Vancouver Avian Research Centre

.....Research - Conservation - Education
Summer -2013
Occasionally news reaches us of uncontrolled bird slaughter on a scale so huge you just feel there is simply no hope for avian conservation and that we are all fighting a losing battle when it comes to birds and the environment. Last year it was Amur Falcons in India but the scale of slaughter of migrant songbirds in Egypt makes that pale in to insignificance!

Songbird slaughter in Egypt

I’m not sure if anything can be done given the present political situation in Egypt. The truth of the matter in these countries is that the culture is so different, birds are simply viewed as a resource to be harvested like fish and nobody really cares enough to change it. Governments pay lip service to these issue but do precious little about it and it’s basically impossible to police anyway! It's the same in Cypress, Malta and some other Mediterranean countries.

The Royal Society for the Protection of Birds (RSPB) in the UK has been very vocal and lobbied governments to change the laws relating to the illegal trapping of songbirds but still it goes on. We have contacted both the RSPB's media centre and BBC to ask if some immediate attention can be brought to this issue - when you consider how much time the world's media has spent on the royal birth in the last few weeks you really do wonder where our priorities lie!

It’s totally depressing and it seems that we won’t be happy as a species until there are no animals left on the planet!

Germany's largest wildlife conservation group has drawn up a petition encouraging the Egyptian government to act against uncontrolled bird slaughter. A link to an English-language version is available to sign at the end of the article - please take a moment to sign it!

On a lighter note the highlight of our summer was the installation of a washroom at the banding station!

This was particularly welcome for the VARC ladies who after 5 years of squatting behind bushes now have their very own spa!

OK so it's not exactly a spa but it is the nicest 'wilderness station' we've ever seen and with increasing numbers of visitors, our schools and youth program and now scheduled 'Family Days' it will definitely see plenty of use!

A huge thank you to Mike Nutter and Kyle Norris for designing and building this thing from scratch, to the Home Depot in Port Coquitlam for supplying all the materials at staff discounts, to Stacie Kalyn and Dillon Consulting for providing funding for the materials, to MHC Gutters for supplying and installing the gutter system for free, to Superior Propane for discounts for the gas hook-up and to TD Friends of the Environment Foundation (TDFEF) for additional funding for this project.

After the songbird slaughter in Egypt the kindness and generosity of all the people involved in this project really restores your faith in human nature - thank you all again!

P.S. The building is designed to be environmental friendly and pollution free incorporating an incinerating toilet and is also bird friendly with Barn Swallow nesting ledges above the covered main door and a Barn Owl nesting box under the rear eaves (photos below) - all colour coordinated of course!

And shortly after it went up a visitor left a calling card at the station!
Speaking of youth groups we hosted the annual Catching The Spirit (CtS) Youth group to the banding station in July. Some 20 plus kids came out as part of a stewardship project set up for their summer camps which included doing some invasive plant species removal work at Colony Farm.

Catching the Spirit is an outdoor environmental stewardship and learning program that encourages leadership development and social responsibility for youth in the Metro Vancouver area.
 
Everyone had a great time and said that the trip to the banding station was the highlight of their working weekend!

Summer is dominated by hatch year birds in juvenal plumage all registering 10 on the cuteness scale and they don't come much cuter than this newly and locally fledged Cedar Waxwing which almost looked too young to have left the nest!

Streaked/spotted plumage is another characteristic of juvenile birds as demonstrated by this hatch year (HY) Swainson's Thrush. Most songbirds spend the first part of their lives either on or near the ground making them very vulnerable to predation. Streaked/spotted and/or dull plumage helps provide camouflage during this susceptible period of their lives.

Another characteristic is the presence of fault bars which can be see on the rectrices (tail feathers) of the hatch year (HY) Swainson's Thrush in the photo below.

The conspicuous growth bars near the tip of this young SWTH's tail tell us that this bird probably was not well fed for two consecutive days, perhaps the first two days after it fledged from its nest.

These so called ‘fault bars’ are the result of environmental or nutritional stress that the bird encountered while it was growing in the feathers. Groups of feathers on hatch year birds are grown concurrently so a stress that results in a fault bar on the feathers is distributed in an even line. Adult feathers are sequentially grown so a fault line on the feathers is normally distributed in an uneven line.

Fault bars are caused when actively growing feathers cease to grow resulting in a dark line across the feathers. Young birds begin to grow their rectrices as nestlings and growth continues after fledgling. At this time the birds are dependent on their parents for their nutrition (the food required for the energy and proteins necessary for feather synthesis) but these adults are typically not only feeding themselves but also several hungry fledglings. This is a tremendously energetically taxing time for adults often resulting in undernourished young and the presence of fault bars.

Fault bars can be useful as an ageing criterion but banders should be aware that adults do sometimes lose all of their tail feathers at once accidentally. When such accidentally lost feathers are regrown adventitiously (outside the normal molt cycle), it is not unusual for such adult replacement rectrices to have prominent fault bars like those more often seen in juveniles.

This hatching year (HY) male Hairy Woodpecker (HAWO) was showing an extensive red juvenal crown patch. As mentioned in previous blogs Peter Pyle's excellent book the Identification Guide to North American Birds Part I suggests that both male and female Hairy and Downy Woodpecker juveniles have a red juvenal crown but it has been proven that those with an extensively red juvenal crown are, in fact, males, while those with a black, or mostly black, juvenal crown are young females.

This bird was already in the midst of it's first prebasic molt when unlike most passerines it will molt primaries (photo below right) but not corresponding primary coverts. Hatching year (HY) woodpeckers normally retain all of their juvenal primary coverts in this first prebasic molt.

During this males first prebasic molt, its red juvenal crown will be lost and a red nuchal patch (on the back of the head) characteristic of 'adult' males will molt in.

We had lots of opportunity to raise awareness of the plight of our aerial insectivores in August when we were invited to talk to Terry Donnelly at CBC radio. He also ran an article on the CBC website which can be viewed here:

CBC News Article

We were then contacted for an interview with the Vancouver Sun and also did a radio interview on Chris Cook’s weekly public affairs program at CFUV Radio at UVic. The podcast can be heard by clicking here:

CFUV podcast

Global News has also been in touch and is coming out to the station to interview us – so lots of profile for our Barn Swallows and more opportunity to raise awareness of environmental issues as they relate to birds.

When one considers the steady and consistent decline of swallow species as can be seen in the graphs below  it is difficult to imagine how the current decline of aerial insectivores can be forestalled, let alone reversed and time is running out if we are to find the answers in time!

Barn Swallow
(Hirundo rustica)
Canada (Long-term)

Northern Rough-winged Swallow
(Stelgidopteryx serripennis)
Canada (Long-term)

(Environment Canada, 2013. North American Breeding Bird Survey - Canadian Trends Website, Data-version 2011. Environment Canada, Gatineau, Quebec, K1A 0H3)

The articles were timely in that August is always swallow month at Colony Farm as hatch year birds like this Barn Swallow use the old fields to forage - they really are such beautiful birds and it really is sad to see such precipitous declines.

This hatch year (HY) Northern Rough-winged Swallow was showing buffy fringes to all of the lesser, median, greater coverts, alula and tertials, diagnostic of birds in juvenal plumage. The barbs on the outer primary (P9) discussed and photographed using super-macro photography in the summer blog last year were inconclusive to sex this particular bird.
Late summer is an exciting time for banders as birds undertake their annual prebasic molt, molting back in to their basic or winter non-breeding plumages, and it's the only time of the year when it is possible to use every available age code. Accurate ageing and sexing of landbirds in the hand requires a complete understanding of the molt cycle of the individual species being studied and August is the time to put all of that theory in to practice!

Birds in active molt give us an opportunity to see molt as it is happening. This is particularly helpful to new banders who have an opportunity to learn the sequence of events in both complete and less than complete molts.

The photo below left shows a second year (SY) male American Goldfinch (AMGO) at the start of its first definitive adult prebasic molt. We discussed ageing and sexing AMGOs in a photo essay in the May 2012 blog when we said that two ageing shortcuts could be used by banders for this species. First we look for a buffy tip on the carpal covert and that in the spring only second year birds molt their inner greater coverts as part of their prealternate molt. So in spring SY AMGOs show three generations of feathers; juvenal, first basic and first alternate but in this photo we can now see FOUR generations of feathers:
Yellow arrows: Retained juvenal feathers (outer primaries P4-P9 and corresponding primary coverts, outer secondaries S1-S6, outer greater coverts carpal covert and alula, the red arrows pointing to the buffy fringes on the retained juvenal carpal covert and alula mentioned earlier)
Purple arrow: First basic inner greater coverts replaced during the birds 1st prebasic molt after the breeding season last year.
Blue arrow: First alternate inner greater coverts replaced during the birds first prealternate molt during the late winter/early spring this year.
Green arrows: Adult prebasic inner primaries (P1-P3), corresponding primary coverts and tertials being replaced as part of the birds adult prebasic molt now!

Molt may not seem like the  most exciting thing in the world but it is the holy grail for ageing landbirds in the hand!

Birds in heavy molt are not at their most attractive - this hatch year (HY) Swainson's Thrush showing extensive pin feathers on its head and molt limits in the making with median coverts, inner greater coverts and carpal covert in sheath. Notice the olive edged emerging inner greater coverts and buffy tear drops on the retained juvenal outer greater coverts.
And scruffy doesn't really do justice to describe this after second year (ASY) male Common Yellowthroat (COYE) in the midst of its definitive adult prebasic molt where all body and flight feathers will be replaced.

Adults in heavy prebasic molt like this bird can often still be identified as second year (SY) or after second year (ASY) until the alula feathers are lost. The alula covert (indicated with the red arrow on photo right) is a key molt limit in many species. It is part of the tract of median coverts and molts with them prior to the molt of the main two lower alula feathers which are among the last feathers replaced.

As can be seen in this photo there is no contrast among the as-yet-unmolted alula feathers and the molted alula covert - both are worn but too brightly colored to be juvenal feathers. Within another week or so this bird would have to be aged simply after hatch year (AHY)

The rectrices of the same bird (bottom photo) are as yet unmolted and show fairly heavy degree of wear but considering they belong to a COYE which spend most of their lives skulking low down in wet thickets and this bird has been through one long Neotropical migration and likely an entire breeding season in and out of the brush feeding hungry nestlings the degree of wear on these adult feathers was not nearly as much as it would have been on retained juvenal feathers and further supported our age determination that this bird was an adult alive in at least its third calendar year going through another definitive adult prebasic molt.
 

 

 

And the significance of the alula covert (red arrow) can again be seen in this photo of a hatch year (HY) White-crowned Sparrow (WCSP) in the midst of its partial 1st prebasic molt. The sequence of events in a partial 1st PB can be clearly seen here as this bird replaces lesser, median, greater coverts, the alula covert and two innermost tertials. White-crowned Sparrows are among the Emberizid family which often show this key alula covert (A1) molt limit .

This 'Brown-eyed' Vireo was a good get for us in the old field habitat where we band. Red-eyed Vireos are tree top birds preferring the mid and upper canopy of taller trees and they rarely stray in to the low elderberry brush and lower trees of the banding area.

This hatch year (HY) bird of unknown sex was showing the very dull brown irises diagnostic of first year birds versus the bright red irises of adults.

Ageing warblers and vireos at this time of the year requires close scrutiny as molt limits can be difficult to see when hatch year (HY) birds still have very fresh retained juvenal feathers. This wing of the above REVI is a good example of this. Under magnification the contrast between replaced lesser, median, greater coverts and carpal covert and retained primary coverts and main alula feathers (A2/A3) can be seen the molt limits indicated with red arrows between the outer greater covert and inner primary covert and alula covert (A1) and main lower alula feather (A2). Molt limits like this can be quite subtle with birds in the hand and for this reason, especially after adults of these same species begin to show signs of approaching the end of their complete prebasic molt age should always be confirmed by additional criteria such as skull ossification. In this instance eye colour was also pretty conclusive!

Tail shape can also help being generally more tapered in hatch year birds and more truncate in adults although determining the age of birds by tail feather shape alone is generally not very reliable because of individual variation and the possibility of accidental loss and replacement (i.e., adventitious molt). Tail shape should always therefore be used with caution and only in conjunction with other ageing criteria (e.g. molt limits).

Another good get for us was this hatch year (HY) Brown Creeper (BRCR) of unknown sex. Much is not known about molt in BRCR - the 1st prebasic molt apparently including few if any lesser or median coverts, no greater coverts or tertials, but apparently the rectrices.

This bird obviously hadn't read the book as it had molted most median and great coverts - the retained buffy fringed feathers illustrated with the red arrow (photo blow left) and retrices R2-R5 on both side of the tail leaving only the central retrices (R1) and outer retrices (R6) as retained feathers! One of the most interesting things about molt and ageing in landbirds is that there is always something new to learn!

Orange-crowned Warblers arrived in good numbers with both the pacific coastal (lutescens) subspecies (below left) and the duller, grayer Interior (orestera) subspecies (below right) caught for banding.

And speaking of Interior subspecies this hatch year (HY) male Black-throated Gray Warbler (BTYW) was likely also of the Interior (halseii) subspecies based on size and showing very extensive white in the rectrices (photo below right) than is normal in the coastal subspecies (nigrescens).

The 1st prebasic molt is partial in this species with all lesser, median, greater coverts, carpal covert and greater alula covert replaced, the red arrow (photo below left) pointing to the molt limit between replaced outer greater coverts and retained primary coverts. First year males can be separated from first year females by the mixed gray and black (rather than grayish) crown and auriculars, distinct black centers to the back feathers and median coverts with white tips usually without black shaft streaks (blue arrow on wing photo below left) Compare this to the median coverts of the second year female in our June 2011 blog (white arrow on this photo)

Nashville Warblers are uncommon birds for us in the Vancouver area and this drab hatch year (HY) female was almost overlooked among a number of drab HY female MacGillivray's Warblers banded the same morning.

The inner greater coverts in sheath (red arrow on photos above and left) on this hatch year (HY) Western Tanager show another molt limit in the making. Many molt limits are only visible on birds in the hand but the one on this bird would allow birders to identify this bird as a hatch year female in the field.

Accurately ageing and sexing birds in the field both increases enjoyment of birding and can add more accurately to baseline data for those participating in citizen science projects like the Breeding Bird Atlas.

Molt cycles and plumages are complex in raptors and variable in timing, location and sequence. It can be difficult to define certain molts and plumages and sometimes unraveling them can seem like the ultimate riddle, wrapped in a mystery, inside an enigma!

This male Cooper's Hawk was aged after hatch year (AHY) but likely a third year (TY) bird based on the distinctive white spots on one or two lesser coverts and rump feathers (red arrows - photos below) and buffy fringing. Other than that the distinctive generations of feathers on the wing didn't really seem to make sense! There appeared to be two obvious generations of primaries and primary coverts, at least three generations of secondaries including S1 in sheath and only central rectrices replaced which according to the book was all wrong! Added to that the iris was more orangish than yellowish orange and we decided to call it a day and age it AHY!

Gorgeous bird nonetheless and we would welcome any information from banders with ageing experience with these tricky accipiters!

Less tricky was this tiny hatch year male Sharp-shinned Hawk showing the very dull iris colour and buffy fringes to all coverts diagnostic of first year birds.

FIVE hatch year (HY) Lazuli Buntings in one morning was a new record  for us and took our LAZB count to a season high record questioning whether we should be changing our logo!

And records tumbled for Hummingbirds too with record numbers of both Anna's (ANHU) and Rufous (RUHU) Hummingbirds banded this year. In fact the number of ANHUs were extraordinary sometimes outnumbering RUHUs with 18 banded on one morning at Colony Farm. ANHU 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.

Towards the end of August many of the RUHUs had amassed large fat deposits to fuel the energy demands of long distance migrations for the these extraordinary little birds, one male weighing in at 4.3 grams which is a whole gram heavier than the lean body mass of a male RUHU and as heavy as the average and much larger Anna's Hummingbird!

This hatch year ANHU was coated in thick, sticky pollen covering most of his head and body and looked as though he had been totally immersed in a flower prior to capture!

Bill deformities are not common in birds so to get two in one morning was very unusual - a hatch year male Common Yellowthroat and after hatch year (AHY) female 'Crossbill' Pigeon!

And finally our first of the season Western Wood-Pewee (WEWP). Having listened to them calling all summer along the edge of the riparian woodland adjacent to our playback nets it was nice to finally catch one - this hatch year bird (HY) of unknown sex showing the conspicuous buffy wing bars diagnostic of birds in juvenal plumage. Like most Tyrant flycatchers WEWP molt primarily on their winter grounds so separating adults from hatch year birds is relatively easy.

Freshly molted wing bars of HY flycatchers are buffy/cinnamon in appearance and fresh looking having just grown in this summer. An adult bird now carrying 6-8 month old feathers that have been used for one long distance migration, and which have been worn for an entire breeding season appear worn and whitish, not buffy like this bird.

The photo below right shows the smudged undertail coverts and extremely long primary tips extending beyond the undertail coverts which easily separates WEWP from any of the Empidonax flycatchers in the hand.

Thanks to Mark Habdas, Kerry Kenwood, Carol Matthews, Jason Jones, Debbie Wheeler, Mike Nutter, Kyle Norris, Louise Routledge, Monica Nugent, Sara Legros, Sarah Gray, Christine Bishop, Rufus Macintyre, Dev Manky, Cyril Chan, Ivand Pulido, Kirsten Wilcox, Andrew Venning, Kaye Simard, Lauren Orjala, Shannon LaFontaine, Eric Demers and Eleanor Duifhuis, for their help with banding in July and August.

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