The incident occurred in August last year in the town of Świebodzice in Poland's southwestern Lower Silesia region.
According to prosecutors, the 42-year-old man, fully aware of the presence of fledglings in the nest, deliberately knocked it down from a second-floor window corner, the PAP news agency reported.
A witness to the event found the fledglings, one of which had a severed leg. The woman took care of the injured birds, handed them over to an animal rescue group and notified the police.
The Świdnica prosecutor's office charged the man with the attempted killing of three house martin fledglings by destroying their nest.
"The perpetrator did not achieve his intended goal as the fledglings received veterinary care," Świdnica District Prosecutor Marek Rusin was quoted as saying.
The court found the man guilty and imposed a fine of PLN 5,000 (EUR 1,160).
This marks the first conviction of its kind in Poland, according to Rusin.
"The verdict is satisfying for us and sets a precedent nationwide," he told reporters.
House martins are under strict species protection in Poland. Regulations allow for the removal of a swallow nest only between mid-October and late February, and solely from buildings or green areas if required for safety or sanitary reasons.
(mo/gs)
Source: PAP