Concentric Boulder Lichen vs Rufous-tailed Hummingbird

Porpidia crustulata compared with Amazilia tzacatl

Key Differences

Concentric Boulder Lichen is Vulnerable while Rufous-tailed Hummingbird is Least Concern.

Taxonomic Classification

Rank	Concentric Boulder Lichen	Rufous-tailed Hummingbird
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Ascomycota (Sac Fungi)	Chordata (Chordates)
Class	Lecanoromycetes (Lecanoromycetes)	Aves (Birds)
Order	Lecideales (Lecideales)	Apodiformes (Apodiformes)
Family	Lecideaceae	Trochilidae
Genus	Porpidia	Amazilia
Species	Porpidia crustulata	Amazilia tzacatl

Conservation Status

Concentric Boulder Lichen

VU — Vulnerable

Rufous-tailed Hummingbird

LC — Least Concern

Physical Characteristics

Attribute	Concentric Boulder Lichen	Rufous-tailed Hummingbird
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Concentric Boulder Lichen

Habitat

Native to Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, Portugal, Sweden, and United States. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Rufous-tailed Hummingbird

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Distributed across Colombia, Ecuador, Norway, and Venezuela.

Concentric Boulder Lichen

<em>Porpidia crustulata</em>, commonly known as the Concentric Boulder Lichen, is a crustose lichen in the family Porpidiaceae formed through a symbiotic relationship between a fungal partner (mycobiont) and photosynthetic green algae (photobiont). Like all crustose lichens, it grows tightly appressed to its substrate—typically siliceous or acidic rock surfaces including boulders, cliff faces, and pebbles in open, well-lit habitats—forming thin, grayish to pale thalli marked by scattered black apothecia (reproductive discs). <em>Porpidia crustulata</em> derives nutrition entirely through photosynthesis conducted by its algal partner, requiring no external organic food source. The species has been documented in Denmark, Norway, Portugal, Sweden, and the United States, suggesting a broad boreal to temperate distribution across the Northern Hemisphere. It is currently classified as Vulnerable by the IUCN, indicating significant conservation concern, likely linked to threats including air pollution, acidification, quarrying of rocky habitats, and changes in land use that reduce the availability of suitable substrates. Crustose lichens are typically slow-growing, long-lived organisms with limited capacity for rapid range shifts in response to environmental change. Biological traits such as individual lifespan, growth rates, and reproductive output remain poorly documented at the population level.

Rufous-tailed Hummingbird

One of the most common hummingbirds in Central America and northwestern South America, rufous-tailed hummingbirds are medium-sized with green upper parts and a diagnostic bright rufous-orange tail. Found from Mexico to Ecuador and Trinidad in a wide range of habitats including forest edges, gardens, plantations, and secondary growth from sea level to 2,100 meters. Aggressive territory defenders at feeders and flowering plants, they are frequently seen in gardens across their range. Listed as Least Concern.