กบกอดจะผสมพันธุ์วางไข่ในฤดูหนาว ระหว่างเดือน ธันวาคม ถึงเดือนกุมภาพันธ์ โดยจะจับคู่วางไข่เป็นกลุ่ม กลุ่มละ 2–48 ตัว อยู่ใต้โพรงหินในลำธารภูเขาที่ระดับน้ำ 2–5 เซนติเมตร ทำให้สามารถจับได้ง่าย เป็นสาเหตุหนึ่งของการจับแบบทำลาย

คำสำคัญ: กบกอด กบอกหนามเมืองเหนือ ชีววิทยาบางประการ

A study on some biological aspects of the northern spiny-breasted frog, Paa bourreti. (Dobois,1981) in Chiangmai province has been carried out from October 2001 to February 2002. The total number of 166 samples (87 male and 79 female) were collected from Omkoi district, Chiangmai province, 5 times during the study period. Sex ratio between male and female was 1 : 0.886. In the spawning season, male have bigger forearms than female. Only male frog have numerous circular warts wich contain many fine black spines, on mid-pectoral or breasts area, finger, lips and chin. The length-weight relationship of the northern spiny-breasted frog was W = 4.8206 L^3.7140 or logW = -5.3169+3.7140 logL, with the coefficient of correlation = 0.9585. The length-weight relationship of male frog was W= 2.9717 L^3.8353 or logW = -5.5270 +3.8353 logL with the coefficient of correlation = 0.8941. The length-weight relationship of female frog was W = 3.0116 L^2.7658 or logW = -3.5121+2.7658 logL, with the coefficient of correlation = 0.8478. Stomach content composed of plants, ants insects, earth-worm and crabs.

Spawning season of the northern spiny-breasted frog is in the winter season, December to February. The group of brood frogs about 2 – 48 frogs paired and spawned in the big-hole under the rock witnin mountain creek at 2 – 5 cm water level. This spawning behavior caused population decreasing substantially and threatened to extinction, because of over catching.