Distribution and trends
Distribution
seabird trend
Data derived from systematic counts of migrating individuals. For each location the hourly average number of birds are given. Seasons run from July to June.
Population trends
seabird trend
Data derived from systematic counts of migrating individuals. For each season, the hourly average number of birds (red dots), the trend line (dark blue) and associated standard error (light blue lines) are given. Seasons run from July to June.
- vanaf 1980
- significant increase, < 5% a year (+)
- laatste 12 jaar
- significant decrease, >5% a year (--)
Breeding success and survival
Not enough data.
Seasonal occurrence
seasonal pattern
Data derived from systematic counts of migrating individuals. Shown is the monthly average number of birds for for the last five seasons. For each month is indicated which part is counted flying to the left or to the right.
Occurrence description
Buiten broedtijd
Middelste Jagers worden gewoonlijk alleen langs de kust gezien. Van voorjaarstrek wordt amper iets gemerkt. De najaarstrek speelt zich hoofdzakelijk af tussen september en december, met de piek in november en begin december. Verreweg meeste waarnemingen vallen tijdens harde aanlandige winden. De getelde aantallen wisselen sterk van jaar tot jaar. In sommige najaren volgend op een goed broedseizoen in het hoge noorden (veel lemmingen), zoals 1985 en 2007, is de soort talrijker. Dan worden tot enkele honderden vogels per dag op zeetrektelposten gezien en verschijnt deze jager ook mondjesmaat in het binnenland. Het merendeel van de vogels is in onvolwassen kleed.
Birds directive
Conservation status
The Birds Directive focuses on the conservation of all naturally occurring wild bird species in Europe, including the Pomarine Jaeger.
This means that EU Member States must take measures to maintain or bring the populations of these species to a level that corresponds in particular to ecological, scientific and cultural requirements.
The Birds Directive requires Member States to maintain habitats for birds of sufficient size and quality, including through the designation of Special Protection Areas for the benefit of the European Natura 2000 network. No special protection zones have been designated for the Pomarine Jaeger in the Netherlands. The national population must be able to maintain itself at a favorable level.
What is the methodology to assess the conservation status of birds
non-breeding bird
The conservation status of the Pomarine Jaeger as non-breeding bird in the Netherlands is favourable.
| State of Conservation Assessment | ||||
| Distribution | Population | Habitat | Future | Final verdict |
| favourable | favourable | favourable | favourable | favourable |
Assigned areas
No areas assigned
Counting guidelines
No counting guidelines available.