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Tuesday, July 13, 2021

invasive

A large hot and dry dust cloud has blown in from the Sahara desert delayed the monsoons in New Mexico. This atmospheric turmoil has caused the water levels of the Scuzzy ditch to rise and fall unpredictably.
The largest bullfrogs have staked out the best stable water places and can often be found resting midstream on pond weed. The usual weed found in still, shallow water is Eurasian watermilfoil which is definitely not a native species. But the thicks growth offers frogs great protection from shore predators.
When the water disappears, the algae dries and consolidates to form mats on the mud. When the water comes back, the water lifts these mats up as they can trap air beneath. The shade created is ideal for many types of small fish and crustaceans.
The toadlets have begun to emerge from the river's backwaters and hop into the forests. That any survive is pretty miraculous.
The thick willow stands at the edge of mud flats provide ideal hiding places for these tiny guys. The short grasses at the boundary also provide the bountiful small insects, like mosquitos, that the amphibians also need to survive the early weeks. They can live for 10-20 years.
These mud flats are the ideal nursery for seedlings like cottonwoods and willow. There is a wide mix of substrate, such as sand, gravel, clay, and humic earth. The nutrient levels are lower than in the interior ditches, which often turns out to be a good thing. The speed of the water just before it disappeared controls the material on the bed.
The cicada emergence holes also help provide safety for the those toads. The hard packed surface where people walk allows the holes to keep their shape without collapsing.
This cicada wasp was acting oddly by chasing off other wasp species. It seemed to be looking for something specific. It should be nesting. I had no idea the velvet ants predate the larvae with their own larvae. It was likely a male waiting for a female to emerge from a nearby hole.
The cicadas are trying to mate before they die or end up in the nest of a cicada killer wasp. The drones (males) of most insect species are pretty expendable and die shortly after mating.
This male velvet ant also died after a brief and energetic life. The corpse is difficult for ants to break up, bu those insects are nothing if not persistent.
The water's surface is dotted with ripples of something unseen that is resting on the stems of plants.  This is the best picture I could get. I think they are emerging dragonfly nymphs, but I am unsure.

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