Dicromantispa interrupta

Dicromantispa interrupta

Monday, February 1, 2010

Caracaras and other Road Raptors

I have returned to working full-time on the pipeline job that I had most of last year doing imperiled species work. I am staying in Lake Placid, FL and wishing there were some good restaurants here. I work as far afield as the other side of the city of Okeechobee (“Oh, Ah’m proud to be an Okee from Lake Chobee…”), and they don’t have any good restaurants, either. At least they aren’t expensive, but I can tell you, my friends, it is grim here, culturally speaking.

But the wildlife is anything but boring. Ranchers down here like to tell me that they have a lot of wildlife, but I want to tell them that they don’t, either, it just looks like they do. Ranches are mostly barren of trees and shrubs, so wildlife can’t hide very well. You can look out over a large field and see whatever lives out there pretty much as plain as day, and you might see a flock of turkeys, a few soaring raptors, feral pigs and armadillos, but mostly what you see is cattle. Ranches do not have a lot of wildlife and they do not have a lot of species, but at least their openness makes my job easier.

I am checking on all the nests of the crested caracara that we found last year to see if they are in use again this year. If so, I mark it down and move on. If not, well then why not? Has the pair moved to another site? We know about one pair that has nested in three places in as many years. Or have they just not yet started nesting for this breeding season? But other caracaras are nesting already, so that cannot be it. Or can it? Maybe some territories are not ready for caracara breeding. Maybe there isn’t enough food for some of them to successfully breed this year?

South Florida’s upland fields are typically dormant and brown right now at the beginning of the nesting season, so there are few grasshoppers and no reptiles to hunt. Caracaras cannot ordinarily make effective use of small upland mammals because those are nocturnal whereas caracaras are diurnal. Only when nights are so cold that rabbits and rodents will forage in the late afternoon when there is still good light can caracaras get some of that. Oh, you want to know why caracaras have such long legs? Last year, one of our team members watched a caracara run down and kill a young rabbit! Those long legs also give the bird a leg up to see above the native prairie and exotic pasture grasses.

Last year at this time, freshwater marshes had water and prey items for the hungry caracaras and their nestlings. Last year there were plenty of frogs, snakes, turtles and fishes in the shallow marshes and ditches, but this year the marshes are all but dried up and have been for months. Cattle have so heavily grazed the marshes that either there is almost no greenery at all in them or only coarse, unpalatable graminoids like soft rush and sand cordgrass. There are no frogs, no reptiles and no fishes in well over 90% of the marsh acreage that was inundated last year.

Uplands do have another prey item available, but I do not know whether caracaras go after them. The fields are chock full ‘o meadowlarks, the males standing decoy with their bright yellow breasts while females hide on their nests in the laid-over cut grass. I have several times watched caracaras walk slowly, zig-zagging through the grass, watching to either side as they go to see what they might flush, but have not yet seen them capture anything.

There is plenty of carrion on the highway for them to eat. I counted five road-killed otters, a dog, a striped skunk, a deer and innumerable opossums and raccoons over the last two weeks. But there is a lot of competition for that carrion, too. Did I ever tell you about “Road Raptors?” This is what I call the group of black bird species that patrol the highways for fresh meat in a predictable manner first thing in the morning. Just as soon as you can see 10ft in front of your nose, the crows (American and fish) and “blackbirds” (common grackle, redwing blackbird, Brewer’s blackbird) hit the pavement looking for small things to eat, like insects and pieces of meat ripped off corpses by mud tires. When you can see 50ft in front of yourself, out come the bald eagles and caracaras. Next is the turkey vulture and last is the black vulture. So, the small road raptors get the really easy pickings, then the caracara and eagle face off over the meat, then the turkey vulture arrives and squabbles with the eagle and caracara, and then the black vultures arrive en masse and run everybody else off. Then the fire ants find the meat and run off even the black vultures! Oh, and the cars. Often I will see birds trying to snatch carrionnettes between vehicles, and remember this is rush hour and it might be foggy too. A few days ago, I spotted two juvenal caracaras dodging hurtling irons, so I pulled over and dragged the (raccoon) carcass off the road.

All in all, I believe the caracaras may not get as much prey this year as in wetter years because of the effective loss of wetland marsh habitats. If so, then there is a good possibility that many of last year’s caracara nesting pairs may not reproduce this year. It was hard enough to find the nests that existed last year, but it is going to be much harder this year if we have to look for nests that aren’t there. On the other hand, if nesting this year is successful overall despite continued drought, it will tell me a sad something about the nursery power of the highway.

And there are other complications. One pair of caracaras nested close to a road in 2009, but that nest had been abandoned and was almost totally gone when I checked it this year. I continued my walk on the mile-square property, inspecting every cabbage palm along the way and discovered the nest they had built for this year. But looking closer, a familiar furry body could be seen in the nest and it wasn’t a bird – it was a raccoon. Either the ‘coon had run off the caracaras, and hopefully they won’t come back and lay eggs where the raccoon can easily find them, or the ‘coon had eaten their eggs or nestlings and then run the adult birds off. Looking around some more, I found a bald eagle nest on the property that had been hitherto unreported (my first “new” eagle nest!). This nest is located in an area with numerous cabbage palms (97% of Florida caracara nests are in cabbage palms), but the likelihood of the caracaras nesting so close to a pair of top carnivore raptors is probably slim. The irony is that this property has a lot of surface water, naturally and by wells, so its wetlands should be able to support a breeding pair and their young, maybe even two broodings. Egad!

Let’s hope that continued surveys of this property will reveal a third, successful nest for these hard working avians.

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