are grackles aggressive to other birds

What do they eat?

Common grackles primarily eat insects and other invertebrates during the breeding season. In addition, the diet might contain small frogs, salamanders, mice, goldfish, minnows, crayfish, and bats that are caught from the air. Common grackles consume mostly grains from farm fields and seeds, especially corn and acorns, during migration and the winter. They also eat some fruits.

As opportunistic foragers, common grackles exploit any food source that they come across. They frequently follow plows, grabbing the plowed-up grubs and even consuming human waste. Adults sometimes steal earthworms from robins. Grackles primarily forage on the ground, though they can also look in trees and shrubs for food. They feed in large flocks, especially in winter. When grackles look for food on the ground, they use their bill rather than their feet.

Common grackles have not been seen drinking water. They may get enough water from the foods they eat. (Peer and Bollinger, 1997; Terres, 1980).

Primary Diet
carnivore
- insectivore
- eats non-insect arthropods

Animal Foods
birds
mammals
amphibians
fish
insects
terrestrial non-insect arthropods
terrestrial worms
aquatic crustaceans

Plant Foods
seeds, grains, and nuts
fruit

Where do they live?

Almost all of eastern North America east of the Rockies is home to common grackles, which during the summer breeding season also extend far into Canada. (Terres, 1980).

Biogeographic Regions
nearctic
- native

How do they reproduce?

Sometimes, adult common grackles assist other birds in their species. In one instance that has been documented, there was no hostility between the two males when they regularly visited the same nest to feed the young. One of the men is thought to have been the child’s father. (Peer and Bollinger, 1997; Skutch, 1996; Terres, 1980).

Common grackles are usually monogamous. Males and females form breeding pairs in early spring. Potential mates fly together and perform displays for each other. After forming a breeding pair, a male and female take off from the flock and fly together to sing.

The female usually chooses the nest site. She typically does this after finding a partner, though occasionally she selects a location in advance. The male remains extremely close to his mate after they form a breeding pair. He’s never far away, perching next to her, trailing her, and flirting with her. It is likely that males take this action to stop other males from mating with their partner. But after the eggs are laid, males typically stop protecting their partners. (Peer and Bollinger, 1997; Terres, 1980).

Mating System
monogamous
cooperative breeder

Common grackle nests are built by the female. They are typically found in coniferous trees, but they have also been discovered in osprey nests, woodpecker holes, rafters, under barn eaves, and in cattail clusters. The nests are large and bulky. They are lined with mud, fine grasses, and horsehair and composed of woody stems, leaves, and fine grasses.

The moment the nest is finished, the male and female start copulating. The female typically lays between five and six eggs. Smooth and typically light blue to pearl gray in color, the eggs While some are immaculate, others have blackish brown stains, particularly near the larger end. The female incubates the eggs for 12-14 days. A pair’s male and female communicate with one another during incubation by making calls and putting on displays. Many males leave their mate during incubation and do not come back to assist in caring for the young.

The majority of common grackle females raise their young alone, though some males assist. When the chicks are young, the female tends to them and provides food. After hatching, the chicks spend one to two days near the nest before leaving it after 12 to 15 days. After the chicks leave the nest, the parents continue to feed them for a few weeks.

Common grackles breed between March and July. Though some may raise two broods, most common grackles only raise one brood of chicks annually. (Peer and Bollinger, 1997; Skutch, 1996; Terres, 1980).

How often does reproduction occur? Common grackles breed once yearly. Common grackles typically have one brood, however in certain places they may have two.
Breeding season

Common grackles breed between March and July.
Range eggs per season

1 to 7
Average eggs per season

5
Average eggs per season

5

AnAge
Range time to hatching

12 to 14 days
Range fledging age

12 to 15 days

During incubation, about half of all grackle males depart from the female and do not come back to assist with caring for the chicks. The remaining males stick with the female and assist in taking care of the chicks.

When the chicks hatch, they are eyes closed and defenseless (altricial). The majority of the chicks’ feeding and caring is done by the female. However, males have been seen helping to feed the young. After hatching, the chicks depart the nest between 12 and 17 days later. For a further day or two, they remain close to the nest. After the chicks leave the nest, the adults continue to feed them for a few weeks until they are able to feed themselves. (Peer and Bollinger, 1997; Skutch, 1996; Terres, 1980).

Parental Investment
altricial
pre-fertilization
- provisioning
- protecting
  - female
pre-hatching/birth
- protecting
  - female
pre-weaning/fledging
- provisioning
  - male
  - female
- protecting
  - female
pre-independence
- provisioning
  - male
  - female

FAQ

Do grackles bully other birds?

Grackles are also aggressive in nature and can exhibit violent behavior towards smaller songbirds, raiding their nests and even killing adult birds, most of the time House Sparrows. Flocks of grackles can eat feeders clean in minutes, wasting your bird seed and discouraging your regular feeder visitors.

Do grackles chase other birds away?

When the grackles come in, it chases most of the other birds away. Most of the grackles have learned by now that the squirrel-proof feeder demotes them to harvesting the spillover from the smaller birds.

Are grackles good birds to have around?

But they control insect populations, and a lot of those insects are harmful to plants, she says. And they fit into the food chain well they eat things and things eat them. Grackles serve as prey food for other valuable creatures, including foxes and hawks. And their behavior is interesting to watch.

What is the problem with grackles?

Grackles often invade fields and parks in huge destructive flocks. They will drive out other species and take over an area, creating excessive noise, leave damaging and disease-carrying bird droppings in their wake.