Purple Martins – First Confirmed Nesting in Burnaby

Back in September 2012 I wrote a blog post here on the pre-migration gathering of Purple Martins at Deer Lake Park.

In Martins Departin’? the birds involved in the “… noisy, energetic, and exuberant convocation in the tree tops along the boardwalk”  were almost certainly from the colonies at Maplewood Flats, North Vancouver, and at Rock Point, Port Moody. There were no breeding locations in Burnaby at that time.

Adult female and immature Purple Martins, August, 2012.

But now, almost five years later, I’m delighted to report that Purple Martins are actually breeding here in Burnaby, down at Burnaby Lake on the pilings at the west end of the rowing course. Not only is this a first modern-day record for the City (they likely did breed here historically), but there’s a special bonus involved here too.

The spectacular, province-wide recovery of Purple Martins, described in the earlier post, has been almost entirely due to the use of nestboxes erected by many dedicated volunteers here on the Mainland, and on Vancouver Island. Nearly all these locations have been over salt water, usually on wooden docks and pilings.

For some years now there has been great anticipation that, with the expanding population, martins will nest again over freshwater locations, which they historically did. Bingo! Burnaby Lake is freshwater, and the nesting here is one of only four very recent locations where nesting around freshwater has been confirmed – the others being in the mid-Fraser Valley.

How do we know they are nesting at Burnaby Lake? Well, head down to the Rowing Pavilion and take a look for yourself. With a little patience, every 10 to 15 minutes you’ll see the martins entering the upper-right nestbox on the fourth piling from the left. If all the numbers on the box were were readable, it would be 06 – 24. See the picture below.

Adult male Purple Martin exiting the occupied nestbox

A brief aside: this post is notable for its poor pictures. Unfortunately, the birds are distant, fast moving, and adding an additional murky quality today, was the smoke-filled air. Earlier pictures like the above are a little brighter. Today’s are, well, foggier.

Take your binoculars, and you’ll notice the returning adults are carrying food (mainly dragonflies and other large flying insects) into the nest. Try clicking once on the picture below for a larger view. Look carefully at the bird’s bill to see it’s stuffed with insects.

Male Purple Martin about to enter nestbox with food

Carrying food into the nest is one thing, but are there actually young birds inside? We can’t see them after all. However, a higher level of certainty is provided by the picture below. Here you can see the female departing the nest which a large white blob in her bill which she will very quickly drop into the lake. Like many birds, young Purple Martins’ poop is contained in a white mucous membrane “bag” which enables parents to keep the nest clean.

Female Purple Martin carrying fecal sac from nestbox confirming “someone” pooped inside.

Parents carrying out the fecal sacs suggests the youngsters are older than 8 days. After about 13 to 14 days, the young will defecate at the entrance to the nestbox from where parents carry off the fecal sac. I saw no evidence of fecal sacs at the nestbox entrance during my two visits. I estimate from these observations that the young are between about 10 and 14 days old.

Natural Hazards

After about 28 days the young should be ready to fledge i.e. take their first flight – always a risky time for all young birds as they learn the skills of flying and maneuvering, catching prey and avoiding predators.

An added hazard for these young martins is that there is at least one, and probably a pair of Merlins in the area, probably nesting too. I have seen one on both my visits. The parent martins are very vigilant however. Along with the Barn Swallows, which are quite numerous here, they instantly go into attack mode, calling loudly, and vigorously diving and swooping at the Merlin to drive it out of the area. The male seems to be more aggressive than the female in these interactions.

Distant shot of Merlin. The bird was aggressively chased from this perch by the adult male Purple Martin soon after this photo was taken.

However, Merlins, small falcons, are for their size, powerful bird predators. Often making their captures in mid-air after a high speed chase, they could be a significant threat to an inexperienced young martin taking one of its first flights.

A Long History Finally Rewarded

Joe Sadowski, a founding member of the Burnaby Lake Park Association, trail builder, and nestbox constructor extraordinaire, has been waiting 20 years, he tells me, for the Purple Martins to nest in the nestboxes he was instrumental in putting up at the lake. Along with the Park Association, Roy Teo, and Kiyoshi Takahashi have been monitoring these nest boxes and other Purple Martin nesting colonies for many years.

It’s a credit to all their hard work that we finally have these largest North American Swallows nesting in our midst. Rewarded indeed.

 

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Kestrels Breeding in Burnaby

This past Sunday (July 16), following my own advice to “… get out there and take a look”, I was cycling east along North Fraser Way in Burnaby’s Big Bend area when an interesting bird silhouette caught my eye.

Kestrel silhouetted on a dead snag in the Big Bend area

Grabbing my bins from the bike pannier to get a better look, I was soon able to resolve the dark shape into that of a Kestrel. A “good” bird anywhere in the Lower Mainland, and a real and unexpected treat to see in Burnaby.

Grabbing my camera, I started a slow walk along Abbotsford Street toward the perched bird hoping for some good pictures, or at least a record shot of this Burnaby rarity, when I noticed a second Kestrel, this one sitting low down but half hidden in a thicket next to the tree in which the the first bird was perched. Two Kestrels! Wow!

Juvenile American Kestrel

Juvenile Kestrels are difficult to visually tell apart from their adult parents; however, this guy (yes, it’s a male), was making the occasional begging call, and when the adult male swooped down into the grassy road edge to catch some prey, and then flew up with it, junior was in hot pursuit for a meal.

So this was a recently fledged bird, which virtually guarantees it was hatched right here in the Big Bend area. In the 1 to 2 weeks immediately post-fledging, the young birds solicit food from their parents. After this period they cease begging as they become adept at capturing prey independently. So this young guy left the nest and took his first flights within the previous 2 weeks, and as a young, relatively weak flyer would not have travelled into the area from outside. It was Burnaby born and raised. Yay!

The Kestrel diet is primarily insects, especially grasshoppers, beetles, and dragonflies, and small rodents, especially voles and mice. All of the these prey items would be available in the area. The farming here is predominantly mixed vegetables, with some large areas of cranberry bogs to the north. The field edges are nicely unkempt, scruffy, and weedy providing lots of just the kinds of foods Kestrels need. Farming and wildlife can happily co-exist if the farming isn’t too industrialized and intensive.

Fields of vegetables with good Kestrel foraging habitat along its weedy edges in Burnaby’s Big Bend.

 

Fallow field of rough grass meadow full of insects, and small rodents – Kestrel food

I don’t know how much pesticide use there is on these farms, but the insect life was abundant when I visited. Perhaps this is a sign it is minimal, which is not only good for our health, but also that of the insect-eating Kestrels and other birds. Along the Byrne Road side of the area, the organic farm that was Urban Digs is now getting going again under new stewardship and name – Seed of Life Farm. No pesticide use there for sure. Another positive for the Kestrels.

So where would the nest itself likely have been? Kestrels are cavity nesters, using woodpecker-excavated and natural cavities in larger trees which are surrounded by large open areas for hunting food. We’ve got the open patches in Big Bend, but not so much the larger trees in the immediate area where I saw the birds.  However, there are many large black cottonwoods surrounding the fields, and Kestrels are known to use buildings too for nesting. A number of the old farm buildings in the area looked quite suitable to me.

Vegetable fields surrounded by the old farm buildings which may have provided a suitable Kestrel nest site

Both male and female Kestrels feed the young except for a short period after first hatching when the male provisions the female and the chicks on the nest. After 7-10 days both parents feed the young and this continues through the post-hatching period.

Breaking News (July18)

Went down to Big Bend again this morning to check up on the progress of the Kestrels. Despite the fact that somehow I had put a mostly un-charged battery in my camera and as a result missed all sorts of photo opportunities, it was a wonderful morning. The news is getting better.

There were at least 4 kestrels there this morning. Two adults, a male and female, and two juveniles, a male and female. Likely this represents the whole family, but given the birds were very active hunting and begging, I could have missed more family members. The young are still being fed by the parents, but are taking up perches and stances showing they are making the transition to feeding on their own. No more perching low down and tucked in like the juvenile I first observed Sunday.

The accepted common name for this species is American Kestrel. These ones, of course, are “Canadian” born and raised. In fact, I think we can safely claim this family group as “Burnaby” Kestrels.

Adult male “Burnaby” American Kestrel

If you head down to N Fraser Way and Abbotsford St. to see the happenings for yourself, please respect the farmland and private property, and stay on the roads. This area is not a public park.

 

 

Sad End for First Breeding Record of Sandhill Cranes in Burnaby

As I was about to publish the post below, I heard that the good news story that had been unfolding all last week at Piper Spit on Burnaby Lake had come to a sad end. The Sandhill Crane chick (colt) pictured below is no longer with its parents, and has likely died from some unknown cause.

To document the cranes’ story I have decided to let the original post stand, with some slight modifications, because it’s such a good story, and worth telling. While many will consider the outcome a local tragedy, it does illustrate how precarious life can be in the wild, especially for young animals. Survival rates are often low.

Let’s hope the cranes nest again next year. There’s a good chance they will, and we can all hope for a better outcome.

Original post written July 5/6, 2015

The risk with a post like this is that the story gets buried in the overabundance of cute at its centre.

SACRChickAdult27th

Sandhill Crane chick and adult (June 27)

Now I’m not denying (how could I?) the cute factor here , but the story is the historical first that this new arrival represents, and the cute needs no elaboration from me. Just look at the pictures.

And while the chick may be the epitome of cute, let’s not overlook that we’ve got one of the Lower Mainland’s most majestic and uncommon birds breeding right here at Burnaby Lake for the first time since we’ve been keeping records. And they’re putting on a show for everyone.

How do I know these birds have set a breeding record here? A quick search of the literature shows that this new arrival is the first record ever record of breeding Sandhill Cranes at Burnaby Lake, and anywhere else in Burnaby for that matter.

SACRChick&Parents

Sandhill Crane chick and parents (June 26)

The chick pictured above, the first day I saw it, is just a few days old, and was being fed and guarded by both parents. Watching it, I was surprised to see it was picking at and eating some food items independently, which is notable for such a young bird. Usually the parents supply all its food requirements at this early age. After their natal down has dried, and within 24 hours of hatching, Sandhill Crane chicks leave the nest permanently. Such behaviour defines these hatchlings as nidifugous (Sorry, couldn’t resist such an unlikely word), and then they’re off on the risky journey to adulthood.

Sandhill Cranes are rare breeders in only a few locations in the Lower Mainland/Fraser Valley. The wetlands south of Pitt Lake in Maple Ridge were their breeding centre for many years, with just a few pairs actually nesting there. A few more bred in Langley. We do see large flocks of Sandhill Cranes in the Lower Mainland, but only in migration – spring heading north and fall flying south. For the most part these birds continue on their migrations and we are fortunate to see them when they pass over.

However, over the past decade or so, a small breeding population has established itself at the Reifel Migratory Bird Sanctuary in Delta. Birds, likely from that population, have been turning up in Richmond, where they started to breed about five years ago (first time since 1946), and they’ve also been showing up on our local golf courses, where they haven’t nested, perhaps from dodging flying golf balls!

Sandhill Cranes at Reifel Migratory Bird Sanctuary, Delta

Sandhill Cranes at Reifel Migratory Bird Sanctuary, Delta

In British Columbia, Sandhill Cranes breed mostly in the Central Interior (Northern Okanagan and the Cariboo/Chilcotin, with some breeding in the north east (Fort Nelson area), and others on the central coast islands and Haida Gwai. Breeding in the Lower Mainland is much less common.

Sandhill Crane chicks grow rapidly, and “our” Burnaby bird seems to be doing just that. Compare the picture taken June 26 with the one here below taken July 5th. Junior is gaining height and bulk, and both parents are supplying it with food.

Chick and parents, July 5

Chick and parents (July 5)

Unlike many birds that spend their first weeks in the nest, nidifugous birds are incredibly mobile for such young animals.

It can wade, even on its junior-sized legs.

 

SACRSwim

It can swim.

SACR BbyLRun

It can run.

SACR BbyLChick

It can preen.

Or, it can simply look disarmingly cute.

IMG_6735

Sandhill Cranes have been showing up irregularly at Burnaby Lake for the past few years. This year they clearly stayed to breed.

Between one and three eggs is the usual clutch size, with two being typical. One or two young are usual. Both parents incubate the eggs, although the female does the overnight shift which means she does about 70% of the incubation duties. Once the chicks leave the nest, both parents protect and feed the young.

SACR BbyLFed#5

Sandhill Cranes are monogamous and tend to maintain pair bonds over many seasons, especially if they successfully breed together. So barring accidents, this pair may be together for the long haul.

As to which is the male and which the female, the birds know of course, but the sexes are similar and not separable by appearance. During their courtship displays though, the males and females can be identified by their specific bugling calls and head motions.

Postscript

I headed down to the lake this afternoon (July 6) to confirm the reports of the chick’s disappearance. Sure enough the two parents were there, occasionally bugling quietly, but no chick was in sight. Given the birds’ extreme attentiveness to their young, the conclusion has to be that the youngster is dead.

It was apparently showing some respiratory distress yesterday which got progressively worse during the day. The chick was nowhere to be seen this morning. A sad ending, but there is hope for next year.

Pair

Deer Lake Heronry Flourishes

Within sight of Burnaby’s City Hall, the word is out that Great Blue Herons have constructed a huge and rapidly growing colony, and they’ve done it all without a building permit! It’s nesting season, and right now there’s so much going on in the colony at Deer Lake Park, it’s definitely time for us to get out there, take a look, and enjoy all the action.

BranchPluck

Great Blue Heron grabs a tree branch to add to its nest of sticks.
(Click to enlarge)

So head down to Deer Lake Avenue, opposite City Hall, to enjoy the sights and sounds. However, please watch only from the paths and the sidewalks. Entering the colony under the nests is definitely a No No. Peering in from the edges of the colony gives the best views of the birds, their nests, and all the goings on. Standing under the nests is unwise for many reasons, especially when looking up, mouth agape.

Search

Sticks are searched for diligently within the colony. or carried in from further afield.
(Click to enlarge)

Sticks are being gathered, nests built, nest sites squabbled over, and the occasional predator is vanquished. Egg-laying will start soon, if it hasn’t already, and after about 30 days incubation, the young will hatch. Following hatching, it takes another two months before the young fledge. And as the young grow, noise levels will rise, as will the colony’s strong, olfactory presence. Yes, it gets pretty stinky, and furthermore, later in the season the trees will be fully leafed-out, and activities harder to see. Now is a very good time to pay a visit.

Heronry

Almost 30 nests are visible here, most located in just two trees on the west side of the colony. (Click to enlarge)

For the past six years, much to the delight of park users, passers-by, interested scientists, and City and Ministry of Environment staff, the Deer Lake heronry has been growing in size at a fantastic rate. It has made a big jump in numbers this year. Don Jones, who, every season makes a very careful inventory of the nests, counted 104 in March. Last year (2012) the count was 66 nests – a whopping increase! As each nest represents a pair of herons, we now have over 200 birds using the colony. That’s a huge number of these big, spectacular birds.

So just how quickly has this colony grown? In 2008, I made the following notes about the heronry:

”There has been a small colony (2-3 pairs) of GBHE at the west end of the lake for the past 4 years. Last year (2007) the colony was predated by Bald Eagles, and no young were fledged. Up to three young were fledged, or were close to fledging in previous years.

This year the birds, presumably the same ones, relocated north and east of the previous location to a grove of black cottonwoods bounded on the south by Price St., on the north by Deer Lake Drive, and on the west by the trail that heads north-east diagonally from the foot of Price. In early May, three nests were visible with adults standing on and/or next to two of the nests.

On May 30, the leafing-out of the trees made observing the nests very difficult. Only the southern-most nest was fully visible, and an adult was sitting (presumably incubating) on it. The second nest was mostly concealed, and its top was not visible. The third nest was not visible at all.

Jul 02 visit. Two large juvenile birds (fully feathered) standing in and on the edge of the southernmost nest. The second nest seems to be unoccupied by either adults or young.”

So, from three nests in 2008 the colony has now grown to over one hundred nests. It seems that herons take note of which colonies are being successful, and will transfer to these new locations from others where conditions may not be as good.

CondoStyle2

Herons nest quite close together in the tall, 30 meter plus, black cottonwood trees. Separation of nests is governed by stabbing distance from those impressive bills. (Click to enlarge)

In fact, the transfer from another colony seems to be a likely cause of this year’s big jump in numbers. The Colony Farm heronry, visible along the Mary Hill Bypass in Coquitlam, has been abandoned this year, likely due to nearby bridge construction at the start of nesting season. The Deer Lake colony may well be attracting some of the birds from the Colony Farm heronry.

Bald Eagle incursions are also a problem for heron colonies. Bald Eagle attacks frequently cause colonies to be abandoned. Both the Deer Lake and the Colony Farm colonies have suffered from eagle attacks. However, Don Jones reported a very interesting observation at the Deer Lake colony this year. A Bald Eagle entered the colony, but was attacked strongly (pecked from above) by one of the herons. The other herons didn’t abandon, but just retreated a short distance. The eagle was finally driven away pursued by a heron. It makes me hopeful that perhaps the birds are learning strategies to defend their nests, even at this relatively early stage in the breeding season.

NB

Sticks are worked into place to build the nest.
(Click to enlarge)

LgeNest

Some nests are quite substantial structures.
(Click to enlarge)

Activities other than nest building are also taking place in the colony. Unfortunately, I didn’t manage to get a picture, but frequent copulations are happening. Despite that miss, I did, manage to capture some tender moments of mutual preening by a nesting pair.

Preen

Copulation, and mutual preening as shown here, both take place on or adjacent to the nest.
(Click to enlarge)

I was recently asked, if there are so many birds on the colony, how come we only see one or two in the park itself? Great Blue Herons will travel long distances (5 to 10 kms) to good feeding areas to forage. Watching the direction of birds flying to and from this colony suggests they are probably foraging along Burrard Inlet, and as far south as Boundary Bay. Both locations are within easy flying distance.

Some individuals do forage locally, and there are frequently one or two birds in Deer Lake Park itself. Some may not go as far as the Inlet or Boundary Bay. I managed to capture this not-very-good picture just a couple of days ago along Chub Creek, a tributary of Still Creek, of a heron just about to swallow its prey. I suspect it was fishing, but made this opportunistic capture instead.

WithVole

Great Blue Heron about to swallow a Townsend’s vole captured along the banks of Chub Creek.
(Click to enlarge)

It’s wonderful to have a such a success story on our doorstep, and we should celebrate our good fortune. However, we shouldn’t be complacent about the threats to the Great Blue Heron. We have a special, non-migratory subspecies here on the BC coast (Ardea herodias fannini), and it is designated a “Species of Special Concern” due to loss of wetland habitat in the Georgia Basin, and a declining population.

And not to be forgotten, too, is how this success story illustrates the importance of preserving the natural areas in our parks. In the 1980’s, the stand of black cottonwoods in which this colony has now established itself was designated for paving as a parking lot for the park. Thankfully, this City-inspired plan for the Park is long abandoned, and we now live in more enlightened times in Burnaby.

Thirty years ago this stand of trees was seen as dispensable. Today, completely unpredictably, it has become a significant colony for this threatened bird. A great example of why the precautionary principle is best applied consistently, especially to our natural areas.

HuntRCanGr

Great Blue Heron foraging at Deer Lake.
(Click to enlarge)

Let’s hope the success of our local colony will help us continue to enjoy these magnificent birds.

If you’ve been wondering why no posts lately, it’s because I’ve been travelling in South East Asia – birding of course. 

Posts should pick up to a regular pace from now on. Thanks for your patience.

George Clulow