This is the 17448th most frequent Russian word.
тигров
"Тигров" means "of tigers" (genitive plural form).
In this sentence, 'тигров' is the genitive plural form of 'тигр', used to indicate possession or association.
Зона обитания этих тигров находится в тропических лесах.
The habitat of these tigers is located in tropical forests.
Here, 'тигров' is the genitive plural form, used as it follows the direct object rule with the implied possession of the 'photos'.
Получили ли вы фотографии тигров, присутствовавших в заповеднике?
Did you receive the photos of the tigers that were in the sanctuary?
In this instance, 'тигров' takes the genitive plural form to describe the type or classification of the population.