A recent story, that appears to have originated on Chinese news radio and picked up by Xinhuanet, suggests that thousands of dolphins helped protect a Chinese ship from attacking Somali pirates in the Gulf of Aden. Best line in the whole thing:
The suspected pirates ships stopped and then turned away. The pirates could only lament their littleness befor [sic] the vast number of dolphins. The spectacular scene continued for a while.
While the story is, at the very least, over-exaggerated, and likely completely made-up, it’s interesting that this narrative has caught peoples’ attention (as of April 17th, it had been bookmarked 55 times on Delicious and had been dugg 43 times). My simple question is: why?
Blue Tit used under a creative commons lisence by Marko_K. Thanks Marko!
Blue Tits (Cyanistes caeruleus) nesting on the Medeteranian island of Corsica have been known to incorporate fresh sprigs of aromatic plants, like French Lavender (Lavandula stoechas) into their nest cups. New research1 reports that there may be benefits beyond a nest that smells like potpourri: these aromatic plants offer benefits to larger broods of Blue Tit chicks.
The potpourri, interestingly, does not reduce the number of ectoparasites2 found on the birds in the nest. Rather, the researchers suggest that either the aromatic plants offer immune system benefits (mechanism still unknown) or, and I quite rather like this idea, the females that actively incorporate fresh sprigs of aromatic plants are indicating their fitness to males. In other words, the fresher, more aromatic the nests, the “better” the female is as a mate (and subsequently, the “better” the offspring).
Now that makes you think about that stale bowl of potpourri on the back of your great-aunt’s toilet tank differently…
The Griffaroo turned 14 weeks this Saturday and we’ve been living with him for the last four of those. When we brought him home, he was certainly very puppy-like and he continues to be: ankle-biting, mouthing and all that good puppy stuff.
Compared to Ollie, he certainly was (and is) much more assertive. The first two weeks on putting him on his back was always a struggle–he would squirm and bite as though he didn’t want to be there and couldn’t understand why I was doing this to him. Hallmarks of a dominant dog.
During those first weeks in new situations, such as meeting another dog or person, his reaction was to bark. And not a friendly “let’s play” bark but a puppy version of “eff-off…if you come any closer I’ll kill you”. It was worrisome. He would also growl at us in particular situations: once when I took a bull penis away (don’t worry, they’re dog treats) and also once when picking him up. Our reaction to this was to continue to do the actions and not accept a growl as an appropriate behaviour. Letting him know that we’re in charge and he does what we want him to do, we started to hand feed him and interrupt other acts of daily life to see what reaction we would get. 99.9% of the time, he’s fine with everything that’s going on.
We’ve worked hard on this growling and barking through socialization; with other dogs and people. He’s improving on both fronts, and we’re both feeling like he’s making progress toward a less fearful reaction when in threatening situations.
It doesn’t mean it’s all sunshine and lollipops at this point. Dad came to visit today and, with Griff in his lap, bent down to say hello. When he got close to Griff’s face, Griff growled and moved away. An improvement, but still growling in a situation like that is unacceptable. We got the treats out, and had Dad continue to be close to his face and feed him the treats. No more growling and even a few licks. Now, hopefully he’ll be less fearful when a stranger picks him up and gets close: good things happened the last time this happened to me.
All of this is challenging. We need Griff to be a well-balanced, predictable dog. Acting out of fear is not a reaction we can live with. And while it’s scary not to know what the future holds (will he get worse? Become that monster of a Terrier that you can’t trust with anyone?) he’s such a smart, sweet boy the majority of the time that we’re committed to making this work.
Thanks to Flickr member mikebaird for sharing the DCC photo with a creative commons license.
A just-published paper suggests that Double-crested Cormorants (Phalacrocorax auritus) in the Great Lakes may swallow stones to reduce the number of parasitic nematodes–and in so doing, are self-medicating. Many birds ingest stones to help with the digestion of physically hard objects, but fish, the primary meal of the DCC are soft-bodied and don’t need the kind of mechanical assistance. So why are DCCs found with ingested stones?
Researchers found that:
At a Lake Ontario site, females more often had small stones in their stomachs and were less parasitized by nematodes than were males, and males with small stones had fewer nematodes than males without small stones. We did not find similar patterns in small stone presence or parasitism at a Lake Erie site; however, Lake Erie birds had fewer parasites and lower proportions of birds with small stones.
Which, in turn lead to the conclusion that since the birds that had stones were less likely to have nematodes, then the stones are the bird-equivalent of some anti-worm medication. Smart birds.
Small rant:
Interestingly, the Lake Ontario site was located at Presqu’ile Provincial Park and the Lake Erie site was located at Middle Island, Ontario. These are two sites where DCC culls have taken place in the recent past, with websites reporting a May 2008 cull on Middle Island that matches with the date in the paper’s method section. I can’t find any mention in the paper to the “source” of the birds or how the birds were “collected”.
Some may say there is no space for politics in scientific research and regardless about your feelings about recent DCC culls, I think that because the article makes no specific mention of how and where the researchers got their DCC gastrointestinal tracts, it does nothing but reduce the transparancy and therefore, the quality of the work.
The past two days in Toronto have been warmer than normal, leading to a large snow melt and the promise of spring (and I know it’s a tease, but it’s a nice break from what has felt like an especially cold winter). With spring comes the return of migratory birds, so this research seems relevant.
First, some background. Feathers, unlike our bones, lack an ability for self-repair. They can be attacked by feather-loving bacteria1 and suffer from UVB damage (and sunblock doesn’t really help out). So birds moult, or replace feathers, up to twice a year. According to my Sibley Guide to Bird Life and Behaviour, most North American birds replace feathers in a complete moult in the late summer or early fall. Some birds undergo a second moult in the spring, before the breeding season.
Birders out there have experienced these two moults when faced with confusing fall warblers: males no longer are in their colourful, easy-to-identify plumage (which appeared during the spring moult) and we humans suffer under the burden of having to learn, what could easily be described in some cases, as a whole new bird.
Why there is a difference in moults is the subject of this research by Thomas P. Weber, Johan Borgudd, Anders Hedenstram, Kent Persson & Garan Sandberg. Comparing the mechanical strength of flight feathers from two species of similar birds that have different moulting strategies, researchers found that the bird species that moults twice2 have comparatively weaker (more prone to fatigue) feathers than the species that moults once. Since the authors suggest that “the species with feathers that fatigue faster moults twice annually and not once” it would seem the willow warblers moult out of a form of necessity: they would suffer from the consequences of weakened feathers as they migrated to or from their breeding territory.
Now, if this feather weakness is a similar case for birds of the Americas that moult twice, it’s interesting to note that Wood Warblers (Family Parulidae) also change the colour of their plumage with the two moults. Because of this breeding plumage / winter plumage dichotomy, it would seem that feather weakness isn’t the only reason why a bird would moult twice. The interesting question would be if the adaptation to two moults a year “allowed” wood warblers to have a colourful breeding plumage–the ability for males to “change” their appearance for the breeding season and visually demonstrate just how fit they are.
Better described as bacteria that degrades the Keratin, the protein that makes up the feather. [↩]
In this case, the willow warbler, Phylloscopus trochilus, which is a small European insectivore. [↩]
If you’ve ever spent time watching House Sparrows (Passer domesticus), you might have noticed just how, well, squabbly they can be. Just today, I was out walking the dog, and a group of three came screaming (in flight and in sound) out from a pruned cedar shrub, flew across the sidewalk and screamed back into another shrub. They’re social little birds and use that sociality to their advantage–often relying on others to find food to eat. Fights between birds erupt over a number of different reasons (just like us, really) and food is often a source of conflict.
A recently-published paper in the journal Animal Behaviour1 reports the results of a study that looked at the effect of how being related to another House Sparrow might effect reactions over food.
The study suggests that the more closely related an individual House Sparrow was to another, the less likely there would be conflict (called “Aggressive Joining”) over food. If there was conflict with a close relative over food, less food would be taken from that relative.
Interestingly, there was a sex difference reported that was possibly attributed to the fact that female House Sparrows spread out over a greater distance from their original flock. If a male was to take food without conflict from another bird, it was always from a non-relative bird. Females, however, showed no discrimination when they were taking food (without conflict) from others. Since it is females that spread out, they’re less likely to have close relatives in their new flocks–hence they show no preference for taking food from close relatives or non-relatives.
Perhaps most interestingly, but not surprising, was the acknowledgement that House Sparrow have to be able to recognize and know close relatives:
Since we found differences between several aspects of scrounging behaviour towards close kin and nonkin birds, sparrows are likely to be able to distinguish between genetically closely related and unrelated flockmates.
Since House Sparrows neither breed co-operatively or form family groups, their ability to recognize close relatives is seen as significant.
So, now, while you’re sitting on a patio this summer and see House Sparrows at your feet, spend some time watching them and their reactions over food. You might be able to decide if they’re close relatives or simply strangers.
Source Details: Zoltán Tótha, Veronika Bókonya, Ádám Z. Lendvaib, Krisztián Szabóc, Zsolt Pénzesc,and András Liker (2009). Effects of relatedness on social-foraging tactic use in house sparrows. Animal Behaviour,77(2), 337. [↩]
I went to the book launch of the Peterson Field Guide to Birds of North America yesterday (pictured on the left) and I was struck by a couple of design decisions that I think are a bit peculiar. While my caveat emptor is that I spent about 5 minutes leafing through it, two one deficits jumped out at me immediately:
The first is size. The book has grown and now is more in line with the original Sibley’s guide (the website has the book dimensions listed as 6×9 inches). For me, a book of this size no longer becomes a field guide–a book that can easily slip into a coat pocket and is forgettable as you carry it around–it becomes a desk reference. Yet, right there on the cover is the fact that this is supposed to be a field guide. Sibley’s guide as a desk reference is “worth it” in my opinion, because the extra space is used to describe and illustrate a wider variety of colour morphs seen across North America. In the new Peterson guide, the bigger pages are filled with larger illustrations. I don’t know if this is a demographic decision (Houghton Mifflin: “Birders are getting old. We need to make the bird illustrations bigger so they can see them easily”), but I was somewhat surprised that the new edition is essentially an old Peterson Field Guide “super-sized.”
Second, range maps are in the back of the book. Another bone-headed move on the design front. Having to flip around a book to try and find if what I think I’m seeing should actually be where I’m seeing it is extra effort. This is actually a step backwards for the Peterson guides because in the most recent edition of the Eastern guide (and I have to assume Western, too) there are range maps right on the same page as the plates. All the “current-generation” bird books that I own have range maps right with species descriptions and plates. The only reason why I can think the move was made has to do with the size of the maps: they’re much larger then they would have been if they were to have been included with the text. Personally, a small map never was much of a limiting factor when using a guide.
Update (09-11-08): As per the first comment below, it would seem that I managed to miss the inclusion of range maps beside the species descriptions. So, it would appear that you get flip-free small range maps and the larger range maps in the back.
This guide is supposed to assume the mantle of the new edition of Peterson bird guides. I suspect that Houghton Mifflin will, Ã la Sibley Guide to Birds, publish more compact regional versions (previous Peterson guides covered Eastern and Western North America) of this guide sometime in the future. It’s an interesting plan because while this worked for the Sibley guides, I’m not so sure it will work again in the case of Peterson. My resoning is this: at some point people don’t need another field guide. There was enough value-added in The Sibley Guide to Birds to warrant having both a desk reference and a field guide. I don’t see any extra value in owning the first edition of the North American Peterson and a field-guide size regional version too. It will be interesting to see what the future holds for this edition.
My challenge: to take Ollie (at the time, a five-month-old Border Terrier puppy) on our regular summer sea-kayaking trips on Georgian Bay. Canoeing with a dog is easy. Kayaking with a dog seemed a bit more difficult. So I dreamt up a contraption that would allow Ollie to join us on these kayaking trips. Thanks to my Dad helping in the construction!
Witness it, in situ:
My criteria in the creation of the crate:
Traction: Kayak decks are fibreglass with a shiny gelcoat. Ollie would need a surface that would allow him some sort of gription as dog nails on gelcoat doesn’t really work.
An edge: In wavy conditions, the kayak can pitch quite suddenly. Having something that would contain the dog would help him stay on the boat while in swells seemed important.
Sun protection: All day kayaking without sun protection would equal fried puppy. My perfect design would offer some kind of sun protection.
Wind sturdy: Winds on Georgian Bay can be fierce (for example we had one evening this trip of ~ 45 km / h winds or 6 on the Beaufort Scale). Any extras (such as the sun protection) would have to stand up to a whipping wind.
Waterproof: This seems obvious.
Protects the Kayak: Since the Kayaks aren’t mine, I figured it would be bad if it ended up scratching the kayak when installed.
So with these criteria in mind, I set to creatin’. Since the kayak crate was a success, I’ve provided an illustrated step-by-step guide if you’re interested in making one yourself.
Birds migrate at night. Bird tend to flock together.
These two disseparate facts have been recently weaved together to suggest that birds migrate at night in flocks. What I find interesting here is the suggestion that these flock are “loose”–not the tight configurations visible in the preceding video of starlings flying in a flock–birds may be migrating in groups that are as much as 200 meters apart from each other. As the lead researcher, Ronald Larkin, suggests birds flying in the same direction at one point in time is not the same as birds travelling together over long distances:
“Even back in the 1970s it hit me that you can have two birds flying absolutely parallel in the same direction and at the same height, but they can be flying at such a different speed that one of them gains on the other and they’re just, you know, automobiles passing on the expressway,” he said. “They’re simply taking the same route and not keeping together.”
What Larkin has shown through a magic elixer of radar and statistics is that migrating birds tracked were actively travelling together: same speed, same altitude, same direction. Just much further apart then we had ever imagined before.
For me, this finding brings up the obvious question: how? I know I’ve stood outside during spring and fall migration and heard the whisper thin call of migrating passerines, so perhaps they stay in contact via vocalizations. But that’s just conjecture on my part.
And I have to share Larkin’s sense-of-wonder with this phenomenon:
“To me, that’s the marvelous thing – that they’re flying in social groups in the middle of the night in the middle of the air, over territory most of them have never been over before.”
, most North American birds replace feathers in a complete moult in the late summer or early fall. Some birds undergo a second moult in the spring, before the breeding season.
