New moss species discovery on Texel island

Dicranella varia, photo from Austria

Warden Jitske Esselaar reports from Texel island in the Netherlands about moss research.

Ceres is a small meadow nature reserve close to the Wadden Sea.

During research in Ceres, 31 moss species were found. They included common species, like green silk moss. And rare species, like crisped fork-moss.

One Ceres species was new for Texel: Dicranella varia.

Rare Fenn’s wainscot moth on Texel island

Fenn's wainscot

Translated from the Dutch Vlinderstichting entomologists:

Thursday, September 17th, 2015

Near the Schorren nature reserve on Texel Fenn’s wainscot moths have been found. It is in this century only the fourth time that this species has been seen in the Netherlands. That this is not an occasional vagrant was evidenced by the fact that during one evening four individuals were seen. Unique, because in the 1950s of the last century for the last time a viable population of Fenn’s wainscot moths had been found in Friesland in Eernewoude.

Helping wheatears, butterflies on Texel island

This is a northern wheatear video.

Translated from a 10 September 2015 blog post by warden Jitske Esselaar on Texel island in the Netherlands:

At work for the northern wheatear in the Eierland Dunes

Today, 30 employees of BirdLife in the Netherlands have turfed about 15 slopes in the Eierland Dunes in the northern part of Texel. These are small patches of about 5 x 5 meters, where the vegetation has been removed.

The purpose of this turfing is to bring back bare sand and the removal of high grasses. On the barren sand different plants can germinate again, for example dune pansy and heath dog-violet. This kind of vegetation is important for wheatears looking for food here. The Eierland dunes are an important breeding ground for wheatears. In 2015, no fewer than 30 breeding pairs were counted, this is a great number for this species which has declined sharply!

For three rare Texel butterfly species bare sand patches are important as well. The dark green fritillary, Queen of Spain fritillary and Niobe fritillary lay their eggs on violets.

Water in Texel dunes: here.

Long-tailed skua passes Texel island

This is a long-tailed skua video from Sweden.

This morning, a long-tailed skua was reported flying west of Texel island in the Netherlands.

Bird breeding news from Texel island

This video says about itself:

22 March 2013

The Dutch wadden island Texel is a paradise for birds. Photographer Sijmen Hendriks visited it several times from 2007 on . This slideshow video shows the result of these visits. Grey Plover, Avocet, Spoonbill, Stonechat, Brent Geese, Whitethroat, Hen Harrier, Sandwich Tern, Linnet, Yellow Wagtail and many more birds are featured in this video. Texel is the westernmost island in the Wadden Sea and is known for its rich bird life.

Warden Erik van der Spek from Texel island in the Netherlands writes today (translated):

In the Muy lake spoonbills, great cormorants and grey herons have nested in colonies. In 2015 as many as 106 spoonbill couples have bred. This number has never been so high. In 2014 there were 85 nests. The numbers of cormorants have declined: there were an estimated 848 nests in 2015 (census April 20). In 2014 there were still 882 nests. The cormorants may have relocated to De Geul; the colony there has increased explosively, with 661 couples in 2014 and 1040 in 2015.

De Geul

In the Geul there were counted at least 420 spoonbill couples. Since 2011, the number of breeding pairs here has remained about the same. …

Of the approximately 65 little tern couples on the Hors about half the young fledged. Of the others, the nests have been washed away. The four pairs of hen harriers together produced eight young birds; one nest failed. This is comparable to the situation in 2014.

Harbour porpoises off Texel island, new study

This video is called Harbour porpoise (Phocoena phocoena).

From the Journal of Sea Research, 17 July 2015:

Going with the flow: Tidal influence on the occurrence of the harbour porpoise (Phocoena phocoena) in the Marsdiep area, The Netherlands


Porpoise presence in the Marsdiep is studied as a function of tide related covariates.

• Sighting rate is best described by salinity with highest rate at high salinity level.

• This indicates that porpoises enter the area in bodies of saline North Sea water.

• Other studies have shown a higher fish abundance during high tide.

• Therefore, tidal influx of porpoises is most likely related to prey availability.


One of the most important factors explaining the distribution and behaviour of coastal marine mammals are tides. Tidal forces drive a large number of primary and secondary processes, such as changes in water depth, salinity, temperature, current velocity and direction. Unravelling which tidal process is the most influential for a certain species is often challenging, due to a lack of observations of all tide related covariates, strong correlation between them, and the elusive nature of most marine organisms which often hampers their detection.

In the Marsdiep area, a tidal inlet between the North Sea and the Dutch Wadden Sea, the presence of harbour porpoises (Phocoena phocoena) was studied as a function of tide related covariates. Observations were carried out in early spring from a ferry crossing the inlet on a half hourly basis. Environmental and sightings data were collected by one observer, while an on-board Acoustic Doppler Current Profiler (ADCP) and temperature sensor continuously recorded current velocity profiles and temperature, respectively. Sea surface temperature and salinity were measured at a nearby jetty. Sightings (n = 134) were linked to tidal elevation, geographical position, local depth-averaged current velocity, water temperature (with and without trend correction) and salinity.

Variation in sighting rate was best described by salinity, with highest sighting rate at high levels of salinity (> 30 g kg− 1), indicating that porpoises enter the area in bodies of (more saline) North Sea water. Second best variable was time of day, with the highest sighting rate early morning, and decreasing during the day. However, surveys in the morning happened to coincide more often with high water and hence, the apparent time of day effect could be due to collinearity. Most porpoises were present in the northern part of the Marsdiep, particularly during high tide.

Tide dependent sighting rates confirmed that porpoises reside in the North Sea, and enter the western Wadden Sea during the flood and leave during ebb. This tidal influx is most likely related to prey availability, which corresponds to other recent studies in this area showing higher fish abundance during high tide. Documenting information on tide related patterns could be used in practice, when e.g. planning anthropogenic activities or assessing critical habitats for this species.

Texel island bats research

This is a serotine bat video.

On 9 August 2015, Ecomare museum on Texel in the Netherlands reported on bat research on the island.

Only one species, as far as they know, has colonies on Texel: the serotine bat. Serotine bats have been seen on all Dutch Wadden Sea islands; but only on Texel breeding colonies are known.

107 bats were counted during the 2015 Texel count; less than in other years.