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Category Archives: Birds
Last week, my SciBling Jason Goldman interviewed me for his blog. The questions were not so much about blogging, journalism, Open Access and PLoS (except a little bit at the end) but more about science – how I got into it, what are my grad school experiences, what I think about doing research on animals, and such stuff. Jason posted the interview here, on his blog, on Friday, and he also let me repost it here on my blog as well, under the fold:
This week, Dr.Bird answers questions about birds – the raptors, especially those living inside of big cities. Listen to the podcast and join the discussion in the forums:
Listen to an interview about city-dwelling raptors. Download MP3
David Bird is a wildlife biologist at McGill University in Montreal. He directs the university’s Avian Science and Conservation Center.
Bird is editor of the the new book Birds of Canada. He also wrote The Bird Almanac: A Guide to Essential Facts and Figures of the World’s Birds.
On our radio program, we aired a story about how raptors — birds of prey — are struggling to survive in Beijing. You can listen to that story here.
Unlike Beijing, some cities are providing good habitat for raptors:
* Peregrine falcons now nest in churches and skyscrapers in North American and European cities.
* Goshawks are a common sight in Hamburg, Germany.
* Sparrowhawks are found in abundance in Nairobi, Kenya.
Learn about the thrills and perils of city life for raptors, and bring your own thoughts and questions to David Bird. He’s our guest in the Forum through Friday, May 7th. The conversation is just to the right.
* How can you make your community more raptor-friendly?
* Do you live next door to a bird of prey? Tell us about your experiences.
* Have you been involved with conserving raptors in your city or neighborhood?
Aves 3D is a ‘three dimensional database of avian skeletal morphology’ and it is awesome!
This is an NSF-funded project led by Leon Claessens, Scott Edwards and Abby Drake. What they are doing is making surface scans of various bones of different bird species and placing the 3D scans on the website for everyone to see and use. With simple use of the mouse or arrow buttons, one can move, zoom and rotate each image any way one wants.
The collection is growing steadily and already contains some very interesting bones from a number of species, both extinct and extant. You can see examples of bones of the dodo or the Diatryma gigantea (aka Gaston’s Bird), as well as many skulls and sternums and various limb bones of currently existing species.
The database is searchable by
Cladogram, Scientific Name, Common Name, Skeletal Element, geological era, Geographical Location or Specimen Number.
Most of the actual scanning is done by undergraduate students and the database is already being use for several scientific projects. You can get involved and help build the database, you can use the scans for teaching and research, or you can just go and have fun rotating the cool-looking bird bones.
Yes, years after I left the lab, I published a scientific paper. How did that happen?
Back in 2000, I published a paper on the way circadian clock controls the time of day when the eggs are laid in Japanese quail. Several years later, I wrote a blog post about that paper, trying to explain in lay terms what I did, why I did it, what I found, and how it fits into the broader context of this line of research. The paper was a physiology paper, and my blog post also focused on the physiological aspects of it.
But then, I wrote (back in March 2006 – eons ago in Web-time) an additional blog post on one of my old blogs (reposted on this one here, here and here) in which I followed further, thinking about the data in more ecological and evolutionary terms, and proposing hypotheses following from the data that can only be tested in other species out in the wild. As you can see if you click on the links, this post did not receive much commentary.
Then, about a year ago, I received an e-mail out of the blue, from a researcher at the Cornell Ornithology Lab, essentially offering to test one of the hypotheses I outlined in that post. My first reaction was “sure, go ahead, I am happy someone wants to do this, but please cite the blog post as the origin of the hypothesis”… The response was along the lines of “no, no, no – we are thinking about working WITH you on testing this hypothesis”. Wow! Sure, of course, I’m game!
They already had preliminary data which they sent to me to take a look. They are coming from an ecological tradition and are very familiar with the ecological literature, some of which they sent to me to read. On the other hand, I am coming from a physiological tradition and am very familiar with that literature, some of which I sent to them to read.
A month or so later, one of them, Caren Cooper, came down to Chapel Hill. We met and, over coffee, spent a couple of hours staring at the data and discussed what it all means. Then we got started at writing the paper.
And now, the paper is out: Caren B. Cooper, Margaret A. Voss, and Bora Zivkovic, Extended Laying Interval of Ultimate Eggs of the Eastern Bluebird, The Condor Nov 2009: Vol. 111, Issue 4, pg(s) 752-755 doi: 10.1525/cond.2009.090061
In this paper – which is really a preliminary pilot study (who knows, we may yet get a grant to do more) – Caren and Margaret set up video cameras on a bunch of nests of Eastern Bluebirds (Sialia sialis). From the tapes they got times when the eggs were laid. The times were approximate. But the analysis gave us exactly the same result when we used the times when the nest was obviously empty before the bird sat on it to lay the egg, the times when the bird first got up to reveal the egg to the camera, and the mid-point between those two times.
I am not aware of anyone ever looking at timing of egg-laying in wild birds out in the field. There is a huge literature on timing of laying in quail and chicken (and some in turkeys) in the laboratory, but none I am aware of in wild birds. Most researchers, when asked when their species lays eggs are surprised at the question and answer something along the lines of “no idea, but we find the eggs when we come to check the nests in the morning, so perhaps over night, or at dawn?” So, this paper is a first in this domain.
What we have shown is that bluebirds, just like chicken and quail, have an S-shaped pattern of egg-laying patterns (see my older post for theory and graphic visualization).
The question is: how does a bird “know” when to stop laying? When is enough enough? When is the clutch (all of the eggs laid in one breeding attempt) complete? Most of ecological literature is focused on energetics: are birds getting hungry, have they depleted some important source of energy, etc.
But the circadian field looks for internal mechanisms. Running a circadian clock takes very little energy. Even when the animals are extremely hungry, the clock keeps ticking with no changes in frequency (if anything, the amplitude gets bigger, implying even more work!). Even when an animal gets very sick and is dying, at the time when many bodily functions start ceasing, the clock works until the very end. Being produced by a molecular feedback loop in which some reactions use and others release energy, and all of this happening in just a small number of brain cells, the clock is very energy efficient and does not require the organism to be healthy and well fed.
What is important in regard to circadian regulation of egg-laying is to understand that female birds have not one, but two circadian clocks. Let’s call one of them A and the other one B. Clock A is located in the brain (or retinae or pineal or some combination, depending on the species) and is sensitive to light: it readily entrains to a light-dark cycle. No matter what the intrinsic frequency of the clock may be (as uncovered in constant darkness conditions), it is forced to a frequency of exactly 24 hours by the entraining power of the day/night cycle.
Clock B, on the other hand, is intimately tied to reproduction. It is a result of an interplay between the clock in the brain and neuro-endocrine signals between the brain and the ovary (which may itself house its own part of the clock). Brain clock sends hormonal signals to the ovary. Those signals entrain the ovarian rhythms AND result in ovulation. Ovulation itself produces hormones that signal to the brain clock and entrain it. This feedback loop is in itself The Clock. This clock is light-blind and its intrinsic frequency is not 24 hours – it is around 26-27 hours in both quail and chicken, and almost two days long in turkeys.
These two clocks, A and B, interact with each other. Let’s imagine a hypothetical scenario in which clocks A and B are very tightly coupled. The external light-dark cycles that all the birds in the wild are constantly exposed to entrain the clock A to the exactly 24 hours period. Clock B, being tightly coupled to Clock A is then also forced to oscillate with a period of exactly 24 hours. What would that mean to the bird? She would be laying one egg per day, always at exactly the same time of day, every single day of her life: in spring, summer, fall and winter. She’d spend all her resources on making big yolky eggs every day. She would be sitting on a huge pile of eggs throughout her life. She would not be able even to move short-distance to a better nesting ground, let alone prepare and undergo a long-distance migration. Her eggs would be also hatching at the rate of one per day. Thus, she would have progeny of a variety of ages at all times, each age having different requirements for care or abilities to follow the mother around. Some hatchlings would freeze to death in winter, or starve to death at time when the food is scarce. Others would die from predation at times when they are highly visible (in the snow) or just because there are so many of them they cannot all hide under a bush.
An opposite scenario: clocks A and B do not interact with each other at all. In this case, A would be entrained to the 24 hour cycle of night and day. Clock B, being light-blind, would freerun with its own endogenous frequency, i.e., with a period of roughly 26-27 hours. Again, the poor bird would be laying one egg per day all of her life. The only difference is that the eggs would not be laid always at the same time of day, but scattered all over the 24-hour cycle. Both scenarios are obviously maladaptive to the bird.
But, oscillator theory provides a third scenario in which clocks A and B are only loosely coupled. There are phase-relationships between the two clocks when they are coupled: A entrains B. There are phase-relationships when the two are at odds: A inhibits B (and thus no ovulation happens). The phase-relationships are dependent on daylength: when the days are short in winter A inhibits B and no eggs are laid. When the days are very long in the middle of the summer (or in constant light) all phases are permissive to ovulation and the clock B can freerun with its own period of 26-27 hours.
But the interesting phenomenon happens in-between, once the length of the day gets just a little bit longer in spring, in normal breeding season. There is only a narrow zone of phase-relationships in which the two clocks are coupled – outside of that zone, ovulation is inhibited. Thus the clock A starts ticking at the beginning of that zone (e.g., at dawn in some species, at around noon in quail) and starts freerunning through it until it “phase-locks” with the clock A and, for a while, appears to be running with the period of 24 hours. But underneath, the pulses of hormones are gradually shifting later and later, just a little bit each day. Finally, these hormonal influences allow the clock B to again break free from the clock A, freerun some more until it gets out of the permissive phase – the feedback loop is broken and the ovulations stops. The clutch is over.
The resulting pattern is S-shaped: early in the clutch eggs are laid a little bit later each day, the middle of the clutch appears entrained to the 24-hour cycle, and the last egg or two again are laid later until the egg-laying stops completely. In quail, which was bred for centuries for egg-production, the selection affected the strength of coupling between the two clocks. Thus, in photoperiods (daylengths) that are just barely longer than the ‘critical photoperiod’ (the minimal daylength needed to provide any permissive phases at all, thus the first daylength in spring at which the bird can start laying), quail will have S-shaped patterns but the middle portion, the “straight one” that is entrained, is artificially long – I have seen clutches lasting for two months and consisting of 60 eggs!
Birds out in the wild, where natural selection is likely to produce an optimal clutch-size (not a maximal one that humans prefer), may or may not use the same mechanism to determine how and when the clutch starts and ends. So, what we did was see if Bluebirds also show the S-shaped pattern that would suggest they do. And they do:
The first egg in the clutch is laid earlier than the subsequent eggs. All the eggs in the middle (1-6 of them, not 30 – we collapsed them all into one “time-point” in the graph) are laid at about the same time, indicating entrainment of B by A (i.e., to the light-dark cycle). The second-to-last egg may be laid a little later, and the very last egg is laid much later. These results suggest that quail is not a weird unique animal, or that Galliformes (chicken-like birds) are different from other kinds, e.g.., Passeriformes (songbirds). The mechanism is likely the same – not dependent on external factors like food and energy, but a result of a fine-honed system of interactions between two circadian clocks.
Of course, this is just a first observational study, but the results are encouraging. Next steps would be to: a) improve the temporal precision of measurements by, perhaps, installing thermo-couples in the nests (there is a huge but short-lasting body temperature spike exactly at the time of lay), b) increase the sample size, c) compare the bluebirds living in three very different latitudes where both the weather conditions and photoperiodic changes are different to see how the natural selection shaped their responses, and d) do a comparative study of a few more species belonging to other groups. We’ll see if we’ll try to submit a grant proposal in the future.
Unfortunately, this paper is not Open Access. I wanted to send it to PLoS ONE, which I think is the best journal in the world and IS the future of publishing. But it was important for Caren and Margaret to publish in a journal that their peers consider important, and Condor is a fine little journal for this. So I agreed to go along with it.
Also, the listing of the original blog post in the List Of References, to my dismay, disappeared between the Provisional PDF and Final PDF versions. It is now linked to inline in the text, placing it down to the level of the dreaded “personal communication”, once again foiling our attempts to give serious science blogging some respect. Ah well….
Interestingly, I did not know when the paper came out. Apparently, it was published back in November. I learned about it a couple of days ago when I got a first reprint request from a researcher in Russia!
But hey, I am happy. I got a paper published. And now I am using my blog and social networks to promote it… 😉
Cooper, C., Voss, M., & Zivkovic, B. (2009). Extended Laying Interval of Ultimate Eggs of the Eastern Bluebird The Condor, 111 (4), 752-755 DOI: 10.1525/cond.2009.090061
The island of Mainau has been designed, decades ago, as a gigantic garden, natural preserve, and a model of sustainability. Thus, animals roaming the island are exceptionally fearless of humans. For this picture, taken during lunch on the island, all I needed to do was extend my camera-hand, while sitting, until it was about two feet away from the bird:
All sorts of birds, from crows to peacocks roam freely among the throngs of tourists there.
Gunnar Engblom has another hit: Twitter for birders – Part 1. An introduction – which starts introductory enough, but I am intrigued by the last sentence:
In part 2 of “Twitter for birders” I will tell you how something called hashtags will revolutionize birding and make all bird alert services obsolete in a near future.
Can’t wait to see what it really means….
Naughty male Australian satin bower bird selectively steals blue items to decorate his nest. The female bower birds rate their partner by their home decor so they do a lot of stealing.
And blogging about! Obligatory readings of the day:
The Evolution of Poisonous Birds:
This research elegantly demonstrates that the evolution of just one character — in this case, toxicity — can profoundly affect the evolution of a suite of other characters, ranging from body size and behavioral traits to ecological niche.
Within species … across clines or subspecies … this raises very significant (and addressable) questions regarding adaptation in the genetic vs. the ontogenetic realms. If Allen’s rule is primarily an ontogenetic effect in some species, one can still consider the possibility that it is adaptive, but the nature of adaptation becomes somewhat more nuanced. Which is appropriate, because adaptation is probably never as straight forward as the textbook version of it towards which we tend to gravitate.
According to this article: Fascinating birds migration at EuroBirdwatch 2008:
Over the past weekend, 50.000 adults and children from over 30 European countries took up EuroBirdwatch 2008, BirdLife’s invitation to observe the fascinating migration, as birds move south across Europe for the winter.
BirdLife Partners across Europe were involved – from Portugal to Turkey; Malta to Norway – between them putting together 2.700 different events.
And once again birds didn’t disappoint: attendees counted 2.3 million of them passing overhead.
Thanks Bill for drawing my attention to iNaturalist which has the makings of an awesome site!
What is it?
It is essentially a Google Map where people can add pins every time they see an interesting critter: a plant, fungus, animal, etc. What is recorded is geographical coordinates and time when it was posted.
Moreover, people can link from the pins to pictures of the sighted critters if they upload them on Flickr (nice way to interlink existing social networking sites instead of reinventing the wheel). And they can put additional information, e.g., description of the habitat where they saw the creature. They can try to identify it and others can chime in agreeing or disagreeing on the ID. One can also view maps in various ways – by time, by broader groups (e.g., insects, birds…), or by the degree of agreement people have about the ID.
The site has, apparently, just started, thus the number of people and the number of sightings is still relatively small and limited to mainly a couple of geographic locations (mostly California and Washington state).
But, imagine a couple of years from now, with millions of people pinning millions of sightings, providing additional information and then having the community agree on the ID? How about ecologists putting in all their field survey data (at least after publication if not before)? How about everyone who participates in the Christmas bird hunt? What an incredible database that will be! Something that one can search with machines, build and test models, and use the results to test ideas about, for instance, effects of weather events (hurricanes, fires, floods, El Nino, etc.) or broader weather changes (e.g., Global Warming).
In order for this database to become useful, I hope that the developers, as soon as possible, make sure it is possible for all the info to be machine searchable. And also to provide, perhaps, various fields that will lure people to put in more information. Right now, there is a date when the pin is posted, but the date of actual sighting is much more important. Exact latitude and longitude. Perhaps altitude. Perhaps depth for aquatic organisms. Exact time of day of the sighting. Description of the habitat. Number of individuals. Measurements of different kinds (one often cannot infer from pictures if the critter is 3cm or 30cm long, for instance). Behavioral observations. And of course the ID.
Such a database would be biased of course. People will tend to record when they see something unusual, or cool, or charismatic megafauna, rather than grass or field of corn or a bunch of squirrels in a tree. Also, more critters will be found in urban areas, on farms, in parks and by the roadsides than in places where one needs climbing (or diving) gear, or an hour of work with a machete in order to get to the habitat. But ecological models using the database could be made to account for these biases anyway.
In any case, I urge you to bookmark this site, and to use it. And let’s see how it shapes up over time.
I got some old, old pictures of me, in the animal room at NCSU, holding one male and one female Japanese Quail (Coturnix japonica):
There is an exciting new study in Science that reshuffles the avian phylogeny pretty thoroughly – Grrrrl and Greg have excellent summaries.
As a part of the monthly topic being birds in June, there is an ongoing Journal Club on PLoS ONE.
And if that is not enough birds for you today, the new edition of I and the Bird #78 is up on It’s just me.
As part of the monthly focus on birds, there is a new Journal Club in PLoS ONE this week.
Dr.Elizabeth Adkins Regan from Cornell and her postdoc Dr Joanna Rutkowska from Jagiellonian University have already posted their first comments on the paper by Keith Sockman (here at UNC): Ovulation Order Mediates a Trade-Off between Pre-Hatching and Post-Hatching Viability in an Altricial Bird.
You should all join in the discussion!
Miriam points to this set of pictures of the development of the chicken embryo. As I have written before, I did have to learn how to precisely stage the chick embryos, both the older stages and the early stages, in order to manipulate them at exactly the right time. Cool pics.
If you are an astute watcher of the PLoS ONE homepage (or the PLoS Blog, or my blog for that matter), you may have noticed that PLoS ONE now has something like a ‘theme of the month’, i.e., a single, broad topic that we highlight in several different ways on the homepage, blog, in e-mails, etc. We check out the most viewed and downloaded papers on the topic and interview the authors and Academic Editors of those papers, etc. Last month, in May, the theme was Cell Signaling. This month, June ’08, the overarching theme is The Birds!
If you search PLoS ONE for bird + avian (keep clicking ‘Next’ at the bottom of the page again and again), you will see that PLoS ONE has published several dozen interesting articles on various aspects of bird biology. Those articles can be roughly classified into three categories:
– avian flu
Some papers span two or even all three of the topics (e.g., on the way ecology and behavior of migratory birds affects the epidemiology of bird flu). When we checked the stats to see which bird-related papers have been viewed the most, these articles emerged as our Top 5:
Coevolution of Male and Female Genital Morphology in Waterfowl. Interviews with the author and the Academic Editor of this paper can be found here.
A Visual Pathway Links Brain Structures Active during Magnetic Compass Orientation in Migratory Birds (there is also a brief blurb by the author at the above link).
Cross-Clade Protective Immune Responses to Influenza Viruses with H5N1 HA and NA Elicited by an Influenza Virus-Like Particle
Leg Disorders in Broiler Chickens: Prevalence, Risk Factors and Prevention
Cross-Protection against Lethal H5N1 Challenge in Ferrets with an Adjuvanted Pandemic Influenza Vaccine
There will be something new about Birds In PLoS every Tuesday night on the ONE homepage this month, as well as one or two Journal Clubs on bird-related papers (do you want to do one of these – call me). As I am a bird-man myself, this makes me happy. I hope you like what we have as well.
(First posted on July 21, 2006) Some plants do not want to get eaten. They may grow in places difficult to approach, they may look unappetizing, or they may evolve vile smells. Some have a fuzzy, hairy or sticky surface, others evolve thorns. Animals need to eat those plants to survive and plants need not be eaten by animals to survive, so a co-evolutionary arms-race leads to ever more bizzare adaptations by plants to deter the animals and ever more ingenious adaptations by animals to get around the deterrents.
One of the most efficient ways for a plant to deter a herbivore is to divert one of its existing biochemical pathways to synthetise a novel chemical – something that will give the plant bad taste, induce vomiting or even pain or may be toxic enough to kill the animal.
Carel Brest van Kempen, the artist who painted my blog’s banner, shows how it is done, in a time-lapse painting clip:
News from SCONC:
On Thursday, March 27 at 4 p.m., the Zoology Department at NCSU will host a seminar from Patricia Brennan of Yale University entitled “The Biology of Avian Genitalia: Form and Function.” Brennan’s work on the genital anatomy of waterfowl has revealed the existence of a “sexual arms race” between males and females. Unlike 97 percent of bird species, male waterfowl have a phallus, and it can range “from a half-inch to more than 15 inches long.” The seminar will be held in 101 David Clark Labs. Refreshments will be served in the lobby at 3:45.
Today on Quotes of the Day:
Harland David Sanders was born at Henryville, Indiana on this day in 1890. His father’s death six years later led to Harland doing all the cooking for the family. He left school early and led a varied career including street-car conductor, a soldier in China at sixteen, a railroad fireman, justice of the peace (after a correspondence course in law), he operated an Ohio River ferry line, sold insurance, and operated a service station. At the service station, he fed hungry travelers in his quarters above the station. When the food proved more popular than auto service, he moved to the hotel across the street where he could seat 140. In 1935 he was made a Kentucky Colonel for his contribution to the state’s cuisine. The company he founded serves about six billion pieces of chicken every year, so I’ll serve up six Chicken quotes.
You don’t set a fox to watching the chickens just because he has a lot of experience in the hen house.
– Harry S Truman, 1884 – 1972
A hen is only an egg’s way of making another egg.
– Samuel Butler, 1612 – 1680
Regard it as just as desirable to build a chicken house as to build a cathedral.
– Frank Lloyd Wright, 1867 – 1959
If God grants me longer life, I will see to it that no peasant in my kingdom will lack the means to have a chicken in the pot every Sunday.
– Henri IV, 1553 – 1610 (King of France 1589 – 1610)
Love, like a chicken salad or restaurant hash, must be taken with blind faith or it loses its flavor.
– Helen Rowland, 1876 – 1950
I know [canned music] makes chickens lay more eggs and factory workers produce more. But how much more can they get out of you on an elevator?
– Victor Borge, 1909 – 2000
The textbook example of commensalism was always the interaction between trees and the birds who make nests in those trees – it was always assumed that the birds gain from this relationships, while the trees are not in any way affected by it.
Now, a new study came out, demonstrating (for the first time, as far as I know – is that correct?), that the relationship between at least some trees and some birds is actually mutualism, i.e., both partners profit from the relationship:
Chickadees, nuthatches and warblers foraging their way through forests have been shown to spur the growth of pine trees in the West by as much as one-third, according to a new University of Colorado at Boulder study.
The study showed birds removed various species of beetles, caterpillars, ants and aphids from tree branches, increasing the vigor of the trees, said study author Kailen Mooney. Mooney, who conducted the study as part of his doctoral research in CU-Boulder’s ecology and evolutionary biology department, said it is the first study to demonstrate that birds can affect the growth of conifers.
“In a nutshell, the study shows that the presence of these birds in pine forests increased the growth of the trees by helping to rid them of damaging insects,” said Mooney. “From the standpoint of the trees, it appears that the old adage, ‘the enemy of my enemy is my friend,’ holds true.”
Hat-tip: Pondering Pikaia.
I also saw some seagull chicks, learning to fly, but only took a picture of this cormorant at the Pier 39:
A very interesting new paper was published today in PLoS Biology:
Flight Speeds among Bird Species: Allometric and Phylogenetic Effects by Thomas Alerstam, Mikael Rosen, Johan Backman, Per G. P. Ericson and Olof Hellgren:
Analysing the variation in flight speed among bird species is important in understanding flight. We tested if the cruising speed of different migrating bird species in flapping flight scales with body mass and wing loading according to predictions from aerodynamic theory and to what extent phylogeny provides an additional explanation for variation in speed. Flight speeds were measured by tracking radar for bird species ranging in size from 0.01 kg (small passerines) to 10 kg (swans). Equivalent airspeeds of 138 species ranged between 8 and 23 m/s and did not scale as steeply in relation to mass and wing loading as predicted. This suggests that there are evolutionary restrictions to the range of flight speeds that birds obtain, which counteract too slow and too fast speeds among bird species with low and high wing loading, respectively. In addition to the effects of body size and wing morphology on flight speed, we also show that phylogeny accounted for an important part of the remaining speed variation between species. Differences in flight apparatus and behaviour among species of different evolutionary origin, and with different ecology and flight styles, are likely to influence cruising flight performance in important ways.
Update: Grrrlscientist explains the study in plain English.
Actually, the picture (author is Antun Zuljevic, a birder extraordinnaire) is from the village of Svilojevo in northern Serbia (Vojvodina, near the town of Apatin on the Danube) where the Locust Trees have been cut, and nobody is building large haystacks any more, so the storks are forced to build nests in crazy places. This pair of White Storks was not successful in nesting on this factory chimney last year, but they had better luck this time around. Yup, storks prefer nesting on chimneys only in fairy tales. In reality, that is the site of last resort.
Source: Google group of Ptica
An interesting paper came out last week in PLoS-Biology: Projected Impacts of Climate and Land-Use Change on the Global Diversity of Birds by Walter Jetz, David S. Wilcove and Andrew P. Dobson. You can view some bloggers’ responses on The DC Birding Blog, Field Of View and Living the Scientific Life and media coverage here, here and here.
The authors of the paper collected information about all known ranges of land birds and made a mathematical model for predicting how those ranges will be affected by global warming on one hand and the land-use on the other by years 2050 and 2100. They use four Millennium Ecosystem Assessment scenarios. Two of those scenarios assume a global response to environmental problems and two assume a local (fragmented) response. Also, two of them assume a proactive approach to environmental threats, while the other two predict that most problems will be dealt with reactively, i.e., after they happen.
The results differ between scenarios, but even under the best scenario, a strikingly large number of bird species are predicted to lose substantial proportions of their ranges, likely leading to their eventual extinction. Depending on the scenario, approximately 400 (of the 8750 species studied – they omitted seafaring and coastal species) will lose half or more of their range by 2050. That number may increase to 900-1,800 species by 2100.
The main message of the paper is that global warming will disproportionately affect species in higher latitudes, while the land-use will be more detrimental to the tropical species. Why?
In the tropics, there are many species of birds competing for local resources. How do they partition those resources? In one (or both) of two ways: one is to become specialists, e.g., to nest and feed on particular local plants; the other is to divvy up the territory through competitive exclusion. As a result of both of these mechanisms, the tropical species tend to cover very small ranges and, thus, have rather small population sizes to begin with. Clear-cutting a patch of forest may entirely wipe out the range of a local species which, when displaced elsewhere into the neighboring woods, will not be able to compete against the local tenants and will likely go extinct.
In the higher latitudes, the number of species is smaller, the ranges are larger and the population numbers are greater. Here, effects of global warming on the plants will have a greater effect on the range-sizes than land-use (this is for the most part already developed world not in a frenzy of clear-cutting forests any more). As a result, the ranges will become more fragmented and patchy, which can lead to extinction of some species.
The authors are quite upfront about the limits and underlying assumptions of their model, particularly the assumption that avian ranges will remain static, i.e., that the birds will not move their ranges to higher latitudes and/or altitudes. It has already been well documented that birds (as well as other organisms, e.g., insects, plants, mammals and fish) are in fact responding to global warming by changing their ranges: some are gradually moving to higher latitudes (i.e., in the Northern hemisphere, their ranges are shifting North), some retain their breeding grounds while shifting their migratory routes to different wintering grounds, while others are abandoning migration altogether.
Of course, as authors note, land-use and global warming are interconnected: clearing forests increases the albedo of the area so more of the Sun’s energy is absorbed instead of being reflected back out into space. The agricultural use of chemicals and their runoff into the oceans kills dinoflagellates which perform about half of Earth’s CO2 absorption and O2 release (the clear-cut rainforests provided the other half). At the same time, global warming affects human populations and activity, introducing droughts into already poor areas, thus motivating further destruction of forest in order to provide agricultural land.
Let’s assume that there is a fifth scenario, the most pessimistic one, that assumes there will be no response to environmental troubles at all, or too little too late (i.e., let me play an Alarmist here). Thus, both clear-cutting and global warming continue at the current rate. What will happen? According to the model in this paper, land-use will result in destruction of habitat in the tropics and poor countries, leading to mass extinction of local, small-area/small-population avian species. Global warming will bring in the droughts into the areas at higher latitudes, changing the nature of the plant cover, fragmenting the species ranges and leading to at least local extinctions of many more avian species in currently temperate zones.
But, if we reinstate the fact that avian species will move their ranges, what will be the result? In the tropics, there is not much place to move – the specialists have to stay where their host plants and food are. If they try to move, they will encounter different vegetation, different avian competitors who are better adapted to the local conditions, and different predators they are unfamiliar with. In other words, tropical birds have nowhere to go.
In the temperate zones, birds will shift their ranges to higher latitudes and, if we do nothing about global warming, will in the end, all end up at the ends of their continents. The narrow strips of the northernmost coasts of Europe, Asia and North America will become grounds for ferocious competition for limited resources between all those immigrant species. Many will go extinct. Others will survive at small ranges in small populations. There is nowhere else to go, as by this time, there will be no more
Arctic to fly to – it will be all ocean after the Arctic ice melts.
In the Southern hemisphere, the birds of South America may island-hop to and spread across the new lush tropical forests of Antarctica, but the birds of Africa, Australia and Pacific islands will not be able to make such a big leap and will concentrate on the southernmost edges of their continents until many of them go extinct due to competition.
And even this bleakest scenario makes an assumption that makes the picture look prettier. Species cannot just get up and go and move their ranges with no consequences. Species are parts of their local ecosystems. In those ecosystems, some species will shift their ranges faster, some slower, some not at all (changing the timing of annual events instead, i.e., adapting in time instead of space). The predators and prey will leave each other – the former trying to adapt to new prey, the latter trying to avoid new predators. The flowers and pollinators will split their ways. The mutualists may part ways as well. The remodeling of ecosystems will occur, i.e., we cannot expect entire intact ecosystems to migrate to higher latitudes in synchrony. Disruption of ecosystems by such remodeling will certainly lead to extinctions of numerous organisms, way before they reach the edges of their continents.
From John I learned that Serbia is becoming a birding hot-spot!
Two species of pelicans (Pelecanus crispus and Pelecanus onocrotalus), which used to nest in Serbia before but were driven out by draining of marshland for agriculture in the late 19th century, are back (not nesting yet, but some individuals are back) and you can see a picture of one of them here.
A journalist for ‘Birdwatch’ magazine went to the very first birding tour in Serbia back in 2004 and he wrote about his trip and his impressions.
This website provides a lot more information about birds and birding in Serbia. I wish that information was available to me when I was a kid living there. I went to several of the places mentioned there and I saw the birds, but I was never with anyone who knew how to identify them. There is still time to go back and do this….
Welcome to the Fiftieth edition of I And The Bird. It’s been a while since I last hosted an edition of this carnival (#19) and it has obviously grown a lot since then. With such diversity of posts, I decided it was impossible to categorize them, so they are presented here in the order I received them. So, to cut my unimportant intro short, let’s dig in:
Grrrl of Living The Scientific Life reports on a conservation triumph story in The Return of the Rimatara Lory.
The Ridger of The Greenbelt took pictures of some goslings walking around looking like little feathered dinosaurs (post in two parts): Dino babies and Geese in the summer.
YC of the Bird Ecology Study Group wrote about an Adult koel feeding a juvenile. “This is a strange situation where the feeding should be done by the juvenile’s foster parent, the crow.”
Dr. Jeff Wells of the Boreal Bird Blog discovered Boreal birds In Bush’s Backyard, i.e., on the grounds of the White House.
Going birding with Duncan (Ben Cruachan Blog) sounds like great fun: Dirty work at the crossroads.
Sometimes one sees the most birds on those days when one is “not seriously looking”. This happened to Rob of Rob’s Idaho Perspective the other day. The Pied-bellied Grebe with chicks was not the only bird he saw, either: Casual Birding, Great Results.
Bill Eley of Gulf Coast Bird Observatory tries to stay away from politics, but this one is important: Another aspect to the ‘border fence’: “The proposed fence will plow through some of the most unique and valuable habitat in North America.”
Many have commented on the adoption of a chick by a pair of gay male flamingoes. Greg Laden goes the distance by explaining the Ultimate Causes, Proximate Mechanisms and putting the story in the context of evolutionary theory.
Dana of Backyard Birding reports sad news: Bird Expert Clark Moore dies.
John Trapp of Birds Etcetera searched the ‘birdwatching’ category on Amazon.com and discovered some… let’s say ‘unusual’ books listed there:Strange But True.
Celeste Pinheiro aka Wyldthang (Dzonoqua’s Whistle) heard the divine song of a Thrush: The Thrushes Arrive.
Bevson of Murmuring trees was lucky – she saw a Yellow-billed Loon: Surprise!
All’s well that ends well. Robin and Roger of Dharma Bums had quite a crisis at hand in Of All The Nest Boxes…In All The World, but they managed to solve it with some knowledge and ingenuity.
Rick Wright of Aimophila Adventures took some more great bird pictures in Panama: Panama: Purty Pitchers.
Jochen of Bell Tower Birding finds musical associations when confronted with an odd-looking Yellow Warbler: Doin’ the Britney.
WrenaissanceWoman of Wrenaissance Reflections has an easy answer to the question Why maintain a backyard wildlife habitat?
From Drew at the Nemesis Bird, sound advice for everyone, especially a rank amateur like me: 10 Ways to See more Birds.
Liza from The Egret’s Nest is Ravin’ about Ravens, one of my favourite birds. Great shots!
Lisa, the Bird Nerd, is still looking for the elusive Tri-Color, but one can learn a lot from a two-colored bird instead as well: On the hunt for Tri-colored Blackbirds.
Susannah A. of Wanderin’ Weeta posted some great shots of a Great Blue Heron in Great Blue Heron, Gunderson Slough.
Amazing close-up shots of Red-Tailed Hawks by Jayne of Journey Through Grace in Beauty in the trees.
On Trevor’s Birding blog, a pictorial view of the ontogeny of a male Rufous Whistler.
Patrick of The Hawk Owl’s Nest wrote a Book Review: The Complete Birder by Jack Connor.
Roger and Liz (Words and Pictures) had a great birding trip while in the Scottish Highlands, listing more than a hundred species they spotted there: Highland Hundred (plus four).
Mike of 10000 birds, the founder and General Editor of this fine carnival, got out of the City to the Long Island Sound for a great day of birding: Turnstone Turn-out.
Scottcatskill of Lovely dark and deep may have just saved a hurt bird’s life: Almost Squished Wood Thrush (and a fox).
“Early last week the gulls started arriving in Arctic Bay.” That is how Clare (The House & other Arctic musings) starts his post: Nauja – The difference a day makes.
Paul Ollig of The Wandering Tattler finally got to see a Painted Redstart and has pictures to prove it: One Bird at a Time.
Who is eating the Brood 13 cicadas? Cuckoo For Cicada Puffs!. Where? Cicadas are on the Menu. Who wrote this? The Birdfreak Team of the Birdfreak Birding Blog.
Pamela Martin of Thomasburg Walks was walking around the field and made a big discovery, with interesting evolutionary implications: I’ll sing what I want to sing. “The story of a bird singing the song of another species–in a song duel with a bird of yet another colour.”
Nuthatch of Bootstrap Analysis tries to evaluate the effects of exceedingly long ‘Easter Freeze’ in the Eastern USA on migrants: Where I’ve been & who I’ve been seeing.
Rob Fergus (The Birdchaser) knows my weakness for clocks (if I had more walls and less books, I’d have more clocks), but I never really wanted the Audubon Bird Clock. I’d much rather have the clock Rob proposes instead.
A good time for birding during the night and the following morning at Rock Creek Park Bioblitz for John of A DC Birding Blog.
John Riutta is a Born Again Bird Watcher. Why should an amateur join a professional birders’ society? Or read the ornithological scientific journals the way John does? Find out in High Societies.
James is birding in Tanzania and it is not easy to post (especially the pictures) from there, so it took a couple of days until this saw the light of day, but just in time for the inclusion in this week’s edition of the carnival: Camel Safari to Lake Natron.
I hope you enjoyed the wealth, quality and diversity of posts in this week’s edition of the carnival. The next edition will be hosted by Rob on The Birdchaser on June 14th, 2007 so send your entries at: birdchaser AT hotmail DOT com.
Fortunately, Janet Reno is still OK.
The police brought Bill Clinton to the Orange County Animal Shelter, where he later died.
With perfect quote-mining, I made you look, didn’t I?
Tatjana Jovanovic is a fellow escapee from Serbia and a fellow biologist. She got her MS in Biology at the University of Belgrade and has collected enough data before emigrating to be able to immediately get a PhD if someone would sponsor her here. She is currently in Arizona, but she is moving to North Carolina later this year. She will send you her impressive CV on demand – her publications range from immunology to pest control, but most of it is focused on small rodents, their avian predators and the dynamics of predator-prey relationships. She has combined lab and field work, from biochemistry through mathematical modelling to field experiements, in most of her papers and has made discoveries of small mammals not previously known to reside in that part of the world.
Tatjana particularly likes owls (a subject of several of her papers), she has performed the Serbian portion of the research for the Global Owl Project and is active on The Owl Pages.
She is also an artist and has acted as a mentor for several high-school and undergraduate theses in biology (yes, we do simple research and write theses on topics related to our majors in high school in Serbia). Science education is one of her strengths and passions. Environmental protection is another.
If you are in North Carolina and have a place for a hard-working, honest, smart, highly-educated and well-rounded person in your lab, school, organization or company, contact Tanja at: tanjasova AT gmail DOT com
…because weird sex does not only happen on Fridays….
Remember this? Many have asked themselves (I did) where does it go, i.e., what kind of female genital tract can accomodate such a large penis. But one person actually did not stop at wondering but set out to find out. You can find out who and how and why in Carl Zimmer’s today’s NYTimes article about today’s PLoS-One paper.
John James Audubon was born on his father’s plantation in Haiti on this day in 1780. Despite being born of his father’s mistress, he was raised in France by his father’s wife and educated with other young aristocrats. He took an early interest in drawing birds, when he found himself without an income he proceeded to paint some of the finest images of North America’s avians. The modern Audubon Society approves of his art but would hardly approve of his methods: He got the birds to pose for him by first shooting them.
It is not only fine feathers that make fine birds.
The birds I heard today, which, fortunately, did not come within the scope of my science, sang as freshly as if it had been the first morning of creation.
– Henry David Thoreau, 1817 – 1862
I value my garden more for being full [of] blackbirds than of cherries, and very frankly give them fruit for their songs.
– Joseph Addison, 1672 – 1719
The bird has an honor that man does not have. Man lives in the traps of his abdicated laws and traditions; but the birds live according to the natural law of God who causes the earth to turn around the sun.
– Kahlil Gibran, 1883 – 1931
God loved the birds and invented trees. Man loved the birds and invented cages.
– Jacques Deval, 1895 – 1972
To a man, ornithologists are tall, slender, and bearded so that they can stand motionless for hours, imitating kindly trees, as they watch for birds.
– Gore Vidal
From Quotes of the Day
When my ‘Scientific American’ arrived the other day, I was excited to read the article about ravens by Bernd Heinrich, as I loved his book Mind of a Raven. I was also glad to see that new cool experiments have been done since the book came out. But I wondering how to blog about an article that is behind the subscription wall, so in the end, I abandoned the idea.
Now, Grrrlscientist comes to the rescues with an excellent summary of the article, that is well worth your time.
If Dr. John Watson had been chronicling the work of Christopher Templeton rather than the exploits of Sherlock Holmes, he might have entitled the latest research by Templeton “The Adventure of the Avian Eavesdroppers.” The University of Washington doctoral student has found the first example of an animal making sophisticated decisions about the danger posed by a predator from the information contained in the alarm calls of another species.
One does not expect to discover a bird species new to science while wandering around the continental United States. Nor does one expect that such a species would provide much insight into how coevolutionary arms races promote speciation. On both fronts a paper to appear in The American Naturalist proves otherwise.
Julie Smith, now at Pacific Lutheran University, and her former graduate advisor, Craig Benkman at the University of Wyoming, have uncovered strong evidence that coevolution has led to the formation of a species of bird new to science in the continental United States. Benkman discovered in 1996 what appears to be a new species restricted to two small mountain ranges in southern Idaho (the South Hills and Albion Mountains). This species is a morphologically and vocally distinct “call type” of red crossbill (Loxia curvirostra complex), which is a group of seed-eating finches specialized for extracting seeds from conifer cones.
On this day in 1934 the US adopted the Migratory Bird Hunting and Conservation Stamp Act, commonly known as the Duck Stamp Act. Hunters are required to buy a stamp before bagging migratory birds like ducks and geese, with the proceeds earmarked for habitat preservation. The stamps themselves are so beautifully done that many non-hunters buy and display them as art. We won’t be hunting them, but here are a few quotes on Birds.
I once had a sparrow alight upon my shoulder for a moment while I was hoeing in a village garden, and I felt that I was more distinguished by that circumstance than I should have been by any epaulet I could have worn.
– Henry David Thoreau, 1817 – 1862
Use what talents you possess; the woods would be very silent if no birds sang except those that sang best.
– Henry Van Dyke, 1852 – 1933
Be grateful for luck. Pay the thunder no mind – listen to the birds. And don’t hate nobody.
– Eubie James Herbert Blake, 1883 – 1983
The eagle suffers little birds to sing,
And is not careful what they mean thereby.
– William Shakespeare, 1564 – 1616
Birds sing after a storm; why shouldn’t people feel as free to delight in whatever sunlight remains to them?
– Rose Fitzgerald Kennedy, 1890 – 1995
Be as a bird perched on a frail branch that she feels bending beneath her, still she sings away all the same, knowing she has wings.
– Victor Hugo, 1802 – 1885
From Quotes of the Day
I and the Bird #42 is up on Neurophilosophy blog. Beautiful rendition, formatted like Charles Darwin’s diaries from the “Beagle”, which – the ship, I mean – as you know (Day 8), is planned to be rebuilt and sailed again, but only if you help.
Although breeding between close kin is thought to be generally unfavorable from an evolutionary standpoint, in part because harmful mutations are more easily propagated through populations in this way, theory predicts that under some circumstances, the benefits of inbreeding may outweigh the costs.
Researchers have now reported real-life evidence in support of this theory. Studying an African chiclid fish species, Pelvicachromis taetiatus, in which both parents participate in brood care, the researchers found that individuals preferred mating with unfamiliar close kin rather than non-kin.
Actually, this same result was obtained in Japanese quail about 20 years ago or so. The quail breeding colony I worked with is extremely inbred and is thriving. Contrary to expectations of some others in the lab who were trained in classical population genetics, I was confident that we are not going to see a sudden crash of our population due to inbreeding and I was right for all these years.
Because parental work is energetically costly, and kinship generally favors cooperation, one possible explanation for kin preference in breeding in this species is that it offers a benefit by facilitating parental cooperation. And indeed, observations of behavior exhibited by this chiclid species showed that related parents were more cooperative and invested more resources in parenting than did non-related parents.
Together, the findings suggest that, somewhat unusually, active inbreeding is advantageous in this fish species. The findings, reported by Timo Thünken and colleagues of the University of Bonn, appear in the February 6th issue of Current Biology.
Actually, as quail live in tightly-knit coveys of about 10-12 individuals (and the Asian species, livig up in Siberia, may never split the coveys in spring due to thermoregulatory advantages of covey-living), this was exactly the explanation I had for the advatntages of inbreeding in our quail colony.
You can read the actual paper here:
Active Inbreeding in a Cichlid Fish and Its Adaptive Significance
Seventeen out of eighteen Whooping Cranes from the Operation Migration were killed by the recent storm in Florida. The one survivor is being tracked right now via radiotransmitter, so the health state is still not known.
Apparently, I am not the only one to see a hummingbird in Chapel Hill of a species that should not be found around here. While I am quite confident that the visitor to my porch was a female Blue-throated Hummingbird, usually not found this far North, these neighbors of mine have found a Rufous hummingbird. As far as I know, the Ruby-throated Hummingbird is the only species that should be seen around here.
One individual of one species is an anecdote. Another individiual of another species is another anecdote. But if there are more and more such sightings over the next couple of years, we may start looking into the causes. Is it global warming?
You may remember that Clark’s Nutcracker is one of my favourite birds, so I’ll be watching this guy (I am assuming he got his PhD with Nikki Clayton):
Researcher Uncovering Mysteries Of Memory By Studying Clever Bird:
Scientists at the University of New Hampshire hope to learn more about memory and its evolution by studying the Clark’s nutcracker, a bird with a particularly challenging task: remembering where it buried its supply of food for winter in a 15-mile area. Like many animals preparing for the winter, every fall the Clark’s nutcracker spends several weeks gathering food stores. What makes it unique is that it harvests more than 30,000 pine nuts, buries them in up to 5,000 caches, and then relies almost solely on its memory of where those caches are located to survive through winter.