Agricrows
Farmers of the world
Sowering ravens are one of the most successful birds of the world, comprising a large number of species/ecotypes adapted to cultivate different types of fruity vegetation as a supplementary diet. One radiation of these corvids has developed interesting features in recent millions of years, improving their farming and social capacities: the agricrows (family: Agripicacidae).
Only one species is present in Antarctica, the antarctic agricrow (Antarcticpica utensilis), which is also the only member of the genus Antarcticpica: its ancestors arrived in Antarctica about 5 million years ago and then rapidly became reproductively isolated, thanks to genetic drift. They can be found exclusively in the warmest areas of Belgrano and in the lowlands of Weddel island.
They are very large flying passerines that can weigh as much as a golden eagle, but with short and rounded wings (which are very useful to fly inside woodlands), with a small colorful crest on their beak.
They live in highly complex social groups that are called clans, with three separated social castes: paterfamilias, guards and growers.
Paterfamilias are the dominant individuals of the clan, which possess decision-power; they are usually large and old guards or growers, not necessarily blood-related, with lots of experience on their shoulders....or wings.
They know the surrounding territories better than any other members of the clan and know which plants should be cultivated depending on the season. Paterfamilias are extremely respected inside the clan and juveniles are often in charge of bringing food to paterfamilias nests, when they are no longer capable of flying properly. Thanks to collective help, paterfamilias can easily live for 50 years.Guards comprise the strongest members of the clan and they are responsible for keeping juveniles and elders safe from predators. They are also in charge of protecting their cultivated fields from large herbivores: they have learned variable methods to scare away organisms as large as a mastodon bullduck! Guards live the riskiest life and show higher mortality compared to other castes: individuals of this caste rarely exceed 30 years, but the few who manage to survive often become paterfamilias. Guards tend to be bulkier than other clan members due to their combative activities.
Growers, as the name suggests, are the farmers of the clan, capable of cultivating over 20 species of plants across the year. Unlike their sowering ancestors, growers are more protective towards their cultivation: weeding, mulching and watering are a daily routine, which strongly increases plant fitness and production. Most cultivated plants are herbaceous (e.g., strawberries, tallgrasses, dwarf sunflowers, etc.), but several clans also include shrubs and even oak corns, which are kept small (<5 meters high). Despite all these improvements, the type of farming would be classified as archaic from a human point of view.
The beak is used to dig up holes where seeds or fruits are planted; due to this, growers are often the most recognizable members of the clan, since they possess large signs of usury caused by their farming activity. Growers have lower mortality than guards, meaning they can become paterfamilias more frequently.
This society possesses similarities with both prosocial and eusocial organisms: despite the presence of separated castes with specialized roles, these social differentiations can easily blur: paterfamilias aren't born paterfamilias, but they become such as they acquire knowledge and respect from other members of the clan.
Agricrows do not only cultivate plants, but also invertebrates: some undigestible parts of their cultivated plants are taken apart to feed parasitic insects or snails, which will be eaten when mature enough. This "livestock" is kept inside large hollow trees, where it's fed with leaves, roots and rotten fruits.
This behavior probably developed when agricrows had to deal with parasites of their cultivations: instead of trying to eradicate these pests, they turned them into a viable food source. When agricrows have colonized Antarctica for the first time, they've also brought their plantations and their "livestock", causing (voluntary?) introductions of new insects clades, like butterflies of the Pieridae family or snails of Limacidae-Helicidae families.