February 16th – An Impromptu Experiment

Most bird species have a suite of vocalizations that they draw on to use in different situations. Snow Buntings have a marvelous song that, for me, conjures up sweeping Arctic vistas. But they also have an electric alarm call. Snow Buntings nested in rocky nooks and crannies in the huge scree field at the base of the cliffs at Cape Vera on Devon Island. Arctic Foxes would regularly stroll through the rocks looking for bunting nests (or lemmings). You could follow the fox’s progress by listening to the alarm calls as it moved – the bunting in one territory would give the call and follow the fox until it moved into the next territory at which point that bird would pick up the alarm. And so on across the extensive area. It was a loud, sharp call that carried a long distance.

Donald Kroodsma in his book Birdsong of the Seasons, notes that an alarm call “alerts individuals of the same species and other species” of a potential predator. I wondered about this: does a particular species recognize the alarm call of another species and understand its meaning – danger!

We had a chance to check this out yesterday while bunting banding. We were catching buntings consistently (68 banded) but not in large numbers at any one time – small flocks of 10-12 birds would fly in, feed, and then fly off. When the traps collected around 10 birds we’d empty them, band the birds and then let them go – out the window of my car. Almost always when the banded bunting was released it would speed away giving its alarm call.

Usually, when we cleared the traps and returned to the car, birds would be back at them before the door was closed. Initially we were catching only Snow Buntings but a little later in the morning four Horned Larks showed up to check things out. This is a pretty common combination: larks and buntings. We noticed that when a bunting was released after banding and gave its alarm call the birds that were around the traps would fly up and away – both buntings and larks. They would fly about 15-20 meters, land on the snow and then return to the bait area….until another bunting was released. At the alarm, both species took off – it appeared that the larks were responding to the bunting’s alarm call. But…were they?

At one point we had half a dozen buntings in the car for banding and there were only the 4 larks around the traps – the buntings had not returned. Here was our chance to find out. In this scenario, each time a bunting was released and called the larks did not respond at all. This happened with all 6 buntings – no response from the larks; they just kept walking around the traps looking to snap up any corn that had made it outside the mesh.

Often, when we’re releasing freshly banded Horned Larks they will give their alarm call. The larks in the vicinity will usually do one of two things: flatten themselves to the snow surface and scan the sky or take off. But they weren’t doing this in response to the bunting call. I think the important thing here is that the bunting alarm call causes other buntings to take wing. Larks, mixed in with them, respond to their flight and take wing as well. But they are not responding to the call, just to the startled bunting movement.

Of course this was a pretty small sample size (4 birds) and only one test. But it will be interesting to try and follow up on it. Hey! Maybe I can get a grant…..

Rick

February 14th – Busy Morning

The traps were busy from 7:30 on. -MMG

I arrived at the bait site before the sun cleared the horizon and there was a flock of about 85 Snow buntings swirling around the area. They made a couple of passes and then took off heading WSW. I watched them until I couldn’t see them anymore. Hmmm….with their exit was this going to be another slow day? NO. Their place was taken quickly by others and there were birds around the traps throughout the morning. Well….either at the traps or up in the tops of nearby trees checking things out. Passing traffic seemed to bother the birds that were around today and a passing vehicle making even a moderate amount of noise would put them up.

When they weren’t around the bait site, the buntings could usually be found in the top of two large, but isolated from each other, trees. The birds would take a look around and then fly back down to feed. -MMG

Some groups of buntings don’t seem to be bothered as much by traffic noise but these were. We were wondering if this noise tolerance (or lack there of) might indicate birds that nested in proximity to man and were more used to it as opposed to birds from more isolated locations.

Another big difference between yesterday and today is that today there were almost no Horned Larks around. We banded 1 and saw just 7 – and these not until late in the morning. Yesterday they were the most numerous species and we saw twice as many as buntings. Very different today…..

Rick

February 13th – So…Where’d They Go?

Yesterday was very busy. This picture was taken in Lanark County but could have been here….yesterday. -NC

For the past week we’ve been cookin’. We got some COLD temperatures and we got some snow and we know that these two ingredients are necessary for Snow Bunting banding here in far southern Ontario. From the 6th to yesterday, 7 days, we banded 405 Snow Buntings for an average of 58 per day.

Yesterday was very busy: we did 90 and closed up only because new, fresh snow began to blow/drift into the traps covering the cut corn. I put the traps out and finished baiting them at 7:30. Before I even got back to the car, a distance of about 30 meters, they were into the traps going after the corn.

Because there were so many, I decided to “ring and fling” – put a band on the bird, determine its age and sex and then let it go without taking any measurements or weight. I simply didn’t want to hold onto the birds any longer than I had to in these cold conditions – and I was getting 20+ birds out of the traps at each “round”.

When we first started to catch buntings in late January we were getting more than double the number of females to males. This is pretty normal for this area. Males like to stay farther north or northeast as they will leave for the breeding grounds to set up territories well before the females. And it pays to get back early as territory holders tend to hold onto them. But….if the weather deteriorates – colder and/or more snow – then the males will push farther south (as will the females). In the big rush yesterday the female to male ratio was almost 1:1. So males are feeling the weather and moving down.

It was cold again last night and we got about 5 cm. of fresh snow. I was expecting another “big” day. Much to my surprise there were NO birds at the site. After I put down the traps 7 flew by and then a few more dropped in to check things out but I never saw the big flocks that were around yesterday. Hard to figure as I have been putting out cut corn in the afternoons (when I don’t band so the birds can feed without interruption) so I can “hold” them. Perhaps the snow flurries in the afternoon covered the bait piles over and the birds gave up and left. (Although I find this hard to believe as I have found Snow Buntings sitting on a foot of new snow covering bait piles from the day before.)

Horned Larks cleaning up the scraps….outside….the traps. -MMG

Anyway, they were gone and we ended up banding just 8 plus one Horned Lark. We caught 12 larks that had been banded previously. It is interesting to watch larks and buntings around the traps. Unbanded larks walk around and around the traps picking up all they can find outside of them. Some may even venture their heads into the entry tunnels but rarely go in – even though the bait might be only a few centimeters away. Buntings don’t have a problem with this at all. They fly in and hit those tunnels and are in and on the corn before you know it. Yesterday the traps were filling before I even got back to the car. So why the behavioural difference? Snow Buntings nest in rocky holes, tunnels and crevices and aren’t deterred in the least by these narrow entrances that they must navigate to get to the corn. Larks on the other hand are birds of wide open spaces with low vegetation. Tunnels are foreign to them; they don’t know how to work them. Interestingly, and this showed up this morning when we retrapped the 12, once they have reached the bait – have figured out how to do it, so to speak – they have no problem getting into the traps again.

2 Horned Larks hunkered down in the loose snow, getting out of the wind. I wouldn’t be surprised if they spent the night covered over by this “insulation”. -MMG

So where’d they go? A friend of mine reported a flock of 140+ along Regional Road 9 about 5 kilometers south of York. Might be them; might be another group altogether. I have retrapped 3 birds that Mike Furber (on Dry Lake Road, 12.5 km from my site) banded at the end of January. And we know from our experience that these birds range over a large area in their search for sustenance. But they know where the food is….so I think they’ll be back. Maybe tomorrow with this new snow and continuing cold.

2 Horned Lark subspecies. The one on the left is likely the praticola variety (note the white supercilium stripe0 while the one on the right is the usual alpestris (yellow stripe). The praticola is also smaller and it shows.    -MMG

Rick

February 6th – It’s An Ill Wind…….

Male Northern Harrier flying in to see what’s going on. -MMG

It’s an ill wind that blows nobody good. This wind brought the very conditions, the lack of which I’ve been crying about for the last month: cold and snow – Snow Bunting weather. This morning when I reached the trapping site there was a flock of over 60 Snow Buntings waiting for me. They had completely cleaned up the cut corn residue from yesterday and were keen for more. No sooner had Marnie and I put down the traps and loaded them with corn then the birds were around and in them. In 3 hours we banded 60, almost tripling the number – in total – we had done so far this season. We stopped after just 3 hours because the wind was picking up even more and blowing loose snow through the traps – they act like snow fences and the snow piles up inside them hiding the corn.

A white-out obscures these hardy birds, only 30 meters away. -MMG

I ended up going back at noon and again at 3:30 to replenish the corn so that the birds would stick around. Each time there were at least 120 birds spread out over the snowy field but within 50 meters of the me and the traps. As soon as I was done, and before I reached the car just 10 meters away, they were back on the piles.

Trying to figure out why I’m not enjoying the heat of Malawi……which I usually do at this time of year. =MMG

A male Northern Harrier paid us a surprise visit this morning. It flew in to see what all the fuss was about. Birds jumping around in small cages looks pretty interesting to a predator.

Northern Harrier checking out the menu. -MMG

Facing into a strong wind and blowing drift snow, Snow Buntings and several Horned Larks (on the right) dig for cut corn. -MMG

Note the pale supercilium stripe – not your usual Horned Lark. -MMG

Rick