Decline of Pelophylax lessonae in mixed populations of water frogs over the last 50 years

Figures & data

Figure 1. Study sites and changes in frequency of water frogs in an urban (a,c) and a rural (b,d) habitat. R – P. ridibundus, E – P. eculentus, L – P. lessonae.

Table I. Number and frequency of frogs collected in previous and current study.

Locality	Years	Total numer of frogs	LL	RL	RR	Population type
Poznań city
Naramowice	1962–1970	151	35 (23.2%)	68 (45.0%)	48 (31.8%)	R-E-L
	2020–2021	72	0 (0%)	30 (41.7%)	42 (58.3%)	R-E
Żurawiniec	1962–1970	1715	1683 (98.1%)	32 (1.9%)	0 (0%)	L-E
	2020–2021	0	0 (0%)	0 (0%)	0 (0%)	–
Sołacz	1962–1970	30	0 (0%)	30 (100%)	0 (0%)	E-E
	2020–2021	33	0 (0%)	2 (6.1%)	31 (93.9%)	R-E
Edwardowo	1962–1970	181	153 (84.5%)	28 (15.5%)	0 (0%)	L-E
	2020–2021	32	0 (0%)	32 (100%)	0 (0%)	E-E
Junikowo	1962–1970	83	54 (65.1%)	29 (34.9%)	0 (0%)	L-E
	2020–2021	48	5 (10.4%)	42 (87.5%)	1 (2.1%)	R-E-L
Chłapowski Landscape Park
Turew	1977–1982	347	31 (8.9%)	316 (91.1)	0 (0%)	L-E
	2020–2021	31	1 (3.2%)	25 (80.7%)	5 (16.1%)	R-E-L
Rąbinek	1988–1997	1663	1459 (87.7%)	204 (12.3%)	0 (0%)	L-E
	2020–2021	44	2 (4.5%)	42 (95.5%)	0 (0%)	L-E
Rogaczewo	1977–1997	906	709 (78.3%)	197 (21.7%)	0 (0%)	L-E
	2020–2021	24	0 (0%)	24 (100%)	0 (0%)	E-E
Zbęchy	1977–1982	364	7 (1.9%)	356 (97.8%)	1 (0.3%)	R-E-L
	2020–2021	46	0 (0%)	5 (10.9%)	41 (89.1%)	R-E
Łuszkowo	1988–1997	93	89 (95.7%)	4 (4.3%)	0 (0%)	L-E
	2020–2021	24	0 (0%)	20 (83.3%)	4 (16.7%)	R-E

LL – P. lessonae, RL – P. esculentus, RR – P. ridibundus.

Figure 2. Changes in frequency of water frogs at particular sites in an urban (a) and a rural (b) habitat. R – P. ridibundus, E – P. eculentus, L – P. lessonae.

Figure 3. Examples of urban ponds. Żurawiniec: in 1966 (a) and 2020 (b), Edwardowo: in 1964 (c) and 2020 (d). Photo by Z. Pniewski and K. Kolenda.