Ecology

The life of a bird

Danny Stoner
Strawberry Hill Nature Preserve

(4/2020) April is a month that is high in activity for animals and plants. Animals are migrating back from their southern homes during the winter, waking from hibernation, or hatching from eggs while others are already setting up their territories for breeding. Flowers are blooming and buds are breaking to prepare for the next season of growth and seed production. To aid in the seed production, plants are producing pollen for fertilization. Insects who are attracted to the sweet taste of nectar, which is produced at the same time as pollen, are drawn to the plants to carry the pollen sitting at the front of the flower waiting to get picked up and carried from plant to plant.

Plants are not the only thing the congregation of insects help. Birds benefit from these insects. Some birds are insectivores who rely on insects for a food source, such as swallows and flycatchers, while others use them to feed their young. Many songbirds feed young with caterpillars because they are packed with nutrients that the hatchlings need to grow. However, some species of birds do not use caterpillars or other insects to feed their young. Birds such as mourning doves produce crop milk, a fluid that is formed from the crop and the nutrients gained from the parent, to feed their young.

Birds are not the only animals that benefit from insects. Insects are eaten by amphibians, reptiles, fish, and small mammals. Amphibians such as salamanders enjoy smaller insects like springtails and crickets who hide under logs and rocks just as salamanders do. Reptiles such as lizards feed on insects including crickets, beetles, beetle larvae, and spiders. Some species of fish also include insects in their diet. Pumpkinseeds, a member of the sunfish family, often eat insects and their larvae. Insects are the base of most animals' diets and the start of the food chain after plants. Other than eating insects, all these species have another thing in common, they are prey for some birds.

Reptiles and amphibians are prey for some species of hawk, such as the Red-shouldered Hawk, and Herons, such as great blue herons. great blue herons also feed on fish and feed their offspring fish. Fish are also prey for some birds of prey, such as osprey and bald eagles. However, most birds of prey diets consist of mammals. Owls, hawks, falcons, vultures, and eagles consume a variety of mammals. Owls, hawks, and falcons typically prey on smaller mammals such as mice, voles, squirrels, and rabbits. Vultures and eagles feed on larger mammals that are deceased, also referred to as carrion. Birds of prey are not the only birds that feed on mammals. Shrike, a species of passerine, or songbird, prey on small mammals, such as mice. They do not have talons to kill their prey, so they will drop it on a sharp object like barb wire or a thorn on a locust tree to restrain them and kill them.

Birds have a large variety of prey items from berries to dead mammals and play a large role in the ecosystem. They control the populations of species, help clean the environment of decaying animals, and spread seeds to diversify different habitats. Hunting, scavenging, and foraging is only a part of a bird’s life. Migration, setting up a territory, finding a mate, building a nest, and taking care of their young are the other parts of a bird’s life.

Migration is a large quest for some birds, while others are residents and do not migrate. Migration is one of the most dangerous events for birds, killing billions during the fall and spring. The birds that make it must set up their territory. Usually the first to arrive are the males. Red-winged blackbirds are an example of this. The males arrive well in advance to display and sing, to defend and set up territories in wetlands, marshes, and meadows.

Territory is everything for a bird. It is not just a patch of land that represents a territory; it is the resources that it holds. The best patches of land have plenty of food, water, and places to build a nest. For some birds a nest is a cavity in a tree, a woven basket, or a small cup made from spider web, twigs, and plant matter. Some species do not even build a nest. The Brown-headed cowbird is a brood parasite, which means it lays eggs in other bird nests and lets them care for the offspring. Care for offspring is a high demand for birds that takes both parents. Without both parents, the task of defending its territory and feeding the young is almost impossible and almost always results in a failed clutch or the death of an adult.

There are two different types of offspring. There are altricial chicks and precocial chicks. Altricial chicks are laid by songbirds and are underdeveloped, being born featherless, unable to move a lot, and need a lot of parental care. Although they are born without feathers, they develop and fledge within two weeks to a month for most altricial species. However, the care for a precocial chick is a bit different. They are born to species such as waterfowl and shorebirds with feathers and can move around. They do not take as much parental care as altricial chicks. Precocial chicks can forage on their own with the help of their parents. However, the tradeoff is a longer time to fledge. Precocial chicks can take months to fully fledge. The downside of altricial chicks is a lot of energy spent caring for them, but a positive is shorter care time meaning they can have several clutches. The downside of precocial chicks is the long-term investment of the parents and the lack of being able to have as many clutches, but the positive is a lower energy output by the parents causing less stress.

The demands on a bird’s life is a lot. They do not have to study for tests or pay bills, but they make up for that through the effort that is needed to migrate, breed, and raise young among other tasks. As they work hard, we can enjoy their beauty. April, and the months around it, are prime time to go bird watching. At this point, songbirds, birds of prey, and other species are migrating north from their winter homes down south to their breeding grounds up north. If you are interested in getting out to bird the best time for songbirds is earlier in the morning when they are setting down from their long flights at night. Depending on the species you are looking for, a riparian corridor or an un-mowed grassland would be a great place to start. If you want to look for something larger like birds of prey your best bet would be on a warm afternoon on a ridge waiting for them to migrate by or near a farm field bordered by woods to watch them hunt for prey. The most important thing when searching for a bird is knowing their habitat and food source. If those two things are not around then the bird will not be either.

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