Hi,

I rank the threats in the following way:

1) habitat deterioration - very important threat for many species, especially forest species or those with highly specialised habitat requirements, globally important.

2) climate change - may led to shifting distributions and habitat loss.

3) wind energy - important threat to some open space foragers, however a limited number of species is affected.

4) WNS: although huge numbers of bats die, a limited number of species is affected, the disease is still geographically restricted and hopefully the species can recover.

I would like to add traffic (casualties, fragmentation), poisoning (direct and indirect) and pets (especially cats) as additional threats, all three rank for me higher than wind energy.

If you consider mortality in wind farms should also consider mortality on roads (affecting other species: the lower flight, such as the Rhinolophus, pipistrellus or some Myotis) or mortality caused by continuous disturbance in the hibernation season (e.g. roost survey/visitation or cutting trees in winter) and others. So I think we should consider a more global threat, such as non-natural mortality or anthropogenic mortality.

Hi,

I rank the threats in the following way:

1) habitat deterioration - very important threat for many species, especially forest species or those with highly specialised habitat requirements, globally important.

2) climate change - may led to shifting distributions and habitat loss.

3) wind energy - important threat to some open space foragers, however a limited number of species is affected.

4) WNS: although huge numbers of bats die, a limited number of species is affected, the disease is still geographically restricted and hopefully the species can recover.

I would like to add traffic (casualties, fragmentation), poisoning (direct and indirect) and pets (especially cats) as additional threats, all three rank for me higher than wind energy.

The impact of mortality in wind farms is high, but we have to be aware that we have data from nearly all (or most) installed wind farms, however the roads have studies of small sections of roads with mortality. If we extrapolate the mortality found a small road segment to the full extent of an area or country, perhaps the dead of numbers would be more significant. Anyone know of bat mortality estimates on roads in the global context? I have only articles of small segments of roads.

Hi Christian,

That’s a very pertinent question. Quite along the lines of a horizon scan exercise for bat conservation (which I think has been long overdue).

I certainly think non-native species (mainly on islands) and the impact of domestic species (mainly free-roaming cats) is an issue to consider. My mother’s cat brought home a Madeira pipistrelle (classified as Endangered) so I did some research one the issue, here’s some related figures:

• Domestic cat predation was found to represent a significant threat to bats in the Italy, where most adult bats admissions to rehabilitation centres were associated with cat related injuries (Ancillotto et al., 2013).

• Of a total of 9852 mammal prey items brought home by 986 cats in the UK over a 5 month period, 0.2% corresponded to bats (Woods et al., 2003).

• Free-ranging cats were estimated to kill between 6.9–20.7 000 million mammals in the US, surpassing all other sources of human-induced mortality (Loss et al., 2013), however this study provided no breakdown of the mammalian prey species predated and therefore the actual impact of domestic cats in US bat population is still unknown.

• In Puerto Rico cats were observed to systematically visit caves harbouring multispecies bat assemblages and scats revealed that least 5 bat species were regularly consumed by free-ranging felines (Rodríguez-Durán et al., 2010). In this study, and during the period of 8 months researchers have recovered 320 bats wings, representing at least 161 individual bats and in a single night up to 16 cats could be observed hunting in the same cave.

• In New Zealand and over the period of 7 days a single male cat preyed at least 102 IUCN vulnerable short-tailed bats Mystacina tuberculata rhyocobia in two colonial roost trees (Scrimgeour et al., 2012).

• In Christmas Island, cats were reported to prey Pteropus melanotus (Bonnaud et al., 2011) and have been suggested to have contributed to the population decline of the presumed extinct of Pipistrellus murrayi (Schulz & Lumsden, 2004; Martin et al., 2012).

Here’s another very interesting note about the interaction of invasive parakeets and native bats: http://www.italian-journal-of-mammalogy.it/article/view/9989/0

Another two issues to consider would be bushmeat hunting and the pervasive consequences of the association between bats and zoonosis.

Best,

Ricardo

Hi All, 

Thanks for your valuable contributions. So, we could consider including roads as a human-induced causes of mortality in bats. However, we lack comprehensive data about bat fatalaties at roads, and also whether or not they affect populations. Similar to wind energy, bat fatalities at roads affect a limited number of species. In the temperate zone, this would be most likely low-flying gleaning bats and posisbly commuting bats, whereas wind energy affects open-space foragers and migrant bats. But what about tropical and subtropical regions?

Regarding cats, we could subsume those under the category 'invasive species', which would include as well parrots, racoons, pythons, among others. But how does that relate to habitat deterioration, which is more subtle in its dynamics. And how does it stand in our global perspective, considering that the vast majority of bat species and bat numbers live in tropical and subtropical areas. 

Possibly, the latter two factors - and correct me if I am wrong - is more of a local scale. Also, how does it compare to such long-term changes as global climate change. Any ideas?

Christian 

In North America it would be hard to argue against white-nose syndrome as being the top threat to bat biodiversity and conservation for obvious reasons. We recently ranked causes of "incidental take" to birds in Canada (including road kills) and the statistics on cat fatalities was overwhelming (see special issue of Avian Conservation and Ecology: http://www.ace-eco.org/). I wonder if these sorts of takes can also be quantified for bats? My only other thoughts are to relegate "climate change" to the last position as this has become a favorite throw-away catch all that has almost become meaningless in the conservaiton field. It is merely an excuse to do nothing while we watch more pressing issues like habitat destruction go unimpeded. Moreover, it is currently almost impossible to model the way in which climate change will play out in all but the simplest scenarios.

I agree with the previous answers, but I think that the order of threats depends on geographical area. Therefore, we need to study these phenomenons in this context and we cannot discard the sinergies between different factors.

I would like to add: bothering in their roost (especially for cave-dwelling bats, increasing of speleology), lost of roost (especially for urban bats, where the new constructions avoid that they can roosting), lost of insect-preys due the use of pesticides (now the common birds are suffering a high decrease in their populations), and presence of heavy metals or toxic substances.

Dear all,

We (other authors and I) have done horizon scan evaluations about relevant topics for bat conservation here in Brazil that may be useful to this forum discussions.

Basically we compiled 17 topics for bat conservation in Brazil and ranked each of them 1-10 (from "little or well-known topics, less important" to "little known or well-known and very important topics". Although I was one of the authors I consider some particularly threatening and the put a "TOP" in front of those

1 Rank 9.1 - cave destruction (particularly because of recent changes in the Braziian laws for cave protection); TOP TOP

2 Rank 8.7 - Quantification and ranking values of ecosystem services provided by bats

3 Rank 8.1 - Impacts from the alteration to the Brazilian forest code (basically habitat destruction) TOP TOP

4 Rank 7.8 - Physyology applied to conservation (belief that physiological markers may help conserving bats)

5 Rank 7.8 - Molecular studies ( belief that lack of molecular studies would impair studies)

6 Rank 7.8 - Plague extermination industry

7 Rank 7.7 - Lack of basic information on bat distribution within Brazil TOP

8 Rank 7.7. - Hidreletric dam construction (lots of over the last years particularly changing the Amazonia rivers) TOP

9 Rank 7.3 - Windmills

10 Rank 7.3 - Data deficiency TOP TOP

11 Rank 7.2 - Lack of investiment and basic structure for museums and scientfic collections TOP TOP

12 Rank 7.1 - Lack of professionals in Systematics and Taxonomy TOP

13 Rank 7 - Lack of programs to study migration patterns (marking)

14 Rank 6.9 - Cattle raching rabies and other emergent diseases TOP

15 Rank 6.2 - Sugar and ethanol production

16 Rank 6 - Environmental education

17 Rank 5.6 - Crashing with vehicles and other [linear] structures

Basically I would strongly remark on habitat destruction in the Neotropics caused by several factors, most of then associated with the "acceleration of the economy" poorly planed political strategies. Although I am probably repeating the obvious, the situation is - im my view - very seriously dangerous in a medium-short term. It is important to consider separately the habitat destruction and the roost destruction topics because of the specific threats to roosts, such as caves and rock outcrops.

I am very interested in this discussion.

Cheers to all,

Valéria

Hi,

thanks Christian for the very pertinent question and valuable comments, views and opinions provided by contributors. It is rather difficult to agree on the ranking of the main threats affecting bats biodiversity in our times at  global scale, as we live in different continents, regions and countries, and all of us are facing different challenges. However, thinking globally, there is no doubt that behind of all threats mentioned stands the mankind with its demographic explosion (human population has increased more then 5 times in less than 100 years) that has reshaped the whole world. Large scale of habitat loss, destruction, alteration, fragmentation, and deterioration due to urbanization, industrialization, transport, development and intensification of agriculture (mechanization, use of pesticides, and GMOs) along with their related polluting effects on air, water and soil, have altogether made our planet a small and not safety place to live for many taxa, including bats. A lot of species have lost their roosting sites, their food has became either scarce or not healthy, and water is not safe to drink. Consequently, the reproduction rates for many bats species are decreasing and mortality rates, both natural and human-induced mortality, are increasing.  

Climate changes in our times are much related with the use of fossil sources of energy and in-spite of the fact that their current impacts on biodiversity are not significant  (at least we are not able to measure them), my opinion is that in the coming decades,  climate changes, with increased incidents of weather hazardous events (droughts, fires, floods), and increased climate variability,  will be a major threat to biodiversity of bats as well.  The ecosystems' ability to adapt to such climate changes over the last decades is already reduced due to anthropogenic impacts on them, and therefore many bat species will be vulnerable to expected climate changes in the future.

Cheers to all,

Ferdinand

Hola a todos

Desde mi experiencia, en Ecuador, he podido notar que la destrucción de hábitat disminuye sobretodo la diversidad quiropterológica, permitiendo que aumente la abundancia de especies algunas especies del género Carollia. En sitios como el Yasuni o Cuyabeno que mantienen un estado de conservación del bosque

Hi

Horizon scanning is a really valuable exercise (as seen by Bill Sutherland's initiatives for more general ecological issues).

Your question mentioned 'specific taxon'  and to that I'd add specific areas.

So for Old World pteropodids, hunting for bushmeat would be top of my list now.

The mass mortality of some Pteropus species experiencing very high ambient temperatures in Australia suggests this aspect of climate change  could also  become a major threat  to diversity of this taxon.

I am concerned about the possible effects of climate change on reproduction in temperate zone bats, because it may interfere with sperm storage which has evolved with cold winter temperatures and hibernation ( and we still don't have an explanation of why noctule bats gave birth before Christmas in Spain?)    

WNS is top of my list for North America but nowhere else (so far!).

Next would be wind energy in those countries where turbines are abundant (so not Africa....or  SE Asia....?) 

I agree with Christian Dietz: habitat deterioration would be top of my list now for forest bats.

But for many tropical species, the threat to cave roosts in karstic landscapes as they are destroyed by the cement industry is a growing problem, and affects whole bat communities. 

Ricardo 's contribution on predation by cats is interesting as more hard data emerges. I have always been rather sceptical about emergence behaviour being driven by the threat of predation (unless it's the 'ghost of predation past') but cats are a real problem. But doesn't ecological theory predict that predation isn't really a threat to biodiversity  on a longer time scale.........?

We need more information about the ability of different taxa to adapt to the threats posed by habitat deterioration and climate change.

 I think the threat of pesticides  has  receded, at least in Europe (where it was a major threat in the past - although we need to know more about the effects of the newer ones like neonicotinoids). However the fact that a few respondents have mentioned this means that we need more information about what chemicals are used in the tropics and  their effects on bats.

Hope that helps!

Happy New Year!

Paul

Dear Dr. Paul Racey:

Where did you read that the noctules give birth before Christmas in Spain?

In Andalucia, the births occur from end May to first June. I had read and I checked that the bats in south Spain have activity and copulations during the winter, but I never saw births.

It is true that the hibernation season is short and the births occur early when we compare this dates with other European zones.

My view is that habitat loss is the most serious issue in North America for bats (as well as for most species) compounded by political unwillingness to take the importance of bats seriously.

Ibanez 1997. J.Zool. 243:836-840 although I mentioned the wrong species - it was Myotis myotis giving birth six months early in Donana -sorry!

Valéria  - you mentioned 'plague extermination industry' as a threat.

What did you mean?

Thanks

I will try to summarize what we have learned so far. Probably, it is best to split the question into two, one for pteropodids (flying foxes) and one for non-pteropodids (all other bats), since the biology is strikingly different.

So, according to Paul's suggestion, bushmeat hunting might be number one, followed by global climate change (possibly the latter is most or only relevant fo Australia, or some island populations with endemic species) and then habitat deterioration. 

For non-pteropodids, we may have to look at specific continents and therefore will have to switch fro a horizon scan apporach to a bottom-up appraoch (well partly). 

Here are my suggestion: what do you think?

Europe: 

1) Habitat deterioration: I would us this category rather broadly and include deterioration of cave hibernacula as well. 

2) Wind energy

3) Global climate change

I am relucant to list introduced species, such as domestic cats (I am aware that we are talking about a domesticated species and not an invasive species in sensu strictu).

Pseudogymnoascus destructans occurs in Europe, but does not cause any mass mortalities, therefore so-called WNS seems to be not an issue for Europe. I agree with Paul that pesticie + insecticide residues seems to be less of a problem. 

Northamerica

1) White-nose syndrome

2) Wind energy (600.000 bats killed annually according to Hayes 2013)

3) Habitat deterioriation

4) Global climate change

Again, for domestic cats , we lack comprehensive data

Southamerica

1) Habitat deterioration

2) Global climate change (causing possibly some major shifts in local climates on the Southamerican continent, more hurricans in the Caribbean and interfering with El-Nino).

Wind energy plays only a marginal role because there are far too few wind turbines, at this point. 

White-nose syndrome is not a problem at least for bats of the tropical and subtropical region because it is a cold-loving fungus, but how about bats of southern Argentina, Chile , or in the Andes

 Australia (incl New Zealand)

1) Global climate change

2) Habitat deterioration

3) invasive species such (as domestic cats)

WNS does not occur in Australia (at least to the best of knowledge).

Asia (we did not get any input for Asia, yet, did we?)

1) Habitat deterioration

2) Global climate change

Again, no Pseudogymnoascus because of tropical and subtropical climates. Also, no wind energy at large scale.

Africa (no feedback yet from Africa). 

For me, the situation in Asia looks quite similar to Asia, do you agree?

Christian

Hi Christian,

I agree with your proposed approach and suggestion. It makes more sense splitting the question into two (one for pteropodids and the other for non-pteropodids), and having a specific look at each of the continents.

I fully agree with  the suggested ranking of most severe threats on bats for Europe.

Thanks for your efforts to summarize all contributions!

Happy New Year!

Ferdinand

In our area ( Dir lower KPK Pakistan) the most severe threat to bat diversity is the destruction of their habitat. Mostly in our area bats are found in the caves, Kareez, and in old buildings , due to rapid increase in the population these  habitats of the bats are know disturbed that cause great decline in the diversity and population of   bat  

For the bats around my house in Windhoek, Namibia and Epe, NRW only the first would impact on numbers in the immediate future. Wind turbines are sparse and far, the dreaded disease absent and climate change inconsequential at current trend. Closing versus opening my roof for bats would show an immediate response; second best would be ponding versus draining wetlands (mosquitos) within the bat range. 

I think the globe climate change is the most severe to the bats diversity. Because I did the survey in the field, and find a lot of bats vanished by the climate changed in Hainan Island and Guizhou province,China in recently years.

A per region list surely sounds sensible.

Regarding your query about if invasive sp and habitat loss / deterioration would be under the same umbrella here’s an interesting publication about it: http://www.sciencedirect.com/science/article/pii/S0169534707002054 - they certainly interact with synergistic effects.

As for Afria and Asia and as Paul has highlighted, I would add hunting. Here’s some figures about the issue: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3323830/ , http://www.ajol.info/index.php/mcd/article/view/44132 & http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=5487716&fileId=S0030605308000938

Dear Christian,

maybe you know this document, but if not in Chapter 4 there are listed and prioritised threats of bats, compiled within EU countries:

http://www.eurobats.org/sites/default/files/documents/pdf/Advisory_Committee/Inf_StC9_AC19_5_DraftEUBatsActionPlanv14.pdf

(Action Plan for the Conservation of the Bat Species in the European Union 2014 - 2020).

Hi Michal, and Happy New Year to everyone.

Thanks for pointing out this material. I am aware of the very helpful Eurobats brochures. This might help in specfying the threats for European bats. However, from my point of view we are largely missing information from those countries (or areas) where most bat species exist, i. e. the tropical and subtropical belt. When we go back to the global perspective and ask what the most severe threat is for the 1,200+ bat species worldwide, we may not ignore those countries. 

Another important question is: Once we identified the most severe threat, it seems logical that most of our efforts for conservation of bats, but also regarding research, should go into this direction, isn't it? So, in which direction should we go? 

My gut feeling is that most bat conservation related publicatiions focus on white-nose syndrome at this point, then followed by habitat deterioration. The current development of wind energy - although being a pressing and urgent issue for bat conservation in Northamerica and Europe - is not flanked by corresponding research actions and publications (at least to the best of my knowledge). And almost nothing is published on African bats, and only releatively few papers are available on Southeast Asian bats (although more are coming). Obviously, it is always a question of where money comes from and in which direction it has to be spent, but when looking at the global threats from a neutral point of view, we may be missing large parts of the picture, actually most of the picture. 

Christian

Definitely not the WNS:

1) The pathogen is quite common in soil.

2) In the Europe, where it originates from with most probability, it has no effect on bat populations nowadays. It seems it is connected with size and density of winter colonies.

So, according to my opinion, only large, dense colonies in suitable climate are endangered.

1) habitat destruction

2) climate change

Christian

A couple of additional suggestions regarding the categorisation and ranking of threats to local and global bats

The broad separation of mega- and micro bats and geographic zones seems necessary, though broad biotypes might be more precise and useful than administrative continents – e.g.

•  at the very high level being discussed here are the problems of wet forest tropical bats in S.America sufficiently distinct to those in Asia or Africa to merit different lists?
• and do the critical concerns of specific species groups within a continent (i.e. endemic pteropids in every continent) bias the ranking against 100's of other species all facing different pressures in other biotypes.

Inevitably in this exercise you'll need to eventually acknowledge that one category or the other is of more concern but it seems more productive that this does not implicitly ignore whole sub-categories (e.g. sub-tropical dry forest microbats – picked at random as less apparent than some other groups), but explicitly describes the extreme concern for one functional group (e.g. montane endemics, insular endemics) to help focus activity

We all agree that habitat destruction/degradation is high on lists for everywhere, but I’ll suggest splitting the concept into (1) threats to roost habitat and (2) threats to foraging resources.  Many species use one habitat for both, many more exploit flight by using different habitats for different things.  The rationale here is that threats to roosts are more immediately critical than threats to foraging resources – and potentially easier to study.  It also acknowledges that some of the specific issues mentioned elsewhere operate on one or both habitat components, but are not specifically worse than many other non-disruptive land-uses which remove roosting/foraging habitat or fragment landscapes – e,g, inappropriate agricultural expansion, urbanisation

For other categories I suggest lumping to help achieve comparability between lists.  Specific issues have been described for some counties, or are suspected in others, but such global lists have to look beyond what we think we know for one species or one threat.

• Direct anthropogenic threats (includes exploitation/harvesting of species, and other threats which impinge directly on population dynamics – mortality at wind-farms, mortality at roads, glass fronted buildings etc) – these tend to be immediately critical to the survival of bats locally but may also have larger scale effects.
• Indirect anthropogenic effects (Invasive alien species – inc. cats, most environmental pollution)
• Disease (other than that promoted by an indirect anthropogenic effect)
• Climate change

How these rank in different places will probably result in the two habitat threats and direct anthropogenic effects being the current top three in different combinations of orders - what is interesting is speculating whether indirect effects may become more pressing in a 20-50 year timescale (and thus appropriate for current study and mitigation)

James

Hi James, and others, 

thanks for all your input. I agree with most of you is said. The separation of roost and habitat destruction makes sense, however it is difficult to separate in many cases, e.g. when you think about forest bats and intensified silviculture. In Europe, it has been shown that artificial bat boxes can help in supporting local bat populations when forests include mostly younger trees, e.g. pine trees. Yet, artifiical can not substitute natural tree hollows as we have pointed out in a recent article. 

http://link.springer.com/article/10.1007/s10531-014-0620-y

Diseases other than those promoted by human influence: This is difficult because - from my point of view - even the emergence and spread of such awful diseases such as Ebolda among others are due to human action, mostly encroachment of humans into pristine habitats. I would concur that most observed diseases are heavily promoted by human action, possibly with the exception of rabies.

When I look at the contributions to this discussion, it appears as if climate changes is only important for certain areas, e.g. montane endemics, and some other areas where isolated populations are incapable of shifting their distribution range into more suitable areas when climate is getting hotter. Island populations are very susceptible to hurricans and alike and these weather phenomen might be exacerbated when global climate changes. Yet, when we look at it from a global perspective and considering all Chiroptera, global climate change might not be as relevant for bats as for other taxa. 

Since I am visiting Southeastasia for field work at this point, I am becoming more and more aware that direct threats, including killing of large numbers of bats in roosts, e.g. caves, or in habitats, e.g. flying foxes in orchards, might be a big issue in many tropical and subtropical countries. I have heard about culling of Eidolon helvum colonies in Africa and Rousettus colonies in Asia. This might be a new dimension of threat for bats, and not well recognized by researchers and conservationists in the Western world. Our most effective weapon against such conservation threats might become outreach programs. 

Cheers,

Christian

http://link.springer.com/article/10.1023%2FA%3A1023003215329

In the Canary islands the main threat to bats in a recent past was probably the use of DDT to control the plagues of locusts (Schistocerca gregaria), which arrived more or less frequently to the Canaries from the Sahara desert, especially until the 50s. This was also the cause of a severe decline in the raptor populations. Fortunately, bats are recovering in the last decades in the archipelago, and also many of the raptor species. In any case, there are some important threats to our local bats, like:

- Uncontrolled visits to caves inhabited by Plecotus teneriffae and Barbastella barbastellus guanchae (both endemic taxa from the Canaries and considered endangered)

 - Fencing of underground water mines ("galerías de agua") with fences that are not good for bats

- Extensive use of chemical products in the agriculture in areas with good densities of bats

- Demolition or changes in some old houses and other buildings inhabited by bats (mainly by Pipistrellus maderensis and Nyctalus leisleri)

- Forest fires, which can destroy important bat refuges and reduce the quantity of preys for these animals

Habitat deterioration

Please take a look at this useful RG link.

Article A review of the major threats and challenges to global bat c...