Revealing the contributions of reproduction and survival to the Europe-wide decline in meadow birds: review and meta-analysis
Roodbergen, M. ; Werf, D.C. van der; Hotker, H. - \ 2012
Journal of Ornithology 153 (2012)1. - ISSN 2193-7192 - p. 53 - 74.
redshank tringa-totanus - oystercatchers haematopus-ostralegus - lapwings vanellus-vanellus - godwits limosa-limosa - farmland birds - agricultural intensification - breeding population - adult survival - nest success - demographic parameters
In this review, we summarize available data on nest success, chick survival and reproductive output, and adult and juvenile survival of five meadow breeding waders in Europe: Eurasian Oystercatcher (Haematopus ostralegus), Northern Lapwing (Vanellus vanellus), Black-tailed Godwit (Limosa limosa), Eurasian Curlew (Numenius arquata), and Common Redshank (Tringa totanus). The survival data from the assembled studies did not show an overall decline in adult survival in any of these species. However, our meta-analyses on reproduction data show that chick survival declined strongly in the last 40 years in western Europe and that nest success declined in eastern Europe in the period 1995-2005, in Scandinavia in the period 1985-2005, and in western Europe in the period 1950-1980. Predation of nests has increased by c. +40% in all five species in western Europe during the last four decades. Results on reproductive output, the number of fledglings produced per breeding pair, were less clear. A decline was apparent in Eurasian Oystercatcher in the period 1963-2005; an initial decline in 1953-1990, but slight recent (1990-2006) recovery in Northern Lapwing; an initial decline in Black-tailed Godwit in the period 1985-1995, but again slight increase from 1995 onwards; no trend in Common Redshank (1992-2006) nor in Eurasian Curlew (1961-2006). In all five species the results indicate that present population declines are caused by a decrease in reproduction, not in adult survival, and that reproductive output is presently too low to compensate for adult mortality.
Seasonal distribution of meadow birds in relation to in-field heterogeneity and management
Verhulst, J. ; Kleijn, D. ; Loonen, W. ; Berendse, F. ; Smit, C. - \ 2011
Agriculture, Ecosystems and Environment 142 (2011)3-4. - ISSN 0167-8809 - p. 161 - 166.
agri-environment schemes - lapwings vanellus-vanellus - godwit limosa-limosa - agricultural intensification - farmland birds - food resources - habitat - grasslands - success - england
Effectiveness of European initiatives to restore populations of meadow breeding waders is heavily debated. We studied field preference of meadow birds throughout the breeding season in four areas of over 100 ha each and related observed patterns of individual birds to in-field heterogeneity, sward height and management. Over the four areas, most waders were observed in the more heterogeneous fields at both the period of nest site selection and incubation. Additionally, fields grazed at relatively low-intensity for longer consecutive periods (on average 6 cows/ha for 30 d instead of 20 cows/ha for 2 d) were hosting high densities of lapwings but also black-tailed godwits. Our results suggest that in-field heterogeneity may be important for meadow breeding waders at the nest site selection and incubation stages. Conservation initiatives aimed at meadow breeding waders might improve their effectiveness when they increase the heterogeneity of fields. Grazing for longer consecutive periods at relatively low stocking rates might be a way to achieve this, if carried out at stocking rates low enough to allow waders to reproduce successfully.
Direct and indirect effects of the most widely implemented Dutch agri-environment schemes on breeding waders
Verhulst, J. ; Kleijn, D. ; Berendse, F. - \ 2007
Journal of Applied Ecology 44 (2007)1. - ISSN 0021-8901 - p. 70 - 80.
lapwings vanellus-vanellus - site-fidelity - agricultural intensification - natal philopatry - food resources - birds - management - habitat - farmland - biodiversity
1. In the Netherlands, agri-environment schemes are an important tool for halting the ongoing decline of meadow birds and, in particular, waders breeding on wet meadows. The effectiveness of the main scheme, postponed mowing, is heavily debated because it does not result in higher breeding densities. Recently, agri-environmental collectives have become involved in the co-ordination of scheme applications and additional measures have been introduced. One of them is per-clutch payment: farmers are paid per wader clutch without being restricted in their farming practices. 2. We evaluated the effectiveness of the combination of the two measures, postponed mowing and per-clutch payment, by determining the number of birds and territories on 12.5-ha plots where both measures (on average 1.6 ha postponed mowing and 10.9 ha per-clutch payment) were being implemented. Conventionally managed grasslands served as controls. Additionally, on a field with postponed mowing and a paired control field, we measured a number of environmental factors that might influence wader distribution. 3. On plots operating a combination of postponed mowing and per-clutch payment, more territories of all bird species were found and more redshanks Tringa totanus were observed. The same pattern occurred on fields with per-clutch payment alone. On fields with postponed mowing alone, we found more territories of the most abundant wader species but on conventional fields we observed more lapwings Vanellus vanellus. 4. The positive effects of postponed mowing on wader territories were probably caused by small differences in soil moisture and groundwater level between the two field types, as inclusion of these factors in a general linear model rendered all scheme effects insignificant. 5. Postponed mowing affected the form and amount of fertilizer applied to the fields as well as available nitrogen, but none of the other environmental factors that were measured. Additional analyses identified groundwater depth, penetration resistance and prey density (earthworms, Lumbricidae, and leatherjackets, Tipulidae larvae) as the main factors determining wader density. 6. Synthesis and applications. Our results show that conservation measures consisting of postponed mowing and per-clutch payment implemented by agri-environment collectives do not support a higher abundance of waders but do support marginally higher breeding densities of waders compared to conventional farms. These results are probably due to differences in soil moisture and groundwater depth. The effectiveness of agri-environment schemes directed towards conservation of waders might be enhanced by including raised groundwater levels into scheme prescriptions.