Squicks

Squicks are a genus of changeling birds notable for their extremely disparate larval and adult appearances and lifestyles. Larvae are blind, featherless parasites which lack developed lungs and breathe through their thin, moist skin, whereas adults are exceedingly small but fully developed flying birds. Most species reproduce by depositing clusters of eggs upon dead animal tissue, but one species is an obligate endoparasite, biting a small wound in the hide of a large animal and depositing its eggs directly into a living host.

Larval squicks hatch from their eggs at only a few millimeters in length, and some species have the most rapid life cycles of any bird, just two and a half weeks from hatching to reproductive maturity. The group is cosmopolitan across Serina in the middle Pangeacene and all living species except one feed on dead or necrotic tissue. Most species feed as larvae on carcasses like maggots, burrowing deep inside with their spiny forearms and tunneling into the flesh with their jaws as they feed, but some are wound specialists, hatching in wounds and eating the rotting tissue from injuries in large living animals. Only one species feeds exclusively on living tissue, the fleshborer, but it occurs widely across the tropics and can infect almost any terrestrial animal, boring inside the muscle tissue or organs of its host and often causing fatal secondary infection. Fleshborers most often target very young, old, or already ailing animals, hastening their deaths, and are thus the quickest to reach maturity before that occurs, eating continuously and growing rapidly to a few centimeters in length and then dropping from their host at just over a week of age, pupating on the ground and emerging as adults in only five to six days. The adult fleshborer is the smallest flying bird ever to exist, no larger than a honeybee - just two centimeters long from head to tail with a comparable wingspan. Despite this, it is fully feathered, though being so small in size it has also the fewest feathers of any flying bird, only about two hundred, most of which are highly reduced downy plumes which insulate the body. Its wing plumage is also highly reduced and contains the lowest number of flight feathers of any flying species - just five on each wing, all of which are primary feathers. Its feet are tiny but strong enough to let it cling to the hide of large animals, with two toes facing forward and two back just like their distant bloodpecker ancestors. The fleshborer, unlike the flying eft, feeds during its adult stage - mainly on blood, but also on insects and bits of tissue cut from wounds with its hooked bill - but still has a maximum lifespan of only two weeks after pupating, during which time it concentrates heavily on reproducing. Females live longer than males and can lay more than a thousand eggs in their brief lives, depositing them around open wounds on other birds and animals if available and creating their own if an injured host is unavailable. Preferred prey are the young and the sick of large herbivores and nest-bound young of altricial birds, which are usually killed by the parasites in a grisly, drawn-out death from septicemia as they are eaten alive from the outside in. Healthy large animals, such as other changeling birds and circuagodonts, may be infected as well, but will usually survive an infection provided it is not too severe.

above: adult and larval stages of the fleshborer, depicted with a circuagodont host. The larvae's location can be seen in many cases as a red swelling on the skin's surface, the result of a combination immune reaction and bacterial infection in the tissue damaged by the parasite's feeding. A healthy host, as pictured, can survive the borer's predation and heal once it drops out of the body to pupate, but an already weakened individual is likely to succumb, particularly if the infestation involves multiple larvae.

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Even many squicks which feed only on dead tissue as larvae are parasitic as adults, feeding on blood, though some eat only nectar or other food sources, such as flying insects. These species are particularly problematic toward the far north, where they form huge blood-sucking swarms during the summer to the detriment of herd animals which struggle to escape them, finding they are not dissuaded by tactics which work to avoid insects such as sheltering on lingering snow patches, due to the birds' warm-blooded nature. Like many blood-feeding animals, squicks are common vectors of bacterial and viral disease agents. The larvae of some species, however, also serve a beneficial function. By cleaning the necrotic tissue from a wound, they can actually reduce the risk of infection and help an animal to heal, provided the injury was not life-threatening in and of itself.

In cold climates, squicks will overwinter in their pupal stage, cocooned in a protective shell of mucous buried underground, and emerge as flying adults in the spring to search out a new host for their eggs. Almost all squicks are diurnal, but the fleshborer flies by night to avoid detection by its hosts, and is thus equipped with especially large eyes and acute night vision. It is thus also one of the less colorful species, mostly black with white on the head and light speckles on its underside. Diurnal species are often brighter, with bold markings on the head and wings.