Feeder Problems and Pests

Common Bird Table Pests and Problems 

Sooner of later, bird lovers will run into problems at their bird tables and feeders. From hordes of squirrels devouring seed to disease, are just a few of the mishaps that could bestow a feeding station. This week we will go over some of the common pests that we may encounter and some tips and solutions on how to resolve or prevent them.

Squirrels and Rodents

Grey Squirrel 

Fox Squirrel

Squirrels: We all dread the day when a Grey or Fox Squirrel first finds a newly installed birdfeeder. At first it may be fun to watch one or two of these remarkable rodents eating seed or accepting peanuts on the ground, but eventually the entire family or local population may join the feast. In the Carolinas we have four species of tree squirrels, a chipmunk species, and a ground squirrel known as the marmot or woodchuck. In the Cape Fear Region, we have the Eastern Grey Squirrel that occupies deciduous and mixed forests with oaks, beeches, hickories or pines, while the larger Fox Squirrel is more at home in pinelands, treed pastures, parkland, and maritime forests with open grassy areas. Both squirrels occur in residential areas and towns although we are most familiar with the Grey Squirrel. We also have small Southern Flying Squirrel which is nocturnal and also present in the same areas. No chipmunks or woodchucks occur in the Cape Fear Region. Squirrels are fun and interesting creatures that are important for the forest ecosystem. Unfortunately, these animals are among the most difficult creatures to deter from your expensive foods. Any squirrel can easily climb a unbaffled pole, use a roof or branch to jump great distances and gnaw their way through a plastic or wooden feeder. With both species forming large colonies, a single feeder can host dozens of Grey Squirrels at once, leaving the feeders empty and can even destroy them. They love sunflower seeds, corn, peanuts, and just about any nut.

Solutions and Tips

• Use squirrel resistant feeders that have dropdown mechanisms, spinners, or other devices to reduce the chances of a squirrel getting to the food. These are available in bird speciality and big-box stores and are worth the added expense 
• Caged feeders can prevent or reduce the number of squirrels on a feeder 
• Avoid plastic feeders as these will be destroyed if they are in reach 
• Keep all feeders (baffled or not) away from tree branches, rooflines, or fences as squirrels can leap great distances and defeat a mechanism 
• Hot pepper could be effective, I also heard that rodents do not care for safflower or suet
• Provide squirrels food of their own in another area of the garden and increase natural food by planting oaks, hickories, beeches, and native fruit-bearing trees. 
• Second story window feeders are hard for squirrels to reach

Rats and Mice: The other rodents that may find a bird table are rats and mice. These rodents are smaller than squirrels and are usually but not always nocturnal. We have many species of mice and rats in our region although the ones that come to bird tables include Woodrats, Rice Rats, Brown Rats, Black Rats, House Mice, White Footed Mice, and occasionally Golden Mice. Like squirrels mice and rats can wipe out food from a feeder, come in large numbers, and damage or destroy feeders. These rodents could also contaminate food and give-rise infestations when they move on to trash or waste grain. Nonnative Brown Rats may also prey on the eggs of songbirds. While anti-squirrel mechanisms may defeat Brown Rats, the rest of the rodents are small, agile and do not trigger weight devices. They can climb, leap, and circumvent baffles. Despite their problems, mice and rats are important for the ecosystem and prey for hawks and owls, which are prone to rat poisons. Mice  and rats will eat anything but I found them to like suet, lard, table scraps, corn, and sunflower seeds as well as filler seeds in bargain mixes. 

Solutions and Tips

• Keep feeders away from wooded areas, hedges, or outbuildings if possible 
• Take in feeders at night as most rats and mice are nocturnal 
• Pepper dust may deter rodents from the food 
• Both mice and rats are reluctant to venture into open areas due to predators 

Other Mammals

Coyotes are among the animals that adapted to our towns

Our gardens and woodlands host a lot more than birds, lizards, and small rodents. At times animals such as racoons, opossums, weasels (such as skunks), deer, foxes, coyotes, and Black Bears will pass through our our neighborhoods and parks. In the Cape Fear Region, many of these animals actually live amongst our towns and cities, including Wilmington and Myrtle Beach and have adapted to human altered landscapes quite well. Large animals such as racoons and on rarer occasions opossums can destroy even well-built birdfeeders, get into trash bins, and will become a major issue. Foxes, coyotes, bobcats, and weasels may come if rodents are abundant. Black Bears are the least likely to visit your garden but the Eastern Carolinas has the largest population outside of Appalachia and have learned to thrive  in our cities. All of these animals can not only cause destruction to birdfeeders but pose a threat to garden nesting birds, as well as people's pets and property. Aside from foxes, coyotes, deer, and bears, all of these animals are nocturnal, so taking in your feeders nightly or limiting the amount of food put out each day can prevent these problems. Raccoons are also foiled by baffles if there are no branches near by. Remember these animals are part of the natural environment and should be respected and enjoyed for what they do for the ecosystem.

Cats: Feral and free-ranged felines are feared by many bird and animal lovers and chances are there are outdoor cats in your neighborhood. Domestic cats are not native and are opportunistic predators, even if they are fed. While some statistical information about bird mortality to cats may be overstated or limited to a few studies (i.e. on islands), cats can kill adult or young birds as well as rabbits, native rodents, and lizards. I found that cats are the biggest threat to ground or shrub nesting birds and newly fledged youngsters, while most adult passerines can escape from cats and other mammals. A bird table with lots of birds will eventually draw the attention of local cats. Additionally, cats may also try to ambush birds using nest boxes, climb into hedgerows. For human impacts, cats may dig up gardens to make toilet sites, bring fleas and ticks, while feral populations may have rabies. Thankfully, feral cats have natural predators including coyotes, and certain birds of  prey (notably Great Horned Owl), and in our area, we mainly deal with one or two cats from a neighbor rather than a feral colony with dozens. 

Solutions and Tips 

• Keep bird tables and ground feeders away from hedges, thickets or tall garden beds (at least 3-5m or 10-15ft). 
• Cats avoid roses, briers, brambles, and other thorny materials 
• Keep regular birdfeeders higher 1.5m or 5ft from the ground and use a pole baffle.
• Second story windows, and hanging feeders pose less of a cat threat 
• Chase off any cats on your property to reinforce fear and report feral cats to appropriate agencies (for their own good as well as for human safety)
• Educate neighbors, and friends about birds and how unleashed dogs and cats can threaten young
• Keep cats indoors, or in confined areas, especially during the nesting season. 
• Hot pepper on the ground might deter cats from sitting an an area.

Problem Birds

There are a number of birds that can become nuisances in our gardens or are a problem towards other birds. In almost every suburban or urban garden, there are highly adaptable and opportunistic birds that will patronize a bird table and wear out their welcome. Other birds pose a direct  threat to feeder visitors. While any bird can potentially become a nuisance, most of the problems relate to large flocks, aggressive behaivor, or how much food they eat. 

House Sparrows 

House Sparrows, note the male's reddish back

House Sparrows are nonnative and invasive songbirds that were imported from Europe in the 19th Century and are now cosmopolitan in range. These small birds are common in villages, towns, and cities as well as around farms, grain silos, and commercial complexes. While cute and relatable, House Sparrows are highly prolific and will out compete native birds for food, destroy the nests of hole nesting birds like bluebirds, chickadees, wrens, or flycatchers, and can cause problems in our gardens or to farmers. Bird tables are one of the leading ways to bring House Sparrows to a new area and low-end seed mixes with fillers, as well as millet, corn, and bread are likely to encourage these birds. In little time, feeders may become swamped by flocks (50+) of sparrows, and more expensive foods like safflower, sunflower seeds, or premium mixes will be devoured in short order. Do not encourage House Sparrows in the garden. Since these birds are not protected by law, they can be trapped, or removed but check local laws before doing any control measure. For bird table managers, it is best to minimize the habitat appeal to House Sparrows by avoiding grains or corn, fixing crevices in buildings, keeping sparrows out of birdhouses, and creating wooded habitat. I may discuss more about House Sparrows in a later article but for now I will focus on ways to mitigate sparrows at your birdfeeder. House Sparrows, are not related to our native sparrows such as the Chipping, Field, Song, White Crowned, and White Throated Sparrows that visit our feeders during the winter months. Native Sparrows mostly feed on the ground.  

Solutions and Tips

• Limit your feeder station to one or two setups as yards with too many feeders will attract House Sparrows 
• Avoid millet, wheat, barley, milo, and corn, or bargain seed mixes with a lot of red or yellow kernels. These seeds attract  more House Sparrows, cowbirds, and rats than native birds. 
• House Sparrows do not care for swinging feeders, window feeders and struggle to hang upside down. 
• Sparrows generally do not bother suet, large striped sunflower seeds, nuts, or thistle/niger seed
• Reduce House Sparrow breeding sites by plugging or repairing cavities or voids in buildings, using birdhouses smartly and not putting too many out in one area.
• Birdhouses with holes less than 3cm 1.5" cannot be used by sparrows while chickadees, wrens, bluebirds, and Tree Swallows can use them safely.

Cowbirds, Blackbirds and Grackles

Male Red Winged Blackbird "Redwing"

Another problem we may face are flocks of blackbirds that come from time to time. In the Cape Fear Region, blackbirds and occasionally starlings (another nonnative bird) are mainly a problem during the winter months. From September to March, Red Winged Blackbirds, Brown Headed Cowbirds, and Common Grackles pass through our area to winter and form flocks that may number into the millions. Starlings also form flocks. In the summer months, Common Grackles, Redwings, and cowbirds may visit feeders in rural gardens and return day after day. While these birds are interesting creatures and are native to our area, blackbirds will quickly get old. A flock of redwings or grackles can empty a feeder in minutes, while preventing all but the toughest birds from visiting the feeders. Common and Boat Tailed Grackles also occasionally prey on small birds, while cowbirds are brood parasites that have a major effect on local bird populations if they are over populated. On the bright side, blackbird and starling flocks often contain oddities such as Rusty Blackbirds or Meadowlarks and in most cases flocks move on after a few days. Blackbirds love grains, corn, and milo/millet, although grackles will eat virtually anything and can make short work of expensive blends, and suet. The unrelated Common Starling is a rather uncommon bird table visitor with most visits occurring during the nesting season and targeting suet. House Finches, and Pine Siskins may overwhelm bird tables during the winter.  

Solutions and Tips 

• Redwings, grackles, and cowbirds are most likely to visit bird tables, ground feeders, or hopper/tray feeders in open areas 
• Avoid corn, milo, millet, or grain if cowbirds or grackles are in the area 
• Don't put too many birdfeeders up as an abundance of food will lure in flocks
• Cage feeders keep grackles, and most larger birds out of feeders meant for chickadees, buntings, or finches. 
• Provide grackles their own food station or increase natural food sources with native plants and trees 
• Common Starlings are rarely a problem in gardens and mostly visit during nesting season

Mockingbirds

Mockingbird at cage with table scraps 

Every garden has its group of bully birds with Blue Jays, Common Grackles, Red Bellied Woodpeckers, and even sometimes nuthatches, cardinals, orioles, or goldfinches being rather bullish at feeders. However, the most problematic garden resident is the Northern Mockingbird which is a resident in most gardens, parks, and roadsides from the countryside to the city center. When a mockingbird claims a bird table, it will chase off all other birds, even if it does not eat the food. Suet, mealworms, and fruits are likely to attract mockingbirds. Additionally mockingbirds can be aggressive towards people when they nest in dooryards. Despite their problems, these birds are interesting residents with complex songs, and voracious appetites for garden insects and snails. There is usually one pair of mockingbirds per garden. Ruby Throated Hummingbirds can also cause similar problems 

Solutions and Tips 

• Simply chase off any mockingbirds that come to the feeder (easier said than done), or give them a feeder of their own  
• There are no feeders that deter mockingbirds as they can easily hover, hang upside down, or exploit a mechanism. The only way to "prevent" mockingbirds is to not offer suet, fruits, mealworms, and forfeit the warblers, orioles, catbirds, and wrens that visit 
• Mockingbirds are less likely to visit feeders in open grassy areas or wooded gardens and cannot get into caged feeders
• Move feeders away from shrubs with mockingbird nests 
• Provide natural food sources such as fruit bearing shrubs to occupy mockingbirds   

Crows, Geese and Turkeys

Canada Geese (top left) are generally rare at feeders

 On rare occasions a bird table may be visited by Common or Fish Crows  while geese, and turkeys are primarily a situational issue. Most hanging feeders and caged feeders are difficult for crows to reach. Fish Crows can become a problem in urban gardens or areas near water and raid bird nests, and may be attracted to table scraps, corn, or nuts on the ground or a open tray. Common Crows are mostly in inhabit the countryside or live near forests and generally avoid people although they feed on lawns. Crows usually move between food sources and rarely stay in one area for long. Wild Turkeys and Canada Geese occasionally come to birdfeeders and the excitement will quickly wear off if they become regulars. Aside from emptying or knocking over food, large birds can overwhelm smaller birds while geese leave droppings and other mess. 

Raptors

Cooper's Hawk juvenile  

Cooper's Hawks will sometimes visit birdfeeders to prey on songbirds. These medium sized sparrowhawks are abundant in the Carolinas and often breed in parks and towns. While these birds are fascinating to watch and keep populations in check, a hawk at the feeder means danger to the visitors. A pair of hawks can ambush songbirds from shrubs or trees, taking birds from warblers to grackles. When a hawk frequents a bird table, it is best to take it down for a few days or relocated it to another area of the yard. Feeders located near woods, hedges, or shrubs are more likely to attract  sparrowhawks. The smaller Sharp Shinned Hawk occasionally comes to feeders, while the large Red Tailed and Red Shouldered Hawks are more of a threat to squirrels and rarely come to feeders.

Additional Avian Problems

Aside from the examples above, observers may notice some other problem birds at their feeders. While minor, some of these issues can lead to problems down the road. The main issues in this category include crowding, seed-throwing, and birds that are ill. 

Crowding Feeding stations that are close together may become overwhelmed by visitors, particularly during the winter. This is most likely to happen with finches, House Sparrows, and persistent blackbird flocks. The best way to reduce crowding is to spread out feeders, offer different types of food, and avoid feeder designs that provide ample perches. A small window feeder and suet cage like my setup has a lower chance  of becoming crowded than a feeder station with multiple tube and tray feeders on a pole. Overcrowding can lead to disease, and may deter shier birds like wrens, thrashers, or native sparrows from visiting. 

Disease: Poorly cleaned bird tables can become disease hotspots. Bird droppings, seed husks, and just the crowding of birds in a small area can cause diseases to spread across the visitors. Diseased birds often look sickly, lethargic, and often do not fly away when approached. It may sit on the feeders for hours on end. Birds with certain bacterial disease disease often have crusty eyes (notably House Finches and House Sparrows) rendering them unable to see. Sick birds may eventually die of their ailment, succumb to the environment or get preyed upon. Cleaning feeders with dish soap, or a mild bleach solution monthly is the best way to prevent disease, while reducing overcrowding, cleaning up waste, and discouraging House Sparrows and Red Winged Blackbirds are other solutions. If there is a sick bird, take down the feeders and discard the remaining food. After cleaning the feeder, wait a few days or weeks or set up the feeder somewhere else. Moldy or damp birdseed, corn, or peanuts, can become toxic to birds as it contains bacteria. 

Seed Throwing: An commonly overlooked problem at bird tables is the waste of food due to birds raking through feeders to get what they want. This is mostly a problem with nuthatches, woodpeckers, chickadees, Pine Warblers, and Carolina Wrens as they are after specific items. Seed-throwing birds may empty a feeder and leave seeds on the ground to germinate, attract pests, or mold. While there is no direct solution to prevent his behaivor, seed-throwing can be reduced by offering feeders with different foods, or switching to a tray or hopper setup. Most of our birds will toss out filler seeds from low-end mixes, while switching abruptly from one seed type to another may cause certain visitors to search for their old favorites. A tray under a feeder can be used to catch fallen or tossed seeds. 

Other Problems

Ants: Ants are sometimes a problem at bird tables during the summer months. While largely a minor issue, ants can ruin the value of the feed by eating the insides of seeds, while Red Fire Ants can pose a danger to adult birds and ground nesting species. Never use pesticides near bird tables as it will also sicken the birds. Nectar and fruit feeders will almost certainly bring ants as well as hornets, yellowjackets  and honeybees. Keep these feeders away from doors, sitting areas, and parking areas. For other feeders, certain ants may infest corn, sunflower seeds, mealworms, suet, and seed mixes with fruits in them. A little bit of food-grade diatomaceous earth (DE) in the seed mix will deter ants outside and prevent granary moths from hatching in stored food. Pure food-grade DE is not harmful to birds but cuts the exoskeletons of most insects that get in the food. Move ground feeders away from active fire ant colonies if possible as the food source will only bring more ants. 

Mold: Mold is a common issue in the Carolinas due to our warm, humid climate and sometimes rainy periods. Mold infestations can render food useless to birds as they will avoid it due to its taste or condition. Birds that do eat the food could become sick from the mold itself or bacteria that may also be present. Some sources say that decaying corn and peanuts could be deadly to birds and mammals. The best solutions to mold is to keep seeds and suet from getting wet, removing moldy food and cleaning the birdfeeders, and limiting the amount of food offered on the ground. Do not offer corn, shelled peanut, or table scraps on the ground in rainy weather. Once mold gets in the food  it will need to be discarded. 

These are just some of the problems that we could encounter while managing a birdfeeder or bird table. Proper sanitation, a right balance of feeders and foods, and the use of preventative measures can keep a birdfeeder set up running with a little maintenance. Problems at bird tables often affect the surrounding environment and bird populations.