Science Interview : Marshall Iliff, Cornell Lab of Ornithology

USFWS Mountain Prairie via/Flickr
February 24, 2014

Ornithologists at Cornell are deep into analyzing data from last weekend’s Great Backyard Bird Count. Birdwatchers were asked to pick a spot and count the birds there for at least 15 minutes. So far, participants from 131 countries have reported sightings of more than 40% of the world’s bird species. Morning Edition host Monica Sandreczki talked with Marshall Iliff of the Cornell Lab of Ornithology about some of this year’s trends.

MARSHALL ILIFF : This is probably the best year ever for snowy owls, certainly the best year in decades. Snowy owls, one of these species that has wild swings from year to year. One year there’ll be just a handful of them that come to the northeastern US and another year there’ll be these waves of many birds that come down. So this is definitely one of those years. And it seems that this is driven by really high rodent abundance in their breeding areas which are very very high Arctic.

So we know that the lemming abundance in Quebec this year was really really high. Some researchers there with snowy owls would find nests with just dozens and doznes of lemmings waiting to be fed to the young because the parents were just having so much luck hunting for the young. So what we think that did was drove the productivity so each nest was fledging more owls than usual. We also know snowy owls are nomadic, so they may nest in the western Arctic one year and in the eastern arctic another year, so probably a large group concentrated in the eastern Arctic, say Quebec, fledged more young than usual, then this huge population boom in a certain area is probably what drove large numbers to come south once winter set in.

It’s been a really fascinating year to watch snowy owls make it down to the Carolinas and Florida where they’re almost NEVER seen. So this is definitely one of the best snowy owl years ever. And the GBBC, last time we checked, had six or seven hundred snowy owl reports from this year. That’s really far more than we usually ever see.

MORNING EDITION : Still on this cold weather vain, we’ve had some really cold weather so far with the polar vortex coming through. How has that influenced migration?

MI : Yeah, so that’s one of the really interesting questions. And a lot of the answers are going to require closer looks at the data coming in this week. But all this cold weather has caused the Great Lakes to freeze for the first time in decades, so pretty much all the GL except Lake Ontario are entirely frozen. But, there’s a number of species of waterfowl that will winter on the GL when the water remains open, so as the ice has set in, those birds have been forced to migrate. So, white wing scoter is one species that’s been very obvious. .Scoter’s are typically Atlantic Coast wintering ducks that then migrate to the GL in stage. Some birds over winter on the GL, but then nest in the high Arctic, so the places they’re typically seen is on very large lakes or the coast. But with this freezing, a lot of those birds have fled the GL and turned up on small ponds and rivers pretty much all throughout the eastern US. That raises a lot of interesting questions about which lakes are these are coming from.

ME : Are there any projects in our area this data is used for?

MI : One of the concerns is a bird that migrates to South America is not really going to have any signal that the spring is so much earlier in the northern hemisphere and it might migrate back too late. So the concern is not that you’re going to freeze to death, but that the insect cycles are going to be too far along, that when you really want to hit the peak abundance for insects, you’re gonna miss that. That’s been shown through some studies in Europe and then this study in North America using eBird data is showing that birds are not keeping up with that shift as well as they should.

ME : Besides America, you’ve had people reporting from the Antarctic Peninsula. Who’s there reporting from Antarctica?

MI : (laughs) I think those are birdwatchers on cruise ships down to Antarctica that are visiting penguin colonies. He’s got snowy sheath bill and adehli penguin, southern tern and even Wilson’s storm petrol and that’s an interesting one because that’s a bird that’s nesting down there now during our winter, but during the Antarctic winter, they migrate up. It’s actually a common bird off the New York coast. It’s thought to be the most common bird in the world because they occur throughout the oceans. Little black bird with a white rump that spends almost its entire life at sea except when it comes on shore to nest.

ME : From the trends you’re seeing, is there one for you that’s the most exciting?

MI : Certainly the snowy owls this year are just amazing. One of the great things about them is they’re such a popular bird for the public. Harry Potter sort of brought snowy owls to everyone. I think a lot of people who wouldn’t say they’re interested in birds have had a chance to see it and connect with it. Plus, I love snowy owls and we’ve never seen a movement that’s this big before. For this winter, snowy owl is the bird of the winter. Sometimes they turn up in cities, so there was a famous one that turned up in downtown Washington DC this winter and people walking to work would look up and see this owl sitting in a tree over a park in DC. I think that one ultimately got hit by a car. And so, was taken into a rehabilitation center, but they do occasionally turn up in cities. But they do live quite happiliy there living off of rats and pigeons.