Common Whitetail and Widow Skimmer

Here are a couple dragonflies I've talked about before, a Common Whitetail (upper left) and a Widow Skimmer (lower right), each perched next to one another overlooking a pond. They're both robust-looking dragonflies, and can look a little similar when the Widow Skimmer has more pruinose and thus has a while abdomen. (I suspect the Widow Skimmer is a little on the young side, and will eventually look whiter.)

My recollection is that on this day there were a lot of dragonflies out there, mostly males flying back and forth, presumably trying to carve out an area that females will find appealing. But all that flying uses up energy, and so it's not uncommon for them to conserve energy by finding a perch where they can survey their territory.

Though these guys are competitors for food, being separate species they don't compete for mates. Most of their aggression is spent on harassing/intimidating males of their own species, though occasionally they appear to have inter-species aerial dogfights. I'm not sure whether those are cases of mistaken identity or whether someone else had their favorite perching spot.

Dragonfly interactions remind me of intra-species and inter-species interactions of birds at bird feeders. There's an awful lot of activity, there's probably a loose "pecking order", some of them probably look at others of them as potential prey, some view others as rivals, and I'm probably failing to understand most of the interactions.

June 15, 2022 at Sourland Mountain Preserve
Photo 210217644, (c) jpviolette, some rights reserved (CC BY-NC)


Comments

Post a Comment

Popular posts from this blog

Northern Watersnake

Image
This April I went to Great Swamp National Wildlife Refuge with the hope (among other hopes) of seeing the Northern Watersnakes during mating season. There were 2 problems with this: I think it was slightly late in the season for this. The boardwalk trail where I had seen them in the past was partially closed due to repairs. So although I didn't see any of the 2+ intertwined snakes that I'd seen in the past, but there were still Northern Watersnakes warming themselves in the sun: April 13, 2023 at Great Swamp Photo 272117862, (c) jpviolette, some rights reserved (CC BY-NC) And here's another one coming out of the water. April 13, 2023 at Great Swamp Photo 272119139, (c) jpviolette, some rights reserved (CC BY-NC)
Read more

Female Brown-headed Cowbird

Image
Like quite a few birds, this bird is easier to identify when spotted with her significant other ; she's a Brown-headed Cowbird . Due to their tendency to be monogamous plus plain old birds-of-a-feather behavior, I usually see them with prominently brown-headed males around, greatly improving my confidence in IDing them. My understanding is that Brown-headed Cowbirds are the only obligate brood parasites in my area. Obligate brood parasites have essentially lost all their parenting skills, and thus if they were ever unable to fool other birds into raising their young, they would (almost certainly) go extinct [1]. There are, however, other brood parasites in New Jersey. These are called facultative brood parasites, and these birds will usually raise their own offspring, but will also engage in brood parasitism. (Exactly when birds perform facultative brood parasitism seems variable; one source said it occurred when resources were scarce while another said it occurred when resource
Read more

Rooftop Turkey Vultures

Image
I met these Turkey Vultures by just walking out of my apartment. (I theoretically could have gotten a picture without going outside, but that extra layer of glass can degrade picture quality a little.) Although they don't show up on these rooftops daily, they're not an uncommon visitor to my apartment complex. Similar to this spot of the woods , I wouldn't expect this to be a great place to find carcasses. I'm thinking they're here mostly because: They don't have to worry much about predators up there. They get a pretty good view of the area in case something should happen to succumb. (This apartment was near the top of a hill, providing a better view than most of the other apartments.) Since this picture was from February, it's probably a slightly warmer spot, especially near those furnace vent pipes. Although these are Turkey Vultures, it's also not unusual to see Black Vultures up there too. February 28, 2023 at Finderne Photo 264703396, (c) jpviole
Read more