Changes in ring recovery rates over the last 50 years: shall we continue to ring ducks?

Abstract

Although knowledge of ring recovery rate is of crucial importance to establish demographic parameters, such as survival probability, this information is generally unknown for the dabbling ducks. The almost single existing value from the North American Mallard (Anas platyrhynchos) is thus generally applied to other species or geographic areas, even though this assumption may be strongly misleading. In the study reported here, we have relied on a proxy for actual ring recovery rate, namely, the proportion of rings fitted each year that were eventually reported, to test for differences between duck species (Mallard and Teal Anas crecca) and between countries [England (UK) and France] for Teal. Potential trends over time were also assessed. Ring recovery rate was found to have sharply decreased and at a similar rate over time in both species in France, and in both countries for Teal (e.g. from 22.7% in 1952 to 7.2% in 1992 for the British Teal). Teal rings were, however, reported more frequently than Mallard ones, and Teal rings were more frequently reported in the UK than in France. In recent years, a phone number for reporting the information has been included on the bird mark, with the immediate result of a doubling in the recovery rate in France. Adaptations to current ringing procedures that would improve ring reporting would appear to be necessary in the future if researchers are to keep ringing as a valuable source of information for bird demography studies.

Conditional modelling of ring‐recovery data

“…Recent years have seen a decline in the reporting probability of many species of wild birds; see Baillie & Green (1987), Robinson, Grantham & Clark (2009), Guillemain et al. (2011) and Mazzetta (2010), and as yet no models for conditional ring‐recovery data have been proposed which can incorporate this decline in recovery probability.…”

Band reporting probabilities for mallards recovered in the United States and Canada

“…Band reporting probabilities reflect human behavioral characteristics and social perspectives that may vary over space and time (Nichols et al , Guillemain ). Other factors such as changes in band inscriptions, band solicitation efforts, and more convenient reporting methods (e.g., telephone or web‐based communication) may also affect reporting rates (Tautin et al , Royle and Garrettson , Guillemain et al ). Prior to 1993, nearly all standard leg bands placed on waterfowl were inscribed with “AVISE BIRD BAND WRITE WASHINGTON DC USA.” From 1993 to 1994, a United States postal zip code was added to the band inscription, and beginning in 1995, the BBL introduced a more convenient method to report bands, via a toll‐free telephone number (Tautin et al ).…”

Determinants of bird ring return: a questionnaire to duck hunters

“…Similarly, the recovery rate (i.e. proportion of marked birds that later got returned) for birds with nasal saddles from the Camargue, Southern France, was almost twice as large as that for metal ringed only teal (13.2% and 6.6%, respectively; Guillemain et al 2011). One saddled bird was reported 1,824 days after recovery and was counted as an outlier.…”

“…These were reported indirectly through the national ringing centres and these hunters were not contacted for interview. Hunters from foreign countries may have different attitudes towards ring reporting (which may translate into different ring reporting rates; Guillemain et al 2011). However, hunters mostly report birds that had been ringed in their own country, and hence the present study was restricted to French hunters.…”