Simply Symbiotic
The phainopepla is a pretty bird. I’ve seen quite a few of them at the Oasis of Mara in Twentynine Palms and flitting up and down washes where willows are plentiful. The males are jet-black with white patches under the wings, the females are sort of a blue-grey and both have the redest eyes I’ve ever seen on any kind of animal.
They eat seeds and berries, but when in season, their favorite food is the berries of the parasitic desert mistletoe. They will fly from tree to tree and eat the plump, juicy little berries and spend the day perching on branches socializing and watching the day go by.
The relationship between mistletoe and its host is a parasitic, win-lose symbiosis. The mistletoe digs its roots into the host tree and sucks water and nutrients from its branches. This will continue and the parasite will grow and eventually kill the host. Of course, this isn’t good news for the mistletoe; the plant doesn’t have the capability to survive on its own. This is also terrible for the little phainopepla, who will either starve, or at least have to concede to a bland diet/existence without the essential fruit, and working harder to catch bugs in flight.
So when I first heard of this, I thought, “So how come there are still phainopeplas and mistletoe?”
The answer lies in the behavior of the phainopepla.
The life of the little passerine is not totally idyllic. They have to avoid being eaten by predators, for example, a kestrel. This is why they flit- I don’t know if that is the proper name for it. But, they come in low under the branches and hop to the fruit and hurriedly gobble the berries whole.
After a meal, being a perching bird (passerine), they find a nice branch to sit on and watch for danger. The berries, eaten in their entirety, are processed through the sytem and excreted (pooped) as waste. This material lands on the lower portions of the perch and contains the undigested seeds that were in the berries. This organic conglomerate remains in place until the winter rains ravage the land.
After the rains have softened the seeds and initiated botanical processes, the parasitic mistletoe may have found a healthy host to extract nutrients from. This in turn, produces more berries for the phainopepla, who gobbles them whole, transports the seeds to a new host, and etcetera, and so on.
So what about the poor host plant? Well, they die. Then they rot and decompose. The dead branches and twigs are used for little homes for rats and nests for birds and bugs. The seeds they produced while they were alive are scoured by the rain in the sand and sprout into new trees and shrubs. Eventually they grow big enough for the little phainopepla to use for a perch, to socialize, watch for danger and digest a meal.