"This bird is eating rice."
Translation:Cet oiseau mange du riz.
It has to do with the different way that verbs are conjugated in English versus French. Also, French does not use a present continuous tense. So...
- je mange = I eat (or) I am eating. There is no extra word for "am".
- tu manges = you eat (or) you are eating.
- il/elle mange = he/she eats (or) he/she is eating
Take a look here for detailed information: https://www.thoughtco.com/introduction-to-french-verbs-1371059
When saying "this bird" or "that bird" it is "cet oiseau" ("oiseau" is a masculine noun). If the noun was feminine, it would be "cette". The only issue between "cet" (m) and "cette" (f) is the gender of the noun. The issue that may be confusing you is when using possessive adjectives, e.g., mon/ma, ton/ta, son/sa. For example:
- mon ami = my friend ("ami" is masculine)
- mon amie = my friend ("amie" is feminine but still uses "mon" because the noun starts with a vowel). You cannot say "ma amie".