Cliff Mining Bee vs Clinging Snakefern

Andrena thoracica compared with Microgramma heterophylla

Key Differences

• Cliff Mining Bee is Extinct while Clinging Snakefern is Least Concern.

Taxonomic Classification

Rank	Cliff Mining Bee	Clinging Snakefern
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Tracheophyta
Class	Insecta (Insects)	Polypodiopsida (Polypodiopsida)
Order	Hymenoptera (Ants, Bees & Wasps)	Polypodiales (Polypodiales)
Family	Andrenidae	Polypodiaceae
Genus	Andrena	Microgramma
Species	Andrena thoracica	Microgramma heterophylla

Conservation Status

Cliff Mining Bee

EX — Extinct

Clinging Snakefern

LC — Least Concern

Physical Characteristics

Attribute	Cliff Mining Bee	Clinging Snakefern
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cliff Mining Bee

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Denmark, Luxembourg, Norway, and Sweden.

Clinging Snakefern

Habitat

Typically found in moist, shaded forest floors and tropical canopies.

Range

Found in Cuba.

Cliff Mining Bee

The Cliff Mining Bee, Andrena species in the family Andrenidae, is a solitary ground-nesting bee that excavates tunnels in cliff faces, earthen banks, and compacted sandy or loamy soils, where the loose or friable substrates exposed in cliff profiles provide ideal nesting conditions. Mining bees in the genus Andrena are among the most species-rich solitary bee genera in the world, with hundreds of species across the Holarctic region, many narrowly specialized in their choice of pollen host plants. Female cliff mining bees construct vertical or angled burrows in cliff faces, with lateral cells off the main shaft, each containing a pollen ball and a single egg. Males are typically smaller and emerge before females to establish territories near nesting sites. Many Andrena species are oligolectic, collecting pollen from only a small number of plant species, making their populations sensitive to the availability of specific flowering plants in the landscape surrounding nesting areas. Cliff and bank nesting habitats provide well-drained, sun-warmed substrates essential for brood development. The loss of natural cliff faces and earthen banks to development, vegetation succession, and quarrying reduces available nesting habitat for cliff mining bees.

Clinging Snakefern

Clinging Snakefern, Microgramma species, is a genus of small epiphytic ferns in the family Polypodiaceae found in tropical and subtropical forests of the Americas, from Florida and the Caribbean through Central America to South America. The ferns cling tightly to tree bark and rock surfaces using creeping rhizomes with specialized clinging scales, making them true epiphytes that depend entirely on the host surface for physical support while deriving all their water and nutrients from rainfall and atmospheric deposition. The common name 'snakefern' refers to the slender, creeping rhizomes that resemble snakes threading through moss and bark. The fronds are small and simple, either entirely fertile bearing sori on their undersurface or sterile with entire margins. Clinging snakeferns contribute to the high epiphyte diversity of tropical forest canopies and are important components of the moss-and-lichen matrix on tree trunks in humid forests. They are sensitive to moisture availability and desiccation and are among the first species to decline when humid forest is cleared or fragmented. Several Microgramma species are used as ornamental plants in warm-climate gardens for their ability to creep over rocks and tree stumps. Conservation status varies by species within the genus.