Bluebells are flowering, blossom is falling and the buds of elder are erupting, suddenly the still frozen mornings are interrupted with warm waves of sunshine and a cacophony of bird song.
Birds here in the UK tend to nest and lay their eggs between March and the end of August, with a noticeable peak in May and June. There are a few exceptions, as always with nature, with early nesters such as the long-tailed tit and species that breed over a longer period and have multiple broods throughout the season.
Nest site selection for individual birds is a significant factor in achieving their ultimate goal of raising chicks to fledglings and passing on their genes to the next generation. There are a number of factors that influence nest site selection in different bird species. These include physical and environmental factors such as shelter from the elements and security from predators, as well as social factors such as territory boundaries and competition.
Some birds, such as swallows, will return to the same nest site year after year, whereas others, even those with multiple broods in the same year, will start a new nest in a different location, albeit recycling material from old nests.
The male wren will build several nests within his territory, allowing the female to inspect each in turn before selecting one to complete and breed in. Females tend to then select the nest which is most cryptic, likely to reduce the risk of predation.
Given the huge variables exerting influence on nest site selection, it can be difficult to understand why some sites, which may not appear suitable, are selected over others. It is, however, well known that a variety of species, typically our garden and woodland birds, will readily use man-made alternatives.
The addition of artificial nest boxes is a great way of increasing the value of a space for birds, whether integrated into a building or attached externally to a structure or tree. However, the range in nest site selection and habitat preferences between bird species has driven the design and availability of many different types of boxes. For example, appropriate lodgings for house sparrows allow for communal nesting, robins prefer open type boxes, swifts will nest in a ‘bowl’ type box or a special integrated brick box. With regards to materials, there are boxes constructed from wood and woodstone, those that are painted, or with bitumen lined roofs, as well as those that have predator protection. This variety and choice can prove confusing when choosing the best box for your space.
Given the increasing expectation for integrated biodiversity enhancements within local development and the importance of selecting and placing nest boxes, it is always recommended that any required or potential habitat enhancement measures are discussed early within the design phase.
Native Ecology are experienced in assessing the current and potential future value of sites for nesting birds, whether as part of a Landscape and Ecological Management Plan (LEMP) for a large housing development, a enhancements plan for a single dwelling, or a detailed management plan for a Local Wildlife Site. Please call us today for site-specific ecological advice on the integration of opportunities for nesting birds.