Mother’s day redux

Monday I observed (and posted about) the newborn Chinese mantises (Tenodera sinensis,) while wondering if the all of the viable eggs had hatched – I’ve seen cases produce multiple ‘broods,’ for want of a better word. I was up late Monday night, so didn’t get out as early as I should have Tuesday morning. Nature has a way of making one regret such actions; the twig that supported the egg case was literally covered in newborn mantids by the time I checked it, with no apparent activity from the case at that time. It would be nice to think I’ve learned my lesson, but I probably haven’t.

newborn Chinese mantises Tenodera sinensis clustering close to where they hatched
You have to appreciate the one up top, who appears to be directing operations…

newborn Chinese mantises Tenodera sinensis on day lily leavesTo say that the front garden is loaded with baby mantises now is selling it short – it looks like an invasion, and one does not have to look hard to find them anymore. In fact, it’s a challenge to find a plant that doesn’t have one on it, including a potted flower on the steps, which is an indication that some of them had to cross the steps to get there, making me even more self-conscious of where I walk. But at the same time, a lot of arthropod species reproduce in vast numbers because the loss rate is high, the newborns being too vulnerable to survive on average. If each offspring has a 5% chance of survival to adulthood but 100 are produced in a brood, this means five will (again, on average) make it through. I’ve seen several hatchings now, and despite the large numbers at first, by the time egg-laying season rolls around I can only find two or three at best.

It might seem harsh to us, especially with how protective we are over baby anythings, but if we really did have most mantids surviving to adulthood, the impact on the ecosystem would be severe. They would, of course, be eating a much greater number of other arthropods, including pollinators; we tend to label certain insects as “beneficial” because they consume the “pests” that damage the plants we like, such as vegetables and decorative species, but this is a narrow and egocentric perspective, and mantids don’t feed solely on the species we’d prefer. Nature doesn’t make value judgments, it just tends to balance out excesses.

Come to think of it, in all my time observing I’m not sure I’ve seen more than one of two mantids actually meet their demise; one of them was from another mantis, very close to egg-laying time. It’s obviously happening, but what factors are most responsible for culling the numbers, I cannot say. I’ll have to keep my eyes open.

The light was on-and-off today, vacillating between sporadic sunlight and overcast, and most of the time when I was observing the hawks’ nest it was overcast. When some sunlight finally did start hitting it, the neighbors (in whose yard the tree actually sits) were mowing and the parents had vacated the nest, though one of them would pass through the area periodically, calling loudly; whether this was typical territoriality or in protest over the noise and proximity of the mower I can’t say. Once the noise stopped I kept an eye out, as well as an ear; the parents tend to issue some calls as one approaches with food. It wasn’t long before dad had returned bearing a gift, and I was ready.

red-shouldered hawk parent Buteo lineatus bearing snake to feed offspring
I’m fairly certain that this is the male, and the female has a notably red breast (see yesterday’s post,) but I could be mistaken – usually it’s the males that are more colorful in the avian kingdom. I like the coloration of the other better, but this one was a lot more cooperative in standing aside and letting me watch the feeding process.

The principle diet of red-shouldered hawks (Buteo lineatus) is considered to be frogs, and we have a pond very close by that should be able to provide plenty – not to mention another source even closer – but so far I haven’t seen such being presented to the young. Granted, I’ve only seen three feedings in detail, but two of them were small rodents such as voles, and a casting that I found in our yard supported this diet. And this is the second time I’ve seen them snag a snake. I really shouldn’t link to those posts since the hawk photos are so much better.

But then again, they don’t show the fuzzy little bobbleheads stretching their wings after feeding, either.

red-shouldered hawk Buteo lineatus nest with nestling spreading its wings
This photo made me pause, because if you look closely at the nestling on the right, you’ll see that something seems to be in front of it. I went back through dozens of photos, trying to determine if there was any evidence of three newborns, without any confirmation – I’m fairly certain, even from my photos of the feeding behavior of the adults, that there are only two. So what I think we’re seeing is the outstretched wingtip of its sibling on the left.

fishing spider Dolomedes tenebrosusWhile I’m still on the subject of motherhood, I’ll just throw this one out there. The fishing spider (Dolomedes tenebrosus) that I first introduced a month ago disappeared for a while, only to be found again a few nights back. Just this evening I photographed her again, and suspected that she looked a bit smaller in the abdomen than before; comparing the images offers tentative confirmation. Now, this could be because the cold weather forced her and any handy prey back into hiding for a bit, or it might be because she has now produced an egg sac of her own, likely hidden down in the crevice that serves as her home. I know the six-spotted fishing spiders suspend their egg sacs in the leaves of pond plants, and I have a nice selection of such that could serve that purpose, but perhaps D. tenebrosus is different? We’ll just have to see if the property explodes with tiny newborn fishing spiders, I guess.

[I have not said anything like the above sentence to The Girlfriend or The Younger Sprog – neither of them would really want to hear it. It’ll be our secret, okay?]

At the same time that I was obtaining that image, I went in close to one of the two resident frogs (which are so far avoiding the red-shouldered hawks, mostly by being nocturnal.) While I had long thought we had two green frogs (Lithobates clamitans,) I’m now fairly certain this one is an American bullfrog (Lithobates catesbeianus) – it’s still a juvenile, but now bigger than typical adult green frogs and showing the bullfrog coloration. The other, however, remains a green frog. They’re both growing in size so apparently finding plenty to eat; if they like the massive millipedes that frequent the yard, I suspect they’ll be able to grow to the size of Clifford…

American bullfrog Lithobates catesbeianus posing for portrait
In closing, I offer another mantis photo, but this is more to be fartsy rather than illustrative. Taken about a week ago before the big hatching (thus from another brood, an egg case I’ve never spotted,) I snagged this one after a heavy rain, the drops acting as nice magnifiers for the leaf veins. If we get the expected rains tomorrow – uh, later today – maybe I’ll be lucky enough to do that raindrop-lens thing with a mantis as the subject.

newborn Chinese mantis Tenodera sinensis on day lily leaf with water drops