the birds of tarquinia salinas: regional and local determining factors

(working hypotesis)

The birds of Tarquinia Salinas: regional and local determining factors

E.Lanzuisi1, M.Biondi2, J.Cecere3, G.Nascetti1 & G.Tallone3

1 DECOS Department, Tuscia University, Viterbo2 GAROL, Rome3 LIPU, Parma

Corresponding Author: Elisa Lanzuisi, lanzuisa@libero.it

Study goals1. Description of the Salina’s bird fauna2. Analisis of temporal dynamics (year-

round cycle)3. Historical trends4. Local environmental factors -

possible correlations with species presence

5. Definition of management prescriptions for the site

Tarquinia Salinas

•State Reserve from 1982•Salt production ended in 1997

Description of the Salina’s bird fauna

Historical data analysis (bibliography and non-published data)Check-list of species recorded in the siteQuantitative description of the bird species during year-round cicle (migratory, overwintering and nesting species)

MethodsField surveys and complete count of waterbirds only, counts every 10-15 days [December 2004-April 2006] for the year-round cycleFrequent winter counts (october-march), every 15 days [2006-07 and 2007-08 winters]Midwinter counts data (INFS-IWC) from 1982 to 2008 – mid January countsData for the winter 1975-6 published by Allavena (1977)

Main determinants at regional scale

(working hypotesis)

Year round biological spatial dynamics (migration, overwintering) at continental scale (Europe, Mediterranean)Wheather (Temperature, rainfall, …) Sub-continental factors (“island effect”: wider site, larger numers)

Main determinants at local scale (working hypotesis)

Hyperaline “extreme” environmentConspicuous gradient in salinity (from N to S)Oxigen, pHWater level Water inputs: salt water from the sea, rain, floodings during stormfallsTrophic availabilityDistrurbance (humans inside, planes, predation, fast water level modifications)

(working hypotesis)

1.Description of the Salina’s bird fauna

(nesting species)

Nesting species (shorebirds)Stilt – Cavaliere d’Italia (Himantopus himantopus): irregular breeding (not in the study period)Kentish plover - Fratino (Charadrius alexandrinus): irregular breeding (not in the study period)Little Ringed Plover - Corriere piccolo (Charadrius dubius): irregular breeding (not in the study period)Redshank - Pettegola (Tringa totanus): possible breeding in the pastAvoset – Avocetta (Recurvirostra avocetta): attempt to breed in 2007

Nesting species (waterbirds)

Shelduck - Volpoca (Tadorna tadorna): one or two pairs, regular breedingEgret - Garzetta (Egretta garzetta): nesting in a site nearly the reserve with 20-30 pairsAirone Guardabouoi (Bubulcus ibis): first nesting in 2008;Bee-eater - Gruccione (Merops apiaster): nesting attempts in 2005 (aborted for disturbance), nesting of a colony in 2006-7-8

Why so small success in nesting?

Small area, low idoneityDisturbance from water level fast variationDisturbance from predators (Gulls, dogs, rats, …)Direct disturbance (humans inside for management works, researchers, … example: Merops apiaster colony attempt to breed)

(working hypotesis)

2. Analisis of temporal dynamics

(year-round cycle)

Results: Year-round cycle

Strong stagionality, typical in Mediterranean wetlands, and especially in salinasLow number of breeding speciesMaximum numbers in winter (December-January)

Species richness (S) – for count

Species richness (S) – monthly average

Abundance (N) – monthly average

Abundance (N) – monthly average

•Different species•Terns•Gulls•Shorebirds•Gruiformes•Anseriformes•Greater Flamingo and Spoonbill•Herons, Egrets and Cormorants•Grebes

(working hypotesis)

3.Historical trends

Results: Historical trends(Overwintering birds)

Long historical series – IWC Counts (from 1982)Recent data during study (2004-2008)Species richness and abundanceGeneral trend: increasing in numbers

Trend: increasing(For 1982-2008 seriesR=0,643; F=16,921; p=0,0004)

N. max=2.742

Abundance (N) – IWC Counts (January)

•Different species•Terns•Gulls•Shorebirds•Gruiformes•Anseriformes•Greater Flamingo and Spoonbill•Herons, Egrets and Cormorants•Grebes

NB 1992 lack of data

Why an increasing?

Local factors: area legal protection from 1980, fence around the site from the ’80, more patrolling since half of ’90Regional factors: increasing in numbers after new hunting regulation in 1992

Carring capacity reached?

Site is quite smallSome other large site in the sorrounding Tyrrenian coastal area (Burano, Orbetello)

A size-number effect?Tyrrenian wetland Area

Overwintering birds 2004

(IWC Counts, January)

Lago e Palude di Massaciuccoli 1907 1666

Diaccia Botrona, La Trappola e altre zone umide grossetane

2048 26381

Laguna di Orbetello e Lago di Burano4179 20871

Saline di Tarquinia 149 2742

Macchiatonda 25 571

Litorale Romano 103 5296

Laghi Pontini 2200 20962

Lago di Fondi 702 1066

A size-number effect?

R=0,72752078; R²= ,52928648; F(1,6 DoF)=6,7466; p<0,04080

Tarquinia

(working hypotesis)

4.Local environmental factors

(possible correlations with species presence)

Greater Flamingo - Fenicottero (Phoenicopterus ruber)

-Filtratore iperspecialista hypersaline environments

-General trend to increasing (R= ,72104457; R²=0,51990527; F con 1 e 25 gdl=27,073; p<,00002)

Common Teal - Alzavola (Anas crecca)

- Mostly herbivorous

- General trend to increasing R= 0,393; R²= 0,154; F con 1 e 25 DoF=4,5814; p<,04226)

Wigeon – Fischione (Anas penelope)

- Mostly herbivorous

- A general trend for the whole period doesn’t exist, but since 1987 a decreasing statistically signifiant is present (R= 0,607; R²= 0,369; F (1,20 DoF)=11,701; p<,00271)

Coot – Folaga(Fulica atra)

- Mostly herbivorous

- Constant, a peak in 2000, without any signifiant trend

Dunlin - Piovanello pancianera (Calidris alpina)

- Feeding on invertebrates in mud

- Trend to increasing presence (R= 0,39353967; R²=0,15487347; F (1, 25 DoF)=4,5814; p<,04226)

“Anatre” guild distribution

Concentred in ponds inthe north of the salinas,with sea-like salinity anddeep water column

“Erbivori” guild distribution

Concentred in ponds inthe north of the salinas,with sea-like salinity anddeep water column

“Filtratori” guild distribution

Distributed in near allponds, with differentsalinity anddeep water column

“Gabbiani” guild distribution

Distributed in near allponds, with differentsalinity anddeep water column, but concentrated insouthern ponds

“Limicoli” guild distribution

Distributed in near allponds, with differentsalinity anddeep water column, but concentrated incentral andsouthern ponds

Possible local determinants

SalinityWater column deepOxigenpHBiomass (plancton, benthos)

First evidences

Guild "Vasca" Var. "Water column deep" Var.

Anatre - Ducks F=14,86; p>0,00001 n.s.

Erbivori - Vegetarian F=25,88; p>0,00001 n.s.

Filtratori - Filter feeders F=13,542; p>0,00001 n.s.

Gabbiani - Gulls F=4,14; p>0,000067 n.s.

Limicoli - Shorebirds F=3,926; p>0,0001 F=2,6; p=0,0256

Piscivori - Fish eaters F=19,27; p>0,00001 F=4,39; p=0,0008

Greater Flamingoes with markers

DATA CODICE COLORE ANELLO

VERSOLETTURA

TARSO NOTE

9.1.2005 IDJC Blu ?/Scritta bianca

28.7.2005 FLTP Bianco Dx Anello metallico su zampa sx

13.10.2005 FSHA Chiaro Dx Anello metallico piccolo su zampa sx

13.10.2005 MPDT Sx

18.11.2005 ITO Scuro/scritta chiara Sx Anello metallico su zampa dx

1.2.2006 FHXJ Bianco Dx

1.2.2006 FVAM Giallo Dx

1.2.2006 FSHA Giallo chiaro Dx

1.2.2006 FSBB Giallo chiaro

1.2.2006 MLHD Giallo

1.2.2006 1 | JTF Giallo Dx Barra dopo prima cifra

1.2.2006 IFLZ Verde/Scritta chiara Dx

(working hypotesis)

5.Definition of management prescriptions

for the site

Management prescriptions

Water level management for shorebirdsMantaining salinity gradientAvoiding disturbance (hides, access, …)Creating islands for bird nestingDeveloping birdwatchingMantaining patrolling