Effects of structural and functional habitat gaps on breeding woodland birds: working harder for less

The effects of habitat gaps on breeding success and parental daily energy expenditure (DEE) were investigated in great tits (Parus major) and blue tits (Cyanistes caeruleus) in urban parkland (Cardiff, UK) compared with birds in deciduous woodland (eastern England, UK). Tree canopy height, the percentage of gap in the canopy and the percentage of oak (in the wood only) within a 30 m radius of nest boxes were obtained from airborne remote-sensed data. Breeding success was monitored and parental DEE (great tits: both habitats; blue tits: park only) was measured using doubly labelled water in birds feeding young. In the park, mean (± SD) tree height (7.5 ± 4.7 m) was less than in the wood (10.6 ± 4.5 m), but the incidence of gaps (32.7 ± 22.6%) was greater (9.2 ± 14.7%). Great tits and blue tits both reared fewer young in the park and chick body mass was also reduced in park-reared great tits. Park great tits had a higher DEE (86.3 ± 12.3 kJ day-1) than those in the wood (78.0 ± 11.7 kJ day-1) and, because of smaller brood sizes, worked about 64% harder for each chick reared. Tits in the park with more than about 35% gap around their boxes had higher DEEs than the average for the habitat. In the wood, great tits with less oak around their boxes worked harder than average. Thus structural gaps, and functional gaps generated by variation in the quality of foraging habitat, increased the costs of rearing young

Cushing's syndrome in women with polycystic ovaries and hyperandrogenism

BACKGROUND: A 41-year-old woman presented to an endocrinology-gynecology clinic having been diagnosed 7 years earlier with polycystic ovarian syndrome on account of hirsutism, subfertility, greasy skin, acne and multiple ovarian cysts. Ovulation induction had led to a successful pregnancy. Subfertility recurred, however, and persisted alongside a new diagnosis of hypertension and progressive weight gain. Upon examination, the patient was hypertensive with facial plethora, rounded facies and violaceous abdominal striae. INVESTIGATIONS: Low-dose dexamethasone test, bedtime salivary and 24-h urinary free cortisol estimations, CT scan of the abdomen, and serum hormone and gonadotropin analyses. DIAGNOSIS: Cushing's syndrome due to a right adrenocortical adenoma. MANAGEMENT: The patient underwent laparoscopic right adrenalectomy, which led to resolution of all symptoms, signs and biochemical abnormalitie