Tag Archives: birds

Winter song

I love these wintry days in the Central Valley when its dirty brown air has been washed out by the infrequent (but not this winter, gracias El Niño) rain and wrung out to dry with cottonball clouds hanging as if on invisible clotheslines across an impossibly blue sky. Days like this I can even see snow on the mountains of the Sierra Nevada from my office window, pulling my gaze away from the computer screen to wander off daydreaming…

View from my office window, drawing me away from my screen to the snow-frosted mountaintops of the Sierra Nevadas in the distance. This iPhone's camera doesn't do justice to what my eye sees...you may have to squint into the middle distance to glimpse the mountains underneath the floating clouds.

View from my office window, drawing me away from my screen to the snow-frosted mountaintops of the Sierra Nevadas in the distance. This iPhone’s camera doesn’t do justice to what my eye sees…you may have to squint into the middle distance to glimpse the mountains underneath the floating clouds.

Such days I imagine were the norm in this valley a century ago, before our vehicles and agricultural industry started filling up the air with so many of our effluents as to turn this beautiful air into some of the least breathable in the nation, a murky brown veil hiding the mountains on most days of the year. Yet the people keep coming to fill up this valley, remaking it in our own industrial image, flattening the topography and bending the natural and ancient rhythms of this land and atmosphere to our will. Days like this remind me of those rhythms, of what once was, what might have been, and what could be again in this beautiful place, even as the vision of those mountains seems to melt away the grimy sealed glass pane on my office window out of which I goggle at that impossibly blue sky like a goldfish trapped in a bowl.

Urban conifers against that impossibly blue winter sky. There be Great Horned Owls in some of these trees...

Urban conifers against that impossibly blue winter sky. There be Great Horned Owls in some of these trees…

That window glass is not thick enough to keep out the occasional soft hooting of the young Great Horned Owls hidden in the branches of those conifers, where they were raised a summer ago. And this morning, as I stepped out onto the external staircase, I was startled by the liquid burbling notes of a song that is common throughout the spring and summer around here, but shouldn’t be so loud so early in the year. A House Finch was sitting high up in one of the trees singing his heart out against a background humming with the urban noises of building atmospheric devices and traffic in the distance, and roaring with an occasional airplane flying over.

Looking out east from his high perch, I wonder if the House Finch noticed the snow on the mountains, or heard the chirping of the winter migrants in the trees nearby, but even if he did, these weren’t enough to dissuade him from following whatever internal hormonal clock was telling him it was time to start singing to attract a mate. Already, and it isn’t even the middle of January yet. Global warming, is it, or just the local warming effect from the urban heat island? No matter, this boy is already serenading the ladies about the bountiful spring to come.

Meanwhile, the chipping sounds you hear at the end of the sound clip above might well be the mild panic setting into the heart of the migrant Yellow-Rumped Warbler foraging in the branches nearby, perhaps wondering if it was time to leave its winter ground already even though the air felt cold and the clouds spoke of more rain to come.

Its been a topsy turvy winter (or a few) in California, and living in these disconnected urban landscapes beneath the gaze of those parched snow-covered mountains must be discombobulating even to the wild creatures trying to make this ever stranger land their home. I know the feeling well.

How the White-Crowned Sparrow changes its tune to be heard through the urban din

Last October, I was invited by Laurel Serieys (a graduate student at UCLA)  to present a paper at The Wildlife Society’s 20th Annual Conference in a symposium on how urbanization can cause wildlife populations to diverge by altering behavioral, physiological, and genetic aspects of populations occurring in cities compared to non-urban areas. This is an emerging field of research as we are beginning to build a better understanding of how different cities are as habitats for many species, and the different ways by which they may adapt to city life – or not. This approach is part of the research strategy which should help explain some of the broader patterns we are observing in the distribution of biodiversity in the world’s cities.

I spoke about the effects of urban noise on bird song, based on the excellent Masters thesis project by my (now former) graduate student Jenny Phillips, who studied migratory White-Crowned Sparrows spending the winter in California’s Central Valley. Jenny has since gone on to a Ph.D. program at Tulane University, working in the lab of Elizabeth Derryberry, who was on her MS thesis committee (and with whom I intend to continue collaborating to extend this research).

Photo of White-Crowned Sparrow sitting in a fence

A white crowned sparrow framed in the demarcated landscapes of California’s Central Valley. Photo by Madhusudan Katti, 2008.

I just remembered that TWS was recording talks and sessions throughout the conference, and went looking to see if my talk was recorded. Indeed it was! So if you are interested in hearing about some of Jenny’s and my work on urban bird song, have a listen to my talk on this page, which shows you my slides coupled with my ghati-accented voice:

Singing in the urban din: the effects of anthropogenic noise on song structure in urban birds

Note: the audio had glitches when I tried listening through Safari, but worked fine on Google Chrome; YMMV.

Here’s my abstract for that talk:

Female birds often use male song as an indicator of mate quality; thus the study of song provides insights into reproductive success. Song structure is constrained by the acoustic environment with selection favoring songs that transmit best through available channels given ambient noise and atmospheric conditions. Ecology_specifically those components of the environment that influence sound transmission_thus influences the cultural evolution of songs. One relatively new selection pressure on many birds’ song, is anthropogenic noise, from car traffic as well as industrial machinery and other urban sources. Urban noise resonates at low frequencies and has been shown to influence song frequencies in sedentary populations of song sparrows, great tits, and blackbirds. Increase in ambient noise has also been shown to diminish discriminatory ability in female zebra finches. I first present a brief conceptual overview of the potential and documented effects of urban noise on bird song and behavior. I then share results from ongoing studies of the effects of noise on song in White-crowned Sparrow, Zonotrichia leucophrys gambelii, a long distance migrant wintering in urbanizing areas of central California. Songs and noise were recorded across the urban-rural noise gradient in Fresno-Clovis Metropolitan Area and compared for acoustic differences in frequency and duration. Modulated note components of the song, the buzz and trill, decreased in bandwidth with increasing noise. The duration of the buzz portion can also be predicted by noise and habitat type. This trend towards short, pure tones in noisy areas is likely an adaptation to be better heard through the roar of the city. Playback experiments also found increased latency to respond to territorial simulations under high ambient noise levels. This may contribute to a breakdown of territoriality in urban habitats. Anthropogenic noise is likely to be an important driver of population divergence due to urbanization.

More birds and plants in the world’s cities than expected – a new paper from my NCEAS team

Tea with sparrows

A special present to celebrate this Darwin Day: the publication of the first paper from my global collaboration to study patterns and processes in biodiversity among the world’s cities. This first fruit of a collaboration that started 3 years ago under the aegis of the National Center for Ecological Analysis and Synthesis (NCEAS) in Santa Barbara has just been published in the Proceedings of the Royal Society B:

M. F. J. Aronson, F. A. La Sorte, C. H. Nilon, M. Katti, M. A. Goddard, C. A. Lepczyk, P. S. Warren, N. S. G. Williams, S. Cilliers, B. Clarkson, C. Dobbs, R. Dolan, M. Hedblom, S. Klotz, J. L. Kooijmans, I. Kuhn, I. MacGregor-Fors, M. McDonnell, U. Mortberg, P. Pysek, S. Siebert, J. Sushinsky, P. Werner, and M. Winter 

A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers

Proc R Soc B 2014 281: 20133330-20133330 doi: 10.1098/rspb.2013.3330

The paper has 24 co-authors, from 10 countries, and involved a number of other collaborators who contributed data in some way. It is easily the biggest scale project I’ve ever been involved with, and one that promises to be very productive over the next few years. We started in 2011 by building perhaps the largest database of bird and plant diversity in cities, with 147 cities analyzed in this paper, and have continued to work on analyzing the data and expanding the database. This paper is the first in what we plan to be a series of articles analyzing the distribution of bird and plant species in urban areas worldwide to develop a deeper understanding of how cities interact with biodiversity. As such, this overview article has been a big first step in getting our work through peer review and into publication so the rest of the world—you—can read and see what we have discovered.

It is gratifying to see that there is broad interest in our results. The BBC News posted a report covering our paper even before the paper was available online, and the BBC World Service will shortly be interviewing Mark Goddard, one of the coauthors. Meanwhile, the Australian Broadcasting Corporation’s program The World Today spoke to coauthor Nick Williams earlier today, and you can hear his interview online in the show’s podcast. US media hasn’t quite woken up yet, so let’s see how much interest there is on these shores.

I will be writing more about this research, and explaining our findings in greater detail in a blog post or two over the coming few days (as and when I find time to finish writing the posts in between classes and committee meetings). For now, let me share this press release I helped put together for NCEAS:

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Julie Cohen
(805) 893-7220
julie.cohen@ucsb.edu
Pat Leonard
(607) 254-2137
pel27@cornell.edu

February 12, 2014

Cities Support More Native Biodiversity Than Previously Thought
Researchers at UCSB’s NCEAS compile the largest global dataset of urban birds and plants, which shows world’s cities retain a unique natural palette.

(Santa Barbara, Calif.) — The rapid conversion of natural lands to cement-dominated urban centers is causing great losses in biodiversity. Yet, according to a new study involving 147 cities worldwide, surprisingly high numbers of plant and animal species persist and even flourish in urban environments — to the tune of hundreds of bird species and thousands of plant species in a single city.

Contrary to conventional wisdom that cities are a wasteland for biodiversity, the study found that while a few species — such as pigeons and annual meadow grass — are shared across cities, overall the mix of species in cities reflects the unique biotic heritage of their geographic location. The findings of the study conducted by a working group at UC Santa Barbara’s National Center for Ecological Analysis and Synthesis (NCEAS) and funded by the National Science Foundation were published today in the Proceedings B, a journal of the Royal Society of Biological Sciences.

“While urbanization has caused cities to lose large numbers of plants and animals, the good news is that cities still retain endemic native species, which opens the door for new policies on regional and global biodiversity conservation,” said lead author and NCEAS working group member Myla F. J. Aronson, a research scientist in the Department of Ecology, Evolution and Natural Resources at Rutgers, The State University of New Jersey.

The study highlights the value of green space in cities, which have become important refuges for native species and migrating wildlife. This phenomenon has been named the Central Park Effect because of the surprisingly large number of species found in New York’s Central Park, a relatively small island of green within a metropolis.

Unlike previous urban biodiversity research, this study looks beyond the local impacts of urbanization and considers overall impacts on global biodiversity. The research team created the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities).

Findings show that many plant and animal species, including threatened and endangered species, can flourish in cities, even as others decline or disappear entirely. Cities with more natural habitats support more bird and plant species and experience less loss in species as the city grows. Overall, cities supported far fewer species (about 92 percent less for birds and 75 percent less for native plants) than expected for similar areas of undeveloped land.

“We do pay a steep price in biodiversity as urbanization expands,” said coauthor Frank La Sorte, a research associate at the Cornell Lab of Ornithology. “But even though areas that have been urbanized have far fewer species, we found that those areas retain a unique regional flavor. That uniqueness is something that people can take pride in retaining and rebuilding.”

Conserving green spaces, restoring native plant species and adding biodiversity-friendly habitats within urban landscapes could, in turn, support more bird and plant species. “It is true that cities have already lost a substantial proportion of their region’s biodiversity,” said Madhusudan Katti, a faculty member in the Department of Biology at California State University, Fresno. “This can be a cup half-full or half-empty scenario. If we act now and rethink the design of our urban landscapes, cities can play a major role in conserving the remaining native plant and animal species and help bring back more of them.”

The human experience is increasingly defined within an urban context, the authors noted. They maintain it is still possible for a connection to the natural world to persist in an urban setting, but it will require planning, conservation and education.

“Given that the majority of people now live in cities, this group’s synthesis of data on plant and urban plant and animal diversity should be of broad interest to ecologists as well as urban and landscape planners,” said Frank Davis, NCEAS director.

# # #

Note to editors: Frank Davis is available at frank.davis@nceas.ucsb.edu or at (805) 892-2502. Downloadable images are available at http://www.news.ucsb.edu/node/013947/cities-support-more-native-biodiversity-previously-thought.

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Of course, feel free to also contact me if you have questions about the paper or our ongoing research into global urban biodiversity patterns, and if you need a reprint pdf of the paper. I would love to hear your thoughts on this work.

Urban gardens

 

How Bilbo Baggins saw the world, clinging on to Gwaihir’s back?

Well… maybe… not quite, because this doesn’t exactly looks like Middle Earth this bird is soaring over:

No, this is not an excerpt of a CGI scene from The Hobbit movie. Nor does the bird look quite like the greatest Eagle who ever lived in the annals of human mythology.

Better still – this is a clip from a real video camera mounted on the back of a real eagle, almost literally giving us the bird’s eye view of the Alpine landscape of the Mer De Glace area of Chamonix, France.

Pretty damn cool, eh?

2012 Ravi Sankaran Memorial Lecture by Mahesh Rangarajan

As mentioned here recently, the inaugural Ravi Sankaran Memorial Lecture was given by historian Mahesh Rangarajan during the Student Conference in Conservation Science in Bangalore a couple of weeks ago. The entire lecture is now available on youtube for those of us who were not able to attend in person. It is a long video, but well worth the listen, so settle down with this when you have an hour or so free:

Here is my own tribute to Ravi, written during the immediate pangs of grief when he died.

It is time again, for another round of the Great Backyard Bird Count!

The 2012 GBBC will take place Friday, February 17, through Monday, February 20. Please join us for the 15th annual count!

The Great Backyard Bird Count is an annual four-day event that engages bird watchers of all ages in counting birds to create a real-time snapshot of where the birds are across the continent. Anyone can participate, from beginning bird watchers to experts. It takes as little as 15 minutes on one day, or you can count for as long as you like each day of the event. It’s free, fun, and easy—and it helps the birds.  

As it happens, unfortunately, for the second year in a row, I am going to be away from my favorite birding partner during the 2012 GBBC! Last year, she was in India while I was stuck in the US. This time its the other way around. Perhaps she will be able to get her class to participate. What about you? Will you spend a morning counting birds in your backyard next week?

Exploring the world of birds and biodiversity with the Cornell Lab of Ornithology

As a thank you to its supports, the Cornell Lab of Ornithology shares this video montage filled with wonderful sequences of birds from their archives. Enjoy: