Hello !

I have been studying the birds of forest plantations in Ukraine. Maybe I can help you. Are you interested in methods or data Interpretation?

Sincerely, Mikhail.

Dear Yonny,

Yes, point count method is recommended to survey birds in forest.

Regards,

Hi Yonny,

I would recommend you look at some of  the numerous paper by David Edwards using this technique in various vegetation types in Sabah.

works well if area allows big numbers of independent samples

hi yonny...

yes, point count method is very recommended...i use it in sampling the bird community in mangroves and oil palm plantation.

This paper has some good ideas for standardizing point count methods. It includes mention of how to correct for detection biases. 

Reviving common standards in point-count surveys for broad inference across studies

Steven M. Matsuoka1,a*, C. Lisa Mahon2, Colleen M. Handel3, Péter Sólymos4, Erin M. Bayne4, Patricia C. Fontaine1, and C. John Ralph5

http://www.bioone.org/doi/abs/10.1650/CONDOR-14-108.1

What kind of biases are you concerned about, specifically?

Point counts are indeed widely used in a variety of environments, including forests. Particulary in dense vegetation there are some pitfalls, however. The most obvious is detectability, which differs greatly between species. Visibility is generally poor in dense forest, therefore perfect knowledge of all bird vocalisations is essential. Even so, comparisons of species densities or communities may be problematic if data are not corrected for differences in detectability. Use distance sampling (in itself a challenge in a dense forest environment) to make it possible to calculate species specific probability density functions (and you may also need to calculate these specifically for different seasons, different sites, ... etc.). If you are only interested in comparing within species (over time or space) it is (somewhat) less of a problem. 

Hi Yonny,

as stated by other researchers, point counts are widely used for surveying birds in forest environments (both natural and managed), but some points must be borne in mind. 1) Point counts can be used to survey songbirds and few other orders (for example columbiformes, piciformes and apodiformes in Europe) but are not suitable for most of the other orders. 2) Point counts are appropriate for sampling of wide areas with a low economic and time effort, but, in small areas, territory mapping allows to have a more precise estimate of the number of birds/couples inhabiting the study area. 3) Data collected by means of the point count technique can include some bias, such as the low sample size, double counting, spatial autocorrelation and imperfect detection. To overcome these problems, you should adopt an adequate sampling design, representative of the statistical population that you are monitoring. For example, points can be spaced according to the species detection radius and replicated in time (within and among seasons) to estimate the species-specific detection probability and its dependence on survey conditions (distance sampling is a good alternative, as Marc stated).

Greetings,

Valerio

Thank you very much Michail,Taqiyeddine, Dr Colin, Fares, Aainaa, Nicole, Dr Sven, Tariku, Dr Marc and Valerio :). i am very excited getting useful and positive feedback from you.

i learn to use the distance sampling and analyze it using Distance software. but, this is my first time using the Distance software and having a hard time using it (even after reading method). i hope that there will be recommended way on how to learn this software.

thank you very much!

Regards

Yonny, my student are also going to be using Distance - so I will be running a quick introduction to that and estimateS probably next week. You can join in if you want. 

Hola Jonny,

Estoy de acuerdo con Valerio en que el método de puntos puede excluir algunas especies de aves como las que tienen bajas densidades y las que son viscosas al observador. En ese caso podrías combinar el conteo por puntos con un muestreo de trayectos (transects) y tener información de ambos métodos, con lo que podrías responder a tus preguntas de investigación. Estos dos métodos son complementarios entre ellos y van a darte buena información.

Saludos desde Colombia,

Leonardo

Hi.

In the Canary Islands we have used both point counts and line transects to study forest bird communities in different ecosystems, like laurel forest and Canary Pine forest. In my opinion, when the surface of the forest studied is small or it is highly fragmented the best method is the point count. We place normally point counts at a minimum distance of 400-500 m between them, and sometimes even of 1 km. 

Hello Johnny, sorry to respond in Spanish ... my translation is not very good but you forwarded the message

I agree with Valerio in the point method can exclude some species of birds as those having low densities that are viscous and the observer. In that case you could combine the point count with sampling paths (transects) and have information from both methods, which could answer your research questions. These two methods are complementary to each other and will give you good information.

Regards,

Leonardo

Hi again.

Regarding to the possibility to exclude some species in the point counts, I agree that sometimes it occurs, but there is a key factor: the time spent in the counts. Normally point counts are of 10-15 min., even 20 min., and it's clear that when you have more time to make the points there is the possibility to detect some more secretive/elusive species, but, at the same time, the birds move more in 20 min. than in 10, so there is the possibility to overstimate the number of individuals. So 20 min. is good to have a better idea of the species composition of the avifauna, but may produce a confusion or overstimate in the number of individuals. This is our experience with the avifauna of forest ecosystems in the Canary Islands, where we have a small number of breeding species. 

With regards to the methodology of point counts and line transects for bird monitoring I can recommend a scholar book:

BIBBY, C.J. & N.D. BURGESS (1992). Bird Census Techniques. Academic Press. London. XVII + 257 pp.

(There are more recent, revised editions of it). 

Yes, it is. But read the book Bird Census Techniques from Bibby et al to take care about the possible bias.

Yes Point count is one of the techniques used to assess bird populations in a forest. But I would recommend going through some papers on the same topic to make sure that it is the perfect methodology for your study. 

Check also the book Monitoring bird populations by point counts from ‎Ralph:

https://scholar.google.co.in/citations?view_op=view_citation&hl=en&user=glrYPksAAAAJ&citation_for_view=glrYPksAAAAJ:8k81kl-MbHgC

If your work involves studies in tropics, the above link would have some useful comparison studies.

If your questions are about diversity and abundance then point counts are a great method. Training, testing and calibrating surveyors prior to the study and throughout are a good way to feel more confident about your results. There are numerous studies on statistics and detection probability for point counts to help you know where you uncertainty is.

Hi again.

May be useful to see this interesting work in pdf:

http://www.fs.fed.us/psw/publications/documents/psw_gtr149/psw_gtr149.pdf