Bright Goes North

Guest post by Kate Davies, a recent MEnvSc Graduate from the University of Toronto-Scarborough

She could feel the pull in her body. It was time.

She had done this journey before, but even the first time it felt familiar. Like a memory that she was born with.

She was called Bright because she was known by the others for her deeply golden tail feathers and her clear eyes. Bright was late leaving her winter home this year, and many of the others had left already, departing at the first signs of change. The air had started to feel heavy signaling that the rains would come soon. She had to start north before daybreak. Bright hopped around the tree canopy from branch to branch. She dropped her wings by her sides and fanned her tail to spook the insects and quickly grab them in her beak. She had spent her winter in brushy scrubland that was not the best feeding grounds, but she was older now and had less energy to defend her place in the boggy wetlands filled with ripe insects. She ate her fill before she spread her wings and started to carry her small light body out over the immense open waters. Crossing the gulf was frightening the first time, but she knew even on her first trip that the sky would end, and she would see green again. She traveled in a loose flock with some other Redstart females, some yearlings and others Bright knew from previous flights. She hoped some of her daughters were here, now grown she would not have known their calls. The males always left first; they would meet them in the northern home.

Illustration by Kate Davies

The journey across the gulf lasted into the night, the winds were not favourable this year. Bright and the others she travelled with were weak and needed to eat. There was a wetland they had visited as a stop every year, but Bright was worried they had taken a wrong turn. This was the right place but there was not water, few plants, and it had been filled with stone, humans and a glowing hum. It seemed as she flew north every year there were more angular stone forests filled with humans. Some could tolerate these stone forests but Bright and her companions preferred trees and grass. The birds who lived there like pigeons and house sparrows spoke a different language than the other birds she knew, and some said they came across the water bigger than the gulf. So, despite their exhaustion the females kept flying until they could find somewhere to eat and sleep. They had to settle for an area where the plants all grew in rows, a farm, but there was a river and some insects so it would do for today. These human places had different dangers and predators than in the forests and fields. Bright knew to be cautious of owls, hawks and snakes but where there were humans, other dangers were lurking. They were too tired to find anywhere else to sleep. Bright noticed that her party had shrunk by a few - some were so tired they may have rested in the stone forest. Bright hoped the others would be alright and would catch up to the group.

They travelled for a few more days, finding quiet places to rest. They avoided the stone forests as much as they could with their bright lights, constant noises and hums. They rested at another farm on the fifth night. Bright and her companions were huddled in a dense thicket of bushes near a field and river. They had fallen sound asleep for the night. In the nearby tall grasses, a pair of green eyes shone in the moonlight. A barn cat had been stalking the birds, she moved quietly, softer than the wind. The cat slinked under the low branches of the bush without a sound and spotted a bird on a low branch she could easily reach.  Bright opened her eyes to see one of the yearlings was in the cat’s fangs - she was lost. Bright and her companions moved to another row of bushes closer to the stream, they were all shaken and tired. Fear and anxiety overtook the small flock, they didn’t sleep anymore that night. Bright was relieved when the sun crept over the horizon and they could continue northward.

Illustration by Kate Davies

The air was warm, and they had been lucky that there were no storms along the way. They started to see some males that day, and a few of her companions ended their journey to find a mate. Bright continued her northward flight as did most of the females until they made it over the big lake. It was not as big as the gulf, but it could be dangerous, as there were many humans and stone forests around the water. There were predators near every shore, some had been here all winter and were eager for the small songbirds to return so they could fill their bellies.

Since Bright had left late this year, she was eager to build a nest and find a mate. She decided to end her journey on an island at the north shore of one of the long lakes. Most of the others continued north. She was near a stone forest but on an island that was far enough away that the sound of the waves drowned out the hum and noise. It was the time of year where the air was filled with song from many different birds. She fluttered around the island listening for males of her kind, trying to find one who sang strong and clear. She followed a song to a male high up in a red maple tree. In her mind she identified him as Flicker - he was very expressive in the way he flicked his tail. He took her to the sites he had scouted for nesting to see if she approved of any. She was happy that she would be his first and maybe only mate, which would afford her more protection. She picked the third site he showed her. It was a dense area of red dogwood that was covered in fresh young leaves. They were close to a pond in an area rich with insects. She started to gather twigs and build her nest there while Flicker stayed close singing to warn others away from his mate and territory. Together they had four eggs and Bright was happy with her clutch size; it was more than last spring. She left the nest to find some food in early morning and Flicker guarded the eggs. She was chasing a particularly acrobatic fly though the bushes when suddenly a great force stopped her flight and she fell to the ground. She could feel and taste the warmth of blood in her mouth, her beak was fractured, her head pounded, and she could not catch her breath. She had only seen branches before her, it was like a reflective pond in the air made of stone. Bright wanted to live, she wanted to get up go back to Flicker and the young. She could not move; she let out her last breath and died.

The new gardener came around back of the building to trim the forsythia that was long overgrown. At the base of the bush under the window lay a female American Restart, she was dead. The garden gasped and cried out ‘Oh no!’ Another window strike, this was the sixth one this month and perhaps it would encourage management to finally birdproof the windows, thought the gardener. She buried the bird in the garden with a tear for its loss of life and trimmed the forsythia. On her break she reported the window strike on the Fatal Light Awareness Project (Flap) website and continued her duties.

Flicker realized that Bright would not return - what had become of her? He could not care for the babies alone. He would have to leave them. He sung a mournful song for Bright and flew off in search of a new mate hoping that it wasn’t too late.

 

 

Further Reading and References

Further reading: Online resources

The Cornell Lab - All about birds – American Redstart

Overview: https://www.allaboutbirds.org/guide/American_Redstart/overview and

Species account: https://birdsna.org/Species-Account/bna/species/amered/introduction

Toronto and Region Conservation Authority. The American Redstart: A Bird On the Rise In the GTA https://trca.ca/news/the-american-redstart-a-bird-on-the-rise-in-the-gta/

Boreal Songbird initiative. A guide to boreal birds https://www.borealbirds.org/bird/american-redstart

Ontario Nature. Migratory Birds https://ontarionature.org/campaigns/migratory-birds/

North American Birds Declining as Threats Mount By Mel White for National Geographic https://www.nationalgeographic.com/news/2013/6/130621-threats-against-birds-cats-wind-turbines-climate-change-habitat-loss-science-united-states/

Birdwatchers Digest. Your Bird Questions Answered: Flight and Migration https://www.birdwatchersdigest.com/bwdsite/connect/youngbirders/your-bird-questions-answered-flight-migration.php

 

 Further reading: peer reviewed literature

Cohen, E. B., Rushing, C. R., Moore, F. R., & Hallworth, M. T. (2019). The strength of migratory connectivity for birds en route to breeding through the Gulf of Mexico. Ecography, 42(4), 658–669. https://doi.org/10.1111/ecog.03974

Cooper, N. W., Sherry, T. W., & Marra, P. P. (2015). Experimental reduction of winter food decreases body condition and delays migration in a long-distance migratory bird. Ecology, 96(7), 1933.

Hill, G. E. (2004). A Head Start for Some Redstarts. Science, 306(5705), 2201–2202.

Germain, R. R., Marra, P. P., Kyser, T. K., & Ratcliffe, L. M. (2010). Adult-Like Plumage Coloration Predicts Winter Territory Quality and Timing of Arrival on the Breeding Grounds of Yearling Male American Redstarts. The Condor, 112(4), 676–682. https://doi.org/10.1525/cond.2010.090193

Norris, D. R., Marra, P. P., Bowen, G. J., & Ratcliffe, L. M. (2006). Migratory connectivity of a widely distributed songbird, the American Redstart (Setophaga ruticilla). The Auk, 123(4), 14.

Norris, D. R., & Marra, P. P. (2007). Seasonal Interactions, Habitat Quality, and Population Dynamics in Migratory Birds. The Condor, 109(3), 535–547.

Marra, P. P., & Holmes, R. T. (2001). Consequences of Dominance-Mediated habitat segregation in American Redstarts during the nonbreeding season. The Auk, 118(1), 92–104.

McKinnon, E. A., Stanley, C. Q., & Stutchbury, B. J. M. (2015). Carry-Over Effects of Nonbreeding Habitat on Start-to-Finish Spring Migration Performance of a Songbird. PloS One, 10(11), e0141580.

Morris, S. R., & Glasgow, J. L. (2001). Comparison of spring and fall migration of American Redstarts on Appledore Island, Maine. The Wilson Bulletin, 113(2), 202.

Smith, R. J., Mabey, S. E., & Moore, F. R. (2009). Spring Passage and Arrival Patterns of American Redstarts in Michigan’s Eastern Upper Peninsula. The Wilson Journal of Ornithology, 121(2), 290–297. https://doi.org/10.1676/08-051.1

Wuethrich, B. (1998). Songbirds Stressed in Winter Grounds. Science, 282(5395), 1791–1794.

 

 

Where is south? Uncovering bird migration routes

Guest post by John Viengkone, currently enrolled in the Professional Masters of Environmental Science program at the University of Toronto-Scarborough

Wilson’s Warbler http://www.utahbirds.org/birdsofutah/BirdsS-Z/WilsonsWarbler.htm

There are approximately 450 native migrating bird species that for at least part of the year reside in Canada, but where do they go when they aren’t in the True North Strong and Free? If you ask just about anyone, they’ll tell you that birds fly south for the winter, but where exactly is south? South could be as close as the next city, the USA or as far as Tierra Del Fuego. Also do they make stops on their way to this “south” and do they mix with other populations? The truth is there isn’t much information on where many migrating species go or the route they take to get there.

But why should we care where they go when they leave Canada, they seem to always come back in the spring. The truth is not all birds are coming back, there has been a marked decline in the population size of many migrating neotropical bird species. As the leading cause of species loss, humans need to figure out whether these bird populations are facing stressors in their breeding, wintering, stopover range or some combination of the three so we can help manage them. The first step in doing this is learning the birds’ migration route. 

The effort to understand the movement patterns of birds began in North America during the 1800s when the famous ornithologist John James Audubon started tying silver string to the legs of eastern phoebes, Sayornis phoebe, to see if individuals that left in the fall returned in the spring. Of all the birds Audubon marked, 2 returned in the spring. This little experiment transformed into the bird banding/ringing program we know today with different coloured metal bands replacing the pieces of silver string.

Though the bird banding program has been essential to the understanding of bird ecology, life history and migration it is has one major flaw. This flaw is that banded birds must be spotted again and it’s estimated that only 1 in 10,000 banded birds are recaptured, leaving a large data gap. So why use bands, why not use GPS tracking devices? Well, they do for larger birds but for many bird species the size and weight of a tracker is too much of stress so a better solution is needed. This solution is up and coming from Dr. Kristen Ruegg’s lab at UCLA and it has been dubbed The Bird Genoscape Project.

Ruegg and company have taken on the task of creating a protocol that will allow them to identify where a migrating bird has come from by using just a feather. To get a full comprehensive understanding of this protocol please refer to Ruegg et al. 2014 but I’ll briefly explain their methods here: Variation in DNA is what makes individuals unique but a huge portion of an organism is actually shared with the individuals of the same species. As groups or populations of a species become more isolated and breed with other individuals in their populations more, the populations start to diverge, this is population differentiation. Individuals in a breeding population will be more similar to each other than to other populations.

The UCLA team used the concept of population differentiation to find the small bits of DNA, called single nucleotide polymorphisms (SNPs), that are unique to each breeding population, a genetic fingerprint some might say. For their study they looked at the Wilson’s warbler, Cardellina pusilla, taking small blood samples from individuals in each breeding population and each population’s genetic fingerprint was made.

With a genetic fingerprint for each breeding population Dr. Ruegg and her collaborators were able to collect feathers from Wilson’s warblers across North America and identify where it came from with an 80-100% success rate. So a feather collected in Colorado in the late fall could be traced back to the British Columbia breeding population, meaning Colorado is a stop off point. This solves the major problem that banding had; you don’t need to come in contact with the same bird to get information, any bird in the species will work. 

From Ruegg et al. 2014. Each colour depicts a breeding population, arrows are stopovers and circles are wintering grounds

An interesting finding from UCLA’s study was that there are 6 breeding populations of Wilson’s warblers opposed to the 2-3 that biologist previously thought and that 3 of the breeding populations actually share a wintering ground and flight path. Two of these three breeding populations are stable but one population is declining, suggesting the cause of decline stems from the declining population’s breeding ground. If the issue stemmed from the wintering ground of the flight path, the other populations should be affected too.

So what’s next? Ecological managers now know where the issue is likely originating from for the Wilson’s warbler but still need to identify the root cause. As for The Bird Genoscape Project, Dr. Ruegg has moved on to repeating this study with the American Kestrel. There is also work being done with museum samples to see if ranges and flight paths have shifted with time. It’s looking like The Bird Genoscape Project can only get bigger, spreading to more migrating bird species and become an essential tool for bird conservation just as bird banding did in the past.

For more information see:

Ruegg K.C., Anderson E.C., Paxton K.L., Apkenas V., Lao S., Siegel R.B., Desante D.F., Moore F., and Smith T.B. 2014. Mapping migration in a songbird using high-resolution genetic markers. Molecular Ecology 23:5726-5739.

Kristen’s interview with Podcast Eye’s on Conservation is available on iTunes