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 40 50 60 95
GE 45 65 80 75
HV 40 55 60 90
TI 49 50 51 87
TW 50 50 50 75
Jam GB 40 50 60 95
GE 45 65 80 75
HV 40 50 60 90
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
  • GB: The discussion helped me understand the lowest and highest percentage values.
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 150 190 300 90
GE 150 190 300 90
HV 175 200 250 86
TI 150 190 300 91
TW 150 200 300 85
Comments
Population size
  • TW: I increased the confidence level in my answer because of the information provided by GE
  • GE: Recently wrote paper on this topic quoting this statistic.
  • GB: Another expert in the group claimed to know this information.
  • TI: Simon Spiro has just published a paper and knows the populations so I have said the same as him!!!




Comments


Question 3


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 80
GE 1 5 100 100
HV 5 25 60 80
TI 0 5 100 50
TW 10 25 50 55
No biosecurity GB 0 15 50 80
GE 1 50 100 100
HV 5 30 60 80
TI 0 10 100 50
TW 10 25 50 65
Comments
Biosecurity
  • GE: Wide range given as depends on definition of “infected”. A. fumigatus is ubiquitous and it is near impossible for a bird to not have spores in its lungs, but infected may imply only active disease
  • GB: I still think that I would need more information on other factors e.g. husbandry, stress reduction, release methods to be able to increase my confidence.
No biosecurity
  • TI: I have no information on this disease so this is simply a guess. Logic dictates that the lowest possible chance is zero and the highest is 100%. Most likely is simply my guess. I set the confidence value at the lowest I could.
  • TW: Biosecurity is unlikely to change the likelihood of exposure to A fumigatus
  • GB: I don’t think that biosecurity is the most important factor associated with aspergillosis, but I think that it may make a small difference

Question 4

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
  • GB: I think that there are probably more severe welfare implications associated with release of adults based on other avian re-introductions, 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.
  • 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.
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
  • GB: I think there might be higher welfare implications for both sets of birds than I had realised before the discussion.
  • 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.