Duringthe first monitoring campaignon thewaterfowlreproductionin constructedwetlandsof the AlbuferaSPA, interesting resultshave been obtained. For itsdifferent configurations,constructed wetlandsoffer slightlydifferent habitatsfor waterfowlinrelation to the levelof flooding,thevegetation structureand floristiccomposition of theirplots.It isby studyingthevariationofmicrohabitats that we will getover thetwo years that we will obtainpreciseinformationofthe habitat requirements and the interactions between the species. We are slowly beginning to understandsome of the processesineach of thesites:
- The Tancat de la Pipa, with more open lagoons and a filter system with sparse vegetation, offers environments suitable to a wider variety of species of waterfowl, but in small numbers.
- he Tancat de Milia, with greater coverage of bulrushes on flooded soil, but with low density offers suitable environments for the reproduction of two of the most interesting species for the project: the coot and little bitterns.
- The Tancat de l’Illa, with a very high density of eneas, together with an abundance of small and medium-sized fish, is a highly appropriate place for breeding heron and bittern.
With regardtosmall birdsthat breed in constructed wetlands(marsh passerines), with a similar compositionof the community,largedifferences ineffectivebreedingare observed in some couples.Thus, thefollowing table summarizesthe information obtained duringthisbreeding season, indicating the number ofbreeding stock(inmorphological characters) and highlightingthe speciesof interest inthe project:
| Tancat de la Pipa | Tancat de Milia | Tancat de l’Illa | |||
| ♂ ♂ | ♀ ♀* | ♂ ♂ | ♀ ♀* | ♂ ♂ | |
| Great reed warbler | 15 | 10 | 15 | 11 | 12 |
| Moustached warbler | 2 | 3 | 3 | 1 | 14 |
| European reed warbler | 64 | 41 | 12 | 4 | 8 |
| Cetti’s warbler | 2 | 2 | 4 | – | – |
| Savi’s warbler | 1 | – | 1 | – | 1 |
| Kingfisher | 1 | – | – | – | – |
| Bearded reedling | 2 | 2 | – | – | – |
- The number of breeding females is generally regarded as the minimum number of breeding pairs.
But the importance ofmonitoring the reproduction processis notonly limited to getting to know reproductive habitsof the species. There ismuch more information to measurethat defines the suitability of nesting habitat orfeeding birds: productivity, for example. To realise the monitoring of family groupsand learn more about thehabitat they use and the survival of their offspring gives us the ideal opportunity to assess whether a habitatis suitableor just seems to be suitable. A place where four birds are born and out of those three reach adult size is more adequate than a place where 12 birds are born and none of them reaches adult size.
In the case ofwaterfowlthis information isbeing prepared, while for thepasserine birds, interestingadditional information is provided in the above tablefollowing the PASER methodology (Bird Bandingin Spring) developed by SEO/BirdLife. Asmeresuperficial analysis, these data show that despite thehigh number ofpairs ofreed warbler, productivity has been low(still the highest in theTancatde la Pipa). On the other hand, although there are fewer couples of moustached warblers in theTancatde la PipaandMiliacompared toIlla,their productivityis higher. However, theTancatde la Pipa, home to farmorepairs of European reed warblers, produces less thanMiliaand Illa, which are very similar.
Theinformation shown hereis used tohave an initialidea of how thedifferent configurationsof constructed wetlandsstronglymodulatetheresponse of birds, both in terms ofhabitat selectionand in terms ofproductivity.Subsequentanalysis realised in greater detailwill show infuture reports inhow far these parameters affectthe management ofconstructed wetlands, but also theuse ofhabitatchampions, territorialityor physical conditions. This is valuable informationto be usedin developingfuture plansfor managing these territories.