In biology, we approach citations differently than you might have seen elsewhere.  In general we aim to avoid direct quotes in scientific writing. Instead, we paraphrase what the author has said or found.

Primarily cite by using a parenthetical reference at the end of the sentences providing information from your source.

Rufous hummingbirds (Selasphorus rufus) spent more time feeding as flower length increased (Temeles and Roberts                                          1993).

Alternatively, you may cite by directly referencing authors.  This should be done much less frequently.

Experiments by Temeles and Roberts (1993) showed that Rufous hummingbirds (Selasphorus rufus) spent more time                                           feeding as flower length increased.

Additionally, contrary to what you may have seen elsewhere, we cite every sentence that comes from an outside source.  Therefore, even when you have multiple sentences occurring in a row citing the same source, cite at the end of each sentence referring to that source.