The “fast food” that urban birds love and the healthier alternatives
Just like humans, birds have a sweet tooth that can throw their diets off-balance.
IT'S COMMON FOR city slickers to feed birds. Whether its ducks at the park or the sulphur-crested cockatoo that perches on your apartment windowsill, we act as 24 hour all-you-can-eat fast food restaurants.
According to Michelle Shaw, a nutritionist at the Taronga Animal Nutrition Centre, urban birds suffer far more than other birds as they’re made to cope with different kinds of disease and deficiencies caused by the conditions they live in and the “junk food” made easily available.
“Regardless of whether it’s an ibis or a lorikeet, these birds are perfectly adapted to eat their natural diet in urban areas. But now that they have all these different options their mechanisms are being disrupted,” Michelle tells Australian Geographic.
“These birds are a lot like humans. If we can get high energy foods, we’re going to eat that and we won’t stop eating it. Our bodies are telling us that for survival we should eat as much high energy things as you can because tomorrow it might not be available.”
It would seem that our own addictions to junk food aren’t all that different from the “junk food” now favoured by our beloved urban birds.
Favourite junk food: Hot chips and bread products
Natural diet: Insects, crustaceans, seeds and vegetation
Ibis are by far the most visible birds in most, if not all urban areas, often rummaging through bins or lapping up leftovers.
Michelle says that because the ibis is a generalist type of omnivore they basically eat anything. But now their “little slips” in their diets are causing them a lot of harm.
“They are adapted to eat high protein foods like insects so we don’t see it as much in ibis but the higher fat items, will cause fatty livers and liver disease.”
Michelle recommends properly disposing of anything that may attract the ibis.
Favourite junk food: Fruit juice, sugar sachets and mince meat
Natural diet: Nectar, pollen and blossoms
The biggest issue for rainbow lorikeets, Michelle says, is people serving them fruit juice. But, as urban sugar addicts, they’re also partial to stealing the sugar sachets off café tables.
“When they come to get fruit juice from someone, which is 90 per cent sugar , they’ll go to that because that’s where the sugar is and it’s an easy meal, rather than going to all the plants that naturally balance out their diet.”
A lorikeet’s natural diet is very low in protein meaning they are adapted to seek it out, which has, in some cases, turned them carnivorous.
“People will say ‘I put out meat for the kookaburras and the lorries pick it up’ and they’ll come back again and again because they know that’s a place where they can get a lot of protein,” Michelle says.
Instead, Michelle recommends planting the native, nectar rich plants that will attract lorikeets to your backyard so they can balance their own diet.
(Image Credit: Nicolas Jooris)
Favourite junk food: Peanuts
Natural diet: Seeds, berries and native nuts
The sulphur-crested cockatoo is one bird that would not turn down the complimentary packet of peanuts on a flight.
Michelle says that people feeding cockatoos peanuts and other nuts that are really high in fat make it hard for the bird to balance their diet.
“There are a lot of interactions between the nutrients that animals take in. If they take in a high fat diet they’ll need more vitamin E and without having that, which they won’t get supplemented anywhere else, it can cause a deficiency. These interactions between nutrients are important.”
Favourite junk food: Mincemeat
Natural diet: Small rodents, birds and lizards
Mincemeat to carnivorous birds like the kookaburra is what a late night cheeseburger is to humans — it’s easy to get and, without any bones, takes little effort to eat.
The diet of a kookaburra, however, is heavily reliant on a strict calcium to phosphorus ratio.
“Kookaburras are adapted to eat whole prey items and that prey package includes everything. When you feed them mincemeat you’re missing all of the bones that provide the kookaburra with calcium,” Michelle says.
“Metabolic bone disease is typical in urban kookaburras. If they don’t get calcium from a food source they’ll pull that calcium out of their bones in order to use it for other functions,” she adds.
Raw meat also poses a potential threat to the bird’s health.
"It could be contaminated and they’re used to eating fresh, living things that don’t tax their system with different contaminants.”
Michelle recommends avoiding feeding carnivorous birds altogether and instead, providing fresh water, which is far scarcer than food in urban areas.
(Image Credit: Richard Taylor)
Favourite junk food: Bread and more bread
Natural diet: Aquatic plants, seeds and grass
Feeding ducks by the pond, while a popular past time, has to stop, says Michelle.
“Bread doesn’t have the type of protein that ducks need; it’s just very high energy. They have a low energy, high fibre diet.”
Michelle says that when ducks eat too much bread they can grow too big for their skeletons.
“The best thing for a bird is to grow slowly and have very strong bones so they can support their really heavy wings.
“When the bodies of ducks and geese grow too big they get a condition called angel wings. You might see a bird in a park with a wing that looks twisted or is hanging at a weird angle. That’s something humans are completely responsible for.”
She also says that fruit shouldn’t be used as an alternative to bread.
“Our fruit is not a natural thing for them to eat. That high sugar item will do the same thing as the high starch items. It feeds the wrong microbes and causes acidosis, which will burn their intestines.
“If you’re going to feed ducks you need to get a bag of duck feeder because that at least will have some balance for them and it won’t throw their system completely out of whack. But make sure it’s not just a duck attractant.”