1. The spatial dimension of population ecology Case study I The local scale: necrophagous flies and their parasitoids Arion ater Megaselia sp Basalys parva Aspilota sp Kleidotoma psiloides Limosina ?sylvatica

2. The spatial distribution of individuals 100 boxes arranged in a regular 10x10 m grid each with a dead slug What is the spatial distribution of flies, parasitoids, and hyperparasitoids Does spatial distribution change with abundance? Do parasitoids and hosts differ in spatial distribution? Is spatial distribution linked to resource availability? Does spatial distribution contributes to population stability? Photo Polystyrol Each slug was covered by a beech leaf

3. The complete food web of dead Arion snails

4. The sequence of colonisation The limiting factor of colonisation was carcass desiccation Desiccation is dependent on plant cover

5. Slug weight (g) Conicera schnittmani Megaselia ruficornis Megaselia pulicaria Gymnophora arcuata Limosina spPsychoda sp Fannia immutica Panorpa sp N weight (mg) N N N N N N N 2.31 0.0006 33 60.0066000000000000 2.50010.001120.00220030.0018000010.026 3.10090.0099001 0.0031 5 00000000 2.60020.0022000000000000 2.80070.00770000100.00610.000910.004300 Coordi- nates Slug weight (g) Aspilota sp1Aspilota sp2 Orthostigma sp1 Aspilota sp4Aspilota sp5 Kleidotoma psiloides N parasitism rate N N N N N 90752.320.33300.00040.66700.0000 0 90782.520.66700.0000 0 0 0 90823.100.00060.66730.33300.0000 0 90842.600.00010.5001 00.0000 0 84732.800.0000 0 71.00000.0000 The raw data

6. Conicera schnittmanniMegaselia sp1 Aspilota sp1Orthostigma sp1

7. Aspilota sp1Orthostigma sp1 Aspilota sp1 Kleidotoma psiloides

8. Spatial aggregation Coefficient of variationMorisita index Mean crowding (Lloyd index) Poisson random distribution Poisson random: J = 1 Regular (segregated, overdispersed): J << 1 Clumped (aggregated, underdispersed): J >> 1 N denote the occasions in each of the N sites. Statistical inference has to come from a Monte Carlo ranodmisation.

9. Lloyd index and species abundances Parasitoids Diptera Necrophagous flies and their parasitoids : Highly aggregated Aggregation decreases with average abundance Both guilds have the same degree of aggregation

10. Conicera schnittmani Megaselia ruficornis Megaselia pulicaria Gymnophora arcuata Limosina spPsychoda sp Fannia immutica Panorpa sp Conicera schnittmani -0.290.000.520.000.030.260.43 Megaselia ruficornis -0.11-0.690.960.970.620.420.23 Megaselia pulicaria 0.47-0.04-0.340.000.390.840.49 Gymnophor a arcuata -0.070.00-0.10-0.560.570.840.31 Limosina sp0.320.000.36-0.06-0.060.400.88 Psychoda sp0.22-0.050.09-0.060.19-0.830.56 Fannia immutica 0.11-0.08-0.020.02-0.090.02-0.00 Panorpa sp0.080.120.07-0.10-0.01-0.060.33- Aspilota sp1Aspilota sp2Orthostigma sp1Aspilota sp4Aspilota sp5 Kleidotoma psiloides Aspilota sp1-0.180.510.580.640.08 Aspilota sp20.14-0.780.010.100.18 Orthostigma sp10.070.03-0.740.910.60 Aspilota sp4-0.060.26-0.03-0.430.48 Aspilota sp50.050.170.010.08-0.33 Kleidotoma psiloides0.180.13-0.05-0.07-0.10- Spatial segregation of species? Table of Pearson correlations (lower triangle) and the respective significance levels (upper triangle)

11. Aspilota sp1 Aspilota sp2 K. psiloides C. schnittmanni Limosina spBiplots of principal component analyses PCA separates sphaerocerid species from C. schnittmanni and the other phorid species PCA separates the abundant Aspilota sp1 and sp2

12. Necrophagous DipteraParasitic Hymenoptera Large number of species Higher diversityLower diversity Colonization susceptible to desiccation of the carcassParasitism fairly independent of carcass desiccation Densities of early colonizers do not depend on the weight of the carrion Parasitism rates independent of the weight of the carrion Densities of late colonizers correlate positively with the weight of the carrion Parasitism in dominant species is not density dependent Low interspecific competition Pronounced interspecific competition only at high parasitism rates High competition between the necrophagous flies and large predators and necrophages - High impact of large predators and necrophages on the mortality rates Parasitism rates not influenced by the presence of larger competitors of the hosts High degree of aggregation in the populations Negative correlation between abundance and degree of aggregation No marked correlation between parasitism and degree of aggregation Aggregation of late colonizing species negatively correlated with the weight of the carrion Aggregation independent of the number of hosts Differences in the populations of necrophages and their parasitoids

13. Case study II The regional scale: fragmented landscapes and meta-populations Meta-populations refer to the spread of local populations of a single species within a fragmented landscape. Local populations are connected by dispersal Questions: Minimum fragment size Minimum dispersal rate for survival Percentage of fragments colonised Speed of genetic divergence within fragments What is the influence of fragment edges? How do corridors influence dispersal rates?

14. The spatial distribution of species is scattered among isolated fragments. Fragments differ in population size The higher the population size is, the lower is the local extinction probability and the higher is the emigration rate Distance Case study II The regional scale: fragmented landscapes and meta-populations The Lotka – Volterra model of population growth Levins (1969) assumed that the change in the occupancy of single spatially separated habitats (islands) follows the same model. Assume P being the number of islands (total K) occupied. Q= K-P is then the proportion of not occupied islands. m is the immigration and e the local extinction probability. Colonisations Emigration/Extinction The Levins model of meta-populations

15. Colonisation probability is exponentially dependent on the average distance I of the islands and extinction probability scales proportionally to island size. The canonical model of metapopulation ecology Metapopulation modelling allows for an estimation of species survival in fragmented landscapes and provides estimates on species occurrences. If we deal with the fraction p of fragments colonized The standard equation of metapopulation modeling

16. Extinction times When is a metapopulation stable? The meta-population is only stable if m > e. If we know local extinction times T L we can estimate the regional time T R to extinction 0 200 400 600 800 1000 1200 01234567 p K 0.5 Median time to extinction The condition for long-term survival If m and e are known p denotes the proportion of fragments colonised

17. Bird metapopulations Zosterops abyssinicus Zosterops poliogaster The lowland Z. abyssinicus has a continuous distribution. The highland Z. poliogaster has a scattered mountain distribution. It has a meta-population structure. The highland species occurs in forest fragments

18. SpeciesRegionNWingTarsusWeightGPS Z. poligasterCH-Satellite2562.920.912.72°35´S; 37°51´E Z. poligasterCH-Simba valley1061.121.211.42°42´S; 37°55´E Z. poligasterMount Kasigau20592110.63°49´S; 38°39´E Z. poligasterMt. Kulal3263.421.713.62°39´N; 36°56´E SpeciesRegionSite Starting frequency Lowest frequency Highest frequency Frequency range Length of call Z.abyssinicusChyulu LowandsHunters Lodge3501293738489110.1733 Z.abyssinicusChyulu LowandsHunters Lodge3473319138536620.2049 Z.abyssinicusChyulu LowandsHunters Lodge3321325640487920.1952 Z.abyssinicusChyulu LowandsHunters Lodge34952865409112260.1588 Z.abyssinicusChyulu LowandsHunters Lodge37033038409410560.2133 Locatio n Locus Fragme nt length Mt. Kasiga u TH Chawia TH Mbolol o TH Nganga o Chyulu Hills Aberda res Mt. Kulal Chulu lowlands Cu_281160000000000000 Cu_2821620.45240.01920.0250.016100.08620.0238000.0200 Cu_2831640.54760.98080.9750.983910.91380.9762110.9811 Zl4412140000000000.0200 Zl442218000000000000 Zl4432201111111110.740.86670.9286 Zl4442240000000000.240.13330.0714 Zl445226000000000000 Zl411820.95240.961510.983910.94830.9762110.979211 Morphological raw data Bird call raw data Allele frequency raw data Data collected by J. C. Habel, TH Munich

19. Bird call patterns Species P. abyssinicusP. poliogaster Region Chyulu lowlandsTaita lowlandsChyulu hillsTaita hills Aberdare s Site Hunters Lodge Kibwesi Mtito Andei MumoniDembwaMwatateSatelliteSimba Mt. Kasigau MbololoNgangao Aberdare s P. abyssinicus Chyulu lowlands Kibwesi0.33 Mtito Andei <0.0010.42 Mumoni0.490.990.31 Taita lowland s Dembwa0.950.980.080.99 Mwatate0.990.210.030.930.99 P. poliogaster Chyulu hills Satellite0.49<0.001 Simba0.980.620.060.99 <0.001 Taita hills Mt. Kasigau 0.470.990.370.99 0.98<0.0010.99 Mbololo<0.001 0.99<0.001 0.07 Ngangao0.130.990.630.990.790.12<0.0010.360.99<0.001 Aberdar es <0.001 Mt. Kulal 0.05<0.001 0.010.55<0.001 0.99 Local birdcalls within Z. poliogaster are more different than between Z. poliogaster and Z. abyssinicus Birdcall within the lowland Z. poliogaster do not significantly differ ANOVA probabilities for no difference

20. : Bird calls : Allele frequencies : Morphology Northern and southern populations of Z. poliogaster differ considerable in bird dialect. Soon gen flow will cease despite of occasional migration. Bird call patterns within Z. poliogaster differ more between local populations than do genetic and morphological charcters.

21. DistCH-SatelliteCH-Simba_valleyMt_KasigauMt._KulalChawia CH-Satellite 14003.5515397.0583023.0113299.94 CH-Simba_valley14003.5515701.0670770.713718.35 Mt_Kasigau15397.0515701.0671486.182332.959 Mt._Kulal83023.0170770.771486.1872338.83 Chawia13299.9413718.352332.95972338.83 Geographic distances in m Sum10418.2215576.445139.174321.6410382.77 Rel sum0.1253810.187460.0618480.8944470.124955 The average relative distance of a site to all other sites. Species population occupancy modelling SPOM Site IA [ha]p0p1p2p3p4p5p6 CH-Satellite0.1253810.770.50.2860.1900.1350.0990.0740.056 CH- Simba_valley 0.187466.990.50.5680.6290.6810.7220.7540.777 Mt_Kasigau0.0618486.210.50.5770.6450.7010.7430.7730.793 Mt._Kulal0.8944474.050.50.4890.4800.4720.4650.4580.452 Chawia0.1249555.940.50.5680.6290.6790.7180.7470.767 Fururu0.0772979.210.50.5890.6690.7350.7850.8210.844 =AE56+$W$53*EXP(-$Y$53*$W56)*AE56*(1-AE56)-$X$53*1/$X56*AE56 a = 0.5 b = 0.5 c = 1

22. a0.50.10.5 b 0.10.5 c1115 Sitep6 CH-Satellite0.0560.0030.6720.017 CH-Simba_valley0.7770.4240.9090.565 Mt_Kasigau0.7930.4170.9290.719 Mt._Kulal0.4520.2680.7040.232 Chawia0.7670.4010.9160.615 Fururu0.8440.4790.9380.760 MachaE0.6730.2970.9020.571 Mbololo0.8100.4540.9210.633 Mwachora0.8490.4850.9390.764 Ndiwenyi0.7870.4130.9260.690 Ngangao0.4500.1390.8450.307 Ronge0.2140.0370.7640.099 Vuria0.8410.4810.9340.720 Wundanyi0.5850.2250.8820.471 YaleS0.5770.2200.8790.454 Species population occupancy modelling SPOM High dispersal increases the probability of occupancy. High local mortality decreases local colonisation. Distance between fragments has a high impact on colonisation probability. The highly isolated Mt. Kulal has low occupancy probabilities. 3/√15 = 0.77 For long-term stability of the meta-population at least 77% = 12 sites have to be occupied

23. Is the species endangered? Site p61-p6 Extinction time CH-Satellite0.5082510.4921.478 CH- Simba_valley 0.7253870.2753.115 Mt_Kasigau0.876940.1237.615 Mt._Kulal0.4383940.5621.213 Chawia0.7948410.2054.355 Fururu0.8720290.1287.303 MachaE0.8324550.1685.453 Mbololo0.7695420.2303.817 Mwachora0.8715790.1287.275 Ndiwenyi0.8542690.1466.349 Ngangao0.7267550.2733.133 Ronge0.5954810.4051.929 Vuria0.8344690.1665.526 Wundanyi0.8020870.1984.534 YaleS0.7912030.2094.270 TLTL 4.491 P11 TRTR 16636092 Zosterops poliogaster is regionally not endangered despite of the higher local extinction probabilities Extinction time 1.478 3.115 7.615 1.213 4.355 7.303 5.453 3.817 7.275 6.349 3.133 1.929 5.526 4.534 4.270 4.491 6 33.18457 The loss of habitats might provide to fast extinction