I don't know. From a natural history point of view, population-specific or species-specific movements of surviving fledglings leaving study plots might be more or less biased, perhaps also depending on environmental structures and characteristics surrounding study plots.

Species identity is not enough when local populations differ in underlying mechanisms influencing local offspring recruitment rates, I think

Marcel, I don't really get your point.

I will try to clarify my problem to help.

I have ringing data for a bird species. We have information on broodsize and we would like to add information about chick survival (from hatching to independence, around 40 days). However, we do not have repeated visit to nest to check whether some chicks died or not. For our population, we only have the age at ringing of individual. The range of age is 0-41 days. For post-fledging period, we will rely on reencounter to estimate survival. Thus, we were wondering whether we could extract survival index about the first month of life when chicks are in the same area. Even if the result are biased, it could be a starting point for further estimations.

Thanks for the help.

Guillaume

I suggest to contact specialists in demographic/survival methods that also work on big birds like gulls, albatross, raptors or stork (e.g. Weimerkirch: Chizé; Pradel or Lebreton: Montpellier). OK?

Klaas, I am working on lapwings. There are some information from other populations or with low accuracy. I have the age at the ringing for all ringed individuals as nestlings, but no biometric information. After your answer, I provided more information.

Marcel, this is an advice I give quite often to people new in demographic parameters estimation. However, I am familiar with recapture-recapture methods and with Pradel or Lebreton as my Phd and post-docs were in the Biostatistics team in Montpellier about estimating demographic parameters with CMR models, and I developped myself a new approach with Pradel.

Classical methods seem not applicable here due to absence of subsequent visits at the nest once chicks were ringed. So, before trying to develop something new, maybe, one of you may have advices.

Thanks

Guillaume

HI Klaas, knowing which species you work with can help us tell you methods available. That said, if you are working with Passerines, and have repeated visits to the nest, you can try the Mayfield method to check for daily survival at the different stages of the nesting period. Or simple do a straight-forward nest survival statistics. Good luck, RY

If you know all nests and monitor them frequently, simple percentages will already give a good impression... The difficulty will be to link survival to environmental key factors, which is not an easy task given that observers only briefly visit nests, i.e.

Hi everyone,

I may repeat myself but it seems confusing: I do not have nest monitoring. I have just ringing data with the age of chick at the ringing moment.

The goal is: I was thinking to use these data to provide some kind of index of chick survival, to ultimately calculate some productivity index (nb of chicks surviving to independance).

I am aware of previous methods but classical methods rely on multiple visits to the nest but as I said, I only have ringing data, not nest monitoring.

As an other topic, linking env covariable to survival is not so difficult. Several methods are available.

Guillaume

For your data to be statistically significant/relevant, the number of samples (birds) must be large. The area and habitat quality variation over which the data is collected should also be large. (Unless of course you want to set strict limits, such as habitat type, for instance, or you are studying a species that is very uncommon and your study includes a large proportion of that population.)

Interestingly (perhaps?), if you search the literature, post fledging survival of species with broadly stable populations routinely doubles the prebreeding population in very many species from many families, occupying a large range of habitats.

Guillaume,

It's an interesting question. It looks like lapwings can renest up to four times if their first nest fails. Unless you have an estimate of renesting rate, I'm not sure estimating chick survival will help you much in the IPM (because you'd be replacing one unknown (total reproductive output) with another (a component of reproductive output).

I also don't think I have a good answer to your actual question, unless you're willing to ignore detectability. It sounds like if there was a good method for this already out there, you probably would have heard of it!

Jeff

Hi Guillaume,

I think you are able to get some estimations only if you have also data on breeding density of a population of a species in a given year or number of nests found in a population before ringing (first encounters). If you have the latter data (I understand you don't) than it would be quite easy to calculate nest survival of the young using Mayfield method, as you've been already suggested.

My experience on reed warblers suggests that number of young ringed correlates both with nest losses (survival of young at the nest stage until ringing) and breeding density in a year. And even in a stable populations that do not show any long-term trend quite important variation in breeding densities between years exists. Number of nests found is affected also by searching effort.

So without some extra information you are unable to get reasonable estimations of chick survival before fledging based only on number of young ringed, I guess.

Lucyna

Hi all,

thanks a lot for all your answer. It is very interesting to have external point of view.

My first guess was that it would be quite difficult or requiring strong assumptions to extract chick survival from such data, and it is ^^

To Lucyna: I have breeding census but not density nor number of nests, so I think I will let the IPM estimate the chick survival for me !

To Jeffrey: yes, I am aware of renesting in lapwings, sometimes up to 4 attempts in the same breeding seasons. Some previous studies tried to estimation the proportion of females for each case, so we should be able to include such information in our IPM.

Thanks all !

Cheers !

Guillaume

I believe that the Mayfield method is the best to use for this methodology. Good luck!

Mayfield 1961 Wilson Bulletin, or Wikipedia (see key word Mayfield method)

Look at http://www.juvaste.fi/risto/survival.php

Perhaps it helps..

risto