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Barn Owls in Idaho dying in large numbers
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owlboy
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PostPosted: Tue Jan 09, 2007 6:53 am    Post subject: Barn Owls in Idaho dying in large numbers Reply with quote

Large numbers of Barn Owls are dying along Highway 84 in southern Idaho. Boise State University just finished a 3 year study into why so many Barn Owls are being killed along this highway. During the study they collected 800+ dead Barn Owls along this highway. You can read more about the story at: http://www.ktvb.com/news/localnews/stories/ktvbn-jan0507-dead_owls.ff2ebc0.html

You can also see a video clip on http://www.cnn.com
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Last edited by owlboy on Wed Jan 10, 2007 6:25 am; edited 1 time in total
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nightowl



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PostPosted: Tue Jan 09, 2007 7:55 am    Post subject: Reply with quote

Thats terrible ! Crying or Very sad
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PostPosted: Mon Dec 17, 2007 6:51 am    Post subject: Reply with quote

thats sad Crying or Very sad
barn owls r cool
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romillyh



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PostPosted: Sun Dec 23, 2007 11:19 am    Post subject: Reply with quote

Since this has come back to the top, this useful link on the topic could be added. The Barn Owl Trust in Devon, England, has done a 15-year study of Barn Owl mortality on major roads. Their report on the results is extensive and detailed. It gives recommendations for preventing the deaths on major roads.

The pdf is on this page:

http://www.barnowltrust.org.uk/infopage.html?Id=21

Go to near bottom of page, in the section "Major road mortality and its effect on Barn Owl populations", and click on the pdf in the margin titled "Barn Owls and Major Roads: results and recommendations from a 15-year research project".

It's not a good situation. They too ended up with freezer-fulls of poor little barnies I seem to remember.

romillyh
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marbro



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PostPosted: Sat Aug 08, 2009 4:42 am    Post subject: Barn owl mortality Reply with quote

Although barn owl mortality on roads in Idaho and other places is high, keep in mind that barn owls produce large amounts of young and that the high numbers of deaths in Idaho means the population is doing very well. In other words, how many dead barn owls do you see on the roads in places like Pennsylvania, Ohio, or Illinois? Almost none. Thats because the barn owl populations there have dwindled to almost nothing. It remains to be seen if roadkills are any factor in actually reducing numbers of breeding pairs in Idaho. This doesnt mean that such high mortality by one cause is not of concern and researchers there continue to investigate.
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owlboy
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PostPosted: Sun Aug 09, 2009 7:14 am    Post subject: Reply with quote

Welcome to the forum Mark.

I checked out your web site www.barnowlbox.com. Very nice site, with lots of good information about barn owls. Very nice barn owl houses.

Barn Owls do have a problem with flying low to the ground and car impacts can significantly reduce populations. We had the same problem in the hudson valley of new york. We have lost almost all of our barn owls. We still have a significant amount of farm land, but very few barn owls. Car impacts seems to be the reason why. But, Idaho does have a lot of open space, so I don't believe that they will become endangered there.

But, at the same time, SEOs were the most popular owl in America 100 years ago. But today, they are very rare. Mainly because of car impacts.
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marbro



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PostPosted: Sun Aug 09, 2009 9:51 am    Post subject: Reply with quote

Thanks for the reply Owlboy, and thanks for your comments on my website. We put a lot of work into it.

I have to disagree over the cause of both owls declines in NY. Once again, high mortality does not necessarily lead to a decline in populations. Finding dead owls from one cause or another does not necessarily mean anything serious in terms of the species. Roadkills are simply easier to find. Kills by great horned owls are not--the larger owl eats the evidence! And deaths by starvation do not occur where people routinely find them. Both cause high numbers of deaths.

I would submit that both the short eared owl and the barn owl have declined in NY from one main cause--the destruction of natural grasslands. Mortality studies of both owls would lead anyone to believe that they were being totally annihilated--since the natural mortality rate is 70 to 80% in the first year. But if proper habitat is present, there should be viable populations.

Two other reasons for decline for the barn owl in NY are that many neighboring states have seen declines, so immigration of young owls is down; and secondly, nesting cavities for these owls continue to dwindle due to the disappearance of old wooden barns.

Pennsylvania will likely see a resurgence of the barn owl due to its CREP program designed to bring back grasslands, and it is good news that other states are following suit.
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owlboy
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PostPosted: Mon Aug 10, 2009 10:59 am    Post subject: Reply with quote

The decline of CBO, SEO, and LEO in New York over the last 100 years are well known, and backed with scientific studies. I don't know of any reputable biologist who would dispute this. The causes have been known since the early 1900's. The percentage of reasons for mortality of each species of owls are also well known. We have one of the most extensive databases of information in the country. Fortunately for New York, we have one of the largest State Conservation departments in the world. But, then again, New York has the highest taxes in the country. We can afford to study them in detail.

Death by GHO is basically irrelevant in concerns to CBO. GHO eat ALL owl species in North America. Not just CBO. The mortality rate by GHO hasn't changed in over 100 years.

In regards to good habitat and availability of prey, this has absolutely no correlation to population of CBO in New York. This is well known.

In many areas of New York, we have not had a significant destruction of farmland. Most expansions are closer to city life. Rural areas are still in tact. In fact, we have had a very significant purchases of land by DEP, DEC, conservation groups, etc. Our available areas of good habitat has actually increased significant. We have seen over 5 BILLION dollars spent in the last couple years on just large tracts of land that will never be developed.

While I do agree that we have lost more barns in the last five years. When farmers discovered that they can get big bucks for old barns, we saw more barns lost. But, in the last year, this has come to an end. It was probably more of a factor during the building bubble. But, more barn owls have better access to more deteriorating barns. We have also had a significant increase in tree cavities. 98% of viable tree cavities are not occupied during nesting season.

We have seen a significant rise in migrating owls and birds in New York. The factors for this also expand outside New York and the United States.

We already know that increase in grassland and availability of prey will have no result in population density for the CBO.

As for the CBO, we have known for close to 100 years that car impacts are the cause of their population density decline. It is not a theory, but a fact that has been repeated by study-after-study. We have plenty of viable habitat for them.

I know that some other states do have a problem with the availability of viable habitat for CBO. But, New York as a whole does not have that problem. There are some conservation groups in NY that do allege that they need more habitat for the return of CBO, but this is not supported by science. What is needed for a recovery is a change to highways, but the NYS DOT will not consider what needs to be done.
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marbro



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PostPosted: Mon Aug 10, 2009 2:06 pm    Post subject: Reply with quote

Okay. Sounds like you're going to stick to guns on this one. I am mystified by the recurrence of 100 years. But all such figures aside, can you quote me some research papers that show these kinds of conclusions? This idea that highways or roads cause a severe decline in barn owls (and short eared owls) is new to me. How is it that New York's roads are any different that California's or Florida's (where there are robust populations of barn owls)? I know New Yorkers drive faster but figure that cant be a deciding factor.

There are plenty of studies and summaries that do point to habitat loss, and I can refer you to those. But this interesting argument holds conservation methods in the balance. I will contact my fellow researcher in Idaho to see what he has found in any population studies.

In the meantime, thanks for your rejoinder.
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owlboy
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PostPosted: Wed Aug 12, 2009 3:20 am    Post subject: Reply with quote

You can probably start with Tony Warburton. He did a 15-year study on Barn Owls and car impacts. The study was presented at the 2007 World Owl Conference in Europe. The final paper was 100+ pages and involved changing habitat and road designs to mitigate the terrible number of car impact deaths for Barn Owls.

In regards to SEO's I would do a Google search on out-of-copyright books back in the early 1900's This is when there was an increase of habitat, and the start of the automobile industry. SEO went from the most common owl in North America to almost extinction. You can find many of those books also at Archieve.

Both owls are low fliers, and this is the main cause of their demise. The impact has been more significant for the SEO then the CBO. They like to quarter fields, and if the fields cross roads, they live a very short life

In regards to California and Florida, the situation is different. Most Barn Owls I know in southern California are in the canyons which are either protected or not developed. The situation is similar in Florida. Their population centers are mainly on the ocean, with the exception of Orlando. And the state population maps of CBO correlate to this. There are also other factors, such as, population density of prey and the correlation coefficient of the density. This can affect the amount of flight and where they fly.

In regards to habitat issues, there are a mountain of studies done by special interest groups with a particular agenda in mind. In reality, there is a very SMALL group of biologist who have dedicated their lives to owls. You can find them on one of our sister sites, www.globalowlproject.com . When I see studies by Holt, Clark, Claus, Warburton, etc I tend to believe them. Sadly, owls are often used to promote a "Green" initiative for those who aren't that "Green". So, I tend to be a little cynical about "studies" done by non-owl biologist.
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marbro



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PostPosted: Sat Aug 15, 2009 1:40 am    Post subject: Barn owl declines and relevant studies Reply with quote

Okay, finally got around to seeing your last reply. Thanks. I wanted to respond in general to the whole question of barn owl and short eared owl decline (in respect to roads versus habitat) but before I do, your last paragraph threw me for a real loop.

What mountain of studies (or even hill) has been done by what special interest group for what particular agenda? Are you talking barn owls? Habitat? Conservation? I mean, name a special interest group that skews erroneous barn owl studies or habitat studies in order to affect some hidden agenda and what that agenda is. This is highly interesting to me. If such a thing is happening it should be brought out in the open.

Your statement on "non owl biologists" is just as confounding. You even put their "studies" in quotations as if they really werent studies at all. First, if you look in the back of any of the great works on barn owls, (Stewart's paper in the 1950's, the book by Bunn, Warburton, and Wilson, as well as Ian Taylor's excellent book) you will see page after page of references to studies by grad students, college professors who do research in the off season, ornithologists, geneticists, rodent researchers, etc. etc.

The authors of the big works rely heavily on work done before them--work done by such researchers as described above. Almost every page of their work contains references to such works that the author relied on. Why? Because such authors would need to live 10 lifetimes in order to do the studies themselves, and because the scientific community has very high standards of publication and review. The way it works is that each paper is submitted to a scientific journal. In ornithology this often includes The Wilson Bulletin, The Auk, Condor, The Journal of Raptor Research, to name a few. Each paper must present methodology, hypotheses, and conclusions prior to publication. It is reviewed by highly experienced peers, and any that seem questionable are rejected. Even later, after a paper has been published, others in the field often counter the study with another paper that may point out previously unseen flaws. So the high majority of scientists are very careful in their methods. That is what SCIENCE is.

No one has ever made a living being an "owl biologist." One researcher may have done a few studies on dispersal, another on diet, another on habitat--and together their studies and expertise form a body of knowledge that other researchers later rely on. So to believe that there are only a handful of people who are reliable about barn owls goes against the reality of how scientific knowledge is accumulated. Nonetheless, as can be shown, the field is in strong agreement about barn owl biology. There are no huge controversies within the field.

And lastly, I had to once again shake my head about the mysterious statement that "Sadly, owls are often used to promote a "Green" initiative for those who aren't that "Green". Please name a single "green" intitiative that used owls to promote a false agenda.

I appreciate the exchange, and I will also very much appreciate hearing specifics about the above. Thanks.
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owlboy
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PostPosted: Tue Aug 18, 2009 2:24 am    Post subject: Reply with quote

This post is about Barn Owl deaths in Idaho, and we have moved completely off that subject. Furthermore, this is an old post. Therefore I am going to lock this post.

Marbro, I realize that you are new, and you don't know much about this forum. But, we don't have contentious and argumentative debates here over every little subject matter. We try to conduct ourselves professional. From time-to-time we do have a difficult subject matter where some people have strong opinions. Demanding that people cite journals is like calling someone a liar. We consider that inappropriate. We do have quite a few professional owl biologist on this forum, as well as homeowners who have an owl visitor and want information. We do realize that there are many bird forums and blogs that just love to debate every little bit of information. Generally those people are avid amateurs birders. We don't conduct our forum that way. We welcome you to post and reply respectfully to subject matters that interest you. But, try to keep contentious issues to a minimum. You will get the best biologist responding to professional post and replies.

Some people see my user name, "Owlboy", and think that I am some young kid who is avid about owls. I have actually been studying and watching owls for 40 years. I got a nice pile of scientific degrees about 30 years ago. So, when you went on for several paragraphs about how scientific papers are created, some people got a good laugh out of it. It would be like teaching Einstein how to do simple math.

I would venture to guess that you don't have a degree in biology, and that you don't work as an owl biologist. Especially, since you allege that you cannot make a living being an owl biologist. When students get ready to graduate from college with a degree in biology, you soon learn your options for making money with this degree: (A) If you can find a job being an owl biologist that would be great, but this possibly is very remote. Getting grants is very difficult unless you are well known; (B) You can go work for some corporation who will force you to publish, testify, or "doctor" your work to meet their needs; (C) You can go work for Legal groups who want you to publish, testify, and "doctor" your work so that they can sue some corporation for millions a dollars for fraudulent finds; (D) You can go work for some government agency and become a Ranger. Maybe they will let you do some population study on some animal. A majority of jobs in the biology related fields require you to "doctor" your work to keep you job. This is how so much fraudulent scientific work get published. It is a big problem in the scientific world, and virtually all of us complain about it. So, when I made a reference to it, I automatically assumed that you knew what I was talking about. Sorry if you misunderstood my comment.

In regards to your statement, "No one has ever made a living being an "owl biologist". This is not true. There are owl biologist in the North America, and around the world. Like I said, go look at www.globalowlproject.com . There is a nice list of owl biologist there.

In regards to your request for a "green" initiative that has a fraudulent appearance, you just need to get a copy of Advertising Age. Advertising Age is the largest and best known marketing trade journal in the world. There has been a strong movement by marketing execs to use owls in marketing campaigns to make their non-green products look green and sell more products. Just look at Subaru. They had a GHO on the cover of their Fall 2008 Drive magazine. Is Subaru "green". I don't think so. Their outback get 27 mpg for a little 4 cylinder engine. Even the Chevy Corvette get 26 mpg with it's big V8 engine. My dealer told me that it was me that prompted them to put it on the cover. I hope that is not the case. I can't tell you how many companies are using owls to "pimp out" their products. Just watch TV, and you see ad-after-ad using owls.

You have a nice product, and I hope that Deane has listed your web site on our list of owl houses. If not, you should contact him about getting your site listed here.
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owlpages
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PostPosted: Fri Aug 28, 2009 10:52 am    Post subject: Reply with quote

Hey guys, I know this is an old thread, but after reading this, i think it would be good to see more discussion on this interesting topic. i don't know if you want to start a new general thread, (say 'causes of barn owl population decline' or similar) or continue with this one... would be good to track down some papers on the subject too, perhaps put them in the downloads section...
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owlboy
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PostPosted: Sat Aug 29, 2009 12:19 pm    Post subject: Reply with quote

The thread moved off into why Barn Owls were dying in New York. And, I think we addressed it here. But, the issue is much more complicated. In different regions of the USA, there are completely different reasons why Barn Owls populations are declining. Some regions are having problems with habitat, where other areas are having problems with car impacts. Some areas have different problems. I think we are okay at this point.
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marbro



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PostPosted: Sun Aug 30, 2009 3:53 am    Post subject: Barn owl decline in NY State Reply with quote

Thanks Deane. I appreciate your interest. Actually this thread on the major causes of the barn owl's decline in New York goes to the issue of just what methods of conservation should be applied to a situation that affects not only the barn owl, but all grassland species. New York is a state that shares the same precipitous decline (during the same decades) with a number of other states in the same latitude, stretching across Pa, Ohio, Indiana, Illinois, and beyond. I would submit that research shows that these states have strong similarities in why the barn owl (and the short eared owl) have declined, and that both species would benefit in those states from the same type of conservation efforts.

Regardless of various causes of mortality, often quite high, (70 to 80% of young barn owls perish in their first year) what provides the continuing momentum for a healthy population is good habitat. For instance, the Ramsden paper on UK road deaths (quoted above as the Warburton study) concluded that possibly 40% of rural England had been made uninhabitable by major roads. But by the same token, that leaves 60% of rural England unaffected by road deaths--and though significant, it is not enough to cause a cross-country decline. And in fact, barn owls in the UK are still quite common in many areas. Then take a look at the difference in population density between England and New York. Both the same size, yet England has 53 million people versus New York's 19 million--all moving around on the roads.

It is widely agreed by researchers that the widespread destruction of grasslands (not pasture, but wild grasslands with their inherent biodiversity) and wetlands, combined with changes in farming practices (the clearing of hedgerows and intermittent wild areas), has been the major cause of decline in both owls throughout the northeast and north central states. And the movement in various states, backed by significant investment, is toward bringing back grasslands and wetlands.

I am currently traveling, and would be interested in adding a few references to works and quotes by researchers that support the above. I have a number at home and will post them when I return.

Once again, thanks for your interest.

Mark
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