Category Archives: Birds

Helpers at the nest and brood parasites. Coincidence? I think not….

The vast majority of the 10,000+ living species of birds are passerines, and the vast majority of those have a similar system of breeding: Mom and dad bird make a nest and share parental responsibilities roughly equally, if not identically. There are variations on that theme, of course. Even the non-passerines often follow this pattern. So, when we find a pattern that is different it is reasonable to try to explain this in adaptive terms; what features of this variant pattern provide enhanced fitness, and what ecological or social factors underly it?

There are two patterns that are fairly extreme that fall into this category: brood parasitism and helper-at-the-nest strategy. In the former, a female lays her fertilized egg in the nest of another species, in the hopes that her offspring will be raised by the unwitting hosts. In the latter, three or more adult individuals contribute to the raising of offspring. In the case of brood parasitism, made famous by the many species of Cuckoo as well as cow birds and some fiches, among others, one might expect the host birds to evolve anti-parasitism strategies. In the case of helpers-at-the-nest one might expect that this strategy arose because of certain ecological or social conditions. It turns out that the two strategies may be related. Brood parasites might parasites helper-at-the-nest species because the latter are so darn good at raising offspring under certain conditions. Or, helping-at-the-nest might be a good strategy to avoid parasitism.

A recent paper in Science, Brood Parasitism and the Evolution of Cooperative Breeding in Birds by Feeney, Medina, Somveille, et al, looks into this interesting possible relationship. …

Read the rest here, in my latest post on 10,000 Birds.

Fish Eating Birds

First, we had giant catfish eating pigeons (remember this?). Now, we have scientifically confirmed reports of tiger fish eating swallows on the wing. The pigeons were just standing around on the beach, but these swallows are fast moving birds in flight being snatched out of the air as they forage over the lake’s surface. Please visit my latest post on 10,000 Birds, where I write a monthly thing: Swallows, Swallowed.


Photo Credit: brian.gratwicke via Compfight cc

The World’s Rarest Birds

There are something over 10,000 species of birds (thus the name of the famous blog). Of these, just under 600 are in very very serious trouble, some to the extent that we are not sure if they exist, others are so rare that we know they exist but there are no good photographs of them, others are merely very likely to go extinct. There are patterns to this rarity, having to do with what threatens birds on one hand and what makes certain birds vulnerable on the other, but the range of birds that are threatened, in terms of size, shape, kind of bird, habitat, etc. represents birds pretty generally. It is not just obscure frog-like rainforest birds of Borneo that are threatened. Chance are you live in a zone where there are bird species that have gone extinct over the last century, or are about to go extinct over coming decades, including birds that you will never see unless you are very very lucky.

Lots of pretty data rich pages.
Lots of pretty data rich pages.
The World’s Rarest Birds is one of those books that crosses over from coffee table (it is bigish and quite beautiful) to field guide (it is species-level informative) to conservation science (it is about the rares, and thus often most threatened). Birdlife International has been dealing with rare and endangered birds for years, and this organization has produced a number of products bringing attention to bird conservation, including various books and calendars and such. This particular volume is their finest product ever, and is quite amazing. The World’s Rarest Birds covers just over 500 of the aforementioned rare and endangered birds in more detail than most bird related references that you’ve got in your house now.

It is a rather interesting concept if you think about it. The average bird ID book, or more detailed reference book, may address about 500 birds, using a variety of graphical techniques, text, and other resources. The World’s Rarest Birds is a larger format book with about 360 pages. Fitting information about 500 birds into a somewhat larger than average bird book allows for a lot of detail.

Much of the book is like any other bird book, but with species that you'd give up your best binoculars to see.
Much of the book is like any other bird book, but with species that you’d give up your best binoculars to see.
The first several chapters of the book included detailed, interesting, informative, and beautifully laid out information. These chapters cover the geography of endangerment, the kinds of threats, bird-human interaction, how the process of keeping track of endangered and rare birds works, and so on.

Then the book is divided into seven regions covering the entire planet. Each region has a long introductory section followed by something that looks a lot like a field guide covering each and every one of the rare birds in each area.

The book is educational, promotes conservation, looks nice, but at the same time is a reference source for those rare birds. This, somewhat morbidly but worthy of note, allows The World’s Rarest Birds to serve a special role in certain birders libraries. If you have bird guides and references for several different parts of the world, there may be a number of species missing because they are just too rare or unknown. The World’s Rarest Birds is like that stuff you put in your gas tank to add oomph to your engine, but with birdbooks. A regional library of references will suddenly have high octane information on some of the least known species.

QR codes bring you to the Birlife International database entry for that bird.
QR codes bring you to the Birlife International database entry for that bird.
Birdlife International actually commissioned many of the photographs in the book, and many, possibly most, of the species of concern are under some degree of study or investigation. Or, at least, new information is emerging now and then to supplement what is in the printed volume. In order to keep up with the latest information about your favorite rare bird, you can use the QR codes that go with each entry. Scan the QR code and you’l be brought to a BLI web page with the most current info. If you know how to use QR codes and stuff.

This book is for any birder, but I have a specific suggestion. Do you have a birder in the house or family or as a friend with a birthday coming up in the next two months? Get them this book. It’s new, they don’t have it yet, and they’ll like it.

The New Crossley Raptor ID Book: You Want It

A couple of years back, the The Crossley ID Guide for Eastern Birds came out and it caused a huge splash in the birdwatching world. For some time now it has become apparent that bird watching, especially the identification part of it, was changing in its approach. We describe it this way, though I think the reality is more complex: In the old days we used logical links to known reliable field marks to turn carefully made field observations into species identifications of varying degrees of certainty. Now, a new approach has been developed where we look at the whole bird and get an identification using an overall gestalt, and then to the extent possible verify the identification with tried and true field marks.

picture of Peterson's field guide page
Old Style: Carefully drawn images or photos showing keys to identification.
This consideration of methodology would be a great way to get into how humans make observations and draw conclusions … how we think and how we know things, in fact … and would not be done well enough without bringing in semiotics and other areas of philosophy. Some day we’ll do that. In the meantime, just consider the difference between a typical field guide and a guide like Crossley.

Well, now, we have a new book to play with: The Crossley ID Guide: Raptors. This new volume follows the same principle as the original Eastern Birds book, but with some important differences. A very large portion of Raptors is not images, but rather, very information rich species accounts along with pretty darn good range maps. The first half or so of the book consists of the usual Crossley style plates. Here, we have gone back to an old style layout: Text and details in one section of the book and plates in the other. Another important difference is that there are more images per species, for the most part, in Raptors, and in some cases, variants are given their own sets of plates.

Crossley plate
Crossley Style: Lots of photos of one species as they appear in real life, in an appropriate context.
Also, there are plates showing many individuals of more than one similar looking species, with the key indicating which image is which species located elsewhere in the book so you can’t cheat by just looking at the caption, and get to learn the differences without leaving the comfort of your birding gazebo, or wherever it is you hang out.

Overall, there is far more information about each species than in the Eastern guide, which is of course exactly what we would expect from a more specialized volume such as this. There is also a handy comparison-of-everything graphic in the front cover with page numbers, a nice map in the back, and the other usual amenities found in most bird books these days.

I used some of these images to construct the quiz I put HERE (the winners of that quiz to be announced soon).

I can not do the images justice with inserts into a small format thing like this blog post, but here are a few examples to give you an idea:

CrossleyExample01

CrossleyExample02

CrossleyExample03

This is not a book review, in that I’m giving you the negatives and positives of a particular book so you can decide if you want it or not. This is, rather, a notice that the book you want is available now.

While we are on the subject of raptors, you will probably want to check out this video of a red tailed hawk trying to get at the eggs or chicks of a bald eagle, but instead, becoming the eagle’s lunch. Caution: It is gruesome.

Enjoy your new bird book!

Golden Eagles and Free Coffee!

You’ve heard of the The Crossley ID Guide: Eastern Birds (The Crossley ID Guides). It is a revolutionary new way to assemble a field guide, where each page has a drawing of what it would look like if suddenly outside your living room there was a full blown habitat for some species of bird, with individuals from that species flying or sitting all over the place in different positions, doing different things, and at different distances. These pages in the field guide almost give you the experience of having seen many of this partiuclar species of bird, like you were suddenly an experienced birder. In preparation for a birding trip, you can prepare by going over the birds you hope to see, and during or after the trip you can use this guide to check your ID’s.

Well, now, there is also the The Crossley ID Guide: Raptors. This is the same thing but for Raptors. The book is coming out RIGHT NOW so Princeton has organized a major blogging tour, and right now, you’re on the tour! The other blog posts are as indicated here, on this schedule. I recommend visiting all the other entries. Some of them are giving away prizes, so especially check those out.

As a matter of fact, we’re giving away a prize here, right now, on this blog post, and you may be able to win it. Details are below. But first, a word about ….

… Golden Eagles …

Golden Eagles are a bit of a sore spot with me because they are rare and said to be hard to distinguish from immature Bald Eagles. This is not their fault. But when one claims to have seen a Golden Eagle the automatic reaction among most birders is to claim that you are wrong, that it was an immature Bald Eagle you had seen. This is especially true in Minnesota. If you look at bird books, they are sometimes not shown to be here at all, even as migrants, or otherwise, only rarely.

Stan Tekiela’s Birds of Minnesota Field Guide, Second Edition does not even list Golden Eagles. The Smithsonian Field Guide to the Birds of North America shows northern and central Minnesota as a migratory route, but the rest of the state is indicated as “rare.” Birds of Minnesota and Wisconsin indicates them to be an uncommon migrant or winter visitor in parts of the region. The Birds of North America and Greenland: (Princeton Illustrated Checklists) shows them as occassional winter visitor in only a small area to the West of Minnesota. National Geographic Field Guide to the Birds of North America, Sixth Edition shows them only rarely in Minnesota, but more in the eastern part of the state. Hawks and Owls of the Great Lakes Region and Eastern North America shows them as an occasional winter species in Minnesota and a very large area of the plains and the eastern US.

The Kaufman Field Guide to Birds Of North America shows them totally absent in the state, but this book also has another interesting geographical observation. There is a huge area of eastern Canada with a dotted line around it indicating that they may or may not breed there. This is an interesting thing about Golden Eagles. When you look into it, you find that there is this large not very mountainous region in which this mountain bird seems to breed, migrate to and from, but is not observed within. Like they were hiding out there. The Birds Of The Great Plains shows them rare in Minnesota and more common to the west than the east.

Of course, one always wants to consult the bible in these matters. The Peterson Field Guide to Birds of North America (Peterson Field Guides) shows them totally absent in Minnesota, but also indicates the big mysterious region to the north where they may or may not breed.

Now that we’ve established that there is no agreement whatsoever on the distribution of, timing of, or even existence of, the Golden Eagle in Minnesota, let me tell you about two of our sightings of the bird (there’s been a few but these two are particularly interesting).

The firs sighting was about 10 years ago. Julia was about seven, and we were visiting the Minnesota Raptor Center in Falcon Heights. We were being given a tour of the cages, where various raptors were kept. These birds were all rescued from somewhere, generally with injuries. Some would be rehabilitated and released. Some would become ambassador birds, traveling around the area with experts from the Raptor Center for educational purposes. Some would simply remain in the cages forever.

As the tour progressed, the tour guide would say a few things about each bird as we approached the cage, then we would look at the bird for a while, then move on to the next cage. At once point, she said, “And here is the Golden Eagle. There are no Golden Eagles in Minnesota, not at all. If you ever think you are seeing a Golden Eagle, I assure you that it is merely an immature Bald Eagle. There are no Golden Eagles in this state.”

Then, as we stopped in front of the cage to look at the bird, Julia pointed to it and said, “There’s one!”

“What?” the guid said.

“There’s a Golden Eagle. It’s in Minnesota. So you’re wrong.”

I was fully expecting to find, on further inquiry, that this particular bird had been found injured along the highway in some other state and brought here to the Minnesota Raptor Center for treatment. So, I asked, “Where is this bird from?”

We were given a very precise location, along a road near a particular town. In Minnesota. In fact, within a one hour drive from where the bird was sitting in the cage. So, there you go.

The second sighting was up at the cabin. It was early fall and we were sitting on the deck overlooking the lake, to the north. Although we were located a short distance outside the Chippewa National Forest, which is known to have the highest number and highest density of Bald Eagles in the US outside of Alaska, the tree line across the lake was in the forest proper, and in fact, this was an excellent place to see bald eagles. A nesting pair lived in sight just a few hundred yards to the left, and hunted in this bay. Sometimes other eagles came by, and the pair often had a young one. If you want to see a bald eagle from that spot, all you had to do is look. If the eagle was not visible that instance, all you had to do was listen and you’d hear either the eagles themselves or some other bird complaining about the eagles. Indeed, that is the main reason for the local loons to holler. If you hear the loon going loony just look up. There will be one or two bald eagles reeling at altitude over the loon, sharing the fishing grounds.

Anyway, we were sitting there looking north when suddenly there appeared over the tree line to the north, across the lake, a bird that was clearly a very large eagle, and it was flapping its wings in powered flight going in a straight line right for us. We knew it was an eagle because of its shape and size. However, it was significantly larger looking than any of the bald eagles in the area. I should note that despite the large number and high density of eagles in Chippewa Forest, these Bald Eagles are smaller than the Alaskan kind. But this bird was whopping big.

Also, it was flying funny. Not only was it not soaring as eagles tend to do, it was flapping its wings in what looked like an unusual pattern. And, it was not a bald eagle. As it got closer, we watched it with binoculars and could see the field markings very clearly.

“That was a Golden Eagle, wasn’t it?” I said to Amanda.

“I guess so,” she replied.

“You could see a bit of white on the upper wings before it came over us.”

“Yeah, I saw that. You could see white on its tail shinning through with the sun.”

“It had a small head.”

“And a smaller bill.”

“I know, and that color was different than an immature Bald Eagle.”

“When it stopped flapping for a while its wings almost looked like a vulture.”

“I know. All the field markings seem to suggest a Golden Eagle, not an immature Bald Eagle.”

“Yeah, and you know what,” Amanda said.

“What?”

“We know what an immature Bald Eagle looks like. That wasn’t one of them.”

And now it’s your turn. The following illustration shows several raptors. Each is labeled with a letter. Some of these raptors are Golden Eagles, some are not.

EagleQuiz

Your job is to identify the Golden Eagles. Put a set of letters that represent only Golden Eagles in a comment. I will collect all the perfectly correct answers and send them to Price Waterhouse in a briefcase, where one of the correct answers will be randomly selected.

If you use a proper email address when you sign in to comment, then I’ll be able to contact you if you are chosen. Otherwise I’ll just mark the correct and chosen comment here on this blog and you can check back later, and if you were the winner we’ll work out how to send you your prize, provided by Princeton University Press.

The prize will be two pounds of Birds and Beans Coffee! It will be sent to you by the good people of Princeton.

Also note that Princeton has a contest in which you can win a pair of Nikon 8220 Trailblazer 8×42 ATB Binoculars and some autographed bird books. Details are HERE.

Happy Birding!


We’ll pick the winner on April 1st.

The Best Raptor Book Ever – The Crossley ID Guide: Raptors

The Crossley ID Guide: Raptors is just now coming out. I was able to spend a little time with it a few weeks ago, though my official copy has not arrived yet. But Princeton (the publisher) is organizing a major blog hoopla over the publication of this new book, and I’ve signed on to participate. Starting yesterday a number of bird-related blogs are producing posts related to this book. My post comes out next Tuesday and it will consist of a quiz, a bird quiz. Anyone who gets the quiz right will be eligible for random selection, and whoever gets randomly selected will be hooked up with Princeton who will give you something nice.

I’ll review the book officially next Tuesday, in the same post as the bird quiz. Meanwhile, you may want to look at these posts that have already come out. I’ll up date this list as I get more information.

Crazy Smart Crows and Migrating Animals

Skeptically Speaking #198 is now available for your listening pleasure. The main part of the show has Desiree Schell interviewing James Gould, co-author of Nature’s Compass: The Mystery of Animal Navigation.

Nature's Compass book
Great book on animal migration
The 15 minute side bar has Desiree interviewing me about recent research on the New Caledonian crows (this research).

Visit the Skeptically Speaking site to download or listen to the podcast.

This week, we’re looking at some of the amazing abilities exhibited by our animal cousins. We’ll speak to James Gould, co-author of Nature’s Compass: The Mystery of Animal Navigation, about the varying strategies animals use to find their way across all kinds of distances. And biological anthropologist Greg Laden discusses new research on the surprising reasoning abilities of some extremely intelligent crows.

The Golden Eagle Video Is Fake, But Not For The Reasons Given

Last night Julia sent me a link to a video of a Golden Eagle swooping down into a Montreal park, picking up an infant/toddler and lifting it several feet into the air before dropping it and flying off.  Since then many on the Intertubes have declared the video to be a fake while others insist it could be real, but unfortunately many of the reasons given for it being a fake or for being real are misconceptions or inaccuracies.  I’m sure the event depicted in the video is faked … no eagle picked up a child as depicted … but the reasons for it being a fake are not as many have suggested.  One of the main reasons that this is interesting is because we saw perfectly intelligent people who clearly identify as “skeptics” writing off the video as fake mainly on the grounds that others said it was fake, or where those reasons were inaccurate. In other words, this may be an example of hyper-skepticism.  The apparent fact that the video really is a fake does not ameliorate the terrible harm that has been done to Truth and Humanity from falsely labeling the fake video as fake for false, fake reasons!

Here is the video:

Some people who have discussed this video may have seen only a shorter version showing the last bit.

Here are some of the arguments given pro and con on this video’s realness, and my assessment of them.

1) It is real because Golden Eagles occasionally eat children.   Maybe. There is no particular reason that a Golden Eagle would not eat a child, though I know of no confirmed reports of this. This particular question … could or would a Golden Eagle do this … is part of a larger theme of belief in non-human animals eating humans. People are mostly divided on this issue. Lions, it is said, don’t eat humans because they don’t like the taste. However, they do now and then. Lions and other cats tend to specialize on their prey, so day to day, healthy pride lions eat one or two species of antelope (or something) as do leopards and other cats. Switching to humans is not uncommon for large predators, but once they do they are killed. So, you don’t have very many long-career human-eating large predators. The idea that a predator won’t eat a human because of some mystical exceptional property of humans (including taste) is wishful thinking. But, predators who do so immediately face serious odds against them because humans are a bad-ass species. There is no a priori reason to say that a Golden Eagle would not or could not attack and/or eat a human infant and/or toddler. It is, however, unlikely. But, unlikely events happen. Conclusion: This point does not tell us if the video is fake.

2) It is real because Golden Eagles can and do eat large prey. This is absolutely true. Golden Eagles are the (mostly) Temperate version of the large Monkey-Easting and other eagles found in many areas across the world, and they tend to specialize on largish prey. The better known (to the average Westerner) “Bald Eagle” and its sister species in Eurasia are in that size range, much more numerous, but specialize in fish, but even they occasionally take a fawn or other large non-fish (and often, they take birds). Conclusion: Plausible.

3) It is not true because Gold Eagles are rare in Montreal. True, they are in fact rare everywhere as most large territorial predators are (with some exceptions) and Golden Eagles are especially rare and “shy” of human settlements. They do live in the general area, though, and they seem to migrate from Canada to points south, so a Golden Eagle passing through is not at all impossible. Conclusion: Plausable.

4) It is not true because it is an Osprey not a Golden Eagle. I believe that this was said by a bird expert who may have seen only the shorter version of the clip. On watching the clip, I believe it is an Eagle because it looks like one. It could be an “immature” (year old, full grown) Bald Eagle, but the markings on the wing actually look like a Golden Eagle. However, telling an immature Bald from a Golden is tricky and actually requires more of a look than we get in this video. Conclusion: Nothing is disproven here.

5) It is not real because an Eagle of this size can’t lift something as heavy as an infant or toddler that high in the air. This is my personal favorite for why the video is faked, and as far as I know I’m the only person to have noted this (on various facebook posts) so far. People have argued against this saying “Eagles take large prey” and “There’s this video of them taking a wolf” and “There’s this video of them lifting mountain goats” but all that is wrong. There is one “real” video shown on Animal Planet shot from above of a gold eagle grasping a mountain goat kid that it has dragged off a cliff and “guiding” its body down as it falls, seemingly dragging it across a ravine to a cliff face. But at no point does the Eagle lift the kid. In other videos of a Golden Eagle attacking (under human command) wolves or in other cases hunting Geese does a Golden Eagle lift anything off the ground.

Bald Eagles, which are about the same size, or a bit smaller depending on which population we are looking at, lift fish they’ve caught out of the water and fly off with them, but it is a struggle. If a Bald Eagle grabs a fish that is too big, the bird will fly just above the water dragging the fish on the surface. In some cases, the Bald Eagle virtually swims atop the water with the entaloned fish under or just on top of the water, to the nearest shore, where it drags it (with difficulty) to the land, kills it, rests for a while, then eats it. (Then spends considerable time drying off!) The fish that are too large for the Eagle to lift out of the water are significantly lighter than a human infant. Conclusion: The part where the eagle lifts the child up into the air is fake. This still leaves the possibility that an Eagle or Eagle like raptor swooped down on a child, but there was no lifting.

6) It is not real because this is not how Golden Eagles hunt their prey, for a couple of different reasons (this is an extention of #5). The large eagles such as the Golden Eagle and the various monkey eating eagles do knock large prey (like monkeys) off of branches or cliffs, pounce on them, rip them up and eat them on the spot. But they only carry off bits and pieces if they carry anything off at all. I’ve seen this in the Congo: You find a monkey killed by an Eagle, but abandoned (because humans came along). You convince the Pygmies to leave the monkey there and come back later in the day and a limb is missing. You come back still later in the day and only half the body is there. You come back even later and it is all gone. Conclusion: Not relevant, but instructive, and there is always room for a Pygmy story.

7) It is fake because the carrying-off of prey behavior is done during nesting and this eagle was not nesting. Eagles carry food to their nests only when they are feeding young that are there. There are no nesting Golden Eagles near any parks in or near Montreal, and this is not really nesting season. When the Canadians are wearing warm clothes, the only “nested” eagles are large enough to fly to the food mom or dad have killed on the ground. The Golden Eagle would have killed the infant/toddler on the spot and eaten it there… But that would not have happened because an Eagle would not try to kill and eat a small human while the other, large humans are standing around ready to stomp the Eagle. Conclusion, the Eagle in question was an idiot.

It is possible, as I suggested above, that a large raptor did swoop down and strike a kid. That is not entirely impossible. Had that happened, a lot less of the video would have to be faked! But the bit of the video where the eagle lifts the child into the air did not happen. That is faked.

UPDATE: 8) It is fake because someone admitted to having faked it. Conclusion: Assuming they are not faking having faked it, this would indicate it was faked.


This is being discussed on my facebook page, Don Prothero’s facebook page, here, here, and here.