The Voyeur Biologist
RSS“Of all courtship rituals in the animal kingdom, the most spectacular by far is that of the Bald Eagle. The male and female climb to dizzying heights and then join in free fall, plummeting toward Earth, locked in each other’s embrace, separating only at the very last moment.”
(Source: skystealing)
An adult tobacco cutworm moth.
The noctuid moth S. litura is prey to bats, and many similar moths, has evolved to produce similar ultrasonic clicks, to confuse the bats’ signals. In this species, however, only the males have the tymbals necessary for ultrasonic emissions, and use them to trick others of their species.
Male moths will mimic bats, and female moths, unable to discriminate between bats and fellow moths, will stop and rest nearby, its only defense against the perceived threats. Males will then exploit the female’s immobility to mate with them.
Gene Involved in Sperm-To-Egg Binding Is Key to Fertility in Mammals
[Researchers] found that when the gene was ‘switched off’ in male mice, less than three per cent of females’ eggs were fertilised compared to more than 80 per cent in mice when the gene was left switched on.
It is the first time that a gene of this type has been linked to fertility.
(Source: fuckyeahgametes)
Sharp-tailed Grouse Lek - Arrowwood National Wildlife Refuge
A male adult warehouse pirate bug (Xylocoris flavipes) with penis extended, and a closeup of its “dagger penis.”
Warehouse pirate bugs mate through traumatic insemination, in which the male’s pointed “dagger penis” breaks the female’s abdominal wall, where it directly deposits sperm.
Research indicates that, because this method of reproduction is so costly, especially in the significant reduction of lifespan, to females, they begin producing eggs in higher quantities, earlier.
(Source: livescience.com)
Mahi-mahi (Coryphaena hippurus)
Also known as the dolphin fish, mahi-mahi are one amongst the fastest growing fish. Males and females are sexually mature in their first year, usually by 4-5 months old. Spawning can occur at body lengths of 20 cm. Females may spawn two to three times per year, and produce between 80,000 and 1,000,000 eggs per event.
Two photographs of adult Bronze-winged Jacana (Metopidius indicus).
Bronze-winged jacanas are territorial polyandrous birds found through large parts of Asia, in which the females are both significantly larger than the males and compete with each other for male mates.
Territory size is directly proportional to harem size, and females will occasionally go into another’s territory and kill their chicks, thereby creating males without young to care for, and who are subsequently assimilated into their harem.
(Source: neomorphus.com)
Male hummingbirds, while courting females, produce a sound with their tail feathers, produced by rapidly spreading and closing them while in a downward dive by a female. These sounds are unique to individual species, varying based on the location, size, shape, mass and stiffness of feathers.
The motivation behind these sounds is unknown, but two hypotheses posit that it may reflect females’ preference for better fliers (as flying proficiency indirectly reflects general fitness), or that the sounds developed incidentally to flying, with no unique purpose.
(Source: laboratoryequipment.com)
Planet Earth: Just the Sex
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