---
title: "Mroczek brunatny"
description: "Eptesicus fuscus — Ssaki. The big brown bat is a species of vesper bat distributed widely throughout North America, the Caribbean, and the northern portion of South America."
canonical: https://animalchecklist.com/pl/animal/big-brown-bat
last_updated: 2026-09-20
---

# Mroczek brunatny

> Eptesicus fuscus — Ssaki. The big brown bat is a species of vesper bat distributed widely throughout North America, the Caribbean, and the northern portion of South America.

- Scientific name: *Eptesicus fuscus*
- Category: `mammals` (Ssaki)
- Habitats: `urban` (Miasta i ogrody)
- iNaturalist observations: 11900
- Wikidata: [Q301254](https://www.wikidata.org/wiki/Q301254)
- iNaturalist taxon: [40509](https://www.inaturalist.org/taxa/40509)

## Names

- en: Big Brown Bat
- de: Große Braune Fledermaus
- es: Murciélago moreno norteamericano
- fr: Sérotine brune
- nl: Grote bruine vleermuis
- pl: Mroczek brunatny

## Countries with the most observations

US (6411), CA (1325), MX (132), CO (5), HN (4), SV (3)

## Summary

The big brown bat is a species of vesper bat distributed widely throughout North America, the Caribbean, and the northern portion of South America. It was first described as a species in 1796. Compared to other microbats, the big brown bat is relatively large, weighing 15–26 g (0.53–0.92 oz) and possessing a wingspan of 32.5–35 cm (12.8–13.8 in).

Text: Wikipedia (en), CC BY-SA 4.0 — https://en.wikipedia.org/wiki/Big_brown_bat

## Photo

![Mroczek brunatny](https://animalchecklist.com/img/animals/big-brown-bat/medium.jpg)

Photo: James Valastro · CC0 · inaturalist — https://www.inaturalist.org/observations/19144537

## Machine access

`GET https://animalchecklist.com/api/v1/animals/big-brown-bat?lang=pl` — see [openapi.json](https://animalchecklist.com/openapi.json).