The mating season for the Hamilton Sheraton’s resident pair Madame X and Surge is still in full flight despite speculation the female peregrine falcon may be nearing the end of her reproductive years. 

Peregrine experts say it's too soon to read too much into the failure of the eggs laid this spring—both for the prospects of more eggs being laid this year and the breeding pair's reproductive future. 

"It's our understanding in what we're seeing that the birds are producing right up until the day they die," said Mark Nash, president of the Canadian Peregrine Foundation. "They don't seem to go through menopause likely people do are are incredibly resilient."

Since 2001, the 15-year-old Madame X has produced dozens of newborns with different mates - the most recent of whom is Surge who fought ousted another male falcon from the nest in 2006. Offspring from the nest now span several generations and have been spotted in five states in the U.S. - some as far away as Pennsylvania and Ohio. 

'Back into breeding mode'

Nash credits the Sheraton and local urban watch plans for their efforts in ensuring the nest is undisturbed and ultimately the recovery of a species that at one point was all but extinct 20 years ago. 

"We now see that these urban nesting peregrines, egg for egg and hatch for hatch, are outproducing our wild non-urban sites," he said. 

The recent disappearance the city’s resident falcons’ eggs may have been the result of environmental stressors such as territorial challenges from other birds, but there’s no doubt hormones among the Sheraton pair remains high. 

'Hormonally they'll be stimulated to go back into breeding mode.' - Mark Nash, Canadian Peregrine Foundation

“Hormonally they'll be stimulated to go back into breeding mode," Nash said. 

The eggs were likely crushed, and possibly even eaten,  by the pair or other migrating peregrines aggressively seeking out a mate.

"When we see this type of behaviour happen it usually spells out territorial challenges," he said. "This is a time of year when all of our northern Ontario peregrines are now starting to pass over from the wintering grounds in the south and they can really cause a lot of disruption." 

Falcon behaviour out of the norm

It's unclear the span Hamilton's falcons consider as their territory, but much of their activity occurs on rooftops where they hunt and prepare food before bringing it back to the nest. 

Hamilton "has a very seasoned pair. They've been around for a number of years, they know the territory and the site and each other's routines and behaviours," Nash said. "To see this type of activity happening it's something out of the norm."

Other stressors in the environment such as downtown construction, or activity on nearby rooftops, may also stir a similar reaction in the bird.

"It really does cause a lot of stresses on the individual pairs and their hormones and it can really cause them do some unusual and bizarre things," Nash said. 

Across Ontario the Canadian Peregrine Foundation monitors approximately 30 peregrine nests.