Mourning geckos are small reptiles that have captivated scientists and enthusiasts alike due to their remarkable biological characteristics. These fascinating creatures exhibit a unique approach to life that sets them apart from most other vertebrates.
The All-Female Truth
A defining characteristic of Lepidodactylus lugubris, commonly known as the mourning gecko, is their overwhelmingly female population. While extremely rare instances of male mourning geckos have been observed, these individuals are typically sterile and do not contribute to reproduction. This means that mourning geckos exist as an all-female lineage.
How They Reproduce Asexually
The existence of an all-female species is possible through a reproductive process called parthenogenesis, often referred to as “virgin birth.” In mourning geckos, this involves a cellular process where the egg duplicates its own chromosomes, effectively creating a full set of chromosomes (diploid) that are necessary for development. Female mourning geckos often engage in a behavior known as pseudo-copulation, where two females interact in a manner resembling mating. This interaction is thought to stimulate egg production and egg release. Females typically lay clutches of one or two eggs every four to six weeks.
Consequences of Their Unique Reproduction
Parthenogenesis has significant implications for the genetic makeup and population dynamics of mourning geckos. Since offspring are essentially genetic copies of the mother, this reproductive strategy leads to very low genetic diversity within populations. While this can ensure the passing on of successful traits, it also makes the population vulnerable to environmental changes or diseases, as a threat to one individual could potentially impact all genetically similar members. Despite the genetic uniformity, this reproductive method enables rapid population growth. A single female can establish an entirely new population, allowing for quick colonization of new habitats and contributing to their widespread distribution.
Life as a Mourning Gecko
The unique reproductive strategy of mourning geckos heavily influences their lifestyle and ecological success. These small geckos, typically measuring 8.5–10 cm in total length, are native to tropical and subtropical regions, primarily found in Southeast Asia and Pacific islands. They are highly adaptable and have successfully colonized diverse human-modified habitats globally, including parts of Central and South America.
Their ability to lay salt-water tolerant eggs aids in their dispersal across oceans. Mourning geckos are primarily nocturnal, becoming active at night to forage, but can also be cathemeral, meaning they exhibit activity during both day and night. They are social animals, often living in groups and communicating through vocalizations and head bobs.