“Eating like a bird” is a metaphor used to describe someone who eats only small amounts of food or pecks at his vittles. Get enough of these bird-size appetites in the form of flocks of nuisance birds, however, and Great Plains cattle feeders can attest to their financial bite.
Birds — both endemic species and migrating flocks — are drawn to feedyards because of their open supplies of grain and water; think of them as large bird feeders. But the concern regarding bird problems goes way beyond simple feed loss.
Bird flocks also pose biosecurity risks with the potential contamination of feed and water sources with coccidiosis and salmonella. Plus, there's the labor and cost of cleaning up after them.
A winter problem
Feedlot bird problems tend to be a winter issue, says Kansas State University's Charlie Lee, director of a statewide program in wildlife damage control. As those flocks break up in the spring and start feeding on insects, the pressure eases. The same number of birds might still linger in the area, he adds, but they're more dispersed than during the winter when feedbunks become prime sources of sustenance.
The predominant culprit is the starling, which he estimates constitutes 90% of the problem in the Great Plains, though redwing blackbirds and brown-headed cowbirds deserve some credit, as well. Sparrows, he adds, aren't typically problematic.
“Starlings are very slow in their migrations and their migratory range is only about 300-400 miles north to south, a range that depends on weather conditions and food resources,” Lee says. “Generally, a single starling will consume 2 lbs. of feed/month, with about half of that coming directly out of the feedbunk and the rest as waste grain in the alleys or picked out of the manure.”
Starlings, like redwing blackbirds and cowbirds, all select for about the same particle size of feed, so they eat wherever they can find the meal that's just right. That's one behavioral trait that can be used against them, he adds.
“Actually, probably five to six months of the year, starlings would be considered desirable by feedlots because they eat undesirable insects; it's in the winter (from October to February or March) that they become a nuisance,” Lee says.
During nesting season, which begins about March, Lee says those large winter flocks tend to break up into small breeding groups and the damage dissipates.
Lee says starlings, which are an introduced species, are pretty much representative of the Great Plains today. Redwing blackbirds (a native species) and cowbirds exhibit very similar habits to the starling, but blackbirds have larger migratory patterns from north to south and tend to roost in cattails or shrubby trees next to marshes. Starlings also will roost in wetland areas but not as exclusively as blackbirds, Lee says.
Control of birds is a unique challenge, particularly in the open-air design common to feedyards. “The choice is really to either prevent access to the feed or get rid of the birds,” Lee says.
The ideal would be to seal off the premises to birds, but it isn't feasible to cover acres of feeding pens and feed-making and storage facilities with netting. But coexistence is possible via a well-thought integrated pest management (IPM) approach. By starting early, realizing that pest control is an ongoing effort and maintaining safety standards, Lee says bird control can be achieved.
Frightening birds with pyrotechnics or noise is likely Lee's first choice of tactics in an IPM program, “but it depends on the size of lot and if it's a feed consumption or roosting problem. If it's a roosting issue, noise can usually resolve the problem.”
Another benefit is that when frightened birds take flight, feedyard staff can evaluate the infestation, which may point the way to other strategies.
“But if it's a consumption issue in a large feedlot, noise will probably just move the birds to another part of the operation. Its effectiveness will also depend on alternative food resources; if the ground is snow covered and the birds have nowhere else to feed, they won't leave.”
Such tactics can be effective in driving off birds, but can eventually prove less so as birds become habituated to the sounds.
Avicides may be recommended in high-infestation areas of 100,000 birds or more. But Lee offers two admonitions on their use. First, check to see if their use is legal in your area. “Next, be sure to survey the premises for nontarget species such as doves, turkeys, etc., that feed in the alleyways,” he says.
There are other variables to consider, as well. “Products like Starlicide or Starlicide Complete kill birds at their roost site one to three days after consumption. So if you have birds roosting in town, you probably don't want to use it because you could end up with a public relations problem.”
Avitrol is a product registered as a bird repellent. While it will kill birds that consume it, Avitrol is actually a hallucinogenic, Lee says. Birds consuming the bait exhibit erratic behaviors and elicit distress calls that frighten other birds. Like Starlicide, Avitrol is applied to bait outside livestock areas, and care must be taken to ensure livestock don't contact it.
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If a feedyard manager has the rights to adjacent land, modifying the environment to discourage birds may be an option. Lee says there's been some success in reducing adjacent roosting sites such as cattail growths, or thinning or pruning vegetation to remove protective cover, but it's generally difficult to retrofit around a feedlot situation. Habitat management, however, usually produces a more lasting effect than other methods and tends to be less expensive in the long run.
Because target species are active only during daylight, feeding early in the evening or late at night is another strategy for severe bird infestations, Lee says.
Regulating particle size of the feed so that birds won't select for it or can't consume it is another. “Try using half-inch or larger pellets if your nutritionist recommends it. Starlings can't eat pellets that big, and that's the costliest part of the ration,” he says.
Lee says one effective repellent is methylanthranalate, a grape food flavoring, derivatives of which are used on golf courses and around airports.
“Methylanthranalate is a GRAS (generally regarded as safe) product and quite often used in an ingredient in many foods. And it works fairly well as a repellent mixed in the feed but its cost is prohibitive to feedlots at this time, at least in the concentration needed to make it work as a repellent in feed.
“But it would probably work better in a roost situation because those often have a roof over them, which would prevent dissipation.”
While all these tactics can be effective in the appropriate situation, Lee says a mix of control options typically provides the best results.