The small tortoiseshell butterfly, a once-common species found in gardens, has declined by 77% in the last ten years. It's thought that the recent cold, wet summers and a lack of habitat are the reasons for this.
The Capercaillie is the heaviest breed of grouse and can only be found in Scottish woodland in the UK. Their numbers have dropped a lot in the past few decades
Common or harbour seals have declined by 31% in Scottish waters since 1996. The reasons for the drop in numbers are described as "mysterious" because their close cousins grey seals have not been affected in the same way.
Turtle doves have declined by 93% since 1970 and it's not the only farm-land bird that's affected. Schemes have been brought in to help the birds keep healthy and boost their numbers by planting sources of rich seeds in areas of natural habitat.
The early bumblebee (Bombus pratorum) has been in decline since 1970, one of the reasons is because of a loss of wildflowers.
The water vole is a semi-aquatic rodent and is sometimes referred to as the water rat. The water vole population dropped by 88% from 1989-1998
The numbers of woodland butterflies, like this Heath Fritillary butterfly, have been dropping since the 1990s. The Heath Fritillary has dropped by 34% in the past 10 years. The report says this could because fewer woodland areas are managed properly.
Hedgehogs have declined by around a third since the millennium. Large-scale farming and housing developments have broken up a lot of their habitat. Gardeners are now being encouraged to make space for the mammals.
Conservationists have been trying to help the natterjack toad for some time now, but despite their efforts numbers of the species have changed little since 1990, with less than 50 breeding populations in mainland Britain.
The Southern Damselfly is a rare breed of damselfly which is mostly found in the south-west of the country. There aren't many records of the insects but scientists say that their numbers have declined a lot in recent decades.
The number of Skylarks in Britain have dropped to 58% since 1970. These small birds can be found all over the UK and are a little bit bigger than sparrows
The brown hare has only decreased by 6% in the past 15 years but this is due to lots of conservation efforts.
The dartford warblers have suffered in the past from severe winters and were down to just a few pairs in the 1960s. Since then, the birds have increased in numbers and can be found in the south of England.
The black tailed godwit birds are down to around 60 breeding pairs and are found in wetland and coastal areas.
The common crane was once extinct in the UK and has only recently been reintroduced to British wildlife. Cranes have been brought over to the UK and it is hoped they will breed so that we start to see an increase in their numbers once again.
The hen harrier is a bird of prey which has declined by almost 100%. There is only one breeding pair of the birds left in England but there are more of the birds in in the rest of the UK.
Cirl Buntings are a success story in new findings. The birds dropped to just 118 pairs in 1989 but after 20 years of conservation efforts, there are now 862 pairs. The birds used to be found all over the south of the UK but are now only found in Cornwall and Devon.