Still worth the travel? : changes in Camargue teal migration patterns, body condition and demographic parameters over 60 years

• Climate and habitat changes linked with human activities have profoundly modified the road maps of waterfowl across their geographic ranges. If new breeding grounds open to the North, traditional wintering sites may gradually get deserted by birds short-stopping during the autumn and shifting their nonbreeding distribution. More than 60,000 ringing data were collected from wintering Teal (Anas crecca) in the area from the early 1950s to the beginning of the 2010s. Migration patterns have changed with birds now arriving much earlier, and overall population movements being much reduced during winter. The body condition of Camargue-wintering Teal has improved dramatically compared to the pre-1970 era, which could be a cause and/or a consequence of such changes in migration processes: Teal may arrive increasingly early in the year because artificial summer flooding of wetlands and baiting now provide suitable habitat and abundant accessible food. In turn, reduced movements linked with greater residency in the Camargue would impose smaller use of the body reserves. The comparison of Teal turnover and survival rates during historical (1950s- 1970s) and modern (post-2002) years provides some insight as to whether the situation has gradually improved for these birds. Conversely, the sustained use of the Camargue could simply reflect these birds being lured by artificially increased availability of food, which they would use at the expense of their survival rate, hence with no positive consequences in terms of population dynamics.

Ämnesord

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

NATURVETENSKAP  -- Biologiska vetenskaper (hsv//swe)

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