This information is posted with the permission of its authors
- the Wildlife Rescue League, Falls Church, VA

More about Birds.........

Altricial Birds

Altricial birds are hatched totally dependent – not feathered, unable to walk, and unable to feed themselves. Songbirds, crows, pigeons and birds of prey (raptors) are altricial. The mother birds, after the nest is completed, lay an egg a day over several days. They start sitting on (brooding) the nest when the first egg is laid. Eggs are rotated by the parent several times a day. In some, but not all species, the father also helps with nest-tending (and later baby-rearing) duties. Because the eggs are laid at different times, they also hatch over several days. A nest may contain babies of varying ages, with some that are still highly dependent and an older bird that is ready to leave the nest. The mother bird will continue to brood the nest until the babies have developed feathers and are able to maintain their body temperature.

Many altricial birds – mockingbirds, cardinals, woodpeckers, and hummingbirds for starters – are territorial, particularly during mating and baby season. This is one reason they tend to crash into reflective surfaces such as windows when they see their reflection; they are trying to chase away an intruder. Mockingbirds will chase away cats, dogs, or humans who get too close to the nest. Crows will gang up on and chase away birds of prey that venture into their roosting area.

Nestlings are young altricial birds who still cannot eat on their own; their beaks are not fully formed, and they cannot walk, hop, or fly. They have no or just a few feathers or pinfeathers. The parents feed them in the nest and remove fecal sacs containing their eliminations. The older and more feathered the baby bird becomes, the less often the parent is sighted, and the quieter the babies are. When approached, the babies will get down and remain still and quiet. The parents zip in and out very quickly to feed. If the babies look healthy and the nest is clean, they are being cared for, even if the parents are not seen. If the babies do not seem to be in good condition, and/or the nest has a build-up of droppings, the caller should be referred to a rehabilitator.

Survival and development of a normal nestling depends on receiving the parent’s saliva and immunities with its food during the first 2-3 days of life. Rehabilitators cannot duplicate the mother’s immunities and babies who are brought in that young rarely survive. We do not recommend attempting to hatch abandoned eggs because of this experience; another reason is because it is very difficult to duplicate the optimum hatching conditions for the eggs – temperature, humidity, and rotation schedule.

Nestlings can fall out of the nest for a variety of reasons – predators, storms, or overcrowding of the nest. Adult birds cannot pick up and renest their own babies – an adult bird that picks up the baby is a predator. We advise callers to attempt renesting as long as the parents are still around, but if renesting is not successful the nestlings must go to a wildlife rehabilitator.

Fledglings are older birds who have fledged – that is, left the nest. They have feathers, short tails (1/4-1/2"), and can walk, hop and fly a little. They can cling to a branch in a bush. They do not fly out of the nest – they jump! Once on the ground, the parents care for them for several days while they learn to identify and pick up natural foods, recognize predators, and develop the strength and tail feathers to fly. In a normal fledgling situation, the bird is not particularly anxious to be caught and will attempt to run away. One or more parents may be seen anxiously hovering nearby and calling to the baby. Fledglings are particularly vulnerable to being caught by cats and dogs; encourage callers to keep their cats and dogs inside until fledglings have become flighted. It is not appropriate to rescue fledglings simply to keep them away from cats and dogs, as they will develop much more slowly with a rehabilitator than with their natural parents.

Sometimes an adult bird has been caught by a cat or other predator and had its tail ripped off, and may be confused with a fledgling. The entire situation (season, behavior, whether or not parents are around) needs to be considered. However, if it is known that the bird has been in contact with a cat, it needs to automatically go to a rehabilitator regardless of its age.

Raptors (birds of prey) are birds who catch their prey in talons rather than using their beaks. They include eagles, hawks, falcons, owls, vultures, and osprey. Owl fledglings are called branchers because they sit on a branch to be fed by their parents. In some species, the parent will not feed the baby if it is on the ground. If an owl is found on the ground, a rehabilitator should be contacted immediately.

Precocial Birds

Precocial birds (goslings, ducklings, and killdeer) are slightly more independent when born. They are down feathered (but not yet waterproof) and able to walk, and are self-feeding. However, they are still dependent on a parent to teach them to identify appropriate foods and necessary survival skills, protect them from predators, and teach them migratory patterns. (However, many of these parents do not migrate, and therefore their offspring do not either.)

Common precocial birds that breed in our area are Canada geese, mallards,  and killdeer. Precocial birds lay one egg a day for 10-12 days (depending on the species). They begin to sit on the nest (brood) after the last egg is laid. The brooding period is up to 30 days. Chicks will all hatch within a few hours of each other; mother will frequently continue to brood for up to 12 hours after the first chick is hatched. When they all hatch, the mother will lead them to water (except killdeer), where they can eat. For one to two days she will also lead them back to the nest at night.

Ducklings and goslings are subject to predation by a variety of animals, including large birds, skunks, raccoons, opossums, rats, and snapping turtles. We do not interfere with this process unless the babies are orphaned. It is normal that only one baby out of ten survives.

Because of their tendency to build nests in what are considered inappropriate places by humans (on median strips, on top of parking garages, in parking lots, in formal fountains) many of the hotline calls on ducklings and goslings concern obstacles parents face getting the babies to water after they are hatched. Mother and chicks often have to cross busy streets to get to water; sometimes babies fall through storm drains, grates, etc. Wood ducks build their nests in trees and after hatching mother and babies jump to the water below; if a baby hangs back it may be left behind.

During the movement to water one or more babies can get separated from the parents. Canada geese will adopt/foster any Canada gosling, but mallards and other ducks will reject and even kill a duckling not their own. If there is an attempt to reunite a baby with the parents, the person trying it must keep close watch to make sure the baby is accepted. Newly hatched goslings/ducklings are not waterproof yet and should not be placed in the water.

Killdeer tend to build their nests on gravel, parking lots, and rooftops. A killdeer mother protects her nest by leading predators away with her "broken wing" act. A killdeer nest is merely a shallow cup of dirt on a bare patch of brown. The nest will contain four eggs speckled with brown and black spots, which hatch about four weeks after being laid. The nest is frequently in a vulnerable place, and while it should not be moved, putting up barriers, etc may protect it. Killdeer babies usually come into rehabilitation when they are found running around on the ground and are mistakenly thought to be orphans. Killdeer are extremely hard to raise and every effort should be made to return them to their parents.

One common concern about Canada geese in particular is a goose with a "broken wing". This is difficult to diagnose from a distance because it may actually be "angel wing", a condition caused by poor nutrition, or it may be an old broken wing injury that healed improperly. In either case, there is little that can be done as long as the bird otherwise appears in good health. There are also many calls about Canada geese that are limping, or have a broken leg. Again, as long as they can fly there is little that can be done, and most of these conditions will heal spontaneously.

Some waterfowl, particularly ruddy ducks, grebes, coots, and loons, are unable to walk on land and must be on water to take off. They may land on wet pavement thinking it is a body of water, and if uninjured need to be transported as quickly as possible to an unfrozen body of water large enough to serve as a runway. These calls should be referred to a rehabilitator.

Bird Habitats and Nesting Habits

Many times it is the nesting habits of birds that get them in trouble or at least raise questions with homeowners. For instance, starlings and house sparrows (being cavity dwellers) are attracted to dryer and stove vents and sparrows also to gutters. They may also nest high up in chimneys or even in attics. Starlings are able to slip under vent flaps and build nests inside the vent if the vent is not covered with screen. Most calls about birds trapped in vents are really birds that have built nests there and are not trapped. Occasionally a bird or nest may slip too far down in the vent and becomes trapped.

Woodpeckers generally nest in old tree cavities. When the nesting areas disappear because the trees are cut down, they will find or create other cavities – such as pecking into wood siding – to nest in.

Chimney swifts can only build their nests deep inside tall, silo-like structures. Their primary nesting sites, old growth forests, have been virtually destroyed and they have no alternative but to nest in brick chimneys. They make a nest of saliva and sticks on one side of the chimney. The nest often falls down, or if the damper is not closed, a baby may fall out of the nest and onto the floor of the fireplace. Chimney swifts cling rather than perching, so they are easy to renest, and the parents will continue to come down into the chimney to feed them. The babies make a chattering or hissing noise when disturbed or begging for food which is sometimes mistaken for rats, bats, or even snakes.

Cowbirds do not build their own nest or raise their own young. Instead, they find a nest with eggs and throw out one or more of the other bird’s eggs, laying their own there. The other mother – sometimes a sparrow or finch – accepts the cowbird baby and struggles to feed and raise it. Many people are perplexed watching a bird feeding a baby three times its size.

Back Yard Feeding

Back yard feeding can be both helpful and dangerous to birds. Many people feed in the winter and pull the feeders in the spring, but seed can be very helpful to birds in the spring and early summer when natural foods are still scarce and their babies are making great feeding demands on them. Natural foods become much more plentiful in the late summer and fall, and people may become concerned because the birds disappear from their yard for days or weeks at a time. The birds will return when the natural food is gone!

During winter, if there is an unusually cold spell, birds who normally use the feeder may also disappear because they have made a short migration to a warmer location.

In addition to feeding, it is important to provide a fresh water source (not ice) year-round, but particularly during droughts or when the temperature is below freezing.

When a person commits to feeding birds, it is important to use a good quality seed and keep the feeder and surrounding area clean. During warm winters, when the ground never freezes, salmonella can flourish in the soil under the feeder, and salmonella outbreaks in birds have been reported in several parts of the country. Spoiled food can also kill birds; during hot weather hummingbird feeders need to be cleaned and refilled every 2 days. Finally, the flocking of birds at a feeder can spread disease – conjunctivitis is an eye disease of sparrows and finches that is spread at feeders. Proper feeder maintenance and pulling feeders at the first sign of disease is important to maintaining a healthy bird population. See additional information in this manual on feeder sanitation guidelines recommended by the US Fish & Wildlife Service.

Back yard feeding potentially attracts other birds and mammals, including squirrels, rats and mice, crows, pigeons, and birds of prey. Many callers are concerned about a hawk at their bird feeder. There are only two options in this situation: try to understand and enjoy nature’ s plan (hawks only are successful in capturing prey one attempt in ten), or pull the feeder until the hawk moves on.

Migration

Migration is an extremely difficult time for birds and leads to reduction of the population. Some of the calls we get during the migratory period come because the bird is exhausted, hungry, disoriented (flying into building or being caught by cat while searching for food) or blown off course by storms.

Human-Caused Problems That Endanger Birds

Humans unwittingly cause many of the problems that afflict adult birds. US Fish & Wildlife Service is interested in human-caused deaths of protected birds, even when they are an accident. Some of the horrible human-caused problems that must be immediately referred to a rehabilitator include birds caught on mouse or insect pest strips; oil-covered birds; birds covered with a "sticky" substance (Roost-No-More or other nuisance bird repellents which are sold as non-toxic but cause death through secondary problems such as blocked respiration or inability to fly and escape predators); birds poisoned by toxic lawn chemicals which they mistake for seeds; birds shot by guns, BB guns or arrows; and birds burned by attempts to smoke them out of a fireplace.

Trash is also a problem for birds, as there are many calls about birds caught with fishing line or hooks, string and other substances built into nests, and six-pack rings. In general, if the bird is still flying or a waterfowl can escape by swimming away, it is almost impossible to do anything to help it until it becomes so weakened it no longer tries to escape.

Finally, there are deliberate attempts to poison non-protected species, particularly pigeons; these seem to occur primarily in the fall. Poisoned birds are generally weak, show no visible injuries, and may be trembling or having convulsions. Death is almost always inevitable. Corn is usually baited to poison them, and corn can often be found in the crop of the poisoned bird. While we not only consider this poisoning inhumane, there is also frequently unintended poisoning of other protected birds or other mammals in the area. In addition predators which may feed on the pigeon carcasses can be secondarily poisoned.

Banded Birds

Except banding of pigeons, all wild bird banding is done by permit from the US Fish & Wildlife Service. Banding is done for a variety of reasons, including tracking the results of rehabilitation and release, collecting data on specific populations, and reflecting ownership of a falconry or educational bird. In our area, banded swans are occasionally found who are part of the Airlie Institute study. If a banded bird is found, dead or alive, it should be reported to the Patuxtent Wildlife Center.

Although most bands are metal around the leg, geese in this area occasionally wear bands around the neck (these look like Elizabethan collars and one caller thought the goose had a styrofoam cup). These bands are also USFWS-authorized and must not be removed without Federal permission.

Banded pigeons are generally privately owned birds that are kept for pets or racing. "Fancy" pigeons are bred for appearance and may not be flighted. Racing pigeons are frequently blown off course during a storm and are unable to care for themselves unless they join a flock of feral (wild) pigeons. If the pigeon is weak, emaciated, or seeks assistance from the caller, it needs help. If the caller wants to try to find the owner, there are sources to contact. However, in most cases it is best to refer the call to a rehabilitator who will attempt to restore the pigeon to health and find it a home. Many times the owner does not want the pigeon back.