More on Pollinator declines

We have a new correspondence article about bee declines that tries to walk the fine line between a non-helping pessimistic attitude about pollinator declines and an unrealistic optimism. As I said before, I think is easier to defend a black or white position about the pollinator crisis, but I think is time to discuss the grey areas. So here I go:

We show two straight forward things. First, that recent papers showing 50% of bee extinctions and papers showing moderate 15% declines (that’s our paper!) are not reporting conflicting results. Is just a matter of scale. Local scale extinctions in heavily altered habitats translate into population declining trends at the regional scale. To read it in positive, we are still on time to revert this declining trends, because the species are there!

Second, we show that not all species respond equally to global change threads, for example some species love agricultural areas. Most important, seems that the species that thrive in crop fields, are the ones responsable of increasing crop production, so the best current ecosystem service providers (a.k.a. bees that visit crops) may be not as threatened as other bees. But please do not take that as “we don’t have to worry at all”. This is the “grey area” where we need to be clear that highly intensified agricultural areas (e.g. huge almond fields in California) may still suffer pollinator shortages. Similarly, we are talking here about crop pollination, but there is a growing evidence that all species are important to maintain (and stabilize) ecosystem functioning in natural areas. So the good news are only partial.

Read it, is a very short piece and is Open access. If someone is curious about F1000Research, just two lines to say that we choose it for the flexibility of formats they allow, the speed of publication and because I was very eager to see how post peer review works. So far we had two very positive reviewers (which made the article indexed in less than 24 Hours!), but no more comments. Is also a short piece so maybe there is not much else to comment?

Is there a pollination crisis?

After some months writing this blog, finally I can do some self-promotion and post about our new article just published in PNAS.

Do you think we are experiencing a pollinator crisis? Take note of your answer and keep reading.

In this paper, we show that most Northeastern US bee species persisted along the last 100 year. And those are 100 years that has transformed the landscape dramatically. However, we show that community composition changed markedly. The loser species are some big species, often specialists and with short activity periods. See a quick figure I made trying to capture the essence to outreach people who only have one minute to spare.

BartomeusPNAS

So, what that tell us about a possible pollination crisis? A crisis is something that leads to an unstable and dangerous situation, in this case regarding the fate of pollinators and the service they deliver. Nobody talks about a bird crisis. Some bird species are doing great, some are threatened with extinction, but nobody would dare to generalize about the fate of all bird species as a whole. I think is time we take the same approach with such a diverse group as the pollinators (including bats, birds, butterflies, bees and a long etc…). In this paper we show that some bumblebees (e.g. Bombus impatiens) are doing great, while others are on the brink of extinction (e.g. Bombus affinis). We need to understand better species responses and stop crying wolf for all pollinators. There is a fine line between raising general aware among citizens about the importance of pollinators and their conservation and an overestimated alarmist call. Every time a farmer reads about the pollination crisis while seeing that his field is full of bees buzzing around, we (scientists) are loosing credibility.

Moreover, if is crop pollination and food security what concerns you, it may be that the winner pollinator species, those that thrive in human dominated landscapes, are also the best ecosystem service providers. And if it’s biodiversity (and its overall functioning) what you want to protect, then we should look at which species/habitats needs maximum conservation. We need to move forward and pose the relevant questions, instead of looking for a general declining pattern that hopefully is not really there.

I am expanding too much for my taste, so more on that next week. But to make clear my point: we need to keep studying pollinators (keep funding me!), but next time you cite worldwide pollinator declines, cite me also (i.e. Pots et al 2010, but see Bartomeus et al 2013).

Bartomeus I., Ascher J.S., Gibbs J., Danforth B.N., Wagner D.L., Hedtke S.M. & Winfree R.  Historical changes in northeastern US bee pollinators related to shared ecological traits, Proceedings of the National Academy of Sciences,   DOI:

*Giving the importance of the subject, it was specially important for us to make all historical bee data available @datadryad (dx.doi.org/10.5061/dryad.…) for further analysis and replicability.