Co-operative breeding is not restricted to birds, but mammals, amphibians, insects, arachnids, and fish also breed in this way. In this article, we will look at what co-operative breeding is and why some birds do it.
Co-operative breeding where other birds help raise chicks that are not their own. The helpers are usually the offspring of the adults that may assist in bringing food for the adults and chicks, building a nest, or helping incubate the eggs.
If you want to know more about co-operative breeding, please read on.
What is co-operative breeding?
Co-operative breeding is a system where a pair of birds is helped with incubation and rearing their chicks by other birds of the same species. Co-operative nesting birds usually move around in groups and are very sociable.
In the example of singular breeding, one pair of the group becomes the dominant pair and starts to breed. Others in the group do not reproduce to assist in raising the young of the breeding pair. Members of the group may help build the nest, incubate the eggs, and bring food for the young and the adults.
Not all species will do everything. Some will help build nests but not incubate, while other species will only assist with feeding the adults and the chicks.
Not all co-operative breeders have just one pair that will mate, as some will have two pairs. The females may lay their eggs in one nest or separate nests, depending on the species.
The number of helpers depends on the population density and the species. Some may only have one helper, while other species may have over ten helping them raise their chicks.
While some species are known as co-operative breeders, they may not do this all the time. Other adults in the group will generally help with duties around the nest. However, juveniles sometimes stay around after fledging to help raise the next generation.
Co-operative breeding depends on the population density. If there is a low population are not many birds are within an area, they may try to establish a pair territory instead.
The European Bee-eater is unique as all birds will breed in pairs at the start of the season. If the nesting attempt fails, the birds will try to re-lay their eggs. If they can’t, then they will help raise other pairs of chicks.
Most communal breeding birds can be found in Australia, Africa, and tropical regions. Most co-operative breeding species can usually be found in the same territory all year and in warmer countries. Co-operative breeders do not normally migrate.
Many species feed on insects found on the ground, making it easier to find food. Dry woodland is where most co-operative breeders make their home because the habitat doesn’t change much during the year in warmer areas.
About 3% of all bird species are known to be co-operative breeders, although they may also use other breeding systems as well.
There are two types of co-operative breeders, colonial and territorial. Territorial species typically occupy larger territories, while colonial breeders breed close together but have much smaller territories.
Advantages and disadvantages
Because more birds raise the young, the chicks have a higher chance of survival. More birds mean that their chance of predation is lower, while the chick should not go hungry as more than one adult brings in food.
Because co-operative breeding is limited to one pair in the group, not all birds will get to breed. While this may seem detrimental to the species, putting all their efforts into raising one brood at a time gives them the highest mortality chance.
For co-operative breeding to be successful, there needs to be a minimum of five or six birds helping to raise the young.
Many of the other birds that help the breeding pair are their offspring that have not gone their own way. The offspring may be one or two years old, but sometimes older. This raises the chance of survival of the chicks and helps the alpha pair, but it does mean that their offspring won’t have an opportunity to breed themselves.
By staying part of the group, they increase their chance of survival against predators and finding food. Raising their siblings is a better way to pass on their genetic material. Siblings share more of their genes than they do with their parents. Raising their brothers and sisters has more chance of their genes reaching future generations.
The offspring of the alpha pair may inherit the area when the parents die, but they can also look at other nearby areas to make their own territory.
Co-operative breeding is usually carried out by birds that are related. Most of the helpers are males, not females. Females are more likely to try and mate and will fly to another area, but as there are not as many free areas or females around, they are more likely to stay and help.
If one of the males leaves after assisting with raising their siblings, they will be at a greater advantage than other males. The knowledge they have gained in parenting will help them when they find their own mate and can even assist them in finding a mate.
Although co-operative breeding has its advantages, most birds that use this system would still be able to breed successfully independently without help.
Breeding is often delayed for a year or two so that their offspring can grow to an age where they can help raise the next generation. Delayed breeding also occurs because of limited numbers of territories or lack of food or females, and these are the main reasons the offspring stick around to help their parents raise their brothers and sisters.