Pond Boss Forums INTRO Questions & Observations Adult Golden Shiner Survival....

This is correct I think. For a little more context ... I once read a study on the effects of turbidity on SMB predatory behavior. What the study found was that SMB would not launch pursuits at the same distances that they would in clearer water. The prey would have to encountered at shorter distances the more turbid the water was to stimulate a pursuit by the SMB. They did find that when a pursuit was prompted ... the success was roughly the same in turbid water as it was in clearer water. But the restriction of closeness of encounter restricts the number of pursuits launched. In turbid water, SMB consume less relative to clear water unless the density of prey offsets the clarity effect.

It may be helpful to show how probability can be expected to work. I do not want to use an example of end-of-life forage because I have already stated that at end-of-life ... forage can be consumed by predators that wouldn't otherwise be able. The key there is to have a gape big enough to swallow the prey.

But I did say an 18" LMB stands a 1% chance of successfully consuming a 7" GSH in a pursuit ... per the probability function. You may say ... there must be little chance of it being consumed where 18" LMB are present. It depends on a few things. What other prey is "out there" is one thing. If the 18" LMB are consuming smaller prey to satiation ... this gives that 7" GSH a better chance at surviving. But let's just suppose that this smaller prey is absent and we have a population of just 18" LMB and 7" GSH. Now the rate of exploitation of 7" GSH by 18" LMB will depend on the probability of successful pursuit and the number of pursuits initiated daily. Esshup, you mention a 4 month period or approximately 120 days. So under this scenario, mortality of 7" GSH will depend on the number pursuits the GSH will have to endure daily. In the beginning it will be a lower number, because the number pursuits will spread across a larger population of GSH. Once an LMB has fed to satiation, it will stop foraging and so as the population dwindles, GSH have to endure increasing higher daily pursuits where the dependence on pursuits becomes more dependent on the density of LMB than the density of GSH. Anyways, lets say this averages 1 pursuit per GSH per day for the entire period. The probability of being consumed in 120 days is very high for those GSH. If GSH were to average 0.5 pursuits per day for the period. The probability of survival is ~40%.

The number of pursuits endured and the sizes of the LMB pursuing them are the important factor and one has to consider the cumulative effects of ongoing pursuits.