It’s a fairy tale or fake news to believe all is sweet and peaceful in the world of birds. We are enchanted by their melodious tweets and beautiful plumage, and are often found among them in seemingly peaceful natural settings, but don’t be fooled. Their world is one without constables or arbiters of justice. There are no rules, other than “might makes right”, “survival of the fittest”, and “it’s okay if you can get away with it”.
Their crimes range from petty theft to rape and murder. We birders are onlookers into this world which is similar to our old Wild West, and are grateful for our, albeit fragile, institutions of justice. As we bird we are witnesses to many of these crimes and often wonder what it would be like living in their world. Occasionally I’m even tempted to intervene on behalf of a victimized bird, but usually hold back and let nature take its course and toll.
Many of their crimes are mere misdemeanors. This would include the holes the Red-bellied Woodpecker is making in my sister-in-law’s cedar siding. The crows, jays, and gulls are perfecters of the art of petty theft. The former two are attracted to shiny objects, while the latter steals food, literally from the mouths of their careless victims. This usually results in a chase, sometimes resulting in a maimed fish dropped back into the ocean with no party getting any satisfaction.
A somewhat more onerous and significant crime is the practice of brood parasitism as I’ve discussed in prior posts. This disgusts our human sense of fairness and personal responsibility, but evolution has apparently blessed it as a successful tactic among many bird species. The initial crime is the stealthy planting of the itinerant egg in the nest of the unsuspecting parent-to-be, but the atrocity is magnified when the robust hatchling pushes the other weaker step-sibling out of the nest.
Many avian disputes are over territory and nesting rights, somewhat similar to those issues which crowd our human court dockets. The Red-winged Blackbird claims his territory with a beautiful song, but don’t let that fool you. He’ll attack any other bird, even a larger foe, that dares interlope into his nesting sphere of influence.
My friends Andy and Sam were accidental witnesses to a spectacular avian air battle between an adult Bald Eagle and Osprey. Andy was even dexterous enough to grab a camera and snap off a shot or two to document the event. Unfortunately, in cases such as that one shoots the pictures first, and checks camera settings later. It seemed like the smaller Osprey got the better of that fight. It was probably a territorial spat with the eagle getting too close to the Osprey’s nest. As you know, Bald Eagles are opportunistic scavengers, often feasting on the killings of others.
Hawks and owls, on the other hand, are merciless killers, always on the prowl to feed themselves and their offspring. Often their victims are other birds, but small mammals are also unsafe around a hungry bird-of-prey. In my yard Accipiters have become good at patrolling the bird feeders, flying in fast and low to take an innocent, unsuspecting passerine. We can take some comfort in that such killings are a necessity of life for the raptor.
In my last post I reported the rape of a Muscovy Duck. I will hazard a completely uninformed guess and venture that most sex among birds is consensual. I may be completely wrong about this, but do point out that many birds do mate for life. That lasting bond would be hard to imagine if it began with a rape, but admittedly I’m anthropomorphizing. Those ducks, however, did seem to cross a line, with no avian justice in sight.
I was recently chasing a rarity Iceland Gull on Fort Myers beach, unsuccessfully, when I snuck up on a Reddish Egret and was rewarded with my closest shots ever of the great bird. Suddenly a second egret swooped in and I witnessed a prolonged battle; or was it courtship and copulation? I find it hard to differentiate these with the birds.
So with all the violence, what is the mortality rate among birds? In this year of the pandemic our human death rates are plastered on the headlines daily. A few things are clear in the avian world. Larger birds live longer than smaller birds, but why is this so? Perhaps it’s because the larger birds are near the top of the food chain and less often preyed upon. Banding data has reported some longevity record life spans: Red-tailed Hawks and Brown Pelicans, 28 years; American Robin, 14 years; Eastern Bluebird, 10 years; and Ruby-throated Hummingbird, 9 years. Most birds, however have much shorter lives.
It’s estimated that 80-90% of birds do not live to maturity. This is a striking number, but when one remembers the numerous eggs laid and multiple broods per year created by a mating pair, it makes perfect sense. If they all survived we would be inundated with birds, just like an Alfred Hitchcock film. It’s also said that the mortality rate of birds is six times higher during spring and fall migrations. Travel is risky, as we all know.
It’s difficult to determine how many birds die at the hands or feet of other birds, or from avian diseases. Data regarding bird deaths caused by us humans is more readily available. Collisions with buildings and glass claim an astounding 600 million birds a year; collisions with vehicles, 200 million, and electric wires, 25 million. Six million birds succumb to electrocution each year and one such case was chronicled in my post of 17 November 2019. Our pesticides claim another 72 million per year, and who knows how many die from their loss of habitat. But all these numbers pale next to the 2.4 billion birds killed yearly by domestic and feral cats. That shocking number is hard to believe.
How can I conclude such a morbid post of avian crime and death? Perhaps by showing you two Great Blue Herons in love, or by simply stating that these are observations of life on our planet as it is, and not as we wish it to be. It’s merely a description of both the beautiful and fair, right along with the ugly and unjust.
brighamstephen 