Ciervo vs. venado

In Spanish, the words 'ciervo' and 'venado' both refer to 'deer', but they have slight differences in usage and connotation.

Ciervo

The word 'ciervo' specifically refers to a male deer, typically a stag. It is often used when referring to the animal in zoological or formal contexts.
El ciervo se escondió en el bosque.
(The stag hid in the forest.)
Durante la caza, avistaron varios ciervos majestuosos.
(During the hunt, they spotted several majestic stags.)
El cuerno del ciervo es muy característico.
(The antler of the stag is very characteristic.)

Venado

The word 'venado' is a more general term for deer and can refer to any species within the deer family or both genders. It is commonly used in hunting contexts or when referring to the animal as a source of meat.
Vieron un venado cruzando la carretera.
(They saw a deer crossing the road.)
La carne de venado es popular en algunas regiones.
(Venison is popular in some regions.)
Hay muchas especies de venados en esta reserva natural.
(There are many species of deer in this nature reserve.)

Summary

While both 'ciervo' and 'venado' translate to 'deer', 'ciervo' specifically refers to a male deer or stag and is used primarily in zoological contexts. On the other hand, 'venado' is a broader term that can refer to any deer, regardless of species or gender, and is often used in hunting or culinary contexts.