During his research, Fitzsimons kept in mind a current increase in reports of raptor frugivory. “In the last years, there have actually been several more records from various species, especially from Central and South America.” He says its possible that frugivory, though not common, occurs more frequently and in more raptor species than previously understood.
So the next time you identify a raptor feeding, remember. Its a long shot, but you just might see a bird enjoying an uncommon fruit snack.
Black kites are usually scavengers, eating garbage, offal, and carrion, though they will likewise hunt little mammals, birds, reptiles, frogs, insects, and fish. Whistling kites (Haliastur sphenurus) have a comparable diet, but are more likely to hunt than scavenge their prey.
Fitzsimons found that frugivory had been observed in black kites only in the savannas of central Ivory Coast in Africa, where the birds were observed consuming oil palm fruits.
” Black kites are all over, and they eat nearly anything,” states Fitzsimons, “so its rather interesting that this behavior hasnt been documented anywhere else, besides Africa, for such an extensive types.”
He includes that northern Queenslands black kites could be the most continuous fruit-eating raptor population throughout the world, other than for the palm nut vulture (Gypohierax angolensis), an African species that focuses on fruit consumption.
A palm nut vulture above the banks of the River Gambia. © Allan Hopkins/ Flickr
Frugivory Around the World
Fitzsimons evaluation found 29 raptor species that dabble in frugivory, including the 2 kites. The palm nut vulture is a fruit expert, delighting in the same species of oil-rich palm fruits grown commercially to produce palm oil.
Carrion-eating types, like vultures, tend to prefer decomposing vegetables and fruit matter. For example, turkey vultures (Cathartes aura) often scavenge decomposing veggies and fruits, consisting of palm fruits, pumpkin, grapes, coconut, cottonwood bark, and juniper berries. Black vultures (Coragyps atratus) have been observed consuming bananas, avocados, copra, sweet potato, rubber tree fruit, and oil and royal palm fruit.
A crested caracara. © José Tadeu Fischer/TNC Photo Contest 2019
Crested caracaras (Caracara plancus) are recorded eating beans, peanuts, palm fruits, pecans, pequi fruit, coconut flesh and dried copra. Fruit is also listed in the diet of swallow-tailed kites (Elanoides forficatus), although the particular types arent pointed out.
Chimango caracaras (Milvago chimango) will eat edible fungus, amongst many other kinds of veggie matter. Ospreys in the Canary Islands have been recorded consuming green algae (not a fruit, but still odd). European honey-buzzard (Pernis apivorus) will eat berries, and the common buzzard (Buteo buteo) has been observed consuming dessert apples and cranberries.
A European honey buzzard (Pernis apivorus). © Ssprmannheim/ Wikimedia Commons
Why exactly do some raptor species get a bit experimental with their diet?
In the case of the black and whistling kites in Australia, Fitzsimons and Leighton believe that the boom-and-bust nature of prey species has something to do with it. Kite populations can take off during wet years in inland areas when there is an abundance of rats to feed hungry chicks. However as those birds mature and move across the nation, that increased population requirements more food than typical to sustain them.
Get in the avocados, which are abundant in lipids (fats) and can offer substantial caloric energy. Its significant that oil palm is the most typically consumed fruit by raptors, as they are also high in lipids.
The kite circles low over the avocado orchard. Travelling above the trees, it scans the ground for its next meal. It drops to the ground, talons clutching a little, dark object.
Its not a rat. This hawk is feasting on an avocado.
We believe of raptors as exclusive predators– searching whatever from fish, to bugs, to mammals, to invertebrates, and even other birds.
Bald eagles and ospreys take fish from the waves. The snail-kite eats, well, snails.
And the birds of prey that do not hunt scavenge carrion from the roadside or carcasses from other predators.
And yet, the natural world has lots of surprises.
A brand-new paper from Australia documents the first instance of frugivory, or fruit-eating, in black kites and whistling kits in Australia. The researchers likewise report that a minimum of 29 types of raptor likewise turn to fruit for supplemental food, based upon a worldwide evaluation of raptor habits.
Black kites feeding on fallen avocado fruit near Mareeba, Queensland. © Jack Leighton
Insects with a Side of Avocado
The black kites chocolate-brown plumage and distinct, fork-tailed shape is a familiar sight for birders outside of North and South America. The types, Milvus migrans, is extensive throughout Africa, Asia, Europe, and Australia.
” Theyre probably the most abundant raptor on the planet,” says James Fitzsimons, a professional birder and the director of conservation and science for The Nature Conservancy Australia.
Current price quotes of the black kite population hover in between 1 and 2.5 million birds, although their numbers can differ widely from year to year based upon victim abundance. In some areas they gather together in substantial numbers, skyrocketing by the hundreds or thousands over trash dumps in Delhi, farming fields pestered by insects, or, in this case, Australian avocado orchards.
In 2002, north Queensland wildlife guide and periodic fruit picker Jack Leighton noticed black kites feeding upon avocado fruits in business orchards. Flocks of kites gathered around the trees, stroking down to consume near-rotten fruit that had actually fallen to the ground after harvest.
An industrial avocado orchard near Mareeba, Queensland. © Jack Leighton
Leighton observed this behavior more than 100 times over the next 10 years, occasionally seeing whistling kites feed on the fruits. The birds seemed to have a distinct choice for the sheppard range of avocado– rather of the haas range– maybe due to the fruits thinner skin.
After taking a look at the clinical record, Fitzsimons understood that this was the very first documented evidence of raptor frugivory in Australia, as well as the first-ever record of frugivory for whistling kites.
” The reality they have been doing this routinely for near to two decades is remarkable,” states Fitzsimons.
Except for the palm nut vulture, which regularly takes in fruits, he states that observations of frugivory in other types are primarily erratic. Birds might rely on fruit or veggie matter occasionally, but not as a regular food source.
It appears that the kites of northern Queensland are bucking the pattern, consuming avocados on a regular basis.
The kite circles low over the avocado orchard. Carrion-eating species, like vultures, tend to prefer decaying fruit and vegetable matter. Turkey vultures (Cathartes aura) in some cases scavenge rotting fruits and veggies, consisting of palm fruits, pumpkin, grapes, coconut, cottonwood bark, and juniper berries. Black vultures (Coragyps atratus) have been observed consuming bananas, avocados, copra, sweet potato, rubber tree fruit, and oil and royal palm fruit.
Ospreys in the Canary Islands have been documented consuming green algae (not a fruit, but still unusual).
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