Red-shouldered Hawks With a Taste for Avocado Join a Growing List of Fruit-Eating Raptors

Mike and Elona Masson think about themselves “hawk individuals.”

Lifelong birdwatchers, they’re notably keen on birds of prey and pay shut consideration to the raptors that go to their Santa Barbara yard. The truth is, once they get dwelling, it’s commonplace to seek out their resident Purple-shouldered Hawk feasting on a Band-tailed Pigeon or rodent. However as Elona stopped to file the chook tearing into its kill one February day in 2020, she seen one thing peculiar: The hawk’s meal wasn’t a kill in any respect—it was a fallen fruit.

“This chook was engaged on an avocado,” Elona says. “And we had been simply totally dumbfounded by that, as a result of he had his pupils dilated. He was taking a look at it with such ferocity, and it was a inexperienced avocado.”

Unbeknownst to the Massons, they had been witnessing the first-known commentary of a Purple-shouldered Hawk consuming avocado—or any fruit, for that matter. However it wasn’t the final: They noticed the identical conduct 4 instances over the following 4 years, managing to file it twice. The pair disagree on whether or not they noticed the identical chook every time—in line with Elona, there have been variations within the feather coloration from go to to go to—however the meals of alternative was plain.  

After the fourth encounter, Elona determined to do a little analysis to see if the chook’s weight loss program was uncommon for Purple-tailed Hawks. Her search introduced her to James Fitzsimons, an Australian researcher at Deakin College in Victoria, who had printed a literature overview on herbivory in raptors in 2021. The couple reached out and despatched him their pictures and movies of the hawk.

In line with Fitzsimons, the Massons’ observations had been notably compelling. Many sightings of raptors consuming fruit are incidental and lack photographic proof. The Massons had been capable of seize a number of clear movies over the span of years, with the hawk displaying plain intent: In a single video, the chook even defended the avocado from a flock of pestering crows.

Fitzsimons supplied to assist the couple formally doc the sighting and conduct. The ensuing paper was published this previous Might within the Wilson Journal of Ornithology, with the Massons as co-authors. The paper analyzes the hawk’s foraging conduct and briefly discusses the established analysis on the weight loss program of Purple-shouldered Hawks and herbivory, or the consumption of residing plant matter, in different raptors. 

Since then, wildlife photographer Simon Arambula captured the weird Purple-shouldered conduct but once more, sharing photos and video on Fb in September. In line with Arambula’s submit, the sighting occurred about 60 miles away from Santa Barbara, in a distinct county, and with one other native hawk.  

Whereas it stays unlikely that Purple-shouldered Hawks are full-fledged omnivores, these observations and different latest analysis solely appear to be broadening the listing of birds of prey that don’t solely eat meat. The Purple-shouldered brings the present complete to 33 raptors identified to complement their weight loss program with crops—nonetheless a small sliver of lots of of species however sufficient to counsel this avian conduct is extra distinguished than realized.

Whereas raptors overwhelmingly give attention to animal matter—from bugs and fishes to rodents and even useless elephants—one exception has been identified for a very long time: the Palm-nut Vulture, with greater than half its weight loss program (58 to 92 p.c) consisting of fruit and different plant matter. However Fitzsimons’ 2021 literature overview recognized 29 species of raptors which have been documented to feed on fruit and different plant matter, together with each Black and Turkey Vultures, Black Kites, and Crested Caracaras. For probably the most half, the meals have a tendency to suit the identical profile as avocados and palm nuts: fruits excessive in lipids, that are chemically much like raptors’ traditional prey and would possibly compensate for a scarcity of animal meals in laborious instances.

Fitzsimons, whose major space of research has to do with environmental science and landscape-scale conservation, says his choice to analyze frugivory in raptors was impressed by his co-author Jack Leighton’s commentary of lots of of Black Kites feeding on non-native avocado orchards in Australia. “It was reported as just a little one-paragraph be aware in {a magazine} again in Australia, maybe within the early 2010s,” Fitzsimons says. “However I believed it is fairly important. We should always try to get [those findings] out a bit extra.”

Avocados include persin, a fungicidal substance which may show extremely poisonous to birds. For home birds like budgies and canaries, as little as two grams can show fatal. Whether or not as a result of raptors just like the Purple-shouldered Hawk are avoiding the pit and pores and skin, the place persin is extra extremely concentrated, or as a result of different elements like their dimension or physiology, Fitzsimons says evidently these raptors aren’t struggling any main in poor health results.

Whereas most of the examples coated by Fitzsimons and Leighton within the paper characteristic fatty fruits like oil palm and avocado, this isn’t all the time the case. The pair additionally described 9 species that consumed berries, figs, and apples, and Ospreys have even been documented deliberately consuming algae and slime.

Since 2021, three different extra raptors have joined the listing: the Roadside Hawk and the Lesser Yellow-headed Vulture, which each eat African oil palm, and the Japanese Screech-Owl. In 2023, researchers led by Arielle Fay witnessed an owl strategy and seem to devour water oak acorns positioned on a viewing platform for a separate research. The workforce published their observations and famous that it wasn’t completely shocking for owls to devour meals exterior of their traditional weight loss program, pointing to meat-eating deer and rabbits as one other instance. The conduct is called opportunistic foraging, and it permits animals to benefit from any accessible vitamins. “As is frequent in nature, there exist a mess of exceptions to the rule,” the researchers wrote.

Or, as Mike Masson extra merely places it:  “Wild animals make decisions, and typically they make moderately attention-grabbing ones.”

In line with Fitzsimons, the explanation for the rise in observations of frugivory in raptors is unclear. It might be associated to comparatively latest ecological or habitat adjustments for the species, however greater than possible, it’s merely the results of extra monitoring with higher tools as birding has become mainstream. “It could be extra frequent than we predict, however we simply do not know,” he says.