Category Archives: Research

Watching Coot-Looting Wigeons at Buttertubs Marsh

I sometimes wonder why I don’t get bored going to the same birding locations month after month, year after year.  A big part of it is that, on any given day, there is a chance that they will see something different or rare or perhaps even totally new.

This past Sunday, while on an organized outing with a bunch of local birders to Buttertubs Marsh Bird Sanctuary in Nanaimo, I got my “something-new” fix.  In this case is wasn’t a new species of bird — instead it was an inter-species interaction that I had never noticed before – that of an American Wigeon stealing food from an American Coot.

Scene 1: Following the Coot

Coot (Fulica americana) & American Wigeon (Anas americana)

The first of the two species, the American Wigeon (Anas americana), is a duck that is part of the genus Anas sometimes referred to as dabbling ducks.  These duck may feed on land or on the water where they can tip themselves upside down and gather underwater plants up to several inches below the surface.

The second of the two species, the American Coot (Fulica americana), is in the family Rallidae of rails and looks a little like a small black chicken.  These birds may feed on land, by dabbling in shallow water or by diving for plants.

I captured a short video of the food stealing behaviour (kleptoparasitism) with my Panasonic DMC FZ-200 camera.  I may have had too much fun and gotten a little carried away with the presentation.  You be the judge:

At one point there were at least 3 or 4 Wigeon-Coot pairs doing similar food-stealing dances.

On another occasion I watched as a Wigeon tried to manage two Coots at the same time and seemed to spend a lot of time in the middle trying to decide which way to go.  Not a good strategy for a low-intelligence bird it would seem.

Some further comments and other notes resulting from forays into online ‘research’:

  • A 1979 article suggested that the Wigeon is the only duck known to be a regular kleptoparasite (ref [3]).
  • A 1984 article documents Gadwalls stealing food from American Coots (ref [4]).
  • Other ‘dabbling ducks’ in the genus Anas include the Mallard, Wigeons, Teals, Shovelers, Pintails, the Black Duck, the Gadwall and a few others.
  • Wigeons apparently will try to steal food from other diving water birds, not just from coots.
  • Coots, in turn, have been known to steal food from other water birds.
  • Coots will also dive to escape predators (the Coot is one of the easiest birds for the Bald Eagle to catch).

References

A good source of information that I like to use is the Birds of North America online service from the Cornell Lab of Ornithology.  The service is not free but for anyone curious about bird behaviour it’s worth the price in my opinion.  They have a one month subscription that costs $5 if you want to give it a try.

[1] BNA online article on the American Wigeon.

[2] BNA online article on the American Coot.

[3] H. Jane Brockmann & C. J. Barnard,  Kleptoparasitism in birds, Animal Behaviour Research Group, Department of Zoology, University of Oxford, UK
Animal Behaviour (Impact Factor: 3.14). 05/1979; 27:487-514. DOI: 10.1016/0003-3472(79)90185-4

[4] Juan A. Amat & Ramón C. Soriguer, Kleptoparasitism of Coots by Gadwalls, Ornis Scandinavica 15: 188-194.  Copenhagen 1984.

Watching a Family of Palila on the Big Island

[Updated December 10 2014 based on feedback.  Additional links on the Palila have been added.]

A recent week-long vacation took us to the Hawaiian Islands (October 26 to November 1). Having previously been to the island of Kauai at the old end of the island chain, we decided to try the island of Hawaii at the other, newer end.  To prevent confusion with the state of Hawaii this is frequently referred to simply as the Big Island.  I had my Panasonic FZ-200 camera along to document the trip.

On the last full day, I signed up for a Rainforest and Dryforest Birding Adventure tour — a day-long outing put on by a tour group called Hawaii Forest and Trail.  They do many other tours too that are not just for birding.  The rest of our group, for instance, went on the Mauna Kea Summit and Stars Adventure trip which takes you up to the volcano’s summit to watch a sunset.

Our trip set out in search of 2 specific target birds.  In the dry forests on the side of Mauna Kea we would be looking for the Palila, a critically endangered species which lives in a single forested area on the volcano’s slopes.  This forested area is the source of the māmane plant which the Palila has adapted to be able to eat and which is toxic to other birds.

In the second part of our excursion, we would travel to some wetter forests where we hoped to find different endemic, the ʻAkiapōlāʻau.

While we were, unfortunately, unable to track down the ʻAkiapōlāʻau, we were extremely successful with the Palila and the rest of this article describes that encounter.

Mauna Kea and the Palila

First, a quick note and the Palila habitat on the slopes of Mauna Kea.

Mauna Kea is still considered to be an active, though dormant, volcano and even though it has not erupted in 4600 years there is still the slim possibility that a lava flow from a future eruption could wipe out this habitat leading to their extinction.  While this might make for a good story in Hollywood, the reality is that there are much more dangerous risks that could well see the Palila gone from these slopes long before they are touched by lava.  Forest fires, for instance could, in the right conditions, very quickly destroy the Palila habitat.  Other threats include introduced species of plants, animals, insects and disease.  The Hawaiian government’s Mauna Kea Forest Restoration Project has lots of good information here.  Finally, according to BirdLife International, the endangered status of the Palila in recent years is also related to rapid population declines as a result of drought that has affected its primary source of food, the māmane plant.

The Palila Plan

The plan was simple.  We parked in an area accessed by a hunter access road on the lower slopes of Mauna Kea.  The trip organizers allowed for up to 4 hours climbing the slopes to find and view the Palila after which time, win or lose, we would head for the second location.

Here is a picture taken near our parking spot and at the lower edge of the area expected to contain the Palila.  Note the sparse trees on fairly open grassland.Mauna Kea slope forest home of the Palila

Here is a second shot taken as we climbed a little further up the Mauna Kea slope.Mauna Kea slope Forest Home to the Palila

Found:  A Family of Palila

According to the guide, on one recent trip they spent most of the allocated time hunting for the Palila and only found them as they were about to quit and move on.  We got lucky and found one after about 15 minutes with another pair showing up shortly thereafter.  In fact it appears that we had found a family unit with male, female and juvenile foraging together.  The juvenile showed typical begging behaviour with fluttering wings and an adult was doing the foraging and feeding of the juvenile though regurgitation as described, for instance, in a Palila wikipedia article.  This article says that both adults will regurgitate to feed the young in our case the male was feeding while the female stood guard, presumably looking for predators.  If the wikipedia article is correct then perhaps they take turns feeding and guarding or perhaps the guarding behaviour only happens occasionally, for instance when a large number of two-legged, orange-vested homo sapiens are also foraging in the area.

If we only consider predators seen historically before the arrival of man on the islands the most likely candidates would probably have been the Hawaiian Short-eared Owl (Pueo) and the Hawaiian Hawk (ʻIo).  It is not clear what threat we birders posed to the Palila though it was clearly not enough to drive them away.  Whether or not the female would have stood guard where and when she did if we had not be there is unclear.

As mentioned earlier, introduced predators are currently one of the Palila’s biggest threats.  These include feral cats and black rats (see for instance this article on the Palila from BirdLife International (birdlife.org).  Mosquitos transmitting avian malaria have also proved very dangerous to the endemic populations of birds.  They are also threatened by habitat degradation especially if it affects the growth and spreading of their primary food sources, the peas from the seed pods of the māmane plant and certain types of caterpillar.  Introduced mammals such as sheep and pigs are particularly bad for disturbing the forest plants.  Through hunting and fencing the threat of these has been reduced.

First Sighting: An adult male processing a māmane pod.

Our first sighting of a Palila was that of an adult male who was processing a māmane pod in the middle of a bush that provided the bird with some protection.  The following 7 pictures, shown in the order that they were taken, cover a period of about 9 seconds.  All of these pictures were cropped from the original size of 4000 x 3000 down to about 1200 x 800.  The displayed images below are shown at a resolution of 640 x 400 though the full-sized cropped images can be viewed clicking on the image and following the link back to Flickr.

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Video of the Male Foraging

The following is a short video that was taken starting 10 seconds after the last picture (above) was taken.  You can hear the group leader describing the bird to some of the birders that were just then discovering it for the first time.  Initially you can see the Palila alternating between working on the māmane pod and raising it’s head up to check its surroundings.

You can also hear the Palila in between the periods where it is working on the māmane pod and also after it appears to be done having released the māmane pod.  Perhaps these calls were communications to the other family members that would be showing up in the seconds that followed the video.  There may even have been a specific message to the juvenile that he (the adult male) was full and that it was time to eat.  This might also explain why he dropped the pod.  It’s not clear why they moved to a different location for the feeding.  Perhaps it was because of our presence or perhaps because it is generally safer to keep moving.

Unfortunately there is a half minute gap between this series of pictures and the next series with adult feeding juvenile.  The only thing that I recall from this period is that the juvenile and adult female arrived to join the adult male and then the female left again.

Second Sighting:  A juvenile begging and being fed by the adult male.

The second set of 7 images were taken over a period of 13 seconds starting 63 seconds after the last picture in the first set or about 38 seconds after the end of the short video.  As mentioned, in these 38 missing seconds the male moved to a different perch and a juvenile and an adult female flew in to join the adult male.  Only the juvenile stayed to be fed by the adult male while the female flew off to, it appears, stand guard (see the third sighting section below).

The sequence between the adult male and the juvenile clearly shows the begging behaviour as well as the regurgitation and transfer of food from adult to juvenile.

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The final image was taken 5 seconds after the previous one and shows the juvenile left alone and somewhat hidden in the foliage while the adult male had moved on, perhaps to start a new cycle of processing māmane pods prior to the next feeding cycle at which point he would call the juvenile to join him there.

Third Sighting: An adult female on guard duty.

The third set of 5 pictures were taken over a period of 24 seconds starting 18 seconds after the last image in the second set.

The adult female Palila, which made a brief appearance off camera took up a position 100 feet or so from where the other two birds were positioned.  Her perch at the top of a bare branch gave her good visibility. She chose a bush that kept all of the birders, which had broken into several groups by this time, on one side of her, perhaps in order to be able to see all of them at once without continually having to look in opposite directions.  As the photos show, she still does look away from time to time, perhaps scanning for other possible threats.  As mentioned previously, the two historic threats where probably the Hawaiian Short-eared Owl (Pueo) and the Hawaiian Hawk (‘Io).  At this point in our trip we had already seen 5 of these owls hunting (one near where we found the Palila) and we had one unconfirmed hawk sighting.

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I was impressed by the fact that both adult Palilas were caring for what was clearly a juvenile bird.  The splitting of the task of feeing the young was split into roles of foraging and standing guard.  It would have been nice to know if they switched roles from time to time.  Many species, particularly migratory ones, leave their young to fend for themselves at a much younger age or only one of the adults take responsibility for the young.

 Final Thoughts

I acquired my Panasonic FZ-200 camera to help with bird identification but on several occasions it has proven useful in seeing behaviours that I would never have noticed using just binoculars.  The ability to capture large numbers of pictures and even videos with sound provides the opportunity to analyze different aspects of bird sightings that happen too quickly in the field.

It would seem that my camera is rapidly replacing my binoculars as my primary birding equipment.  Here are some things that I might change in the future that might lead to better results:

  • Take more pictures and make more use of burst mode.  You can always delete them later.
  • Take more video clips.  Images can be extracted from these videos though not with the same resolution.  Video also records sound which can be useful in understanding bird behaviour.
  • Bring a tripod.  A remote control cable might be useful as well for the still shots.
  • Make sure that the memory card is fast and has lots of space.  Bringing extra fast cards will encourage taking lots of pictures and videos.
  • Add a directional microphone that plugs into the audio in jack on the camera.
  • Get more people involved.  It would be interesting to see if better behaviour could be captured with a coordinated group of birders taking pictures and videos together.  The camera clocks would obviously need to be either calibrated or synchronized to help determine the order of various events.

It was a fun way to get introduced to a new bird and, while it took a lot of time post-processing, it was definitely more satisfying than a brief sighting and a simple pencil mark on a checklist.

For More on the Palila Check Out the Following Links

The Palila article on Wikipedia.

The Palila Status at BirdLife International (birdlife.org).

The Mauna Kea Forest Restoration Project website from the Hawaiian state government has much more detailed and accurate information on current status and threats to the Palila.

The Facebook page for “A Paradise Lost”, an animated movie about the Palila directed by Laurie Sumiye.

Five Harlequin Ducks Video

My second outing with the Ken ‘s Birding Photography class took place August 31, 2013 and started in the same place as the first, at the Reifel Migratory Bird Sanctuary.  This time it ended at the Tsawwassen Ferry Terminal along the South side of the spit.  One of our last sightings was a small group of 5 Harlequin Ducks that were slowly working their way down the length of the spit.

Besides lots of pictures, I took a minute long video with my camera that was sufficiently entertaining that I dressed it up using Microsoft Movie Maker, added some music (to replace the sounds of automobile traffic and birder chit-chat) and made it available for general consumption in the video window below and on both Flickr and YouTube (my first ever YouTube video).

So, without further ado, here are ‘5 Harlequin Ducks’:

Here are the other links:

5 Harlequin Ducks (Flickr: small 484 x 272)
5 Harlequin Ducks (Flickr: medium 854 x 480)

5 Harlequin Ducks (Youtube)

The streaming from Flickr and/or Youtube may not be very smooth so downloading a copy from the ‘Share’ menu or from one of the versions on Flickr and watching locally should lead to a noticeably better experience.

Enjoy!

Adventures in Cackling Goose Subspecies Identification

Sardis Pond and a Whole Lot of Geese

I saw my very first Cackling Geese on Friday September 20 while on an outing with some of the members of a bird-photography course that I am taking. We were at our last stop of the day which was Sardis Pond which sits in the middle of Sardis Park in the middle of Chilliwack.

My one previous visit was in late May when the bird population consisted of small numbers of Canada Geese, Mallards, Red-winged Blackbirds and a few Wood Ducks.  Later in the year, I was told, the pond would get more interesting as a lot more birds move in for the winter including thousands of Canada Geese and, in recent years, a small of population of Cackling Geese.

The photography instructor Ken, with his black-belt in camera skills, thought it worth making a quick stop to look for early cackler arrivals before calling it a day.

We weren’t disappointed.  The first thing that we noticed was the large number of Canada Geese that had already moved in.  We estimated that there were probably 800 to 1000 of them.

Canada Geese - Sardis Park

Canada Geese have taken over in Sardis Park. Can you spot the two Cackling Geese?

After a few minutes of searching, Ken found 2 cacklers hanging out together and, over the next half hour or so, we took a whole lot of pictures.

That might have been the end of the story that would have ended with a checklist indicating two Cackling Geese.  However, Ken noted a partial white neck ring on one of the two geese and we weren’t sure if it was significant.  When I got home I took a closer look at both and wondered if they might be from different sub-species.  This led me on a path over several days that would introduce me to the many of the pitfalls associated with bird identification – in this case, the attempted identification of the specific sub-species of the two Cackling Geese.

The process of trying to identify the subspecies for the 2 geese was quite educational and I decided that it was worth describing in some detail along with some lessons learned drawn from some identification mistakes made along the way.  During this process, I was quite glad to have taken a large number of pictures of the two cacklers (over 50) as well as a short minute long video.

Introducing the Cackling Geese

The following picture shows the 2 cacklers side-by-side. The bills on each bird look similar in size and shape and definitely have the expected stubby form of the Cackling Goose . The bird on the right appears slightly larger, has a squarer head and a partial white neck ring.  While you cannot see it in the first image, the second image shows the larger cackler (now on the left) to have a noticeable throat stripe not present on the smaller goose.

Cackling Geese

Two cackling geese from behind. Note the throat-stripe on the left bird.

The third picture, below, shows the two birds head on providing a good look at the colour of the breast. Both geese show a fairly dark brown. The size difference is also less noticeable in this view.

My usual first stop for bird identification is The Sibley Guide to Birds.  My hard copy only lists Canada Goose since the Cackling Goose was only split from the Canada Goose into its own species in 2004 (in the 45th Supplement to the AOU Checklist of North American Birds to be precise).  The online version of the Sibley Guide on my iPhone and iPad is updated regularly and does the 2 species though does not contain the level of detail that would eventually be necessary.

Another extremely useful guide that I consulted extensively was the online Sibley guide: Distinguishing Cackling and Canada Goose.  Finally, I relied on expert help from the Fraser Valley Birding forum to make up for my own lack of field experience in the fine details and the pitfalls of separating subspecies..

According to the online Sibley guide, the Canada/Cackling Goose species are divided into 7 Canada Goose and 4 Cackling Goose subspecies.  Assuming that we had a pair of cacklers, the two most likely subspecies for our two birds are given below with descriptive information taken from different sources:

  • B h minima: The ‘Cackling’ Cackling Goose and the smallest of the cacklers.  It is described as having a round head, short bill and dark brown breast with a purplish tinge.
  • B h leucopareia: The ‘Aleutian’ Cackling Goose.  It has a dark brown breast and is slightly larger and has a squarer head than B h minima.  Usually has a white neck ring and usually has a black neck stripe.  The bill is longer than that of B h minima as well.

My first thought was that the smaller goose was a B h minima while the second had characteristics suggestive of B h Leucopareia (neck stripe, partial collar, squarer head, larger size).

However, there were several issues with the larger bird being a B h Leucopareia.  First, the breast colour of both birds was very similar having the purplish sheen described for B h minima.  Second, the collar should probably have been a complete collar and not partial as seen.  In any case, both collar and neck stripe can occur on other subspecies and cannot be reliably used for identification according to the online Sibley guide.

If you read the entire online Sibley guide you will find some suggestions as to how to find Cackling Geese in a crowd of Canada Geese.  First, they suggest looking for birds that group together as a good way to identify birds from the same family group or population.  These 2 geese that we were following were definitely sticking together.  Since male geese are typically larger than females, this could explain the size difference.  The difference in head shape is a little problematic as I do not know how important that trait is for a positive identification.  Reference [3] suggests that head shape is not a critical trait and should not be a primary consideration in identification.

Sizing up the Bills

A good method of separating a Cackling Goose from a Canada Goose is to look at the bill size.  This can also sometimes be used to separate subspecies in as well as is the case with B h minima and B h Leucopareia.  The online Sibley guide has a table showing the range of bill length for the different Cackling and Canada Goose subspecies.  In particular, there is no overlap between B h minima and B h leucopareia.  Measuring the exact bill length is not practical however all we really need to compare is the relative bill size.

Consider the first picture of the 2 Cackling Geese walking single-file.  Both geese have their heads pointing in the same direction and are roughly the same distance from the camera.  The following image shows only the heads of the two geese rotated such that their bills have the same orientation.  I marked the upper and lower edge of both bills with pink lines that have the same length and orientation on both birds.  Their bills are effectively the same length which, according to Figure 2 in Sibley’s Guide is strong evidence that if the smaller goose is a B h minima then the larger bird should be as well.
CACG-CACG bill size comparison

The following image shows the re-oriented heads for the larger cackler and one of the large Canada Geese that were present at Sardis Pond and that I captured in a picture where their heads were pointed in the same direction and where both were roughly equidistant from the camera.

A pink line on the lower bill shows my estimate of the bill length for each with the length in units used by the program that I used to manipulate these head shots.  The resulting Canada/Cackling bill length ratio is about 1.74.  If I assume that the Canada Goose is of the western moffitti subspecies that is common in the west then, from Figure 2 in the Sibley Guide the expected ratio would be about 1.66.
CACG(minima) - CANG(moffitti) bill size comparison

The evidence suggests that both of these cacklers were of the minima subspecies.

Seeing a new bird is always satisfying.  Being given a challenging puzzle to determine the subspecies was, in many ways, even more satisfying than the new life-list check-mark.  I certainly learned a lot more about the pitfalls of bird identification.  In fact, I’m still a little worried about that not-so-round head on the bigger cackler so maybe this story is not over yet.

One of the big lessons learned for me was that taking lots of pictures is a good thing, even after I had several good ones to document the new species.

So what to do for an encore?  Well, I’m told that the Taverner subspecies will be showing up in a few months…

Thanks go to Ken for spotting the pair of cacklers, to Gord for correcting some of my identification missteps, and finally to Sibley for the excellent online guide.

References

[1] Sibley Guides: Distinguishing Cackling and Canada Goose.

[2] Stokes Birding Blog: Cackling Geese subspecies in the East.

[3] Monterey Birds: Canada Goose and Cackling Goose.

Bird Migration Movie: Crossing the Gulf of Mexico

Ruby-throated Hummingbird

Ruby-throated Hummingbird by Matt Tillett (Flickr: Ruby-throated Hummingbird) [CC-BY-2.0], via Wikimedia Commons

 I found this hour long online movie about bird migration across the Gulf of Mexico a couple of days ago.  It does a good job of  documenting the amazing migration that many North American birds go through each Spring and Fall.  Birds as small as the Ruby-throated Hummingbird fly non-stop from the Yucatan to the Gulf coast of the US on their way to their breeding grounds further North, a trip that can take most of a day and cover 600 or more miles.  The fall sees a similar migration in the opposite direction back to the wintering grounds in Central and South America.

Link

Among my favourite birds to watch in flight are the swifts. They are powerful fliers that most people will only ever see on the wing since they cannot perch like the swallows that they superficially resemble (they are more closely related to hummingbirds).  A friend of mine recently brought a story a from Discover Magazine (This Bird Can Fly for Six Months Without Landing Once) to my attention. Equipping the some Alpine Swifts with motion sensing equipment, a group of Swiss researchers were able to show that the birds, which breed in the mountains from southern Europe to the Himalayas, can stay aloft for months at a time during their overwinter migration in southern Africa.

Amazing!

Link

The September  2013 issue of the Canadian online journal Avian Conservation & Biology features a number of short research articles associated with Quantifying Human-related Mortality of Birds in Canada.

Individual articles deal with the contributions from specific industries and activities including:

  • Vehicle Collisions
  • House Cats
  • Marine Commercial Fisheries
  • Offshore Oil and Gas Production
  • Industrial Forestry
  • Collisions with Buildings
  • Mowing and Other Operations in Agriculture
  • Oil and Gas Exploration in the Western Basin
  • Collisions and Habitat Loss from Wind Turbines.

All of the articles can be freely viewed online or by downloading a PDF version.

So, which one of the above categories do you think is the biggest contributor towards bird mortality?

The final article, A Synthesis of Human-related Avian Mortality in Canada, puts all the different sources of bird mortality into context.  Table 3 in this article shows bird mortality estimates separated by source and split into the categories of landbird, seabird, shorebird, waterbird and waterfowl.

And the biggest bird killer?  It is, by a long shot, the house cat with an estimated 135 million birds (almost exclusively landbirds) of which 80 million are attributed to feral cats and the remaining 55 million to the domestic variety.  Compare these numbers to the total of 186 million dead birds per year and we have house cats killing over 70% of all birds killed from human-related causes.

There’s a whole lot of interesting information in this issue.  Well worth a read.