Is it a boy or a girl?

WILDECHOES, a project that helps to understand birdsong, recently published a super interesting and very well illustrated article on the calls of the Common Swift (Apus apus).

Chris Hails compares his own recordings with the results of some scientific papers and through the analysis of the sonograms shows us how it is possible to distinguish the calls of males from those of females. He also gives us clues as to how different individuals can identify with each other, such as couples that get together year after year during the breeding season!

These subtle differences are imperceptible to the ears of most of us, but the flocks of swifts screaming on late summer afternoons do not go unnoticed! Now, even though we can't detect every detail of their call, we can understand them better!

Find out more here.

Good readings!

Where are the Pallid Swifts at this moment?

A question we regularly ask during winter is: where are the swifts?

Since, as far as we know, they do not have a very defined route or schedule, they can be anywhere in West Africa. As an example, last Christmas, while one of the swifts marked with a gps logger in the Vila Nova de Famalicão colony was in the vicinity of the Outamba-Kilimi National Park, in Sierra Leone, another one was in the Lake Kainji National Park, in Nigeria, almost 2000 kilometres far away!

As well as being well-travelled, they have very good taste!

New article! What do Pallid Swifts eat?

On the beginning of December an article was published that helps us to understand the diet of the Pallid Swifts (Apus pallidus) during the breeding season, based on the work that is being conducted in Vila Nova de Famalicão and with the support of the andorin project.

Through the analysis of the faeces of swifts captured during bird ringing sessions, it was possible to identify exactly what these birds have been feeding on, but also to answer other questions such as: does their diet vary throughout the breeding season? And do males eat the same as females?

The results show that:

1️⃣ When the availability of their potentially preferred prey (ant queens and males) was high, they hardly fed on anything else! However, when their preferred prey was probably no longer available, they appeared to have started feeding on other invertebrates, resulting in a more varied diet.

2️⃣ Although no differences were found between the diets of the two sexes with respect to composition, males feed on larger prey!

As they are birds that spend almost all their lives in flight, travel great distances and have a very restricted distribution, not much is known about the diet of swifts. The results of this study, apart from opening a window on the super-secret life of swifts, show once again the importance of the services that these birds provide us: the control of agricultural and forestry pests!

You can read the article here!