Birds need to keep their nests clean to stop parasites and debris from building up. A clean nest is essential for the survival of their chicks.
Most birds keep their nests clean to avoid predators and stop parasites from attacking their young. Adults will often defecate outside the nest while young birds of many species use faecal sacs that stop the waste from seeping into the nest.
How birds keep their nests clean depends on their species, where they make their nests and the age of their young. In this article, we look at all of these.
Nest construction and laying eggs
Sanitation starts when the birds start using the nest before the eggs even being laid. At this stage, it is relatively easy to keep the nest clean. Faeces are not really a problem for the adults as they will go over the side of the nest.
However, birds may have to deal with mites, fleas, lice, and other parasites clinging to their skin and feathers. When it is warmer, most birds breed during the summer months, and parasites are likely to enter the nest.
Ground-nesting birds have visitors such as small lizards or snakes as well as many insects. Once the eggs are laid, the parents are more active in keeping the parasites under control.
Many birds dust-bathe to minimise the number of parasites. As well as getting the parasites off them and keeping them in good health, the dust-bath also stops parasites from getting into the nests.
Cleaning the nest after the eggs hatch
The real cleanup starts once the eggs hatch, as this is where the mess begins. Although most of the fluids and membranes that come out of the eggs are absorbed by the nest lining, they soil the nest.
However, the major cleanup is removing the shells. This is quite easy for the adults as they remove them and drop them away from the nest. If this isn’t done quickly enough, the eggshells will attract predators with their scent.
Ants can often be seen taking over an entire nest from birds if the shells are left, and the scent can encourage snakes and larger mammals to find the nest.
Not all birds remove the shells from the nest. Some will crush it and feed it to their nestlings, such as blue and wattled cranes. Others, such as some owls, will eat the shells for a nutrient boost.
Once chicks are born, many have their first few days waste collected into a faecal sac. The faecal sac allows the waste to stop flowing into the nest, eliminating any scent that could cause predators to find them. Faecal sacs act as a bird diaper.
The faecal sac is gelatinous is made from a digestible protein mixture. It allows cleaning to be more efficient and improve hygiene in the nest.
Uric acid combined with the faeces dries to a white residue making the nest easy to spot from predators. Passerines are most vulnerable for the first few days and the faecal sacs help them keep them safe.
The faecal sacs are sometimes put in the nest by the chick, or the adult pulls it off after defecation. This is usually after the prodding of their cloaca has stimulated the young from their parent.
Some species will eat the faecal sac for nutrients while also cleaning the nest. Quailfinches, seedeaters, and the mountain wheatear can often be seen eating the faecal sac. The vital nutrients in the faecal sacs can give the parents much-need replenishment while rushing around to care for their young.
Not all species have faecal sacs, but the parents may still eat the faeces to clean the nest. However, many species will remove the faecal sacs from the nest and drop them somewhere. Bush chats often place the faecal sacs in one spot outside the nest in a neat pile.
Birds that use the same nest for successive breeding usually have chicks that use faecal sacs in the nest.
Birds that don’t clean their nest
While many bird species practise good hygiene to stop parasites from getting into the nest and attracting predators, some do not.
Kingfishers, bee-eaters, fire finches, and waxbills are some species that do not practise good hygiene. They will defecate in the nest or tunnel they have made home.
The smell can make predators think twice about coming close and is a deterrent. Doves hold their nests together using their faeces, while cormorants and gannets use guano to help them construct their mounds.
These can often be smelt from quite a way away due to the overpowering ammonia smell. Guanine comes from the fish they eat and is contained in the skin and scales.
While some large raptors do defecate over the side of their nests, the large whitewash on the tree or cliffside below can still attract parasites to the nest.
Should you clean birds nests out after they have gone?
If you have a birds nest in your garden and you are sure that the birds have gone, then you may want to know if you should clean it out.
While most birds won’t reuse the same nest, some will. Parasites may still be in the nests so that you can help out the next generation of birds. Birds will often clean out the nest themselves, but you can help them if you want.
Be careful, though. Bird nests can be dangerous to your families health. Nests often contain faeces which can have all sorts of bacteria. Nests can also contain parasites as well as ticks and mites.
Once you are sure they have left and are no longer coming back, you can remove the material inside. Scrub the inside with water and a mild detergent. If there are faeces in the nest box, clean the box with a solution of 1 part of bleach to 10 parts water.