When I wrote here about the roe deer (Capreolus capreolus) I gave only a brief introduction. I didn’t mention the research about C. capreolus happening at Aberdeen University.
My fellow blogger Finn Holding tells us more. He tells how the C. capreolus embryo waits in the doe’s uterus, floating around, until it’s good and ready to implant. It times its birth by implanting at the right time for its own survival.
This is fabulous isn’t it? In fact several mammals are at it! Not only C. capreolus. Delayed implantation happens in mustelids including the badger (Meles meles). It happens in rodents including the house mouse (Mus musculus) and the brown rat (Rattus norvegicus) – such important pests and so useful as lab animals. Delayed implantation happens in pinnipeds including the common or harbour seal (Phoca vitulina). In the Dutch Wadden Sea, P. vitulina pups are being born earlier than a few decades ago because their embryos implant earlier. This is associated with changes in fisheries management.
Could other ecosystems be managed in a way that affects embryo implantation? Would that be a good thing? Is it up to us anyway? By now we know a lot about the evolution of delayed implantion. By now we know a lot, too, about the impacts of climate change on ecosystems.
We don’t yet know when embryos will implant in a warming world. We don’t yet know how that will affect other species which interact with the mammals.
Science on the Land 
It happens with many bat species as well.
Eg:
http://www.ncbi.nlm.nih.gov/pubmed/1167300
Yes, it happens in many kinds of mammals. Thanks for that interesting paper. Not much about the mechanisms, though. The authors do consider food supply, as did the people who wrote about the common seal (see my link above).
What surprises me is that delayed embryo implantation isn’t common knowledge. It has obvious drama and cuteness. Most people know about migration, moulting, nesting and other seasonal events. But somebody like me (with lifelong interest in natural history) wasn’t really aware of delayed embryo implantation until Finn Holding blogged about it. Thanks Finn!
On top of the lack of general knowledge about delayed embryo implantation, I don’t see it being discussed much in terms of climate change. Have you seen any science about that?
This
http://www.theriojournal.com/article/S0093-691X%2810%2900039-7/abstract
is about implantation and humidity.
I think that most delayed embryo implantation (at least in bats) is with species in temperate zones, with clear winter-summer differences. In winter, insectivorous bats can find few insects, so the young are born in spring.
What an interesting paper.
Thank you. It is about mice; I don’t know to what extent this also goes for other mammals.
I didn’t know that seal reproduction had adapted the diapause to account for fisheries management. The adaptation in response to environmental stimuli must be a very rapid process.
It’s interesting what Petrel41 had to say about bats too. I guess it makes perfect sense that diapause is mainly necessary where seasonal climate changes can be highly unfavourable.
Yes it does make sense that delayed implantation should happen when seasons are relatively extreme.
The science I found about the mechanisms talks about cytokines and hormones. I can see how when, for example, the common seals find themselves eating more (because fisheries management has favoured the small fish they prey on) they’ll sooner cross the ‘fatness threshold’ after which their embryos implant. (As mentioned in the BBC article I linked to above.)
I wondered whether something like that might happen in roe deer when their food plants start to grow, but seemingly it’s not so. Roe deer embryos implant in winter when the does are using their fat reserves http://www.roedeer.com/roereproduction.htm I don’t see evidence there of a mechanism for responding to climate change – do you?
No, I don’t think roe deer are responding to climate change, they have been diapausing since before climate change was an issue. It seems the rut is timed to when food is at its most abundant which must provide a benefit to the stags because the females would fatten up for the winter at that time of year regardless of when the rut is.
The question of adaptability to climate change is an interesting one and as the more profound effects of it begin to take hold the diapause in roe deer may adapt accordingly to ensure the availability of food at the right time. Although it seems that climate change is introducing such changeable weather that it may not be possible to adapt to it in that way. Time will tell.
I think the creatures that will cope with climate change best are the ones who can change their diet not their breeding behaviour.
As I understand it, Islam teaches that this occurs in humans as well.
I’m no Muslim so I don’t know what Islam says about delayed implantation. But a goofle search leads me to think that it doesn’t happen much, if at all, in humans.
Here’s some science about it http://stke.sciencemag.org/cgi/content/abstract/sci;296/5576/2185 That paper says that the blastocyst (early-stage embryo) ‘implants into a transiently permissive host tissue, the uterus.’ The word ‘transiently’ catches my eye. That particular research used mice as a model organism because, of course, people can’t do experiments on each other. Murine embryos do have delayed implantation as I mentioned in my post above.
In humans, implantation is obviously of great interest esp when people use in vitro fertilisation. Goofle led me to words about that, eg http://www.advancedfertility.com/implantation.htm#window It seems that in humans, there’s a ‘window of implantation of up to 7 days’ which happens a few days after ovulation.
Reblogged this on Ann Novek–With the Sky as the Ceiling and the Heart Outdoors and commented:
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Kangaroo embryo’s can also be included in this esteemed list. Conditions here in arid Australia are not always the best for giving birth and even though kangaroo embryo’s have to be born (tiny) and crawl their way from the birth canal to their mothers pouches (what a journey!) they start their life waiting for the right conditions before they are born. A very interesting topic and something that certainly makes you realise how amazing nature can be 🙂