Officials of the Black Eagle Project Roodekrans are concerned following the disappearance of Thulani, a male black eagle, from the Walter Sisulu Botanical Gardens last Saturday.
Thulani and his mate Makatsa are an institution in Johannesburg and the subject of great interest worldwide.
To make matters worse, it appears that a chick has since hatched and will likely be abandoned by Makatsa if Thulani doesn't return.
According to the project's chairperson, Gerald Draper, Thulani was last seen on June 8 and possibly again on June 9, though this could not be confirmed.
"What concerns us is that they take turns incubating. Now it's just the female on the nest. His timing is really unfortunate," Draper told News24.
Chick has already hatched
"At 07:00 [on Friday] morning she left the nest and came back with small prey. That immediately tells us that there is a chick on the nest.
"Without the male there, it becomes problematic, because she has to sustain herself as well. His job is to bring prey to the nest and she then feeds [the chicks].
"So now, the likelihood of her being able to sustain herself and the chicks, as well as protect them, is very low.
"Crows are intelligent buggers, they'll soon pick up that there aren't two eagles, so if she goes and looks for prey, the nest will be exposed," Draper said.
He said Makatsa might decide to "abort", leaving the nest to look for another mate.
Draper says it is not unusual for an eagle to just take off one day.
"Eagles have been breeding there since the 1940s. So new birds come in all the time. In 1988, the female was sitting on the nest when the male disappeared. Eventually she aborted the chicks and left and came back a few weeks later with a new male, which happened to be Thulani.
"Then, in 2016, the older female disappeared and Thulani came back with Makatsa."
Draper said Thulani's disappearance was worrying and sad and that it was unlikely that Makatsa would attempt to raise the chicks by herself.
"It's pretty cold, so the chick will be exposed to that when she leaves the nest, and it will be left open to predators."
"We will continue to monitor the situation and communicate as and when any developments unfold," Black Eagle Project Roodekrans said in a statement.
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