Milvus

Abstract: The Cape Verde kite (Milvus milvus fasciicauda) is considered to be one of the rarest birds of prey in the world and at significant risk of extinction. For this reason there is great interest in both the taxonomic and the population status of this group. To help resolve its taxonomic status, we provide phylogenetic analyses based on three mitochondrial genes for a sampling of kites in the genus Milvus, including a broad geographical sampling of black kites (Milvus migrans), red kites (Milvus milvus), Cape Verde kite museum specimens collected between 1897 and 1924, and five kites trapped on the Cape Verde Islands during August 2002. We found that the historical Cape Verde kites, including the type specimen, were nonmonophyletic and scattered within a larger red kite clade. The recently trapped kites from the Cape Verde Islands were all phylogenetically diagnosed as black kites. Our findings suggest that the traditional Cape Verde kite is not a distinctive evolutionary unit, and the case for species status, as recently suggested by others, is not supported. We do find support for recognition of at least one clade of yellow-billed kites, traditionally considered as a black kite subspecies, as a distinctive phylogenetic species.

Abstract: -We studied the effect of growth rate, final size, hatching sequence, hatching asynchrony, and fledging asynchrony on the fledging age of Black and Red kites (Milvus migrans and M. milvus). Feather growth explained 43% and 38% of the variance in fledging age of Black and Red kites, respectively. Fledging age increased with hatching sequence and increased fledging asynchrony in relation to initial hatching asynchrony of both species, especially in broods of three chicks. Once the effect of growth was removed, no differences in fledging age related to hatching sequence were found in the Red Kite, but there was still a delay in fledging of third-hatched Black Kite chicks. Synchronous fledging of firstand second-hatched Black Kite chicks seemed to occur when both chicks had grown at a similar rate, and was caused by a delay in the fledging of the first-hatched chick. First-hatched Black Kite chicks did not delay fledging if second-hatched chicks experienced reduced growth. Differences between the two species in the third-hatched-chick fledging delay could be due to differences in nest provisioning by adults during the postfledging dependence period. Red Kites reduced provisioning to the nest as soon as the first chick fledged, while Black Kites maintained nest provisioning longer. No evidence was found supporting the idea that parents may reduce feedings to hasten first flight of their offspring. Received 20 May 1991, accepted 10 February 1992. THE LENGTH of the nestling period in birds is thought to be correlated with growth rate (Ricklefs 1968, Skutch 1976, Zach 1982b, Poole 1989). Thus, it has been used in comparative studies of growth (e.g. Bortolotti 1986a) because growth rates are more difficult to obtain. However, species with similar rates of development may have nestling periods of different length, suggesting that selective factors affecting growth rate are not the only ones acting on fledging age (Maher 1964, Skutch 1976, Zach 1982a, Freed 1988). Some studies have explored the effect of growth rates on the length of the nestling period and the extent to which growth and fledging age are related (Zach 1982a, b, Bortolotti 1984, 1986b). Hatching asynchrony within a clutch is a widespread trait in birds that may result in the development of feeding hierarchies promoting differences in growth rates (Bryant 1978, O'Connor 1984) that can influence fledging age (Clark and Wilson 1981). There also may be a parent-offspring conflict over fledging age (Trivers 1974, 1985), the chicks trying to extend the nestling period and the parents trying to force the first flight of their chicks by a reduction in feeding rates, or by means of special behavioral mechanisms (Rowan 1955, Brown and Amadon 1968, Walker 1972, Skutch 1976, O'Connor 1984, Poole 1989). A prolonged nestling period would give extra parental care (food and defense against predators) to the chicks, increasing their survival expectancy, but also could increase the rearing costs beyond the optimum for parents. Some studies on fledging of species in the Passeriformes have shown a trend for synchronizing the date of first flight among siblings, but it is not clear if fledging synchrony is obtained by a delay in first flight of the oldest chicks (Freed 1988), by an earlier fledging of the youngest (Gibb 1950, Skutch 1976, Zach 1982a), or by both phenomena (Lemel 1989). Raptors follow the general trend of interspecific increase of fledging age with body size (Newton 1979, Bortolotti 1986a). Also, the smaller males fledge at a younger age than the females in size-dimorphic species (Scharf and Balfour 1971, Sherrod 1983, Wyllie 1985, Bortolotti 1986b, Poole and Bromley 1988, Delannoy and Cruz 1988), and this has been related to differences in growth rates and final size between sexes (Newton 1979, Bortolotti 1984). Hatching sequence in the asynchronous hatching Black Kite (Milvus migrans) has been said to

Abstract: The Black Kite (Milvus migrans) has a limited distribution within Taiwan due to a dramatic population decrease during the late 20th century. Prompted by some poisoning incidents of Black Kites and other farmland birds, we hypothesized that poisoning may be an underreported yet important threat. Thus, we created a citizen-science Facebook group in October 2014 in order to receive more information about possible poisoning incidents. By September 2016, we had received reports of 4753 dead birds in 213 separate poisoning incidents in agricultural areas. The types of fields most often associated with poisoning incidents were direct-seeded rice (Oryza sativa), rice that was soon to be harvested, and red beans (Vigna angularis). We tested tissues from 29 dead small birds for pesticide residues. Twenty-eight birds contained carbofuran, and one bird contained terbufos, both highly toxic pesticides. Furthermore, of seven dead Black Kites tested from 2010 to 2016, four contained carbofuran, and three contained second-generation anticoagulant rodenticides. After interviewing farmers and reviewing older agricultural literature, we concluded that most of these incidents represented intentional poisonings by farmers attempting to control avian pests and rats (mostly Bandicota indica and Rattus spp.). We suggest that the Black Kites were likely the victims of inadvertent secondary poisoning incidents. The dramatic decrease of the Black Kite in the 1980s coincided with the rapid increase in the area planted with direct-seeded rice and the widespread use of carbofuran and rodenticides. The recent decreased use of these pesticides due to restrictions has coincided with the recent slow recovery of the Black Kite population. Therefore we initiated public awareness campaigns, and the Taiwanese government has adjusted some pesticide-use policies.