Northwest Arkansas Democrat-Gazette
Cold weather: Is it for the birds?
Local expert explains why bread is foul for fowl, if their feet get cold
BELLA VISTA — Butch Tetzlaff, the owner of The Bluebird Shed in Bella Vista, knows a thing or two about birds.
He earned a bachelor’s degree in biology from Indiana University and did his master’s work in ornithology for three years at Illinois State University.
Recently he has helped his friend, Dr. Jennifer Mortenson, with portions of her ongoing bluebird study in Bella Vista.
Mortenson, who got her Ph. D. in ornithology studying white- breasted thrashers in the Caribbean, is researching the roosting behavior of bluebirds in Bella Vista this winter, looking in particular at parasites in the boxes and how they’re being transmitted by the birds that are occupying the boxes in the wintertime.
“The Bluebird Society allowed us to monitor 100 of the 600 boxes they have installed in Bella Vista for our research purposes,” Tetzlaff said. “Over the last three years she’s monitored the boxes twice a week, banding the nestlings, catching adults when we get the opportunity and studying the parasites.”
The parasites, Tetzlaff said, are not something that’s harmful to the birds. The study is being done to see “how an ecological niche, so to speak, moves from one location to another via bird translation.”
The study has also revealed that some birds are using the boxes not just for nesting purposes.
“We’ve found a couple of bluebirds in the boxes this winter as well as a downy woodpecker,” he said.
DO BIRDS GET COLD FEET?
While gathering information is important work in his role as an ornithologist, dispensing information is one of the ways Tetzlaff benefits Bella Vista as a shop owner and member of the community.
Customers visiting to The Bluebird Shed can not only find a myriad of useful products that help them take care of their feathered friends, but they can also learn interesting tidbits about birds in Bella Vista, Benton County and beyond.
For instance, how are birds able to stand on snow without their feet getting cold?
“It’s called countercurrent heat exchange,” Tetzlaff said. “Their veins and arteries are positioned such that the artery coming down to the feet is exchanging heat with the veins coming up from the foot. They’re really close together. It’s basically warming the blood back up before it gets back to the body.”
He said it’s similar to water pipes in a house.
“So if it’s on the outside, it would be cold all the way through and the body would have to warm it back up,” he said. “It’s basically like hot and cold pipes. If your pipes are next to each other, the hot pipe is going to warm up the cold pipe and you’re going to end up having lukewarm water in the cold pipe. If they’re farther away you don’t get that heat exchange going on and your hot and cold stay hot and cold.
“But in a bird’s foot,” he continued, “they’re really close together intentionally so they can warm up that vein coming up so they end up with warm blood coming back up to the body and it doesn’t cool off the body.”
One might think the bird’s “inner workings” help keep it from getting a shock when it perches on a power line. Tetzlaff said that’s not necessarily the case.
“It’s partly the wire, but it’s also due to the fact they’re not touching anything else but the wire,” he said.
BREAD: A FOUL FOR MOST FOWL
Tetzlaff also has a wealth of knowledge regarding a bird’s diet, especially when it comes to ingredients in bags of bird feed as well as food items not normally found in the feed.
People are often discouraged from tossing bread out for birds to eat. When asked why that is, he explained that bread “doesn’t have the nutritional requirements that birds need,” adding, “it’s a pure carbohydrate and most birds can’t digest a carbohydrate and get much out of it. House sparrows are one of the few that can, and that’s why house sparrows hang around places like the trash dumpsters at McDonald’s. You see them a lot around dumpsters.”
Some companies put grain fillers in their bird feed, which is an ingredient that’s not beneficial to all birds.
“Grain filler is great for us and great for cows and sheep and everything else, but it’s not that great for birds,” Tetzlaff said. “So around granaries you’ll see birds like house sparrows, but you tend not to see a lot of the really interesting birds because they’re not carbohydrate eaters.”
The majority of birds, he said, benefit more from a diet of protein and fat.
“The basic seed here in the store is black oil sunflower,” he said. “That’s what everything is based on. Everything after that is a blend of black oil and something else. But the black oil sunflower is the main go-to seed because of its high fat, high protein content. Birds really like it. And it’s a relatively inexpensive seed that the birds prefer. That’s what I’ve got here.”
The black oil seeds set the baseline for the majority of the food offered at his store with other combinations included on the shelves.
“The derivatives after that are basically blends of things,” he said. “So it’s black oil in the shell, black oil out of the shell and it might have some chopped up peanuts in it. Some has a little bit of white millet in it, which is actually good for the ground feeders. You can actually get whole bags of millet. Perching birds have a tendency not to eat the millet out of feeders and ground feeders eat the millet. So if it gets tossed on the ground that’s fine.”
So if a person puts feed in the feeders that includes millet, the ground feeders — morning doves, dark-eyed juncos, white-throated or white- crowned sparrows — will come in to clean up whatever falls from the feeders.
“But you don’t want something that’s 80% millet and have 60% go to waste,” Tetzlaff said. “What’s better is something that’s 3 to 5% millet so it will get eaten and not go to waste.”
Peanuts are also good for the birds, according to Tetzlaff, who pointed out that while some birds will swallow a peanut whole, others will break it down into more manageable bites.
“It depends on the size of the bird,” he said. “So the larger birds are capable of just swallowing it whole. The smaller ones will take it in their feet and just hack it into smaller pieces.”
Like a human might do when using peanuts in a recipe.
“Think of it as if you had whole peanuts on a chopping board and just started cutting them up into finely chopped pieces — not finely ground up, but chopped up,” he said.
LOW TEMPS = NO BUGS
Cold weather can also impact a bird’s diet because, at certain low temperature levels, it makes it hard for them to find the items they’re used to eating.
“The cold weather does things,” Tetzlaff said. “When we start to get the temperature down to minus 20, then it’s really hard on the guys. They can tolerate freezing temperatures, but it’s the food that’s available that has a hard time tolerating those temperatures, like insects. Most of the birds are still insectivores, even in the cold weather. The toughest time, absolutely, is when there’s a blanket of snow on the ground because that’s when they can’t find anything. That’s when you really see them coming to the feeders and loading up on the high- fatcontent type food.”
Unlike humans, birds are able to better use fat as an energy source.
“Birds have an ability to store fat quickly in their bodies,” Tetzlaff said. “They metabolize that fat during times when food is scarce. They don’t have issues with arterial sclerosis like humans do, so that’s not an issue. They do utilize fat as an energy source far more efficiently than people do, and we have a tendency to use more carbohydrate as a primary energy source and fat as a secondary one. It’s the other way around for birds.”
For the most part, insects are the baseline for the diets of birds.
“Generally speaking, 80 to 90% of the birds coming to your feeders are going to be insectivores,” he said.
Which is what makes winter harder on our feathered friends and why feeding with proper ingredients is important.
“You can do year- round bird feeding. That’s not a problem,” Tetzlaff said. “Studies have shown that the feed at feeders is a supplementary food for birds. They don’t become dependent on it or use it as a primary source of food. You’ll see birds coming in and out all the time; it may not be the same ones. They’ll move around quite a bit; unless they’re actually marked you don’t really know how long that bird has been around.”
STAYING CLOSE TO HOME
Birds in the area have been marked, and those monitoring the tags have been able to tell that some birds stick around, even some from the same lineage.
“We have put tags on birds around the area here, and we do know some will stick around in Bella Vista,” he said. “And we have homeowners with tagged birds coming to their feeders, and they know those birds are there the entire year. Then, for some reason, they disappear. Probably, unfortunately, it’s because of death. But, generally, if they’re around for a long period of time they’ll be there for a long period of time.
“And sometimes we’ve got offspring of those birds that are around,” he continued. “We know that because we’ve tagged those offspring, too. We’ve got second and third generations in people’s yards right now, and that’s nice to see.”
Sparrows seem to be the most heavily populated bird species in Bella Vista.
“We’ve got seven different kinds of sparrows here now,” Tetzlaff said. “It kind of depends on where you live as to what kind of sparrows you end up getting in your yard. A lot of the sparrows will come down from the north.”
He said Harris’s sparrows from Oklahoma will soon be joining the crowd. But, for the most part, he said “most feeder birds that migrate to here have already done so.”
ERUPTION YEAR UP NORTH
Included in the group that is already here are yellow- bellied sapsuckers and red-breasted nuthatches. Both came down from the north, the latter from the northern boreal forest.
“They’re kind of having an eruption year right now, so they moved south about six weeks ago,” Tetzlaff said. “There are quite a bunch of them around here right now.”
An eruption year, he explained, is “when the cone crop up north is not as good as it usually is — and it’s a poor cone crop this year — and so the birds are having to migrate south in order to find food. They’ll move down here to find food, then move back.”
He added, “The eruption term comes from the old days when people thought the population had grown. Well, the population hadn’t really grown; it turns out there’s a dearth of food north and a greater abundance of food to the south, so they tend to move to where the food is.”
OUR FRIENDS THE ORIOLES
One of the more exciting migration events in Bella Vista is when the orioles pass through from the Gulf of Mexico.
“That’s usually from the third week of April through the second week of May,” he said. “It’s a narrow window of about 14 to 18 days when they’re really coming through. We don’t get to see them in the fall. There are folks that do report them in the fall, but nothing like in the spring.”
Tetzlaff said while researching bird banding lab data on an Audubon Society website he decided to look up the migration pattern of the Baltimore Oriole to see why they aren’t seen as much in the fall.
“I looked it up just out of curiosity,” he said, “because I always wondered why people don’t see them in the fall, but they do see them in the spring.”
He found the answer, and what turned out to be bad news for Arkansans is actually good news for Oklahomans.
“It actually turns out that their migratory path comes up from the Gulf of Mexico and pretty much comes up right through our area and then they fan out east to west across the United States,” he said. “But on the return trip, the ones that are in the east have a tendency to move more to the west, closer to Oklahoma, and then go straight down to Mexico instead of toward the gulf. So it’s kind of a loop migration.”
He added, “There are probably more orioles in the OklahomaKansas area in the fall than there are around here.”
“You can do year-round bird feeding. That’s not a problem. Studies have shown that the feed at feeders is a supplementary food for birds. They don’t become dependent on it or use it as a primary source of food. You’ll see birds coming in and out all the time; it may not be the same ones. They’ll move around quite a bit; unless they’re actually marked you don’t really know how long that bird has been around.”
— Butch Tetzlaff, owner of The Bluebird Shed in Bella Vista
DUCKS STILL ON THE MOVE
As for any birds that may currently be heading through Bella Vista, Tetzlaff said that ducks are about the only thing still migrating at this point of the year and those on the move normally find other lakes on which to land in Northwest Arkansas.
“They’re still kind of moving,” he said. “As the weather gets colder a lot of birds will come down from the north. More bluebirds, robins, blue jays … they’re partial migrants, meaning some of the population will migrate and some will not. It depends on the weather.”
He said buffleheads and loons could show up in Bella Vista, but they’re more likely to end up on Lake Fayetteville or Beaver Lake because those lakes are bigger with fewer houses on the shoreline.
“Those lakes get a lot more diversity than we do because they’re bigger, they have fewer houses and greater depth for the ducks to dive down and have more food options.”
Tetzlaff said the next big migrations will start at the end of March and beginning of April.
“That’s when we’ll see the hermit thrushes, Swainson’s thrushes, ruby- and golden-crowned kinglets and northern parula warblers,” he said. “Then in mid-April it will be the tree swallows and barn swallows.”