Chat message
Slack / Private Message Drop, p.828 [SLACK_001042] · slack_pm:msg:08635
Page text: p.828 · original PDF
- Date
- 2021-05-17 18:17
- Type
- chat message · slack
- recipient
- Kristian G. Andersen, Robert F. Garry, Andrew Rambaut
- speaker
- Edward C. Holmes
Recipients on this medium are inferred from channel membership, not per-message addressing.
"It's complicated. Many bats have maternity roosts, so there is sexual segregation for certain parts of the year during breeding, in China that period will vary, but we see most females starting to give birth in late April-May. They will then nurse their baby (typically one) for a number of months, and the Rhinos will leave young in a "creche" duringforaging, whereas some other species will often feed whilst carrying their young. Those activities are finished by November, but at least some species have the mating period then (most species have delayed implantation, or delayed fertilisation etc capabilities). The Rhino's are very polygamous with veryscewed success ratios, so a minority of males mate with all the females (there is paternity data for some colonies,and some males have many tens of offspring in a year whereas others have none). Other taxa have differentpatterns, in Hipposiderids, especially larger species males may fight and they have enlarged glands and areexceedingly aggressive (normally on the face, though some other genera within Hipposideridae have them elsewhere-such as the chest). Following from this there is a shift in cave use, Hipposiderids show evidence ofmigration in some species within China-we see them appearing for a small period of the year and their morphologyand habitat use means they are able to move long distances and are almost certainly migratory (for at least larger species, smaller species like Aselliscus will hibernate, and actually go into a much deeper daily torpour even atmoderately low temperatures).Rhinolophids clearly also change roosts then, possibly choosing deeper, more thermally stable caves. So that periodof the year is basically pretty high stress, most species will be changing roosts, so there are different communities,less sexual segregation than the rest of the year, lower food (so physical stress). This period is also when fungalpathogens like whitenose syndrome appear-so it is likely that during torpour they may be downregulating thefunctions that allow various pathogens to stay at lower levels and it may be that viral load would be higher at this time.In a disturbed cave, with higher stress this is likely to increase, they are also more likely to leave the cave in such conditions, which of course increases the interface for spillover to occur.-Rhinos and Hippos are sister groups, so may share traits, and in some cases roost in close proximaty, during coolerperiods and hibernation smaller species may cluster to roost together, so there is also a potential for spillover between taxa there-though largely in the smaller species (larger Rhinolophids are solitary and rarely use large orcommunal caves, and large Hipposiderids are too aggressive)."