a saucer of vegetation on the ground, lined with softer material. The birds nest in large colonies Recently, they have started nesting on rooftops and buildings. Both sexes are involved in the nest-building process. A single white egg, , is incubated for a period of 50 to 54 days, by both sexes. The altricial chick is brooded for 2 weeks and fully fledges after 70 to 75 days. Again, both sexes are involved. During this period, the parents are nocturnal, and will even be inactive on well-lit nights. Social behaviour The mating ritual of this fulmar consists of the female resting on a ledge and the male landing with his bill open and his head back. He commences to wave his head side to side and up and down while calling. They make grunting and chuckling sounds while eating and guttural calls during the breeding season. Conservation The northern fulmar is estimated to have between 15,000,000 and 30,000,000 mature individuals that occupy an occurrence range of and their North American population is on the rise, hence it is listed with the IUCN as Least Concern. The range of these species increased greatly last century due to the availability of fish offal from commercial fleets, but may contract because of less food from this source and climatic change. The population increase has been especially notable in the British Isles. Anthropogenic impact Northern fulmars' stomach contents are a hallmark indicator of marine debris in marine environments because of their high abundance and wide distribution. A study of 143 northern fulmars from 2008 to 2013 found 89.5% of them containing microplastics within their gastrointestinal tracts. A mean score of 19.5 pieces of plastic and 0.461 g per individual was calculated. This is considerably higher than in past studies on northern fulmars, possibly implying increasing plastic debris in marine ecosystems and shorelines. However, more research is needed to substantiate such conclusion. Long-term data from the Netherlands dating back to the 1980s show an increase in consumer plastics and a decrease in industrial plastics in the stomach contents of fulmars. The increased plastic ingestion can occur through biomagnification: their diet consists of such invertebrates like plankton that have shown an increase of consumption of microplastics entering the ocean. By going deeper into the food web of marine life, it is evident that fulmars could be indirectly affected through tropic transfer and biomagnification, and similarly could