Background

Background on project objectives and questions to be asked

Thank you for agreeing to take part in this online expert elicitation to help inform the development of a national recovery strategy for red squirrels in England. In this exercise, we will seek your expert judgment on a number of parameters that influence red squirrel population dynamics. These parameters span a range of topics, including the life history characteristics of red and grey squirrels, the epidemiology of squirrelpox virus, and the effectiveness of grey squirrel management strategies. Your answers will directly feed into a large-scale population model that aims to predict the recovery of red squirrels under different biological and management scenarios. Essentially, your expertise will help parameterise the model and include uncertainty, ensuring that it reflects the best available knowledge about these species and their interactions.


Admin annotations: Keep in mind the point of this discussion is not to get everyone to agree on a single value, or to convince each other of the values they put in. We want to make sure everyone is a) answering the same questions (i.e. interpreting the questions the same way), b) answering the questions using the same information and insight.

F - Fertility Control

Question F.1

Given an individual grey squirrel orally consumes the fertility control bait being developed, what is the chance that it will develop a physiological response leading to contraception?


Admin annotations:

Expert Minimum Plausible Most Likely Maximum Plausible Confidence
C 0.6 0.75 0.9 71
H 0.2 0.60 0.8 75
K 0.5 0.70 1.0 98
O 0.4 0.70 0.9 60

Comments

Contraceptive efficacy
  • C: it will really depend on contraceptive!
  • K: Contraceptive product would not be viable if it had less than 50% efficacy so this would be the minimum possible. Ideally 100% but this could never be guaranteed, there would always be individual and external factors that could impact this probability. We are aiming for at least 60% efficacy and expecting a minimum of 70%

Question F.2

Given an individual grey squirrel orally consumes the contraceptive bait being developed, what proportional reduction to you expect from its fecundity?



Admin annotations:

Expert Minimum Plausible Most Likely Maximum Plausible Confidence
C 60 70 80 87
H 10 60 90 75
K 0 100 100 85
O 0 100 100 100

Comments

Contraceptive fecundity reduction
  • K: separate question needed for effect on fecundity long term. it is expected that if is a successful dose it is 100% contracepted - but we know that with a vaccine the effect can wane over time which would lead to a less than 100% effect on fecundity and may contribute as a lower litter size but, the question here is the short term - and that reduction in fecundity is not reflected in F.3 either

Question F.3

Given an individual grey squirrel orally consumes the contraceptive bait being developed, how long would you expect that individual to be under the effect of the contraceptive, on average?



Admin annotations:

Expert Minimum Plausible Most Likely Maximum Plausible Confidence
C 3 3 12 82
H 1 5 9 65
K 3 6 24 54
O 1 3 5 70

Comments

Contraceptive duration
  • K: contraceptive product would not be viable if it does not work for at least the length of an average breeding season it will not happen. possible it has an effect for the length of the animal’s life - up to 4?? years. difficult to reflect an average

Question F.4

What is the probability that fertility control methods currently under development will become widely available for use by landowners, government organizations, and volunteer groups to manage grey squirrel populations?



Admin annotations:

Expert Minimum Plausible Most Likely Maximum Plausible Confidence
C 0.6 0.8 0.9 81
H 0.0 0.6 1.0 100
K 0.0 0.7 1.0 66
O 0.0 0.8 1.0 100

Comments

Fecundity control rollout probability
  • C: all stakeholders lumped together

Question F.5

If said oral contraceptive is developed and approved as a management tool available for use by landowners, government organizations, and conservation groups, by what year do you expect it to become available for said groups?



Admin annotations:

Expert Minimum Plausible Most Likely Maximum Plausible Confidence
C 2030 2032 2035 71
H 2025 2028 2030 65
K 2030 2035 2050 75
O 2030 2032 2040 70

Comments