NOx gases react to form smog and acid rain as well as being central to the formation of fine particles (PM) and ground level ozone, both of which are associated with adverse health effects.. NOx is produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at high temperatures.In areas of high motor vehicle traffic, such as in large cities, the amount of nitrogen oxides emitted into the atmosphere as air pollution can be significant.Ox gases react to form smog and acid rain as well as being central to the formation of fine particles (PM) and ground level ozone, both of which are associated with adverse health effects.. NOx is produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at high temperatures.
1 Grey squirrels are mainly herbivorous, eating acorns and hazel nuts, berries, fungi and even bark, buds and shoots. 2  However, on rare occasions when plant food is very scarce they will eat insects, smaller rodents, bird eggs and nestlings. 3  Grey squirrels breed twice a year, December to February and May to June.he hind legs are bigger and more powerful than the front legs. 1  Grey squirrels are mainly herbivorous, eating acorns and hazel nuts, berries, fungi and even bark, buds and shoots. 2  However, on rare occasions when plant food is very scarce they will eat insects, smaller rodents, bird eggs and nestlings.
One explanation for why grey squirrels eat birds' eggs, yet do not appear to cause any decline in bird numbers, is that birds compensate for the loss to their nests. If the number of fledglings falls, for example, the survival rate of those remaining often goes up, as they have less competition for food in the nest.t has long been known that grey squirrels, an invasive species to the UK, predate on bird eggs and will also kill and eat fledglings. Red squirrels, the UK's native squirrel species, do the same. Over the past four decades, many wild bird species have declined in abundance in the UK.