landbirds in the hand.

Our Banding Workshop is gaining notoriety and once again we were really overwhelmed with the feedback we received from workshop participants and thank them all for their very kind and generous course evaluations which can be viewed on our workshop testimonials page.

This workshop included our youngest every participant who was just shy of his 16th birthday when he attended the course. His Mum said "he will do anything to learn how to band" so how could we refuse him?!

He did an outstanding job and amazed us all with his maturity and passion for birds and banding and left the workshop inspired and wanting to do more - another convert!

Wilson's Snipe are most active at dawn and dusk and we occasionally flush them on early morning net rounds but their chunky bodies and fast flight make them very difficult to catch in our nets and this one was only our third banded record at the station. They can fly at speeds up to 60 kph but their European relative the Great Snipe has the air speed record flying at speeds up to 97 kph.
The word 'sniper' originated in the 1770s among soldiers in British India. if a hunter was skilled enough to kill an elusive snipe, he was called a sniper.

Snipe will "freeze" and rely on their cryptic coloration to escape detection. This is an effect that is greatly enhanced for color-blind predators (like most mammals) as can be seen in the photo below right. The position of their eyes far back on their head also gives them an exceptionally wide field of view, making it nearly impossible for an animal (or bander!) to sneak up from behind or above them!

Plenty of oohs and aaghs as the first wave of Western Tanagers arrived, adult males like this one with the bright red head feathers, the colour coming from a rare pigment in birds called rhodoxanthin not made in their own bodies but likely obtained from insects in their diet.

The wing (below left) of the above ASY male is a good example of what definitive adult plumage, with no discernible molt limits among the coverts or alula, looks like in spring. Notice the uniformly adult wing coverts and broad, truncate outer rectrices with a corner to the inner web diagnostic of adult birds.

Savannah Sparrows returned to the old field habitat at Colony Farm in early April, their loud, insect-like song resonating from the fields. Savannah Sparrows have very strong site fidelity (called natal philopatry)  returning each year to the area where they hatched. So precise is this drive that birds banded in previous years are often caught in the very same net where they were originally captured.

Adult males generally arrive before females so early brightly coloured birds like this are most likely adult males, this one showing glossy black tertials replaced in the adult prealternate molt this spring (blue arrow).

In addition to catching birds our J-trap is pretty successful at 'catching' Black Bears which visit at night to take advantage of the sunflower hearts in the feeder.

We designed the trap and the feeder to make sure bears can visit and help themselves to seed without wrecking the trap - some of these bears are decent sized animals as can be seen from our trail cam photos!

 

Our first Lazuli Bunting for the season, this after second year (ASY) male took our total of LAZB banded for the station to 57 which is amazing considering they are such uncommon birds in the Vancouver area.

Cedar Waxwings retuned to the park at the end of May, their electric, high-pitched trills filling the air as they fly around searching for ripening Elderberry fruit.
CEDWs are such exotic looking birds and definitely one of the favourites for visitors.

The name 'waxwing' comes from the waxy red secretions found on the tips of the flight feathers (primaries, secondaries and retrices). The exact function of these tips is not known, but they are age related as is the extent of yellow on the tips of the retrices.
The number and length of waxy tips together with the extent and glossiness of the black patch at the base of the chin allows us to determine sex, the black being brownish black and much less extensive on females (below left) and extensive glossy black on males (below right).
Cedar Waxwings (CEDW) red waxy appendages are usually restricted to the secondary flight feathers of the wing, giving a usual maximum of nine wax tips per wing (seven wax tips is by far the commonest number).

Rarely, some tail feathers will also have the tips of their shafts red.  More rarely still, small red wax tips can be seen on one to a few inner primary wing feathers. This CEDW had large wax tips on all eighteen secondaries, all twelve rectrices and, in addition, small wax tips on the inner four primaries of each wing, for an impressive grand total of 38 waxy appendages beating our previous record of 36!

Finally, our techie extraordinaire and all round good guy Kyle Norris who not only manages to do pretty much all of the station maintenance including mowing miles of trails and net lanes around the station but also designed and built our state of the art electronic Hummingbird trap trippers and remote playback system has just completed the test phase on a new nest box camera for the station. We are eventually hoping to deploy several of these as part of out Tree Swallow nest box monitoring program.
Kyle custom designed and built the nest box camera system from scratch with live streaming to the web and almost immediately the box was occupied by Black-capped Chickadees!

We've all been totally captivated watching Mum brood and the nestlings hatch and now both parents are busy feeding hungry nestlings.

Click here to watch all of the live action from the nest box but be warned it's totally addictive and once you click on the link you'll have to keep it open on your task bar to keep checking on the progress!!

http://537ebce0f3446.click2stream.com/
 

Thanks to Mark Habdas, Kerry Kenwood, Carol Matthews, Jason Jones, Debbie Wheeler, Sarah Gray, Mike Nutter, Kyle Norris, Louise Routledge, Monica Nugent, Sara Legros, Christine Bishop, Rufus Macintyre, Cyril Chan, Ivand Pulido, Andrew Venning, Kelly Palmer-McCarty, Martine Cutbill, Jessie Russell, Yonase Gulbot, Kaye Simard Ben Nickley, Danielle Zandbergen, Amber Richmond, Christian Lunn,  Eleanor Duifhuis and Cadi Schiffer for their help with spring banding - as always VARC would not exist without the energy, enthusiasm and commitment of all of our amazing staff and volunteers!

And special thanks and photo credits to Leslie Bol for the VARC Family Day photos.

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