Genetic variation for the rate of recruitment of novel insect prey into the diet of a bird

Two lines of quail (Cotumix coturnix japonicus) were selected over three generations for the speed of their response to the red colour form of the two-spot ladybird beede (Adalia bipunctata), an aposematic, semi-palatable prey insect. One line was bred for fast recruitment of die new prey into the diet and die odier for slow recruitment. Differences between the lines suggested additive genetic variation. The birds' response to insect prey with different colour patterns and toxicities (brown beetles, green butterfly pupae, melanic two-spot ladybirds and toxic seven-spot ladybirds) demonstrated that die selection involved a specific response to novel prey. The results are discussed in relation to predator strategy and the evolution of aposematism.     

COPULATION AS FEMALES AND USE OF ALLOSPERM IN THE FRESHWATER SNAIL GENUS BULINUS (GASTROPODA:PLANORBIDAE)

Each of 8 snails in 2 groups of Bulinus (Physopsis) globosus,1 group raised in isolation and 1 group raised in community,were paired for 14 consecutive days with a male-acting partnersnail. In each group, the experimental snails, which were notallowed to act as males, were able to copulate as females onapproximately 94% of the days paired. Two copulations as female,with the same male partner, occurred on 50% of the days thatthe snails were paired, in the 2 groups combined. Non-receptivefemale behaviour by the experimental snails occurred frequently,and copulation was prevented by such behaviour during 6 pairings,3 in each group. Young B. (P.) africanus first copulated as females when theywere 31–33 days old. The accessory sex glands of the femalereproductive tracts of these young female-acting snails containedmoderate to large amounts of secretion. B. (P.) africanus, which were raised in pairs, laidcross-fertilizedeggs in isolation for an average of 76 days, and 1559 eggs/snailwere deposited before cross-fertilization ceased. Cross-fertilizedeggs were produced for as long as 120 days. After 1 copulation as female, virgin B. (P.) africanus laidcross-fertilized eggs for an average of 78 days and deposited3654 eggs/snail before crossfertilization ceased. Cross-fertilizedeggs were produced for as long as 113 days. After 2 copulationsas female, 1 copulation on each of 2 consecutive days, virginB. (P.) africanus laid cross-fertilized eggs for an averageof 102 days and produced 4397 eggs/snail before cross-fertilizationceased. Cross-fertilized eggs were produced for as long as 123days. Snails which were homozygous for an allele governing mantlepigment pattern were raised with a partner which was homozygousfor a different pigment pattern. Young produced in a 4-day periodafter the snails were isolated were 100% heterozygous. The snailswere then rearranged into pairs with a partner of the same genotypefor 4 days, during which time 26% of the young produced werehomozygous. The snails were again isolated for 4 days, and 49%of the young produced during this 4-day period were homozygous.The results of this experiment strongly suggest that multipleoutcrossing occurred. In B. (P.) africanus, stored allosperm were used to fertilizeeggs after 1, 4 and 7 weeks of starvation; after 1 and 4 weeksof 15°C low temperature and 4 weeks of 15°C + 4 weeksof 10°C low temperature; and after 1 and 4 weeks of desiccation.After 8 weeks of desiccation, 2 of 3 surviving snails reproducedby self-fertilization and 1 snail did not reproduce. Too fewsnails survived 8 weeks of desiccation for a conclusion to bereached on the ability of allosperm to survive. (Received 1 June 1984;     

Differences between the 7-spot and 2-spot ladybird beetles (Coccinellidae) in their toxic effects on a bird predator

Abstract. 1. Experiments with nestling blue tits Parus caeruleus L. examined the effects of feeding them 7-spot ladybird Coccinella septempunctata (L.), 2-spot ladybird Adalia bipunctata (L.) or controls Tenebrio sp.
2. A feeding rate of 51/3 7-spot ladybirds per day 'killed' nestlings within 2 days. Three of six nestlings fed at half this rate survived 4 days. In contrast, all experimental birds survived sixty-four 2-spot ladybirds fed over 4 days (equivalent by weight to the high 7-spot diet).
3. Nestlings fed 7-spot ladybirds also grew more slowly than birds fed 2-spot ladybirds. The latter birds showed no difference in weight gain from the controls although they begged more strongly for food.
4. Cadavers of birds fed 7-spot ladybirds showed evidence of severe liver damage.
5. The results indicate a substantial difference between the ladybird species in their toxicity to nestling blue tits. They support the hypothesis that 2-spot ladybirds are largely-edible, polymorphic Batesian mimics of well-protected, monomorphic species such as the 7-spot ladybird.     

Testing agri‐environment delivery for farmland birds at the farm scale: the Hillesden experiment

The Hillesden experiment, established in 2005/2006 to test the delivery of biodiversity benefits under Environmental Stewardship, covers c. 1000 ha of arable farmland in central lowland England. It is a randomized block experiment with five replicates of three treatments: (1) CC: cross compliance, the control; (2) ELS: 1% of land removed from production for wildlife habitat provision; and (3) ELS‐X: 5% of land used for wildlife habitat, each treatment being applied to contiguous areas of 70–80 ha. Bird usage of winter food patches, comprising three different seed mixes, was monitored through the winter and was also related to seed yield. Winter and breeding season bird/territory abundance was recorded before and after the provision of the winter food patches. Bird use of the patches differed between seed mixes. There was large variation between individual patches in both seed yield and bird numbers and between individual bird species in their use of different seed mixes, suggesting that the availability of a range of patch types would be beneficial. Use of all patch types declined sharply in late January to February, indicating depletion and/or inability of birds to access shed seed. Winter bird abundance at a farm scale for all species combined, granivorous species and nine individual species increased for all monitored species when seed patches were available. At a treatment level, the increases tended to be greater in ELS‐X, where most of the patches were located. In the breeding season at a farm scale, the numbers of territories for all species combined and granivorous species increased significantly when seed patches had been available in the previous winter. There was little evidence of a treatment‐scale response. The provision of winter food appeared to increase winter bird abundance and to follow on into an overall increase in the breeding population, but if the latter effect is to be reflected elsewhere, this requires that sufficient breeding habitat is available to accommodate an increase.     

Separating Components of Variation in Survival of Mule Deer in Colorado

ABSTRACT Survival is an important parameter for understanding population dynamics of mule deer (Odocoileus hemionus) and other large herbivores. To understand long-term dynamics it is important to separate sampling and biological process variation in survival. Moreover, knowledge of correlations in survival across space and between young and adults can provide more informed predictions of survival in unsampled areas. We estimated survival of fawn, yearling, and adult mule deer from 4 spatially separated regions of Colorado, USA, from 1997 to 2008. We also estimated process variance in survival across time for each age and site using Markov chain Monte Carlo (MCMC) methods. Finally, we estimated correlations in survival among sites and ages with MCMC methods. Average winter fawn survival was 0.721 (SD = 0.024) for the 4 regions. Average winter adult female survival was 0.935 (SD = 0.007). Annual adult female survival ranged from 0.803 (SD = 0.017) to 0.900 (SD = 0.028) for the 4 regions, excluding hunting mortality. The correlation between fawn and adult female survival was high, 0.563 (SD = 0.253). Correlations in winter fawn survival were higher between populations at the same latitude than they were for populations to the north and south. We used survival estimates from our analysis to inform prior distributions for a Bayesian population dynamics model from one population in Colorado and compared that model to one with noninformative prior distributions. Population models including informative prior distributions based on our results performed better than those noninformative prior distributions on survival, providing more biologically defensible results when data were sparse. Knowledge of process distributions of survival can help wildlife managers better predict future population status and understand the likely range of survival rates.     

Schulze, E.-D. (ed.) Carbon and nitrogen cycling in European forest ecosystems. Ecological studies, volume 142

The storage of carbon in forests is a contentious issue of ecological,policy and business concern, both nationally and internationally.Carbon dioxide in the global atmosphere is quantitatively themost significant greenhouse gas so the main concern of the protocoldelivered at Kyoto in 1997 is to stabilize and then to reducethe amount of carbon dioxide in the atmosphere. The most obviousand effective way of making this reduction is to decrease inputsto the atmosphere from the burning of fossil fuels. The alternativestrategy to reducing the inputs is to enhance the outputs, andthat is where forests and the associated controversy come in.At Kyoto, provision was made for removal of carbon dioxide fromthe atmosphere by forests and its subsequent storage withinforests, the so-called carbon sequestration by forests. Thiswas a brave—some would say foolish—step by the Partieswho, with their