Owner Comments:
Our next modern dinosaur is represented by a version of one of the most iconic and well known dinosaur coins of all time: the 1967 Canadian Confederation Centennial Cent, first released as a bronze coin with commemorative versions released at various points in the 2010’s. The coin featured here is the 2017 50th Anniversary version of the coin, struck in gold-plated silver and, like all versions, features the Rock Dove, species name Columba livia.
The wild form of the Rock Dove is a pale grey bird with black bars each wing and orange, red or gold eyes. They have a grey-black beak with an off-white cere and purplish-red feet. Their domestic and feral descendants, known to many as pigeons, vary widely in color. Size wise, Rock Doves range from 11 to 15 inches long, with a wingspan of 24 to 28 inches and a weight range of 8.4 to 13.4 ounces. There is no real sexual dimorphism among Rock Doves aside from decreased iridescence of the feathers of females. Geographically, they naturally inhabit parts of Southern Europe, Northern Africa, the Middle East and Western Asia but they have been introduced into many parts of North and South America, Eastern Asia, Southern Africa and Australia. These introduced populations are largely feral descendants of the domesticated form of the bird. 12 subspecies of Rock Dove are generally accepted to exist by scientists, some of which are descended from feral stock.
Rock Doves are gregarious birds and they live and feed in large flocks. They feed largely on seeds and fruits, but they are adaptable and will scavenge from human garbage cans and other sources of nutrients. They will also take handouts from humans if they are conditioned to do so. Rock Doves are also adaptable as far as habitat is concerned. Rock Doves live in towns and cities in large numbers as our buildings actually provide this species with exactly the type of living and nesting grounds they require and our birdfeeders and garbage provide them with large and easily exploitable food sources. The natural habitat of the Rock Dove is cliffs and caves, which buildings approximate almost perfectly.
Though the large size of Rock Dove flocks and lack of visual differences among individuals make this hard to determine with certainty, but it is thought that Rock Doves mate for life. They can breed at anytime of the year, but breeding is most common in the spring and summer. Nests are a platform of straw and sticks positioned under ledges and other sources of shelter. The nests are constructed entirely by the female from material that is provided entirely by the male. Two eggs are produced and are incubated by both parents for 17-19 days until they hatch. Rock Doves are altricial and are born covered in yellow down and are helpless. Rock Doves feed their young with crop milk, which is a semisolid milk which is high in fats and proteins that is secreted by the crop lining in both parents. The young leave the nest at between 25 and 32 days of age, but this can be longer for young born in cold weather.
The adaptability of the Rock Dove has led to it being vitally important in the recovery of many previously endangered raptors by providing them a major source of food in a variety of habitats, allowing them to find new habitats to live in. The Peregrine Falcon has particularly benefitted from suburban and urban Rock Dove populations and is the major predator of this species in most habitats. Other predators of Rock Doves are mainly avian and they include Eurasian Sparrowhawks, Red-Tailed Hawks, Great Horned Owls, Eastern Screech Owls, American Kestrels and Golden Eagles. Ravens and Crows will also prey upon smaller Rock Doves along with chicks and eggs. Mammalian predators of Rock Doves include opossums, raccoons, bobcats and other small felids, including the domestic cat.
As is mentioned above, the Rock Dove has been domesticated into the pigeon, which is a bird that has been used for food, pets and as message carriers. The Rock Dove has a remarkable talent for both travelling long distances when needed and finding their way back to their point of origin after such a trip. Many domesticated Rock Doves used as carrier and homing pigeons during wars have earned military honors and decorations for their services. There is also a hobby around raising fancy pigeons and showing them, like there is for cats, dogs and aquarium fish. The domesticated pigeon is the form of the Rock Dove that has made the most inroads into new habitats.
In the form of the feral domestic pigeon, Rock Doves have gained a reputation for being dirty or being a pest. In fact, many people refer to them as “rats with wings”, but this reputation is unfair and unwarranted. In fact, there are only four diseases that pigeons can spread to humans. There is a minor risk for humans to contract histoplasmosis, cryptococcosis and psittacosis from prolonged contact to pigeon feces. The one disease that pigeons do pose a risk in spreading, however, is avian influenza but it should be noted that it is rare for influenza to jump directly from any bird to a human. Birds are reptiles and humans are mammals. Our bodies are very different, making microbe jumps difficult and relatively rare, but when jumps do occur they can be serious. But, the truth of the matter is that you are much more likely to contract a disease from a pet cat or dog than from any reptile, including a pigeon. I have had a box turtle for 26 years and I’ve never gotten sick from him, but my dad’s cat gave him a very nasty infection once from a bite.
As far as being a pest, well, I guess that one depends on your perspective. Feral Rock Doves are certainly numerous in many urban and suburban areas and they have to build nests and perform their excretory functions somewhere. However, I prefer to look at them as one of the key links in the amazing ecosystems and food chains that have arisen in our settlements. They provide food for more charismatic avian dinosaurs, such as urban Peregrine Falcon and Red-Tailed Hawk populations. They are also efficient consumers of discarded human foodstuffs, leading them to have a role in cleaning up after us. And they actually do not carry and spread diseases the same way mammalian pests like rodents and feral cats do. I definitely view this modern dinosaur in a fairly favorable light, even if they have used my little Volkswagen Beetle as a toilet when I’m at the grocery store 😊