estrus

American  

[es-truhs] / ˈɛs trəs /

Rarely estrum

noun

Zoology.

1. the period of heat or rut; the period of maximum sexual receptivity of a female mammal.

2. estrous cycle.

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estrus British  

/ ˈɛstrəs, ˈiːstrəs /

noun

1. the usual US spelling of oestrus

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estrus Scientific  

/ ĕs′trəs /

1. A regularly recurring period in female mammals other than humans during which the animal is sexually receptive. Estrus occurs around the time of ovulation.

2. Also called heat

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Other Word Forms

• estrous adjective

Etymology

Origin of estrus

First recorded in 1885–90; from Latin oestrus oestrus

Example Sentences

While it’s well established that lengthening daylight triggers a cat’s estrus, the effect of rising temperatures on kitten season isn’t yet understood.

From Salon

In the other, the whales weren’t pregnant during the first massive progesterone surge, but were instead experiencing a prolonged state of estrus or ovulating.

From New York Times

Otter moms will often go immediately into estrus if they lose a pup.

From Los Angeles Times

Females also occasionally checked in, leaving their mark when in estrus.

From Science Magazine

“We thought, maybe the swamp wallaby is pushing estrus back into pregnancy so it has a longer period of receptivity to find a male in the wild.”

From New York Times