“But the downside is the female is left with all the incubation duties, and it appears possibly having to get her own food. I think what’s happening is every time her male brings her food, the intruder intercepts him and steals it off him or forces him to drop it.”
Hurley said this interrupted incubation puts the pair’s eggs at risk of not hatching when they are due at the start of October.
He added that it was “really unusual” for the incoming bird to arrive after the eggs had been laid and pester so close to the existing bird’s nest, and that others would opportunistically wait well outside the local bird’s territory.
“In all the years I’ve been looking at it, I’ve not come across something like this, where they’ve tolerated this bird for so long. He’s even landed on the next ledge … he’s really cheeky and getting away with it,” Hurley said.
“I suspect by next season we’ll have one male.”
The looming fight above Melbourne’s streets
Hurley said the current battle between the two males was a cold war, with the intruder waiting to pounce on the resident male if it drops his guard.
He said when a previous female was killed by an intruder years ago, their fight lasted more than seven hours, leading concerned building managers to call Hurley after the raptors spent hours screaming and yelling.
Hurley said he suspects some fights are shorter, but with both falcons using the same dive-bombing runs, sharp talons and neck-snapping beaks to kill smaller prey, they are often evenly matched.
“That’s really hard if you’ve got another peregrine because they know exactly what you’re trying to do. So, it often ends up as a bit of a grappling match,” Hurley said.
Almost 40,000 Facebook users are monitoring the falcons at the 367 Collins Falcon Watchers page, with many calling the resident seven-year-old male “Dive Bomb Dad” as he tries to fend off the intruder.
The winner will claim all of Melbourne’s CBD as its own, alongside the resident mother, with the next closest nest in Altona.
“That’s why people are all fascinated by the game of Thrones intrigue that’s going on,” Hurley said.
When asked to pick a winner, Hurley said the slightly larger and younger three-year-old intruder might have a slight edge.
“In any sort of wrestling match, you’re going to put your money on the larger bulk to probably succeed ultimately,” he said.
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