READ OUT LOUD. Choose which marked text you prefer to practice with - macrons in verse form, or macrons in prose order, or accent marks in prose order, or focusing on the meter. You will find materials for all of these options below. :-)
VERSE MACRONS. Here is the verse text with macrons:
Accipitrem milvī pulsūrum bella columbae
Incipiunt dē rēge querī, quod sānius esset
Sī quid agās, prūdenter agās et rēspice fīnem.
PROSE MACRONS. Here is the same text with macrons written out in prose word order:
Columbae accipitrem rēgem accipiunt, milvī bella pulsūrum. Rēx magis hoste nocet. Dē rēge querī incipiunt, quod sānius esset milvī bella pati, quam sine Marte morī. Sī quid agās, prūdenter agās et rēspice fīnem. Minōra ferre volō, nē graviōra feram.
STRESS (ACCENT) MARKS. Here is the prose text with accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Colúmbae accípitrem regem accípiunt, milvi bella pulsúrum. Rex magis hoste nocet. De rege queri incípiunt, quod sánius esset milvi bella pati, quam sine Marte mori. Si quid agas, prudénter agas et réspice finem. Minóra ferre volo, ne gravióra feram.
ELEGIAC COUPLET METER. Below I have used an interpunct dot · to indicate the metrical elements in each line, and a double line || to indicate the hemistichs of the pentameter line.
Accipi·trem mil·vī pul·sūrum· bella co·lumbae
Incipi·unt dē· rēge que·rī, quod· sānius· esset
Sī quid a·gās, prū·denter a·gās et· rēspice· fīnem.
Here's an illustration for the fable (image source) from a Renaissance edition of Aesop:
What follows is an unmarked version of the prose rendering to faciliate word searches: Columbae accipitrem regem accipiunt, milvi bella pulsurum. Rex magis hoste nocet. De rege queri incipiunt, quod sanius esset milvi bella pati, quam sine Marte mori. Si quid agas, prudenter agas et respice finem. Minora ferre volo, ne graviora feram.