Nature Guides

Births in Water, Births on Land

Late May 2012

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Featured Species: Spawn of Sunfish!

Members of the sunfish family such as Smallmouth Bass and Pumpkinseed begin to spawn in late May. In the sunfish family it is the male that does the work building the nest and raising the young.

Spawning Smallmouth Bass can be seen along rocky shorelines or lakes and rivers. Males build a nest by creating a depression (31-183cm in diameter) in sandy, gravel, or rock bottoms in shallow water about 1m deep. The nest is usually located near the protection of rocks or logs, or more rarely dense vegetation.

Pumpkinseeds also build a shallow saucer-like depression, but a bit smaller (13-38cm in diameter) in clay, sandy, gravel or rock bottoms. Their nests are often part of a colony that may number over 100 closely arranged nests. The pumpkinseed male vigorously defends his territory.

In both species the male courts a female, involving swimming in circles and nipping. The female lays her eggs, which attach to the bottom of the nest, and the male will fertilize them (5000-14000 eggs for Smallmouth Bass, and 600-5000 eggs for Pumpkinseed). After spawning the female swims away – her job is done. She may go spawn with another male.

It’s the diligent dad that stays at the nest to protect and aerate the eggs by fanning water over them. Still, many eggs fail due to predators, sudden shifts in water temperature, and fungal infections.

Hatching in Smallmouth Bass takes 4-10 days. It then takes an additional 12 days for the young to absorb the yolk sac. 5-7 days after hatching the young will begin to leave the nest. The male will continue to guard them (young are small black spots) until they eventually wander off too far for him to keep track of all them. Males often return to the same area to nest in subsequent years. 

Pumpkinseed eggs hatch within a few days. Dad will also guard the young for up to 11 days, returning them to the nest in his mouth if the fry stray too far. After this time, the young leave and the male may clean his nest in preparation for a second spawning.

Other Happenings:

  • Nature is getting it on - it’s a bit of a wild rumpus out there!
  • Curious and rambunctious Red Fox kits can be watched playing at their den – so cute! Foxes den in abandoned groundhog holes or in holes dug by adults on sandy slopes. Dens may be used and discretely observed for many years. Kits emerge from dens when they are about a month old. The female stays with the kits, putting up with kit antics, for about a month while the male does the hunting.
  • Reptiles do it too - and Northern Water Snakes are mating. They may be seen entwined on low branches and in other vegetation near the water’s edge.
  • Blackpoll Warblers are passing through, and deserve accolades. This tiny, 12g bird undertakes a very long journey from South America to more northern regions of Ontario. That takes a lot of energy. Before undertaking the trip, the Blackpoll Warbler packs it on - the fat is needed to fuel the flight.
  • Non-breeding Giant Canada Geese start to migrate to James Bay to moult and compete with nesting Northern Canada Geese (see Late April). While moulting their feathers they are unable to fly.
  • Frothy, white masses of spittle become a common sight on the stems of plants. These are created by Spittlebug nymphs that suck juices out of the stem and excrete the excess, which envelops them and likely helps protects them from predators.
  • Watch out for Poison Ivy. Leaf size, colour, and shininess vary, but here are three distinguishing characteristics: 1) the middle leaflet has a much longer stem than the other two, (2) the leaflets droop downward, and (3) at least one of the leaflets is almost always asymmetrical. Poison ivy is thriving in the elevated atmospheric carbon dioxide levels.  Studies show that plants are getting bigger and producing more urushiol, the oil that causes the itchy rash. Everything is connected!
  • Something invisible and remarkable is happening in our lakes again, something that hasn’t happened since October. When ice and snow leave the lakes they are allowed to “breathe” oxygen again. Photosynthesizing aquatic plants begin producing some oxygen, but the bulk comes from the air above. A lake that is uniformly cold allows the water to be mixed. On windy days, wave action extends all the way to the bottom of the lake, distributing dissolved oxygen throughout. This is called spring turnover. As summer approaches, surface water will heat up while the deeper water remains cold. Because warmer water is less dense the water doesn’t mix and only the top layer gets oxygenated. Virtually no mixing will occur again until the fall (see Mid-October), when colder temperatures will cool down that top layer.
  • Monarchs have been reported from Southwest Ontario, and as far northwest as Barrie, so keep your eyes peeled and report that first butterfly!
  • On May 22, Venus and the moon will be very close together after sunset, a sight you will not see for the rest of 2012, so enjoy!