Blue Mason Bee
Daily sighting probability <5% · Rare
at Birmingham

In 3 days ~10% in a week ~20%

8 Verified sightings at Birmingham
May Best month

About the Blue Mason Bee

Osmia caerulescens, the blue mason bee, is a species of solitary bee from the family Megachilidae. It has a Holarctic distribution extending into the Indomalayan region, although its presence in the Nearctic may be due to human-assisted introduction.

Females of Osmia caerulescens are 10–11 mm in length, dark blue-black in color, with a metallic sheen, and sparsely covered with brown hairs with those on the abdomen forming a narrow, dense, flattened band on the hind margin of each of the segments. The dense brush of pollen-collecting scopae on the underside of the abdomen is jet black. The males are slightly smaller, 9mm, more slender in build, distinctly metallic green and clothed with pale hairs.

O. caerulescens occurs in a wide variety of habitats, including woodland and private gardens. O. caerulescens uses a variety of pre-existing cavities for nesting, such as insect burrows in dead wood, drilled borings in wooden blocks, hollow stems, drilled borings in pithy stems, burrows created by other insects in the ground, abandoned cells in exposed nests of other aculeates, cavities in banks, holes and crevices in walls, and glass tubes. The... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability

More parks will be added in future updates.

Cities Where Found

# City Country Daily sighting probability
1 Warsaw 🇵🇱 Poland
~10%
2 London 🇬🇧 United Kingdom
~10%
3 Liverpool 🇬🇧 United Kingdom
~10%
4 Birmingham 🇬🇧 United Kingdom
<5%
5 Barcelona 🇪🇸 Spain
<5%
6 Toronto 🇨🇦 Canada
<5%

Before you go

What are the chances of seeing a Blue Mason Bee in Birmingham?

Rare

Under 5% of wildlife watchers report a Blue Mason Bee sighting in Birmingham on a given day, based on 8 verified sightings from GBIF citizen-science data. It is the 563rd most-seen of the 811 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.

When is the best time to see a Blue Mason Bee in Birmingham?

May and June

In those months about 10% of wildlife watchers report a Blue Mason Bee in Birmingham on a given day, against under 5% in July to April, the lowest months.

Is Birmingham the best place to see a Blue Mason Bee?

4th of 6

Of the 6 cities where we can rate Blue Mason Bee sightings, Birmingham ranks 4th at under 5%. The best odds are in Warsaw (Poland, about 10%), London (United Kingdom, about 10%) and Liverpool (United Kingdom, about 10%).

Where does the Blue Mason Bee sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Blue Mason Bee is recorded against all the insects logged in Birmingham (8 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.

← Back to Birmingham