Foster eggs or chicks of woodpeckers with wild conspecifics

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 3
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How is the evidence assessed?

Effectiveness

41%
Certainty

29%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

Natural variations in reproductive output can be detrimental when populations are very small, for example if pairs fail to produce fertile eggs or some pairs repeatedly fail to raise offspring successfully. One way to minimise this problem is to foster eggs and chicks between nests. Eggs and chicks from nests with more offspring than they are likely to be able to raise can be moved to those with infertile eggs. Alternatively, if a pair produces fertile eggs or healthy chicks but consistently fails to raise chicks then it may be possible to transfer offspring to a more successful pair.

In other circumstances it may be possible to foster chicks with other species (‘cross-fostering’). Studies describing this intervention are discussed in the following section ‘Foster eggs or chicks with wild non-conspecifics (cross-fostering).’

Study locations

Key messages

Three studies from the USA found that red-cockaded woodpecker Picoides borealis chicks fostered to conspecifics had high fledging rates.
One small study found that fostered chicks survived better than chicks translocated with their parents.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A small study in loblolly Pinus taeda and longleaf P. palustris pine forests in South Carolina, USA (Franzred 1999), found that all three red-cockaded woodpecker Picoides borealis nestlings translocated with their parents died, whereas two nestlings fostered to wild pairs in the release site were successfully raised. One (a female) disappeared after months, the other (a male) successfully bred. This study is discussed in more detail in ‘Translocate individuals’.
Study and other actions tested
Referenced paper
Franzreb K.E. (1999) Factors that influence translocation success in the red-cockaded woodpecker. The Wilson Bulletin, 111, 38-45.
A small study in a pine forest site in Mississippi, USA, in 1996 (Richardson et al. 1999), found that two orphaned red-cockaded woodpecker Picoides borealis nestlings introduced into two foster nests fledged successfully (along with the non-fostered nestlings) and that at least one survived to the following breeding season (when it remained at its foster cluster as a helper). The chicks were both male and fostered when approximately 11 days old into broods containing a single nestling. One was added to the nest with the nestling still present, the other was added whilst the nestling was temporarily removed, to ensure the parents fed the foster chick. Between removal from their nest holes and fostering (later the same day), the chicks were supplied with mealworms and crickets.
Study and other actions tested
Referenced paper
Richardson D.M., Copeland M. & Bradford J.W. (1999) Translocation of orphaned red-cockaded woodpecker nestlings. Journal of Field Ornithology, 70, 400-403.
A replicated, paired site study from April-July in 1997-1998 in 20 experimental and 18 control (containing 22 nestlings) red-cockaded woodpecker Picoides borealis nests in 5 forest sites in Louisiana, USA (Wallace & Buchholz 2001), found that fostered nestlings exhibited similar fledging rates to native nestlings in the same nests (85% of 20 fostered and 86% of 22 native nestlings fledged) and nestlings in control nests (68% of 22 control nestlings fledging). On average, fostered nests produced more fledglings than control nests (1.8 compared to 1.3 fledglings / nest). Feeding rates for fostered and native nestlings were similar. Cross-fostered nestlings were matched by age. Native and control nestlings were handled and returned to their native nests.
Study and other actions tested
Referenced paper
Wallace M.T. & Buchholz R. (2001) Translocation of red-cockaded woodpeckers by reciprocal fostering of nestlings. Journal of Wildlife Management, 65, 327-333.

Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2020) Bird Conservation. Pages 137-281 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Bird Conservation

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