|Speckled Mousebird, Arusha. Cute, and really quite interesting...|
So, let's start today, in no particular order, with the Speckled Mousebird.
Identification is straightforward: it would be a small, non-descript brown bird if it were not for the extremely long tail (total body length about 35cm, half of that being tail). Overall, speckled mousebirds are brown with greyer head and red legs and face. They also have a short crest. The only species that it's likely to be confused with are other mousebirds, blue-naped mousebird being the other most common in Tanzania, though that species tends to occur in drier habitats and is always greyer (not brown) and has a completely different call (speckled almost squeek like mice, whilst blue-naped whistle).
|Two mousebirds warming up together! Tarangire|
Humans maintain a very strict body temperature of around 37 degrees Celcuis - 39 degrees and we're seriously sick, 35 and hypothermia sets in. Birds in general are similarly constant, though most species are often a bit warmer, at around 41 degrees (good for keeping hands warm on a cold morning). Speckled mousebirds, however, can drop their temperature by more than 10 degrees overnight (less if they sleep huddled together - an activity that can save them 40-50% of the energetic costs of keeping warm), and so they have to warm up each morning in the sun. It certainly reduces energetic costs, and when food supplies are low they allow their body temperature to fall even more, though they are slow to respond when at low body temperature, so there must be a potential predation risk. They're also cooperative breeders, with helpers from previous breeding seasons helping to raise each season's young as well as the parents - an activity no doubt encouraged by the need to be in groups at night to stay warm. And the final interesting fact I've come up with is the fact that mousebirds are the only avian order that is completely restricted to Africa - ther order used to be much more widespread, but all living mousebirds are today in sub-Saharan Africa, making them something of a living fossil - the last few species of a once widespread and ancient group of birds.
Next up, the African Pied Wagtail.
|African Pied Wagtails are often around buildings...|
Something interesting African Pied Wagtails are almost entirely insect eaters. As well as eating insects that live on the ground, they actively seek flying insects hiding in cracks and holes around our houses, providing a valuable service (other wagtail species have been observed eating at a rate of several insects per minute, giving a total daily intake of over 20,000 flies per day!). Given that the particularly like feeding on dung flies, this is a very helpful job. Their association with humans and our buildings is extraordinary and it's hard to find the species far from towns and villages, suggesting that until recently they were probably rather scarce. Although they usually nest in trees, they will happily even nest on our houses.
Finally, (for today) let's look at the Yellow-billed Kite.
|This Yellow-billed Kite is hunting tourist lunches |
at Ngorongoro (thanks to http://www.tanzaniabirds.net for picture)
Something interesting Yellow-billed kites are common in cities across Africa, with Black Kites taking over as summer visitors to Europe, and resident across Asia and Australasia. As well as a small resident population, 'our' kites are joined be migrants from south Africa between May and September when the species can be very common in many cities and towns. To my mind, the best thing these birds do is some absolutely fantastic flight. If I could fly, I'd want to be as maneouverable as a kite - watching them swoop and glide as they hassle other birds to steal their food (behaviour called kleptoparasitism) - or cleverly stealing unsuspecting tourists' lunch boxes is always a pleasure (though I do the latter from the safetly of my own car...)! Although they do often steal other food, they're also pretty good hunters themselves, and will eat just about everything, from birds at bats caught in the air, to fish plucked from the water!