Question 1


What do you believe is the probability (%) that a dropped piece of toast with a given type of spread will land face-down? Please answer the question for both butter and jam.


Spread Expert Minimum Plausible Most Likely Maximum Plausible Confidence
Butter GB 5 50 95 95
GE 45 65 80 75
HV 20 60 75 95
TI 49 50 51 87
TW 50 50 50 100
Jam GB 5 50 95 95
GE 45 70 90 80
HV 15 50 75 95
TI 49 50 51 93
TW 50 50 50 100
Comments
Butter
  • GE: Experience suggests chance of landing face down is greater than 0.5
Jam
  • GB: I don’t think that butter or jam should significantly affect which way up the toast lands
  • GE: The chance of toast falling spread side down is proportional to the amount of mess that will be made, so p(jam)>p(butter)

Question 2


How many Socorro doves (Zenaida graysonii) do you believe currently exist in the world, across all captive facilities?



Expert Minimum Plausible Most Likely Maximum Plausible Confidence
GB 10 60 200 80
GE 150 190 300 90
HV 50 200 250 75
TI 3 300 450 50
TW 25 200 300 100
Comments
Population size
  • GB: I don’t really know about Socorro doves, but I think that space in captivity is limited and therefore will limit the global population, but also that if too few existed the population would have gone completely extinct by now.
  • TI: Lowest is 1 bird in US, 1 in Europe and 1 in Mexico. Highest is my estimate of 45 zoos having 5 pairs each. Most likely is 10 specialists zoos having 3 pairs each.
  • GE: Recently wrote paper on this topic quoting this statistic.




Comments


Question 4


If a group of 15 individuals are moved from captivity back into the wild, what is the chance that at least one will arrive in Socorro infected with Aspergillus fumigatus? Please answer for two alternatives: one where individuals are kept at a biosecure facility before release, and one where individuals are not.



Alternative Expert Minimum Plausible Most Likely Maximum Plausible Confidence
Biosecurity GB 0 10 50 90
GE 1 5 100 100
HV 25 65 90 85
TI 0 5 100 50
TW 10 25 50 100
No biosecurity GB 0 15 50 90
GE 1 50 100 100
HV 30 80 100 100
TI 0 10 100 50
TW 10 25 50 100
Comments

Question 5

Based on your judgment, how likely is the release of Socorro doves back into the wild will have a welfare impact on released individuals in the following categories?


  • Minimal: Released birds have no, or trivial, short-term negative welfare experience(s); overall there is no significant impairment of their wellbeing or general condition.

  • Minor: Released birds have short-term, mild negative welfare experience(s), and/or there is mild impairment of their wellbeing or general condition.

  • Moderate: Released birds have short-term moderate, or long-lasting mild, negative welfare experience(s), and/or there is moderate impairment of their wellbeing or general condition.

  • Major: Released birds have long-lasting moderate, or short-term severe, negative welfare experience(s), and/or there is moderate, or short-term severe, impairment of their physical/mental welfare status or general condition.

  • Massive: Released birds have long-lasting severe negative welfare experience(s), and/or there is severe long-lasting impairment of their wellbeing or general condition.

Please allocate 100 points across each category according to your belief the welfare impacts of a release will be within that category. Do so for two age classes, juveniles (or first-year individuals) and adults.


Comments
Adults
  • TI: With no information on the species to hand to make a valued judgement, logic dictates that there is an equal chance of all 5 scenarios.
  • GB: I think that there are probably more severe welfare implications associated with release of adults based on other avian reintroductions, which tend to release first year birds.
  • GE: Socorro doves have been in captivity for many generations and may have poor immunity to disease risks, and poor foraging and survival abilities. Without significant risk management they are likely to be moderately to massively affected by release into the wild.
First-years
  • TW: Juvenile birds may not be fully immunocompetent and may suffer from more severe disease following exposure to novel pathogens or stress-associated disease
  • GE: Studies indicate that socorro doves are most likely to die in their first year of age, often from trauma, especially from adult males and birds of other species. In a new environment chicks will be particularly vulnerable.