The Sturnidae family, commonly known as starlings, is a group of passerine birds belonging to the order Passeriformes. This family includes about 30 species of birds that are distributed across various habitats, from open landscapes to urban centers. Starlings are known for their social behavior, complex group dynamics, and their remarkable vocal abilities. Many species of starlings are also famous for their spectacular flocks that form during group flights, creating stunning aerial patterns.
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Sturnidae
Morphological Characteristics
Starlings are medium-sized birds, characterized by a compact body, relatively long pointed wings, and a slender, straight beak adapted for catching insects, seeds, and fruits. Their plumage can vary widely among species but often features iridescent metallic colors, ranging from green and purple to blue, with shiny black feathers in species like the common starling (Sturnus vulgaris).
One of the most distinctive features of starlings is their ability to adapt their plumage during the winter season, with some individuals, such as the common starling, acquiring bright spots that appear to shimmer in the sunlight. Some species, like Sturnus roseus, display more gray or pinkish tones depending on the species and season.
Behavior and Feeding Habits
Starlings are omnivorous, with a diet that includes insects, seeds, fruits, and small invertebrates. Their diet can vary depending on the season and food availability. During the summer months, starlings primarily feed on insects, while in winter, they may turn to berries and seeds from plants. Their ability to forage in large groups makes them particularly efficient at finding food.
Starlings are known for their social behavior. Many species, especially the common starling (Sturnus vulgaris), are highly gregarious and often form large flocks, particularly during the non-breeding season. These flocks can consist of millions of individuals, creating a spectacular aerial display that is both a mesmerizing sight and serves the functional purpose of confusing predators or maintaining cohesion within the group.
Habitat and Distribution
The Sturnidae family is widely distributed, with species found across a range of habitats, from grasslands and wetlands to urban environments. Starlings are particularly adaptable to human environments and have thrived in cities and agricultural areas. The common starling is one of the most widespread and recognizable species, found in cities around the world, often living in close association with humans.
Starlings are native to many parts of the world, including Europe, Asia, and North Africa, and have been introduced to other regions, including the Americas and Australia. While some species are migratory, others, like the common starling, are largely sedentary and remain in the same area year-round.
Reproduction
Starlings typically build nests in cavities, such as tree branches, shrubs, or even on buildings and other man-made structures. The nest is usually made from a variety of materials, including twigs, grass, feathers, and moss. Starlings are monogamous during the breeding season, with pairs forming strong bonds.
Females typically lay 4 to 6 eggs, which are incubated by both parents for about 12 to 14 days. After hatching, both parents take part in feeding and caring for the chicks, which are fed a diet of insects. The young birds fledge (leave the nest) after about 3 weeks, but they may remain dependent on their parents for a while as they learn to forage independently.
Conservation
Many species of starlings are abundant and widespread, with the common starling (Sturnus vulgaris) being one of the most common birds globally. However, some starling species have seen declines in their populations due to habitat loss, competition with other species, and a decrease in food sources. In particular, the decline in insect populations due to pesticide use has affected starlings that rely on insects to feed their young.
The IUCN Red List has classified certain starling species, such as the rose-colored starling (Sturnus roseus), as vulnerable in some regions, where habitat destruction and agricultural changes are negatively affecting their populations. Conservation efforts are focused on preserving natural habitats, encouraging more sustainable agricultural practices, and creating nature reserves to ensure that starling populations can continue to thrive in the future.
Conclusion
The Sturnidae family represents a fascinating group of birds, known for their remarkable social skills and aerial displays. Starlings not only play an important role in ecosystems as insect controllers but their spectacular aerial formations and group behaviors make them one of the most captivating bird families to observe. While many species are stable, some are threatened, and conservation measures are crucial to preserving biodiversity and their place in both natural and urban ecosystems.
References__________________________________________________________________________
Brilot BO, Asher L, Bateson M. Stereotyping starlings are more 'pessimistic'. Anim Cogn. 2010 Sep;13(5):721-31. doi: 10.1007/s10071-010-0323-z.
Abstract. Negative affect in humans and animals is known to cause individuals to interpret ambiguous stimuli pessimistically, a phenomenon termed 'cognitive bias'. Here, we used captive European starlings (Sturnus vulgaris) to test the hypothesis that a reduction in environmental conditions, from enriched to non-enriched cages, would engender negative affect, and hence 'pessimistic' biases. We also explored whether individual differences in stereotypic behaviour (repetitive somersaulting) predicted 'pessimism'. Eight birds were trained on a novel conditional discrimination task with differential rewards, in which background shade (light or dark) determined which of two covered dishes contained a food reward. The reward was small when the background was light, but large when the background was dark. We then presented background shades intermediate between those trained to assess the birds' bias to choose the dish associated with the smaller food reward (a 'pessimistic' judgement) when the discriminative stimulus was ambiguous. Contrary to predictions, changes in the level of cage enrichment had no effect on 'pessimism'. However, changes in the latency to choose and probability of expressing a choice suggested that birds learnt rapidly that trials with ambiguous stimuli were unreinforced. Individual differences in performance of stereotypies did predict 'pessimism'. Specifically, birds that somersaulted were more likely to choose the dish associated with the smaller food reward in the presence of the most ambiguous discriminative stimulus. We propose that somersaulting is part of a wider suite of behavioural traits indicative of a stress response to captive conditions that is symptomatic of a negative affective state.
Lovette IJ, Rubenstein DR. A comprehensive molecular phylogeny of the starlings (Aves: Sturnidae) and mockingbirds (Aves: Mimidae): congruent mtDNA and nuclear trees for a cosmopolitan avian radiation. Mol Phylogenet Evol. 2007 Sep;44(3):1031-56. doi: 10.1016/j.ympev.2007.03.017.
Abstract. We generated a comprehensive phylogeny for the avian families Sturnidae (starlings, mynas, Rhabdornis, oxpeckers, and allies) and Mimidae (mockingbirds, thrashers, and allies) to explore patterns of morphological and behavioral diversification. Reconstructions were based on mitochondrial DNA sequences from five coding genes (4108 bp), and nuclear intron sequences from four loci (2974 bp), for most taxa, supplemented with NDII gene sequences (1041 bp) derived from museum skin specimens from additional taxa; together the 117 sampled taxa comprise 78% of the 151 species in these families and include representatives of all currently or recently recognized genera. Phylogenetic analyses consistently identified nine major clades. The basal lineage is comprised of the two Buphagus oxpeckers, which are presently confined to Africa where they are obligately associated with large mammals. Some species in nearly all of the other major clades also feed on or around large vertebrates, and this association may be an ancestral trait that fostered the world-wide dispersal of this group. The remaining taxa divide into sister clades representing the New-World Mimidae and Old-World Sturnidae. The Mimidae are divided into two subclades, a group of Central American and West Indian catbirds and thrashers, and a pan-American clade of mockingbirds and thrashers. The Sturnidae are subdivided into six clades. The Phillipine endemic Rhabdornis are the sister lineage to a larger and substantially more recent radiation of South Asian and Pacific island starlings and mynas. A clade of largely migratory or nomadic Eurasian starlings (within which the basal lineage is the model taxon Sturnus vulgaris) is allied to three groups of largely African species. These reconstructions confirm that Buphagus should not be included in the Sturnidae, and identify many genera that are not monophyletic. They also highlight the substantial diversity among the major Sturnidae subclades in rates of species accumulation, morphological differentiation, and behavioral variation.
Valente R, Ibañez LM, Lorenti E, Fiorini VD, Montalti D, Diaz JI. Helminth parasites of the European starling (Sturnus vulgaris) (Aves, Sturnidae), an invasive bird in Argentina. Parasitol Res. 2014 Jul;113(7):2719-24. doi: 10.1007/s00436-014-3928-3.
Abstract. The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the European starling Sturnus vulgaris, an invasive bird from Argentina. Seventy-six birds were collected during the spring of 2007 and were examined for helminths. Six parasite species were found: one trematoda of the Echinostoma revolutum "group," four nematodes (Synhimantus nasuta, Microtetrameres sp., Pterothominx exilis, and Ornithocapillaria ovopunctata), and one acanthocephalan (Plagiorhynchus cylindraceus). All species found have been recorded in Eurasia and/or North America previously, although present reports enlarge their geographical distribution. As expected in an invasive host, the parasite community shows much lower species richness (n = 6) than those observed in their native area (79 and 35 in the Eurasia and North America, respectively).
Feenders G, Klump GM. Audio-Visual Interference During Motion Discrimination in Starlings. Multisens Res. 2023 Jan 17;36(2):181-212. doi: 10.1163/22134808-bja10092.
Abstract. Motion discrimination is essential for animals to avoid collisions, to escape from predators, to catch prey or to communicate. Although most terrestrial vertebrates can benefit by combining concurrent stimuli from sound and vision to obtain a most salient percept of the moving object, there is little research on the mechanisms involved in such cross-modal motion discrimination. We used European starlings as a model with a well-studied visual and auditory system. In a behavioural motion discrimination task with visual and acoustic stimuli, we investigated the effects of cross-modal interference and attentional processes. Our results showed an impairment of motion discrimination when the visual and acoustic stimuli moved in opposite directions as compared to congruent motion direction. By presenting an acoustic stimulus of very short duration, thus lacking directional motion information, an additional alerting effect of the acoustic stimulus became evident. Finally, we show that a temporally leading acoustic stimulus did not improve the response behaviour compared to the synchronous presentation of the stimuli as would have been expected in case of major alerting effects. This further supports the importance of congruency and synchronicity in the current test paradigm with a minor role of attentional processes elicited by the acoustic stimulus. Together, our data clearly show cross-modal interference effects in an audio-visual motion discrimination paradigm when carefully selecting real-life stimuli under parameter conditions that meet the known criteria for cross-modal binding.
Hume JP. Systematics, morphology, and ecological history of the Mascarene starlings (Aves: Sturnidae) with the description of a new genus and species from Mauritius. Zootaxa. 2014 Aug 12;3849:1-75. doi: 10.11646/zootaxa.3849.1.1.
Abstract. Two endemic starlings, both extinct, have been described from the Mascarene Islands of Réunion and Rodrigues: the Hoopoe Starling, Huppe or Réunion Crested Starling Fregilupus varius, which is known from 19 skins and a single Holocene proximal end of a fossil femur, and the Rodrigues Starling Necropsar rodericanus, which is known as specimens only from fossils of most skeletal elements. Both were recorded alive in early accounts of Mascarene faunas. A third species of starling Cryptopsar ischyrhynchus gen. nov. sp. nov. is described herein from fossils from Mauritius, but was never reported in the early literature. This paper provides an analysis of the Sturnidae of the Mascarene Islands based on newly discovered fossil remains, and details historical reports and accounts. Their ecology and extinction are interpreted from historical evidence. Necropsar, Cryptopsar and Fregilupus clearly form part of the same clade, but morphological analysis shows that Necropsar and Cryptopsar are more closely related to each other than to Fregilupus and may have been part of a different colonisation event. All three genera appear to have their origins in SE Asia and have morphological similarities with the SE Asian sturnid genera, Sturnia and Gracupica, so they presumably colonised the islands via island-hopping during lower sea level stands.
